Publications by authors named "Zhengxiao Zhang"

18 Publications

  • Page 1 of 1

Prebiotic dietary fibre intervention improves fecal markers related to inflammation in obese patients: results from the Food4Gut randomized placebo-controlled trial.

Eur J Nutr 2021 Feb 5. Epub 2021 Feb 5.

Metabolism and Nutrition Research Group, Louvain Drug Research Institute, UCLouvain, Université catholique de Louvain, avenue E. Mounier box B1.73.11, B-1200, Brussels, Belgium.

Purpose: Inulin-type fructans (ITF) are prebiotic dietary fibre (DF) that may confer beneficial health effects, by interacting with the gut microbiota. We have tested the hypothesis that a dietary intervention promoting inulin intake versus placebo influences fecal microbial-derived metabolites and markers related to gut integrity and inflammation in obese patients.

Methods: Microbiota (16S rRNA sequencing), long- and short-chain fatty acids (LCFA, SCFA), bile acids, zonulin, and calprotectin were analyzed in fecal samples obtained from obese patients included in a randomized, placebo-controlled trial. Participants received either 16 g/d native inulin (prebiotic n = 12) versus maltodextrin (placebo n = 12), coupled to dietary advice to consume inulin-rich versus inulin-poor vegetables for 3 months, in addition to dietary caloric restriction.

Results: Both placebo and prebiotic interventions lowered energy and protein intake. A substantial increase in Bifidobacterium was detected after ITF treatment (q = 0.049) supporting our recent data obtained in a larger cohort. Interestingly, fecal calprotectin, a marker of gut inflammation, was reduced upon ITF treatment. Both prebiotic and placebo interventions increased the ratio of tauro-conjugated/free bile acids in feces. Prebiotic treatment did not significantly modify fecal SCFA content but it increased fecal rumenic acid, a conjugated linoleic acid (cis-9, trans-11 CLA) with immunomodulatory properties, that correlated notably to the expansion of Bifidobacterium (p = 0.031; r = 0.052).

Conclusions: Our study demonstrates that ITF-prebiotic intake during 3 months decreases a fecal marker of intestinal inflammation in obese patients. Our data point to a potential contribution of microbial lipid-derived metabolites in gastro-intestinal dysfunction related to obesity. CLINICALTRIALS.

Gov Identifier: NCT03852069 (February 22, 2019 retrospectively, registered).
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http://dx.doi.org/10.1007/s00394-021-02484-5DOI Listing
February 2021

Not All Fibers Are Born Equal; Variable Response to Dietary Fiber Subtypes in IBD.

Front Pediatr 2020 15;8:620189. Epub 2021 Jan 15.

Centre of Excellence for Gastrointestinal Inflammation and Immunity Research, University of Alberta, Edmonton, AB, Canada.

Diet provides a safe and attractive alternative to available treatment options in a variety of diseases; however, research has only just begun to elucidate the role of diet in chronic diseases, such as the inflammatory bowel diseases (IBD). The chronic and highly debilitating IBDs, Crohn disease and ulcerative colitis, are hallmarked by intestinal inflammation, immune dysregulation, and dysbiosis; and evidence supports a role for genetics, microbiota, and the environment, including diet, in disease pathogenesis. This is true especially in children with IBD, where diet-based treatments have shown excellent results. One interesting group of dietary factors that readily links microbiota to gut health is dietary fibers. Fibers are not digested by human cells, but rather fermented by the gut microbes within the bowel. Evidence has been mounting over the last decade in support of the importance of dietary fibers in the maintenance of gut health and in IBD; however, more recent studies highlight the complexity of this interaction and importance of understanding the role of each individual dietary fiber subtype, especially during disease. There are roughly ten subtypes of dietary fibers described to date, categorized as soluble or insoluble, with varying chemical structures, and large differences in their fermentation profiles. Many studies to date have described the benefits of the byproducts of fermentation in healthy individuals and the potential health benefits in select disease models. However, there remains a void in our understanding of how each of these individual fibers affect human health in dysbiotic settings where appropriate fermentation may not be achieved. This review highlights the possibilities for better defining the role of individual dietary fibers for use in regulating inflammation in IBD.
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http://dx.doi.org/10.3389/fped.2020.620189DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7844368PMC
January 2021

Noninvasive monitoring of fibre fermentation in healthy volunteers by analyzing breath volatile metabolites: lessons from the FiberTAG intervention study.

Gut Microbes 2021 Jan-Dec;13(1):1-16

Metabolism and Nutrition Research Group, Louvain Drug Research Institute, UCLouvain, Université catholique de Louvain , Brussels, Belgium.

The fermentation of dietary fibre (DF) leads to the production of bioactive metabolites, the most volatile ones being excreted in the breath. The aim of this study was to analyze the profile of exhaled breath volatile metabolites (BVM) and gastrointestinal symptoms in healthy volunteers after a single ingestion of maltodextrin (placebo) versus chitin-glucan (CG), an insoluble DF previously shown to be fermented into short-chain fatty acids (SCFA) by the human microbiota in vitro. Maltodextrin (4.5 g at day 0) or CG (4.5 g at day 2) were added to a standardized breakfast in fasting healthy volunteers (n = 15). BVM were measured using selected ion flow tube mass spectrometry (SIFT-MS) throughout the day. A single ingestion of 4.5 g CG did not induce significant gastrointestinal discomfort. Untargeted metabolomics analysis of breath highlighted that 13 MS-fragments (among 408 obtained from ionizations of breath) discriminated CG versus maltodextrin acute intake in the posprandial state. The targeted analysis revealed that CG increased exhaled butyrate and 5 other BVM - including the microbial metabolites 2,3-butanedione and 3-hydroxybutanone - with a peak observed 6 h after CG intake. Correlation analyses with fecal microbiota (Illumina 16S rRNA sequencing) spotlighted as a potential genus responsible for the presence of butyric acid, triethylamine and 3-hydroxybutanone in the breath. In conclusion, measuring BMV in the breath reveals the microbial signature of the fermentation of DF after a single ingestion. This protocol allows to analyze the time-course of released bioactive metabolites that could be proposed as new biomarkers of DF fermentation, potentially linked to their biological properties. Trial registration: Clinical Trials NCT03494491. Registered 11 April 2018 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03494491.
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http://dx.doi.org/10.1080/19490976.2020.1862028DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7833774PMC
January 2021

Metabolite profiling reveals the interaction of chitin-glucan with the gut microbiota.

Gut Microbes 2020 11;12(1):1810530

Metabolism and Nutrition Research Group, Louvain Drug Research Institute, UCLouvain, Université Catholique de Louvain , Brussels, Belgium.

Dietary fibers are considered beneficial nutrients for health. Current data suggest that their interaction with the gut microbiota largely contributes to their physiological effects. In this context, chitin-glucan (CG) improves metabolic disorders associated with obesity in mice, but its effect on gut microbiota has never been evaluated in humans. This study explores the effect of a 3-week intervention with CG supplementation in healthy individuals on gut microbiota composition and bacterial metabolites. CG was given to healthy volunteers (n = 15) for three weeks as a supplement (4.5 g/day). Food diary, visual analog and Bristol stool form scales and a "quality of life" survey were analyzed. Among gut microbiota-derived metabolites, bile acids (BA), long- and short-chain fatty acids (LCFA, SCFA) profiling were assessed in stool samples. The gut microbiota (primary outcome) was analyzed by Illumina sequencing. A 3-week supplementation with CG is well tolerated in healthy humans. CG induces specific changes in the gut microbiota composition, with and genera showing the strongest regulation. In addition, CG increased bacterial metabolites in feces including butyric, iso-valeric, caproic and vaccenic acids. No major changes were observed for the fecal BA profile following CG intervention. In summary, our work reveals new potential bacterial genera and gut microbiota-derived metabolites characterizing the interaction between an insoluble dietary fiber -CG- and the gut microbiota.
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http://dx.doi.org/10.1080/19490976.2020.1810530DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7524357PMC
November 2020

Gut microbiota modulation with long-chain corn bran arabinoxylan in adults with overweight and obesity is linked to an individualized temporal increase in fecal propionate.

Microbiome 2020 08 19;8(1):118. Epub 2020 Aug 19.

Department of Agricultural, Food & Nutritional Science, University of Alberta, Edmonton, AB, T6G 2E1, Canada.

Background: Variability in the health effects of dietary fiber might arise from inter-individual differences in the gut microbiota's ability to ferment these substrates into beneficial metabolites. Our understanding of what drives this individuality is vastly incomplete and will require an ecological perspective as microbiomes function as complex inter-connected communities. Here, we performed a parallel two-arm, exploratory randomized controlled trial in 31 adults with overweight and class-I obesity to characterize the effects of long-chain, complex arabinoxylan (n = 15) at high supplementation doses (female: 25 g/day; male: 35 g/day) on gut microbiota composition and short-chain fatty acid production as compared to microcrystalline cellulose (n = 16, non-fermentable control), and integrated the findings using an ecological framework.

Results: Arabinoxylan resulted in a global shift in fecal bacterial community composition, reduced α-diversity, and the promotion of specific taxa, including operational taxonomic units related to Bifidobacterium longum, Blautia obeum, and Prevotella copri. Arabinoxylan further increased fecal propionate concentrations (p = 0.012, Friedman's test), an effect that showed two distinct groupings of temporal responses in participants. The two groups showed differences in compositional shifts of the microbiota (p ≤ 0.025, PERMANOVA), and multiple linear regression (MLR) analyses revealed that the propionate response was predictable through shifts and, to a lesser degree, baseline composition of the microbiota. Principal components (PCs) derived from community data were better predictors in MLR models as compared to single taxa, indicating that arabinoxylan fermentation is the result of multi-species interactions within microbiomes.

Conclusion: This study showed that long-chain arabinoxylan modulates both microbiota composition and the output of health-relevant SCFAs, providing information for a more targeted application of this fiber. Variation in propionate production was linked to both compositional shifts and baseline composition, with PCs derived from shifts of the global microbial community showing the strongest associations. These findings constitute a proof-of-concept for the merit of an ecological framework that considers features of the wider gut microbial community for the prediction of metabolic outcomes of dietary fiber fermentation. This provides a basis to personalize the use of dietary fiber in nutritional application and to stratify human populations by relevant gut microbiota features to account for the inconsistent health effects in human intervention studies.

Trial Registration: Clinicaltrials.gov, NCT02322112 , registered on July 3, 2015. Video Abstract.
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http://dx.doi.org/10.1186/s40168-020-00887-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7439537PMC
August 2020

Sex-Specific Differences in the Gut Microbiome in Response to Dietary Fiber Supplementation in IL-10-Deficient Mice.

Nutrients 2020 Jul 15;12(7). Epub 2020 Jul 15.

Department of Medicine, University of Alberta, Edmonton, AB T6G 2E1, Canada.

There is growing interest in studying dietary fiber to stimulate microbiome changes that might prevent or alleviate inflammatory bowel disease (IBD). However, dietary fiber effects have shown varying degrees of efficacy, for reasons that are unclear. This study examined whether the effects of isomaltodextrin on gut microbiota and IBD were dependent on dose or host sex, using an Interleukin (IL)-10 deficient murine colitis model. After 12 weeks, colonic IL-12p70 was depressed in male mice receiving high-dose isomaltodextrin supplementation compared to the control group ( = 0.04). Male mice receiving high-dose isomaltodextrin exhibited changes in microbial alpha-diversity, including enhanced richness and evenness ( = 0.01) and limited reduction in the relative abundance of ( = 0.08), compared to the control group. These microbial compositional changes were negatively associated with IL-12p70 levels in the male group (rs ≤ -0.51, ≤ 0.08). In contrast, female mice receiving isomaltodextrin displayed a reduction in alpha-diversity and abundance and a high level of IL-12p70, as did the control group. Together, these results indicate that isomaltodextrin altered the gut microbial composition linking specific immune-regulatory cytokine responses, while the interactions among fiber, microbiota and immune response were dose dependent and largely sex specific. The results further indicate that interactions between environmental and host factors can affect microbiome manipulation in the host.
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http://dx.doi.org/10.3390/nu12072088DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7400915PMC
July 2020

A Diversified Dietary Pattern Is Associated With a Balanced Gut Microbial Composition of Faecalibacterium and Escherichia/Shigella in Patients With Crohn's Disease in Remission.

J Crohns Colitis 2020 Nov;14(11):1547-1557

Department of Medicine, University of Calgary, Calgary, AB, Canada.

Background And Aims: Crohn's disease [CD] is associated with alterations in gut microbial composition and function. The present controlled-intervention study investigated the relationship between patterns of dietary intake and baseline gut microbiota in CD patients in remission and examined the effects of a dietary intervention in patients consuming a non-diversified diet [NDD].

Methods: Forty outpatients with quiescent CD were recruited in Calgary, Alberta, Canada. Based on 3-day food records, patients consuming a lower plant-based and higher red and processed meat-based diet were assigned to the NDD group [n = 15] and received a 12-week structured dietary intervention; all other patients were assigned to the diversified diet [DD] control group [n = 25] and received conventional management. Faecal microbiota composition, short chain fatty acids [SCFAs] and calprotectin were measured.

Results: At baseline the NDD and DD groups had a different faecal microbial beta-diversity [p = 0.003, permutational multivariate analysis of variance]. The NDD group had lower Faecalibacterium and higher Escherichia/Shigella relative abundances compared to the DD group [3.3 ± 5.4% vs. 8.5 ± 10.6%; 6.9 ± 12.2% vs. 1.6 ± 4.4%; p ≤ 0.03, analysis of covariance]. These two genera showed a strong negative correlation [rs = -0.60, q = 0.0002]. Faecal butyrate showed a positive correlation with Faecalibacterium [rs = 0.52, q = 0.002], and an inhibitory relationship with Escherichia/Shigella abundance [four-parameter sigmoidal model, R = -0.83; rs = -0.44, q = 0.01], respectively. After the 12 weeks of dietary intervention, no difference in microbial beta-diversity between the two groups was observed [p = 0.43]. The NDD group demonstrated an increase in Faecalibacterium [p < 0.05, generalized estimated equation model], and resembled the DD group at the end of the intervention [p = 0.84, t-test with permutation]. We did not find an association of diet with faecal SCFAs or calprotectin.

Conclusions: Dietary patterns are associated with specific gut microbial compositions in CD patients in remission. A diet intervention in patients consuming a NDD modifies gut microbial composition to resemble that seen in patients consuming a DD. These results show that diet is important in shaping the microbial dysbiosis signature in CD towards a balanced community.
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http://dx.doi.org/10.1093/ecco-jcc/jjaa084DOI Listing
November 2020

Rational design of a DNA sequence-specific modular protein tag by tuning the alkylation kinetics.

Chem Sci 2019 Oct 20;10(40):9315-9325. Epub 2019 Aug 20.

Institute of Advanced Energy , Kyoto University , Uji , Kyoto 611-0011 , Japan . Email:

Sequence-selective chemical modification of DNA by synthetic ligands has been a long-standing challenge in the field of chemistry. Even when the ligand consists of a sequence-specific DNA binding domain and reactive group, sequence-selective reactions by these ligands are often accompanied by off-target reactions. A basic principle to design DNA modifiers that react at specific sites exclusively governed by DNA sequence recognition remains to be established. We have previously reported selective DNA modification by a self-ligating protein tag conjugated with a DNA-binding domain, termed as a modular adaptor, and orthogonal application of modular adaptors by relying on the chemoselectivity of the protein tag. The sequence-specific crosslinking reaction by the modular adaptor is thought to proceed in two steps: the first step involves the formation of a DNA-protein complex, while in the second step, a proximity-driven intermolecular crosslinking occurs. According to this scheme, the specific crosslinking reaction of a modular adaptor would be driven by the DNA recognition process only when the dissociation rate of the DNA complex is much higher than the rate constant for the alkylation reaction. In this study, as a proof of principle, a set of combinations for modular adaptors and their substrates were utilized to evaluate the reactions. Three types of modular adaptors consisting of a single type of self-ligating tag and three types of DNA binding proteins fulfill the kinetic requirements for the reaction of the self-ligating tag with a substrate and the dissociation of the DNA-protein complex. These modular adaptors actually undergo sequence-specific crosslinking reactions exclusively driven by the recognition of a specific DNA sequence. The design principle of sequence-specific modular adaptors based on the kinetic aspects of complex formation and chemical modification is applicable for developing recognition-driven selective modifiers for proteins and other biological macromolecules.
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http://dx.doi.org/10.1039/c9sc02990gDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7006624PMC
October 2019

Precision Microbiome Modulation with Discrete Dietary Fiber Structures Directs Short-Chain Fatty Acid Production.

Cell Host Microbe 2020 Mar 30;27(3):389-404.e6. Epub 2020 Jan 30.

Department of Agricultural, Nutritional and Food Science, University of Alberta, Edmonton, AB T6G 2E1, Canada; Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E1, Canada; APC Microbiome Ireland, School of Microbiology, Department of Medicine, and APC Microbiome Institute, University College Cork - National University of Ireland, Cork T12 YT20, Ireland. Electronic address:

Dietary fibers (DFs) impact the gut microbiome in ways often considered beneficial. However, it is unknown if precise and predictable manipulations of the gut microbiota, and especially its metabolic activity, can be achieved through DFs with discrete chemical structures. Using a dose-response trial with three type-IV resistant starches (RS4s) in healthy humans, we found that crystalline and phosphate cross-linked starch structures induce divergent and highly specific effects on microbiome composition that are linked to directed shifts in the output of either propionate or butyrate. The dominant RS4-induced effects were remarkably consistent within treatment groups, dose-dependent plateauing at 35 g/day, and can be explained by substrate-specific binding and utilization of the RS4s by bacterial taxa with different pathways for starch metabolism. Overall, these findings support the potential of using discrete DF structures to achieve targeted manipulations of the gut microbiome and its metabolic functions relevant to health.
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http://dx.doi.org/10.1016/j.chom.2020.01.006DOI Listing
March 2020

Impact of Fecal Microbiota Transplantation on Obesity and Metabolic Syndrome-A Systematic Review.

Nutrients 2019 Sep 25;11(10). Epub 2019 Sep 25.

Division of Gastroenterology, Department of Medicine, University of Alberta, Edmonton T6G 2E1 AB, Canada.

Fecal microbiota transplantation (FMT) is a gut microbial-modulation strategy that has been investigated for the treatment of a variety of human diseases, including obesity-associated metabolic disorders. This study appraises current literature and provides an overview of the effectiveness and limitations of FMT as a potential therapeutic strategy for obesity and metabolic syndrome (MS). Five electronic databases and two gray literature sources were searched up to 10 December 2018. All interventional and observational studies that contained information on the relevant population (adult patients with obesity and MS), intervention (receiving allogeneic FMT) and outcomes (metabolic parameters) were eligible. From 1096 unique citations, three randomized placebo-controlled studies (76 patients with obesity and MS, body mass index = 34.8 ± 4.1 kg/m, fasting plasma glucose = 5.8 ± 0.7 mmol/L) were included for review. Studies reported mixed results with regards to improvement in metabolic parameters. Two studies reported improved peripheral insulin sensitivity (rate of glucose disappearance, RD) at 6 weeks in patients receiving donor FMT versus patients receiving the placebo control. In addition, one study observed lower HbA1c levels in FMT patients at 6 weeks. No differences in fasting plasma glucose, hepatic insulin sensitivity, body mass index (BMI), or cholesterol markers were observed between two groups across all included studies. While promising, the influence of FMT on long-term clinical endpoints needs to be further explored. Future studies are also required to better understand the mechanisms through which changes in gut microbial ecology and engraftment of microbiota affect metabolic outcomes for patients with obesity and MS. In addition, further research is needed to better define the optimal fecal microbial preparation, dosing, and method of delivery.
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http://dx.doi.org/10.3390/nu11102291DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6835402PMC
September 2019

Feeding practice influences gut microbiome composition in very low birth weight preterm infants and the association with oxidative stress: A prospective cohort study.

Free Radic Biol Med 2019 10 6;142:146-154. Epub 2019 Mar 6.

Department of Food and Human Nutritional Sciences, Faculty of Agricultural and Food Sciences, 208A Human Ecology Building, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada. Electronic address:

Knowledge about the development of the preterm infant gut microbiota is emerging and is critical to their health. Very-low-birth-weight (VLBW; birth weight, <1500 g) infants usually have special dietary needs while showing increased oxidative stress related to intensive care. This prospective cohort study assessed the effect of feeding practice on gut microbiome development and oxidative stress in preterm infants. Fecal samples were collected from each infant in the early (1-2 weeks of enteral feeding) and late (2-4 weeks of enteral feeding) feeding stages. We performed high-throughput sequencing of V3-V4 regions of the 16S rRNA gene to analyze the fecal microbiome composition of 20 VLBW preterm infants and to determine the association of gut bacterial composition with feeding practice using an oxidative stress marker (urinary F2-isoprostane). Our results showed that feeding practices in the late stage significantly influenced the gut microbiome composition and oxidative stress in preterm infants. Preterm infants fed human milk + human milk fortifier and only formula diets showed a significant increase in F2-isoprostane levels (P < 0.05) compared with those fed human milk + formula diet. The gut microbiome of the infants fed the human milk + Human milk fortifier diet showed the lower relative abundance of Veillonella (P < 0.05) compared with that of the infants fed the human milk + formula diet. The gut microbiome of the infants fed the only formula diet showed the lowest microbial diversity and the highest relative abundance of Terrisporobacter (P < 0.05) compared with the gut microbiome of the infants fed the other diets. Correlation network analysis showed that urinary F2-isoprostane level was positively correlated with Terrisporobacter and Enterobacteriaceae abundance (P < 0.05) in the preterm infants. In conclusion, these data suggest that feeding practice affects the bacterial diversity and composition in the gut microbiome and is associated with oxidative stress in VLBW preterm infants.
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http://dx.doi.org/10.1016/j.freeradbiomed.2019.02.032DOI Listing
October 2019

Impact of xylanases on gut microbiota of growing pigs fed corn- or wheat-based diets.

Anim Nutr 2018 Dec 24;4(4):339-350. Epub 2018 Aug 24.

Department of Animal Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.

This study investigated the effects of xylanase supplementations with cereal-based diets on nutrient digestibility and gut microbiota of growing pigs. A total of 96 individually penned pigs (initial BW = 22.7 ± 0.65 kg) were allotted to 12 treatments and subjected to a completely randomized block design experiment. Pigs in each treatment were fed an isocaloric wheat-based or corn-based diet with or without 1 of 5 types of xylanase supplements (XA, XB, XC, XD, XE). On d 42, all piglets were euthanized to obtain ileal and cecal digesta for microbial analysis, which involved high-throughput sequencing of the V1 - V3 regions of 16S rRNA gene. Corn- and wheat-based diets differed ( < 0.05) in digestion characteristics. Dietary treatments affected the alpha- and beta-diversities of microbiota in the cecum but not in the ileum. The wheat-based diet increased ( < 0.05) alpha-diversity and clustered separately ( < 0.05) compared with the corn-based diet. Wheat-based diet also promoted the relative abundance of genus (g.) while corn-based diet promoted the proportion of family (f.) Veillonellaceae in the community. Among xylanases, only XC within the wheat-based diet altered ( < 0.05) the beta-diversity of the cecal microbiota compared with control. For each cereal-based diet and compared with the controls, xylanase treatments affected ( < 0.05) the proportions of 5 bacterial taxa in the ileum (f. Peptostreptococcaceae, order [o.] Streptophyta, f. , g. and g. ) and 8 in the cecum (g. , g. , class [c.] Clostridia, f. Clostridiaceae, g. , g. , g. and f. Ruminococcaceae). Network analysis showed that across diets under control treatments, Bacteroidetes was the most influential phylum promoting cooperative relationships among members of the ileum and cecum microbiota. Xylanase treatment, however, reduced the influence of Bacteroidetes and promoted a large number of hub taxa majority of which belonged to the Firmicutes phylum. To maximize the efficiency of xylanase supplementation, our data suggest that xylanase C originated from was more effective when applied to wheat-based diets, while xylanase A originated from was more beneficial when applied to corn-based diets.
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http://dx.doi.org/10.1016/j.aninu.2018.06.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6284322PMC
December 2018

Author Correction: Comparison of DNA-, PMA-, and RNA-based 16S rRNA Illumina sequencing for detection of live bacteria in water.

Sci Rep 2018 Nov 22;8(1):17427. Epub 2018 Nov 22.

Department of Animal Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.
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http://dx.doi.org/10.1038/s41598-018-35437-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6250725PMC
November 2018

The impact of epidermal growth factor supernatant on pig performance and ileal microbiota.

Transl Anim Sci 2018 Apr 18;2(2):184-194. Epub 2018 May 18.

Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada.

Weaning of pigs can lead to low-feed intake resulting in a lag in growth performance, reduced gut health, and diarrheal diseases. Epidermal growth factor (), the most abundant growth factor in milk, increased weaned pig BW gain and feed efficiency in our previous work. It is believed that intestinal microbiota plays an important role in gut health and pig growth, but limited data are available on the impact of feed additives, such as EGF, on the microbial communities of the intestines. The objective of the study was to investigate if the positive influence of EGF supplementation on weight gain and gut health was related to differences in intestinal microbiota. To examine the efficacy of EGF, a 21-d animal trial was performed using 72 pigs (two equal blocks of 36 pigs with three barrows and three gilts/pen). Pigs were assigned to one of two dietary treatments at weaning (20 ± 2 d of age; = 6 pens/treatment) balancing across treatment for litter, gender, and initial BW. Recombinant yeast supernatant containing EGF at 120 μg/kg BW/d and without EGF (control) was added to the feed for 21 d, followed by a common diet for 7 d. Pig performance was measured weekly and ileal digesta was collected at day 21 from six pigs/treatment for microbiome analysis. Pigs fed diets containing EGF fermentation supernatant had greater ( = 0.01) daily gain in week 3 and overall resulting in heavier ( = 0.029) BW at day 28, which was consistent to our previous finding. No difference in alpha-diversity (Chao1, Shanon, and Simpson indices) and beta-diversity (weighted and unweighted UniFrac distances) of ileal digesta microbiota between EGF supplemented and control pigs were observed. The relative abundances of bacterial taxa did not differ among treatment groups at the phylum level. The relative abundances of (0.0 vs. 0.9%), (0.003 vs. 0.26%), and (0.0 vs. 0.05%) genera, and Rumminococcaceae family (0.001 vs. 0.08%) were decreased ( < 0.05) in EGF group compared to control and were negatively correlated ( < 0.05, r > 0.60) with growth performance. Pathways related to detoxification and carbohydrate metabolism were differentially represented in the luminal bacterial populations. The improved growth of pigs supplemented with EGF supernatant produced by may be related to changes in functional capacity of the gut microbial populations. However, the impact on mucosa-associated or large intestinal communities is still unknown.
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http://dx.doi.org/10.1093/tas/txy019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7200883PMC
April 2018

Comparison of DNA-, PMA-, and RNA-based 16S rRNA Illumina sequencing for detection of live bacteria in water.

Sci Rep 2017 07 18;7(1):5752. Epub 2017 Jul 18.

Department of Animal Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.

The limitation of 16S rRNA gene sequencing (DNA-based) for microbial community analyses in water is the inability to differentiate live (dormant cells as well as growing or non-growing metabolically active cells) and dead cells, which can lead to false positive results in the absence of live microbes. Propidium-monoazide (PMA) has been used to selectively remove DNA from dead cells during downstream sequencing process. In comparison, 16S rRNA sequencing (RNA-based) can target live microbial cells in water as both dormant and metabolically active cells produce rRNA. The objective of this study was to compare the efficiency and sensitivity of DNA-based, PMA-based and RNA-based 16S rRNA Illumina sequencing methodologies for live bacteria detection in water samples experimentally spiked with different combination of bacteria (2 gram-negative and 2 gram-positive/acid fast species either all live, all dead, or combinations of live and dead species) or obtained from different sources (First Nation community drinking water; city of Winnipeg tap water; water from Red River, Manitoba, Canada). The RNA-based method, while was superior for detection of live bacterial cells still identified a number of 16S rRNA targets in samples spiked with dead cells. In environmental water samples, the DNA- and PMA-based approaches perhaps overestimated the richness of microbial community compared to RNA-based method. Our results suggest that the RNA-based sequencing was superior to DNA- and PMA-based methods in detecting live bacterial cells in water.
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http://dx.doi.org/10.1038/s41598-017-02516-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5515937PMC
July 2017

Characterization of Nitric Oxide Modulatory Activities of Alkaline-Extracted and Enzymatic-Modified Arabinoxylans from Corn Bran in Cultured Human Monocytes.

J Agric Food Chem 2016 Nov 21;64(43):8128-8137. Epub 2016 Oct 21.

School of Healthcare Science, Manchester Metropolitan University , E203 John Dalton Building, Chester Street, Manchester M1 5GD, U.K.

The ingestion of foods and food-derived substances that may mediate the immune system is widely studied. Evidence suggests cereal arabinoxylans (AXs) have immunomodulatory activities that may impart health benefits in terms of immune enhancement. This study extracted AXs from corn bran using alkali and developed a modification process using three endoxylanases to obtain fractions of lower molecular weight ranges. In vitro studies showed extracted and modified AXs significantly (P < 0.05) elevated nitric oxide (NO) synthesis by the human U937 monocytic cell line (ranging from 53.7 ± 1.1 to 62.9 ± 1.2 μM per million viable cells) at all concentrations tested (5-1000 μg/mL), indicative of immune enhancement compared to an untreated control (43.7 ± 1.9 μM per million viable cells). The study suggested the dose range and Mw distribution of AXs are key determinants of immune-modulatory activity. AXs in the low Mw range (0.1-10 KDa) were the most effective at inducing NO secretion by U937 macrophages at low AX concentration ranges (5-50 μg/mL), with NO production peaking at 62.9 ± 1.2 μM per million viable cells with 5 μg/mL of AX (P = 0.0009). In contrast, AXs in the high Mw range (100-794 kDa) were most effective at inducing NO at high AX concentration ranges (500-1000 μg/mL) with NO production reaching a maximum of 62.7 ± 1.3 μM per million viable cells at 1000 μg/mL of AX (P = 0.0011). The findings suggest that dietary AXs from corn bran may heighten innate immune responses in the absence of infection or disease.
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http://dx.doi.org/10.1021/acs.jafc.6b02896DOI Listing
November 2016