Publications by authors named "Alex Mira"

79 Publications

A Single Dose of Nitrate Increases Resilience Against Acidification Derived From Sugar Fermentation by the Oral Microbiome.

Front Cell Infect Microbiol 2021 3;11:692883. Epub 2021 Jun 3.

Department of Health and Genomics, Center for Advanced Research in Public Health, FISABIO Foundation, Valencia, Spain.

Tooth decay starts with enamel demineralization due to an acidic pH, which arises from sugar fermentation by acidogenic oral bacteria. Previous work has demonstrated that nitrate limits acidification when incubating complex oral communities with sugar for short periods (e.g., 1-5 h), driven by changes in the microbiota metabolism and/or composition. To test whether a single dose of nitrate can reduce acidification derived from sugar fermentation , 12 individuals received a nitrate-rich beetroot supplement, which was compared to a placebo in a blinded crossover setting. Sucrose-rinses were performed at baseline and 2 h after supplement or placebo intake, and the salivary pH, nitrate, nitrite, ammonium and lactate were measured. After nitrate supplement intake, the sucrose-induced salivary pH drop was attenuated when compared with the placebo (p < 0.05). Salivary nitrate negatively correlated with lactate production and positively with ΔpH after sucrose exposure (r= -0.508 and 0.436, respectively, both p < 0.05). Two additional pilot studies were performed to test the effect of sucrose rinses 1 h (n = 6) and 4 h (n = 6) after nitrate supplement intake. In the 4 h study, nitrate intake was compared with water intake and bacterial profiles were analysed using 16S rRNA gene Illumina sequencing and qPCR detection of . Sucrose rinses caused a significant pH drop (p < 0.05), except 1 h and 4 h after nitrate supplement intake. After 4 h of nitrate intake, there was less lactate produced compared to water intake (p < 0.05) and one genus; , increased in abundance. This small but significant increase was confirmed by qPCR (p < 0.05). The relative abundance of and negatively correlated with lactate production (r = -0.601 and -0.669, respectively) and positively correlated with pH following sucrose intake (r = 0.669, all p < 0.05). Together, these results show that nitrate can acutely limit acidification when sugars are fermented, which appears to result from lactate usage by nitrate-reducing bacteria. Future studies should assess the longitudinal impact of daily nitrate-rich vegetable or supplement intake on dental health.
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http://dx.doi.org/10.3389/fcimb.2021.692883DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8238012PMC
July 2021

The Subgingival Plaque Microbiome, Systemic Antibodies Against Bacteria and Citrullinated Proteins Following Periodontal Therapy.

Pathogens 2021 Feb 10;10(2). Epub 2021 Feb 10.

Oral Sciences, College of Medical, Veterinary and Life Sciences, Dental School, University of Glasgow, Glasgow G12 8QQ, UK.

Periodontitis (PD) shows an association with rheumatoid arthritis (RA) and systemic inflammation. Periodontal pathogens, namely and , are proposed to be capable of inducing citrullination of peptides in the gingiva, inducing the formation of anti-citrullinated protein antibodies (ACPAs) within susceptible hosts. Here, we sought to investigate whether periodontal treatment influenced systemic inflammation and antibody titres to , , and ACPA in 42 systemically health patients with periodontal disease. Subgingival plaque and serum samples were collected from study participants before (baseline) and 90 days after treatment to analyse the abundance of specific bacteria and evaluate anti-bacterial antibodies, C-reactive protein (CRP), tumour necrosis factor α (TNF-α), interleukin 6 (IL-6) and ACPA in serum. Following treatment, all patients showed reduced periodontal inflammation. Despite observing a weak positive correlation between CRP and IL-6 with periodontal inflammation at baseline, we observed no significant reductions in any indicators of systemic inflammation 90 days after treatment. In contrast, anti- IgG significantly reduced post-treatment ( < 0.001, Wilcoxon signed rank test), although no changes were observed for other antibody titres. Patients who had detectable in subgingival plaques had significantly higher anti- IgG and ACPA titres, suggesting a potential association between colonisation and systemic antibody titres.
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http://dx.doi.org/10.3390/pathogens10020193DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7916579PMC
February 2021

Antibiofilm activity of flavonoids on staphylococcal biofilms through targeting BAP amyloids.

Sci Rep 2020 11 3;10(1):18968. Epub 2020 Nov 3.

Instituto de Agrobiotecnología (IDAB), CSIC-UPNA-Gobierno de Navarra, Avenida Pamplona 123, 31192, Mutilva, Spain.

The opportunistic pathogen Staphylococcus aureus is responsible for causing infections related to indwelling medical devices, where this pathogen is able to attach and form biofilms. The intrinsic properties given by the self-produced extracellular biofilm matrix confer high resistance to antibiotics, triggering infections difficult to treat. Therefore, novel antibiofilm strategies targeting matrix components are urgently needed. The Biofilm Associated Protein, Bap, expressed by staphylococcal species adopts functional amyloid-like structures as scaffolds of the biofilm matrix. In this work we have focused on identifying agents targeting Bap-related amyloid-like aggregates as a strategy to combat S. aureus biofilm-related infections. We identified that the flavonoids, quercetin, myricetin and scutellarein specifically inhibited Bap-mediated biofilm formation of S. aureus and other staphylococcal species. By using in vitro aggregation assays and the cell-based methodology for generation of amyloid aggregates based on the Curli-Dependent Amyloid Generator system (C-DAG), we demonstrated that these polyphenols prevented the assembly of Bap-related amyloid-like structures. Finally, using an in vivo catheter infection model, we showed that quercetin and myricetin significantly reduced catheter colonization by S. aureus. These results support the use of polyphenols as anti-amyloids molecules that can be used to treat biofilm-related infections.
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http://dx.doi.org/10.1038/s41598-020-75929-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7641273PMC
November 2020

Human milk microbiota in sub-acute lactational mastitis induces inflammation and undergoes changes in composition, diversity and load.

Sci Rep 2020 10 28;10(1):18521. Epub 2020 Oct 28.

Department of Biotechnology, Spanish National Research Council (IATA-CSIC), Institute of Agrochemistry and Food Technology, Paterna, Spain.

Sub-acute mastitis (SAM) is a prevalent disease among lactating women, being one of the main reasons for early weaning. Although the etiology and diagnosis of acute mastitis (AM) is well established, little is known about the underlying mechanisms causing SAM. We collected human milk samples from healthy and SAM-suffering mothers, during the course of mastitis and after symptoms disappeared. Total (DNA-based) and active (RNA-based) microbiota were analysed by 16S rRNA gene sequencing and qPCR. Furthermore, mammary epithelial cell lines were exposed to milk pellets, and levels of the pro-inflammatory interleukin IL8 were measured. Bacterial load was significantly higher in the mastitis samples and decreased after clinical symptoms disappeared. Bacterial diversity was lower in SAM milk samples, and differences in bacterial composition and activity were also found. Contrary to AM, the same bacterial species were found in samples from healthy and SAM mothers, although at different proportions, indicating a dysbiotic ecological shift. Finally, mammary epithelial cell exposure to SAM milk pellets showed an over-production of IL8. Our work therefore supports that SAM has a bacterial origin, with increased bacterial loads, reduced diversity and altered composition, which partly recovered after treatment, suggesting a polymicrobial and variable etiology.
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http://dx.doi.org/10.1038/s41598-020-74719-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7595153PMC
October 2020

Isolation and Characterization of Nitrate-Reducing Bacteria as Potential Probiotics for Oral and Systemic Health.

Front Microbiol 2020 15;11:555465. Epub 2020 Sep 15.

Department of Health and Genomics, Center for Advanced Research in Public Health, FISABIO Foundation, Valencia, Spain.

Recent evidence indicates that the reduction of salivary nitrate by oral bacteria can contribute to prevent oral diseases, as well as increase systemic nitric oxide levels that can improve conditions such as hypertension and diabetes. The objective of the current manuscript was to isolate nitrate-reducing bacteria from the oral cavity of healthy donors and test their probiotic potential to increase the nitrate-reduction capacity (NRC) of oral communities. Sixty-two isolates were obtained from five different donors of which 53 were confirmed to be nitrate-reducers. Ten isolates were selected based on high NRC as well as high growth rates and low acidogenicity, all being species. The genomes of these ten isolates confirmed the presence of nitrate- and nitrite reductase genes, as well as lactate utilization genes, and the absence of antimicrobial resistance, mobile genetic elements and virulence genes. The pH at which most nitrate was reduced differed between strains. However, acidic pH 6 always stimulated the reduction of nitrite compared to neutral pH 7 or slightly alkaline pH 7.5 ( < 0.01). We tested the effect of six out of 10 isolates on oral biofilm development in the presence or absence of 6.5 mM nitrate. The integration of the isolates into communities was confirmed by Illumina sequencing. The NRC of the bacterial communities increased when adding the isolates compared to controls without isolates ( < 0.05). When adding nitrate (prebiotic treatment) or isolates in combination with nitrate (symbiotic treatment), a smaller decrease in pH derived from sugar metabolism was observed ( < 0.05), which for some symbiotic combinations appeared to be due to lactate consumption. Interestingly, there was a strong correlation between the NRC of oral communities and ammonia production even in the absence of nitrate ( = 0.814, < 0.01), which indicates that bacteria involved in these processes are related. As observed in our study, individuals differ in their NRC. Thus, some may have direct benefits from nitrate as a prebiotic as their microbiota naturally reduces significant amounts, while others may benefit more from a symbiotic combination (nitrate + nitrate-reducing probiotic). Future clinical studies should test the effects of these treatments on oral and systemic health.
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http://dx.doi.org/10.3389/fmicb.2020.555465DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7522554PMC
September 2020

Topic Application of the Probiotic Improves Clinical and Microbiological Parameters Associated With Oral Health.

Front Cell Infect Microbiol 2020 31;10:465. Epub 2020 Aug 31.

Foundation for the Promotion of Health and Biomedical Research of Valencia Region (FISABIO), Valencia, Spain.

7746, isolated from dental plaque of caries-free individuals, has been shown to have several beneficial effects which could contribute to promote oral health, including an antimicrobial activity against oral pathogens by the production of bacteriocins and a pH buffering capacity through ammonia production. Previous work has shown that was able to colonize the oral cavity for 2-4 weeks after application. The aim of the present work was to evaluate its clinical efficacy by a randomized, double-blind, placebo-controlled parallel group study. Fifty nine volunteers were enrolled in the study and randomly assigned to a treatment or placebo group. The treatment consisted of a bucco-adhesive gel application (2.5 10 cfu/dose) with a dental splint for 5 min every 48 h, for a period of 1 month (i.e., 14 doses). Dental plaque and saliva samples were collected at baseline, 15 and 30 days after first application, and 15 days after the end of treatment. At baseline, there was a significant correlation between levels and frequency of toothbrushing. Salivary flow, a major factor influencing oral health, was significantly higher in the probiotic group at day 15 compared with the placebo (4.4 and 3.4 ml/5 min, respectively). In the probiotic group, there was a decrease in the amount of dental plaque and in gingival inflammation, but no differences were observed in the placebo group. The probiotic group showed a significant increase in the levels of salivary ammonia and calcium. Finally, Illumina sequencing of plaque samples showed a beneficial shift in bacterial composition at day 30 relative to baseline, with a reduction of several cariogenic organisms and the key players in plaque formation, probably as a result of bacteriocins production. Only 58% of the participants in the probiotic group showed increased plaque levels of at day 30 and 71% by day 45, indicating that the benefits of application could be augmented by improving colonization efficiency. In conclusion, the application of 7746 improved several clinical and microbiological parameters associated with oral health, supporting its use as a probiotic to prevent tooth decay.
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http://dx.doi.org/10.3389/fcimb.2020.00465DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7488176PMC
June 2021

Nitrate as a potential prebiotic for the oral microbiome.

Sci Rep 2020 07 30;10(1):12895. Epub 2020 Jul 30.

Department of Health and Genomics, Center for Advanced Research in Public Health, FISABIO Foundation, Avenida de Catalunya 21, 46020, Valencia, Spain.

The salivary glands actively concentrate plasma nitrate, leading to high salivary nitrate concentrations (5-8 mM) after a nitrate-rich vegetable meal. Nitrate is an ecological factor that can induce rapid changes in structure and function of polymicrobial communities, but the effects on the oral microbiota have not been clarified. To test this, saliva of 12 healthy donors was collected to grow in vitro biofilms with and without 6.5 mM nitrate. Samples were taken at 5 h (most nitrate reduced) and 9 h (all nitrate reduced) of biofilm formation for ammonium, lactate and pH measurements, as well as 16S rRNA gene Illumina sequencing. Nitrate did not affect biofilm growth significantly, but reduced lactate production, while increasing the observed ammonium production and pH (all p < 0.01). Significantly higher levels of the oral health-associated nitrate-reducing genera Neisseria (3.1 ×) and Rothia (2.9 ×) were detected in the nitrate condition already after 5 h (both p < 0.01), while several caries-associated genera (Streptococcus, Veillonella and Oribacterium) and halitosis- and periodontitis-associated genera (Porphyromonas, Fusobacterium, Leptotrichia, Prevotella, and Alloprevotella) were significantly reduced (p < 0.05 at 5 h and/or 9 h). In conclusion, the addition of nitrate to oral communities led to rapid modulation of microbiome composition and activity that could be beneficial for the host (i.e., increasing eubiosis or decreasing dysbiosis). Nitrate should thus be investigated as a potential prebiotic for oral health.
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http://dx.doi.org/10.1038/s41598-020-69931-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7393384PMC
July 2020

Microbiology of molar-incisor hypomineralization lesions. A pilot study.

J Oral Microbiol 2020 20;12(1):1766166. Epub 2020 May 20.

Genomics and Health Department, FISABIO Institute, Valencia, Spain.

: An insufficient mineralization (hypomineralization) in the teeth during the maturation stage of amelogenesis cause defects in 3-44% of children. Here, we describe for the first time the microbiota associated with these defects and compared it to healthy teeth within the same subjects. : Supragingival dental plaque was sampled from healthy and affected teeth from 25 children with molar-incisor hypomineralization (MIH). Total DNA was extracted and the 16S rRNA gene was sequenced by Illumina sequencing in order to describe the bacterial composition. : We detected a higher bacterial diversity in MIH samples, suggesting better bacterial adhesion or higher number of niches in those surfaces. We found the genera and associated with hypomineralized teeth, whereas and were associated with healthy sites. : The higher protein content of MIH-affected teeth could favour colonization by proteolytic microorganisms. The over-representation of bacteria associated with endodontic infections and periodontal pathologies suggests that, in addition to promote caries development, MIH could increase the risk of other oral diseases.
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http://dx.doi.org/10.1080/20002297.2020.1766166DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7301705PMC
May 2020

Effect of Dalbavancin on Staphylococcal Biofilms When Administered Alone or in Combination With Biofilm-Detaching Compounds.

Front Microbiol 2020 17;11:553. Epub 2020 Apr 17.

Genomics and Health Department, FISABIO Foundation, Valencia, Spain.

Microorganisms grown in biofilms are more resistant to antimicrobial treatment and immune system attacks compared to their planktonic forms. In fact, infections caused by biofilm-forming and are a large threat for public health, including patients with medical devices. The aim of the current manuscript was to test the effect of dalbavancin, a recently developed lipoglycopeptide antibiotic, alone or in combination with compounds contributing to bacterial cell disaggregation, on staphylococcal biofilm formation and elimination. We used real-time impedance measurements in microtiter plates to study biofilm growth dynamics of and strains, in the absence or presence of dalbavancin, linezolid, vancomycin, cloxacillin, and rifampicin. Further experiments were undertaken to check whether biofilm-detaching compounds such as -acetylcysteine (NAC) and ficin could enhance dalbavancin efficiency. Real-time dose-response experiments showed that dalbavancin is a highly effective antimicrobial, preventing staphylococcal biofilm formation at low concentrations. Minimum biofilm inhibitory concentrations were up to 22 higher compared to standard -test values. Dalbavancin was the only antimicrobial that could halt new biofilm formation on established biofilms compared to the other four antibiotics. The addition of NAC decreased dalbavancin efficacy while the combination of dalbavancin with ficin was more efficient than antibiotic alone in preventing growth once the biofilm was established. Results were confirmed by classical biofilm quantification methods such as crystal violet (CV) staining and viable colony counting. Thus, our data support the use of dalbavancin as a promising antimicrobial to treat biofilm-related infections. Our data also highlight that synergistic and antagonistic effects between antibiotics and biofilm-detaching compounds should be carefully tested in order to achieve an efficient treatment that could prevent both biofilm formation and disruption.
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http://dx.doi.org/10.3389/fmicb.2020.00553DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7180179PMC
April 2020

High-throughput DNA sequencing of microbiota at interproximal sites.

J Oral Microbiol 2020 11;12(1):1687397. Epub 2019 Nov 11.

Genomics & Health Department, FISABIO Institute, Valencia, Spain.

The oral microbiota has been deeply studied by high-throughput sequencing techniques. However, although the interproximal regions have one of the highest caries rates in the oral cavity, information about the bacterial composition at those sites is scarce. In this study, we used 16S rRNA Illumina sequencing to describe the microbiota associated to interproximal regions at two time points. In addition, dental plaque samples at the vestibular and lingual surfaces from the same teeth were also analysed at the two time points. Interproximal-associated microbiota was found to be similar to already described bacterial communities in other mouth niches. and were the most abundant genera in this oral region. Statistical analyses showed that the microbiota from interproximal sites was more similar to that sampled from the vestibular surfaces than to the lingual surfaces. Interestingly, many potentially cariogenic bacteria such as , or were over-represented in the interproximal regions in comparison with vestibular and lingual sites. The microbiota at interproximal regions appears to be specific and stable through time. Potentially pathogenic bacteria may increase caries development risk and gingival inflammation at those sites.
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http://dx.doi.org/10.1080/20002297.2019.1687397DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6853236PMC
November 2019

Corrigendum: Variations in Vaginal, Penile, and Oral Microbiota After Sexual Intercourse: A Case Report.

Front Med (Lausanne) 2019;6:294. Epub 2020 Jan 9.

Department of Health and Genomics, Center for Advanced Research in Public Health, FISABIO, Valencia, Spain.

[This corrects the article DOI: 10.3389/fmed.2019.00178.].
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http://dx.doi.org/10.3389/fmed.2019.00294DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6962768PMC
January 2020

Allergy development is associated with consumption of breastmilk with a reduced microbial richness in the first month of life.

Pediatr Allergy Immunol 2020 04 11;31(3):250-257. Epub 2019 Dec 11.

Department of Biotechnology, Institute of Agrochemistry and Food Technology (IATA-CSIC), Unit of Lactic Acid Bacteria and Probiotics, Valencia, Spain.

Background: Early colonization with a diverse microbiota seems to play a crucial role for appropriate immune maturation during childhood. Breastmilk microbiota is one important source of microbes for the infant, transferred together with maternal IgA antibodies. We previously observed that allergy development during childhood was associated with aberrant IgA responses to the gut microbiota already at 1 month of age, when the IgA antibodies are predominantly maternally derived in breastfed infants.

Objective: To determine the microbial composition and IgA-coated bacteria in breastmilk in relation to allergy development in children participating in an intervention trial with pre- and post-natal Lactobacillus reuteri supplementation.

Methods: A combination of flow cytometric cell sorting and 16S rRNA gene sequencing was used to characterize the bacterial recognition patterns by IgA in breastmilk samples collected one month post-partum from 40 mothers whose children did or did not develop allergic and asthmatic symptoms during the first 7 years of age.

Results: The milk fed to children developing allergic manifestations had significantly lower bacterial richness, when compared to the milk given to children that remained healthy. Probiotic treatment influenced the breastmilk microbiota composition. However, the proportions of IgA-coated bacteria, the total bacterial load and the patterns of IgA-coating were similar in breastmilk between mothers of healthy children and those developing allergies.

Conclusion: Consumption of breastmilk with a reduced microbial richness in the first month of life may play an important role in allergy development during childhood.
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http://dx.doi.org/10.1111/pai.13176DOI Listing
April 2020

A pilot study to assess oral colonization and pH buffering by the probiotic Streptococcus dentisani under different dosing regimes.

Odontology 2020 Apr 17;108(2):180-187. Epub 2019 Sep 17.

Center for Advanced Research in Public Health, FISABIO Foundation, Valencia, Spain.

Bacterial colonization in the oral cavity is critical for efficient action of probiotics. However, limited colonization rates have been reported in many clinical trials. The aim of this pilot clinical study was to evaluate the colonization efficiency of Streptococcus dentisani under different dosing schedules and pre-treatment conditions. Eleven adult volunteers enrolled in the study. A professional ultrasound cleaning was performed in quadrants 1 and 4. The probiotic was applied in all four quadrants at a total dose of 10 CFUs, administered in a buccoadhesive gel for 5 min, either in a single dose (n = 5) or daily for a week (n = 6). Dental plaque and saliva samples were collected at baseline and after 14 and 28 days of first application. Amounts of S. dentisani and the cariogenic organism Streptococcus mutans were measured by qPCR and salivary pH was measured by reflectometry. There was a significant increase in S. dentisani cells at day 14 but not at day 28 under both dosing schedules. A non-significant higher colonization was found in the half-mouth with previous professional cleaning as compared to the intact half. There was a significant increase in salivary pH at day 14 (p = 0.024) and day 28 (p = 0.014), which was stronger in multi-dose patients, and a significant decrease in S. mutans at day 28 (p < 0.01). The results indicate that S. dentisani is transiently able to colonize the oral cavity and that it buffers oral pH, especially after multiple dosing. Future randomized, placebo-controlled clinical trials should evaluate its use to prevent tooth decay.
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http://dx.doi.org/10.1007/s10266-019-00458-yDOI Listing
April 2020

Variations in Vaginal, Penile, and Oral Microbiota After Sexual Intercourse: A Case Report.

Front Med (Lausanne) 2019 7;6:178. Epub 2019 Aug 7.

Department of Health and Genomics, Center for Advanced Research in Public Health, FISABIO, Valencia, Spain.

Bacterial vaginosis is the most common infection in women and it has been proved that dysbiosis of vaginal microbiota can promote the infectious status. This case report shows the effect of oral and vaginal sex over the microbiota of a heterosexual couple who reported repeated problems of vaginal and oral infections after sexual intercourse. A woman (32) reported to have vaginal infections and gingivitis after she had started a relationship with a man (34) and associated them with unprotected sex. No treatments successfully removed the problem and it repeated every time they had sexual encounters. Vaginal, penile and oral swabs were collected before and after sexual encounters in order to analyze changes in the respective microbiotas. DNA was extracted from all samples and the bacterial 16S rRNA gene was sequenced using Illumina MiSeq. occupied the great majority of the vaginal microbiota in all scenarios except after unprotected sex, which caused a bacterial dysbiosis that lasted at least for a week. Similarly, the penile microbiota changed significantly after unprotected sexual relationships. Interestingly, both oral and vaginal sex increased the abundance of in the male oral and penile microbiota, respectively. In conclusion, unprotected sexual intercourse influenced the genital microbiota in the couple studied and future studies with larger sample sizes should study if sex may be a factor promoting vaginal infection through dysbiosis and hampered protection by the resident microbiota.
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http://dx.doi.org/10.3389/fmed.2019.00178DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6692966PMC
August 2019

Sputum Microbiome Dynamics in Chronic Obstructive Pulmonary Disease Patients during an Exacerbation Event and Post-Stabilization.

Respiration 2019;98(5):447-454. Epub 2019 Aug 22.

Fundacion para el Fomento de la Investigacion Sanitaria y Biomedica de la Comunidad Valenciana, Department of Microbiology, University General Hospital of Elche, Elche, Alicante, Spain,

Background: Chronic obstructive pulmonary disease (COPD) affects up to 65 million people worldwide, and COPD exacerbation causes tissue damage and subsequent loss of lung function. It is a multifactorial event in which respiratory infections are involved, but little is known about its dynamics.

Objectives: The objective of our study was to determine the microbiome composition during an exacerbation event and post-stabilization.

Methods: We conducted an observational analytical study of a cohort of 55 COPD patients in which 2 sputum samples (the first taken during an exacerbation event and the second during clinical post-stabilization) were submitted to 16s RNA ribosomal analysis by Illumina Miseq Next Generation Sequencing (NGS). The presence of respiratory viruses was also determined.

Results: Our study found a stable microbiome composition in the post-stabilization sputum samples of COPD patients, and 4 additional microbiomes in samples taken during the exacerbation, 3 of which showed a marked dysbiosis by Haemophilus, Pseudomonas, and Serratia. The fourth exacerbation microbiome had a very similar composition to post-stabilization samples, but some pathogens such as Moraxella and respiratory viruses were also found.

Conclusions: Our study reveals the main protagonists involved in lung microbiome dynamics during an exacerbation event and post-stabilization in COPD patients by NGS analysis.
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http://dx.doi.org/10.1159/000501988DOI Listing
September 2020

Presence of Streptococcus dentisani in the dental plaque of children from different Colombian cities.

Clin Exp Dent Res 2019 06 9;5(3):184-190. Epub 2019 May 9.

School of Dentistry Universidad Cooperativa de Colombia, Bogotá Campus Bogotá Colombia.

Streptococcus dentisani has been identified as an oral cavity probiotic due to its beneficial characteristics. One of its beneficial features is the production of bacteriocins, which inhibit the growth of cariogenic bacteria, and another is its buffering capacity through the production of ammonium from arginine. The purpose of this study was to determine the presence of S. dentisani in the dental plaque of Colombian children and whether the presence of this bacterium is related to oral health and other conditions. Dental plaque and information on diet and oral hygiene habits were collected from children between 6 and 12 years of age from four Colombian cities, divided into caries-free children (International Caries Detection and Assessment System [ICDAS] 0, Decayed Missing Filled Teeth index [DMFT] 0), children with ICDAS 1 and 2, and children with ICDAS >3. Plaque DNA was extracted and quantified, and real-time polymerase chain reaction was performed using specific primers. This bacterium was identified in all samples, with a median of 0.46 cells/ng DNA (interquartile range [IQR] 0.13-1.02), without finding significant differences between the groups ( > 0.05). In caries-free children, a median of 0.45 cells/ng DNA (IQR 0.14-1.23) was found. In children with ICDAS 1 and 2, the median was 0.49 cells/ng DNA (IQR 0.11-0.97), and in children with ICDAS >3, the median was 0.35 cells/ng DNA (IQR 0.12-1.07). However, statistically significant differences were found in the origin of children ( < 0.01), the use of fluoride-containing products ( < 0.01), and the frequency of food intake ( < 0.05). In conclusion, the presence of S. dentisani was quantified in children from four Colombian cities, without finding significant differences in oral health status. Nevertheless, three conditions showed a possible relationship with S. dentisani.
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http://dx.doi.org/10.1002/cre2.158DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6585583PMC
June 2019

Microbiota of human precolostrum and its potential role as a source of bacteria to the infant mouth.

Sci Rep 2019 06 10;9(1):8435. Epub 2019 Jun 10.

Department of Nutrition and Food Science, Complutense University of Madrid, Avda. Puerta de Hierro, s/n, 28040, Madrid, Spain.

Human milk represents a source of bacteria for the initial establishment of the oral (and gut) microbiomes in the breastfed infant, however, the origin of bacteria in human milk remains largely unknown. While some evidence points towards a possible endogenous enteromammary route, other authors have suggested that bacteria in human milk are contaminants from the skin or the breastfed infant mouth. In this work 16S rRNA sequencing and bacterial culturing and isolation was performed to analyze the microbiota on maternal precolostrum samples, collected from pregnant women before delivery, and on oral samples collected from the corresponding infants. The structure of both ecosystems demonstrated a high proportion of taxa consistently shared among ecosystems, Streptococcus spp. and Staphylococcus spp. being the most abundant. Whole genome sequencing on those isolates that, belonging to the same species, were isolated from both the maternal and infant samples in the same mother-infant pair, evidenced that in 8 out of 10 pairs both isolates were >99.9% identical at nucleotide level. The presence of typical oral bacteria in precolostrum before contact with the newborn indicates that they are not a contamination from the infant, and suggests that at least some oral bacteria reach the infant's mouth through breastfeeding.
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http://dx.doi.org/10.1038/s41598-019-42514-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6557856PMC
June 2019

In vitro beneficial effects of Streptococcus dentisani as potential oral probiotic for periodontal diseases.

J Periodontol 2019 11 12;90(11):1346-1355. Epub 2019 Jun 12.

Department of Health and Genomics, Center for Advanced Research in Public Health, FISABIO Foundation, Valencia, Spain.

Background: Periodontal diseases are of high prevalence globally and are characterized by an exacerbated inflammatory response which leads to oral tissue destruction. The use of probiotics is widely extended in the case of gastrointestinal disorders; however, their use in microbial-origin oral diseases is still preliminary.

Methods: We used quantitative polymerase chain reaction to determine the levels of the oral bacterium Streptococcus dentisani 7746 in the tongue, saliva, supragingival, and subgingival plaque. We explore the potential benefits of this probiotic by measuring inhibition of the periodontal pathogens Porphyromonas gingivalis and Fusobacterium nucleatum growth and attachment to human gingival fibroblasts. In addition, its anti-inflammatory activity against cytokines secretion induced by these pathogens was determined in an in vitro model by enzyme-linked immunosorbent assay.

Results: We report that S. dentisani is found at high levels in the gingival crevice. Data show a strong inhibitory action of S. dentisani supernatant against the periodontal pathogens in pure culture. S. dentisani attached to gingival cells in vitro, inhibiting periodontal pathogens by competition, adherence, and displacement mechanisms. Finally, in a simple in vitro model, the oral probiotic strongly increased the secretion of the anti-inflammatory cytokine IL-10 after incubations with P. gingivalis and F. nucleatum, as well as significantly reduced the expression of interferon-γ induced by F. nucleatum.

Conclusion: Altogether, these results highlight the potential of S. dentisani as adjuvant therapy in the management of periodontal diseases, whose efficacy will need to be tested in clinical studies.
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http://dx.doi.org/10.1002/JPER.18-0751DOI Listing
November 2019

Development of an system to study oral biofilms in real time through impedance technology: validation and potential applications.

J Oral Microbiol 2019 6;11(1):1609838. Epub 2019 May 6.

FISABIO Foundation, Centre for Advanced Research in Public Health, Valencia, Spain.

: We have developed a standardized, easy-to-use in model to study single- and multiple-species oral biofilms in real time through impedance technology, which elucidates the kinetics of biofilm formation in 96-well plates, without the requirement for any further manipulation. Using this system, biofilms of appear to be sugar-dependent and highly resistant to amoxicilin, an antibiotic to which this oral pathogen is highly sensitive in a planktonic state. Saliva, tongue and dental plaque samples were also used as inocula to form multiple-species biofilms. DNA isolation and Illumina sequencing of the biofilms showed that the multi-species biofilms were formed by tens or hundreds of species, had a similar composition to the original inoculum, and included fastidious microorganisms which are important for oral health and disease. As an example of the potential applications of the model, we show that oral biofilms can be inhibited by amoxicilin, but in some cases they are induced by the antibiotic, suggesting the existence of responders and non-responders to a given antibiotic. We therefore propose the system as a valid model to study oral biofilm dynamics, including their susceptibility to antibiotics, antiseptics or anti-adhesive compounds.
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http://dx.doi.org/10.1080/20002297.2019.1609838DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6507917PMC
May 2019

Biomonitoring detoxification efficiency of an algal-bacterial microcosm system for treatment of coking wastewater: Harmonization between Chlorella vulgaris microalgae and wastewater microbiome.

Sci Total Environ 2019 Aug 24;677:120-130. Epub 2019 Apr 24.

Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt; Department of Microbiology and Immunology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Cairo, Egypt.

Nowadays, due to worldwide water shortage, water utilities are forced to re-evaluate treated wastewater. Consequently, wastewater treatment plants need to conduct biomonitoring. Coking wastewater (CWW) has toxic, mutative and carcinogenic components with threatening effect on the environment. CWW was selected as a model for complex highly toxic industrial wastewater that should be treated. CWW from Egypt was treated in a nine-liter photobioreactor using an algal-bacterial system. The photobioreactor was operated for 154 days changing different parameters (toxic load and light duration) for optimization. Optimized conditions achieved significant reduction (45%) in the operation cost. The algal-bacterial system was monitored using chemical assays (chemical oxygen demand and phenol analysis), bioassays (phytotoxicity, Artemia-toxicity, cytotoxicity, algal-bacterial ratio and settleability) and Illumina-MiSeq sequencing of 16S rRNA gene. The algal-bacterial system detoxified (in terms of phytotoxicity, cytotoxicity and Artemia-toxicity) CWW introduced as influent through all phases. A significant difference was recorded in the microbial diversity between influent and effluent samples. Four phyla dominated influent samples; Proteobacteria (77%), Firmicutes (11%), Bacteroidetes (5%) and Deferribacteres (3%) compared to only two in effluent samples; Proteobacteria (66%) and Bacteroidetes (26%). The significant relative-abundance of versatile aromatic degraders (Comamonadaceae and Pseudomonadaceae families) in influent samples conformed to the nature of CWW. Microbial community shifted and promoted the activity of catabolically versatile and xenobiotics degrading families (Chitinophagaceae and Xanthomonadaceae). Co-culture of microalgae had a positive effect on the biodegrading bacteria that was reflected by enhanced treatment efficiency, significant increase in relative abundance of bacterial genera with cyanide-decomposing potential and negative effect on waterborne pathogens.
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http://dx.doi.org/10.1016/j.scitotenv.2019.04.304DOI Listing
August 2019

Mycobiome Profiles in Breast Milk from Healthy Women Depend on Mode of Delivery, Geographic Location, and Interaction with Bacteria.

Appl Environ Microbiol 2019 05 18;85(9). Epub 2019 Apr 18.

Department of Biotechnology, Institute of Agrochemistry and Food Technology-National Research Council (IATA-CSIC), Valencia, Spain

Recent studies report the presence of fungal species in breast milk of healthy mothers, suggesting a potential role in infant mycobiome development. In the present work, we aimed to determine whether the healthy human breast milk mycobiota is influenced by geographical location and mode of delivery, as well as to investigate its interaction with bacterial profiles in the same samples. A total of 80 mature breast milk samples from 4 different countries were analyzed by Illumina sequencing of the internal transcribed spacer 1 (ITS1) region, joining the 18S and 5.8S regions of the fungal rRNA region. Basidiomycota and Ascomycota were found to be the dominant phyla, with and being the most prevalent genera across countries. A core formed by , and was shared in the milk samples from the different origins, although specific shifts in mycobiome composition were associated with geographic location and delivery mode. The presence of fungi in the breast milk samples was further confirmed by culture and isolate characterization, and fungal loads were estimated by quantitative PCR (qPCR) targeting the fungal ITS1 region. Cooccurrence network analysis of bacteria and fungi showed complex interactions that were influenced by geographical location, mode of delivery, maternal age, and pregestational body mass index. The presence of a breast milk mycobiome was confirmed in all samples analyzed, regardless of the geographic origin. During recent years, human breast milk has been documented as a potential source of bacteria for the newborn. Recently, we have reported the presence of fungi in breast milk from healthy mothers. It is well known that environmental and perinatal factors can affect milk bacteria; however, the impact on milk fungi is still unknown. The current report describes fungal communities (mycobiota) in breast milk samples across different geographic locations and the influence of the mode of delivery. We also provide novel insights on bacterium-fungus interactions, taking into account environmental and perinatal factors. We identified a core of four genera shared across locations, consisting of , and , which have been reported to be present in the infant gut. Our data confirm the presence of fungi in breast milk across continents and support the potential role of breast milk in the initial seeding of fungal species in the infant gut.
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http://dx.doi.org/10.1128/AEM.02994-18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6495746PMC
May 2019

Nasopharyngeal Microbiota in Children With Invasive Pneumococcal Disease: Identification of Bacteria With Potential Disease-Promoting and Protective Effects.

Front Microbiol 2019 28;10:11. Epub 2019 Jan 28.

Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, Barcelona, Spain.

The risk of suffering from some infectious diseases can be related to specific microbiota profiles. Specifically, the nasopharyngeal microbiota could play a role as a risk or protective factor in the development of invasive disease caused by . We analyzed the nasopharyngeal microbiota of children with invasive pneumococcal disease (IPD) and that of healthy controls matched by age, sex, and seasonality from Catalonia, Spain. Epidemiological, microbiological and clinical variables were considered to compare microbiota profiles, analyzed by sequencing the V1-V4 region of the 16S rRNA gene. Twenty-eight children with IPD (median age 43 months) and 28 controls (42.6 months) were included in the study. IPD children presented a significantly higher bacterial diversity and richness ( < 0.001). Principal coordinate analysis revealed three different microbiota profiles: microbiota A, dominated by the genus (44.3%); Microbiota B, mostly represented by (36.9%) and (21.3%) and a high diversity of anaerobic genera including and ; and Microbiota C, mainly containing (52.1%) and (31.4%). The only explanatory factor for the three microbiotas was the classification of children into disease or healthy controls ( = 0.006). A significant negative correlation was found between vs. ( = 0.029), suggesting a potential antagonistic effect against pneumococcal pathogens. The higher bacterial diversity and richness in children with IPD could suggest an impaired immune response. This lack of immune competence could be aggravated by breastfeeding <6 months and by the presence of keystone pathogens such as , a bacterium which has been shown to be able to manipulate the immune response, and that could favor the overgrowth of many proteolytic anaerobic organisms giving rise to a dramatic dysbiosis. From an applied viewpoint, we found suggestive microbiota profiles associated to IPD or asymptomatic colonization that could be used as disease biomarkers or to pave the way for characterizing health-associated inhabitants of the respiratory tract. The identification of beneficial bacteria could be useful to prevent pneumococcal infections by integrating those microorganisms in a probiotic formula. The present study suggests not only respiratory tract samples, but also breast milk, as a potential source of those beneficial bacteria.
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http://dx.doi.org/10.3389/fmicb.2019.00011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6360994PMC
January 2019

Author Correction: Multiple Approaches Detect the Presence of Fungi in Human Breastmilk Samples from Healthy Mothers.

Sci Rep 2018 Nov 9;8(1):16829. Epub 2018 Nov 9.

Department of Health and Genomics, Center for Advanced Research in Public Health, FISABIO Foundation, Valencia, Spain.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
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http://dx.doi.org/10.1038/s41598-018-35165-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6224588PMC
November 2018

Gut Microbiota and Mucosal Immunity in the Neonate.

Med Sci (Basel) 2018 Jul 17;6(3). Epub 2018 Jul 17.

Department of Biotechnology, Institute of Agrochemistry and Food Technology-Spanish National Research Council (IATA-CSIC), 46980 Valencia, Spain.

Gut microbiota colonization is a complex, dynamic, and step-wise process that is in constant development during the first years of life. This microbial settlement occurs in parallel with the maturation of the immune system, and alterations during this period, due to environmental and host factors, are considered to be potential determinants of health-outcomes later in life. Given that host⁻microbe interactions are mediated by the immune system response, it is important to understand the close relationship between immunity and the microbiota during birth, lactation, and early infancy. This work summarizes the evidence to date on early gut microbiota colonization, and how it influences the maturation of the infant immune system and health during the first 1000 days of life. This review will also address the influence of perinatal antibiotic intake and the importance of delivery mode and breastfeeding for an appropriate development of gut immunity.
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http://dx.doi.org/10.3390/medsci6030056DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6163169PMC
July 2018

Oral microbiome development during childhood: an ecological succession influenced by postnatal factors and associated with tooth decay.

ISME J 2018 09 13;12(9):2292-2306. Epub 2018 Jun 13.

Department of Health and Genomics, Center for Advanced Research in Public Health, CSISP-FISABIO, Valencia, Spain.

Information on how the oral microbiome develops during early childhood and how external factors influence this ecological process is scarce. We used high-throughput sequencing to characterize bacterial composition in saliva samples collected at 3, 6, 12, 24 months and 7 years of age in 90 longitudinally followed children, for whom clinical, dietary and health data were collected. Bacterial composition patterns changed through time, starting with "early colonizers", including Streptococcus and Veillonella; other bacterial genera such as Neisseria settled after 1 or 2 years of age. Dental caries development was associated with diverging microbial composition through time. Streptococcus cristatus appeared to be associated with increased risk of developing tooth decay and its role as potential biomarker of the disease should be studied with species-specific probes. Infants born by C-section had initially skewed bacterial content compared with vaginally delivered infants, but this was recovered with age. Shorter breastfeeding habits and antibiotic treatment during the first 2 years of age were associated with a distinct bacterial composition at later age. The findings presented describe oral microbiota development as an ecological succession where altered colonization pattern during the first year of life may have long-term consequences for child´s oral and systemic health.
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http://dx.doi.org/10.1038/s41396-018-0204-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6092374PMC
September 2018

Stimulated and unstimulated saliva samples have significantly different bacterial profiles.

PLoS One 2018 1;13(6):e0198021. Epub 2018 Jun 1.

Department of Genomics and Health, Centre for Advanced Research in Public Health, CSISP-FISABIO, Valencia, Spain.

Epidemiological studies use saliva on a regular basis as a non-invasive and easy-to-take sample, which is assumed to be a microbial representative of the oral cavity ecosystem. However, comparative studies between different kinds of saliva samples normally used in microbial studies are scarce. The aim of the current study was to compare oral microbiota composition between two different saliva samples collected simultaneously: non-stimulated saliva with paper points and stimulated saliva collected after chewing paraffin gum. DNA was extracted from saliva samples of ten individuals, then analyzed by 16S rRNA pyrosequencing to describe bacterial diversity. The results demonstrate significant differences between the microbiota of these two kinds of saliva. Stimulated saliva was found to contain an estimated number of species over three times higher than unstimulated saliva. In addition, bacterial composition at the class and genus level was radically different between both types of samples. When compared to other oral niches, both types of saliva showed some similarity to tongue and buccal mucosa, but they do not correlate at all with the bacterial composition described in supra- or sub-gingival dental plaque, questioning their use in etiological and epidemiological studies of oral diseases of microbial origin.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0198021PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5983451PMC
December 2018

Inhibition of Oral Pathogens Adhesion to Human Gingival Fibroblasts by Wine Polyphenols Alone and in Combination with an Oral Probiotic.

J Agric Food Chem 2018 Mar 21;66(9):2071-2082. Epub 2018 Feb 21.

Instituto de Investigación en Ciencias de la Alimentación (CIAL) , CSIC-UAM , c/Nicolás Cabrera, 9 , 28049 Madrid , Spain.

Several benefits have been described for red wine polyphenols and probiotic strains in the promotion of colonic metabolism and health. On the contrary, knowledge about their role in the management of oral health is still scarce. In this work, the antiadhesive capacity of selected red wine polyphenols and oenological extracts against the oral pathogens Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus mutans in an in vitro model of human gingival fibroblasts has been explored as well as their complementary action with the candidate oral probiotic Streptococcus dentisani. Results highlighted the antiadhesive capacity of caffeic and p-coumaric acids as well as grape seed and red wine oenological extracts. Both, caffeic and p-coumaric acids increased their inhibition potential against S. mutans adhesion when combined with S. dentisani. Additionally, UHPLC-MS/MS analysis demonstrated the oral metabolism of wine phenolics due to both, cellular and bacterial activity.
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http://dx.doi.org/10.1021/acs.jafc.7b05466DOI Listing
March 2018

Inhibition of biofilm formation by extracts of sp. 20J, a bacterium with wide-spectrum quorum quenching activity.

J Oral Microbiol 2018 30;10(1):1429788. Epub 2018 Jan 30.

Departamento de Microbioloxía e Parasitoloxía, Facultade de Bioloxía-CIBUS, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.

: Previous studies have suggested the quorum sensing signal AI-2 as a potential target to prevent the biofilm formation by , a pathogen involved in tooth decay. : To obtain inhibition of biofilm formation by by extracts obtained from the marine bacterium sp. 20J interfering with the AI-2 quorum sensing system. : The AI-2 inhibitory activity was tested with the biosensors BB170 and JMH597. ATCC25175 biofilm formation was monitored using impedance real-time measurements with the xCELLigence system®, confocal laser microscopy, and the crystal violet quantification method. : The addition of the cell extract from sp. 20J reduced biofilm formation in ATCC25175 by 40-50% compared to the control without significantly affecting growth. A decrease of almost 40% was also observed in DSM20627 and 7747 biofilms. : The ability of sp. 20J to interfere with AI-2 and inhibit biofilm formation in was demonstrated. The results indicate that the inhibition of quorum sensing processes may constitute a suitable strategy for inhibiting dental plaque formation, although additional experiments using mixed biofilm models would be required.
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http://dx.doi.org/10.1080/20002297.2018.1429788DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5795696PMC
January 2018

Multiple Approaches Detect the Presence of Fungi in Human Breastmilk Samples from Healthy Mothers.

Sci Rep 2017 10 12;7(1):13016. Epub 2017 Oct 12.

Department of Health and Genomics, Center for Advanced Research in Public Health, FISABIO Foundation, Valencia, Spain.

Human breastmilk contains a variety of bacteria that are transmitted to the infant and have been suggested to contribute to gut microbiota development and immune maturation. However, the characterization of fungal organisms in milk from healthy mothers is currently unknown although their presence has been reported in the infant gut and also in milk from other mammals. Breastmilk samples from healthy lactating mothers (n = 65) within 1 month after birth were analyzed. Fungal presence was assessed by different techniques, including microscopy, growth and identification of cultured isolates, fungal load estimation by qPCR, and fungal composition using 28S rRNA gene high-throughput sequencing. In addition, milk macronutrients and human somatic cells were quantified by spectrophotometry and cytometry. qPCR data showed that 89% of samples had detectable levels of fungal DNA, at an estimated median load of 3,5 × 10 cells/ml, potentially including both viable and non-viable fungi. Using different culture media, 33 strains were isolated and identified, confirming the presence of viable fungal species. Pyrosequencing results showed that the most common genera were Malassezia (44%), followed by Candida (19%) and Saccharomyces (12%). Yeast cells were observed by fluorescence microscopy. Future work should study the origin of these fungi and their potential contribution to infant health.
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http://dx.doi.org/10.1038/s41598-017-13270-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5638952PMC
October 2017

Isolation of Human Intestinal Bacteria Capable of Producing the Bioactive Metabolite Isourolithin A from Ellagic Acid.

Front Microbiol 2017 7;8:1521. Epub 2017 Aug 7.

Laboratory of Food and Health, Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, Centre for Applied Soil Science and Biology of the Segura - Spanish National Research CouncilMurcia, Spain.

Urolithins are intestinal microbial metabolites produced from ellagitannin- and ellagic acid-containing foods such as walnuts, strawberries, and pomegranates. These metabolites, better absorbed than their precursors, can contribute significantly to the beneficial properties attributed to the polyphenols ellagitannins and ellagic acid (EA). However, both the ability of producing the final metabolites in this catabolism (urolithins A, B and isourolithin A) and the health benefits associated with ellagitannin consumption differ considerably among individuals depending on their gut microbiota composition. Three human urolithin metabotypes have been previously described, i.e., metabotype 0 (urolithin non-producers), metabotype A (production of urolithin A as unique final urolithin) and metabotype B (urolithin B and/or isourolithin A are produced besides urolithin A). Although production of some intermediary urolithins has been recently attributed to intestinal species from family named and , the identification of the microorganisms responsible for the complete transformation of EA into the final urolithins, especially those related to metabotype B, are still unknown. In the present research we illustrate the isolation of urolithin-producing strains from human feces of a healthy adult and their ability to transform EA into different urolithin metabolites, including isourolithin A. The isolates belong to a new genus from family. EA transformation and urolithin production arisen during the stationary phase of the growth of the bacteria under anaerobic conditions. The HPLC-DAD-MS analyses demonstrated the sequential appearance of 3,8,9,10-tetrahydroxy-urolithin (urolithin M6), 3,8,9-trihydroxy-urolithin (urolithin C) and 3,9-dihydroxy-urolithin (isourolithin A) while 3,8-dihydroxy-urolithin (urolithin A) and 3-hydroxy-urolithin (urolithin B) were not detected. For the first time isourolithin A production capacity of pure strains has been described. The biological activity attributed to urolithins A and B and isourolithin A (anti-inflammatory, anti-carcinogenic, cardioprotective, and neuroprotective properties) explains the relevance of identifying these urolithin-producing bacteria as potential novel probiotics with applications in the development of functional foods and nutraceuticals. Their human administration could improve the health benefits upon ellagitannin consumption, especially in metabotype 0 individuals. However, further research is necessary to probe well-established beneficial effects on the host and safety requirements before being considered among the next-generation probiotics.
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http://dx.doi.org/10.3389/fmicb.2017.01521DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5545574PMC
August 2017