Publications by authors named "Edward C Deehan"

15 Publications

  • Page 1 of 1

Repeated Fecal Microbial Transplantations and Antibiotic Pre-Treatment Are Linked to Improved Clinical Response and Remission in Inflammatory Bowel Disease: A Systematic Review and Pooled Proportion Meta-Analysis.

J Clin Med 2021 Mar 1;10(5). Epub 2021 Mar 1.

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

The response of patients with inflammatory bowel disease (IBD) to fecal microbial transplantation (FMT) has been inconsistent possibly due to variable engraftment of donor microbiota. This failure to engraft has resulted in the use of several different strategies to attempt optimization of the recipient microbiota following FMT. The purpose of our study was to evaluate the effects of two distinct microbial strategies-antibiotic pre-treatment and repeated FMT dosing-on IBD outcomes. A systematic literature review was designed and implemented in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A medical librarian conducted comprehensive searches in MEDLINE, Embase, Scopus, Web of Science Core Collection, and Cochrane Library on 25 November 2019 and updated on 29 January 2021. Primary outcomes of interest included comparing relapse and remission rates in patients with IBD for a single FMT dose, repeated FMT dosages, and antibiotic pre-treatment groups. Twenty-eight articles (six randomized trials, 20 cohort trials, two case series) containing 976 patients were identified. Meta-analysis revealed that both repeated FMT and antibiotic pre-treatment strategies demonstrated improvements in pooled response and remission rates. These clinical improvements were associated with increases in fecal microbiota richness and α-diversity, as well as the enrichment of several short-chain fatty acid (SCFA)-producing anaerobes including , , , , , and related species.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/jcm10050959DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7957789PMC
March 2021

Higher intake of microbiota-accessible carbohydrates and improved cardiometabolic risk factors: a meta-analysis and umbrella review of dietary management in patients with type 2 diabetes.

Am J Clin Nutr 2021 Mar 10. Epub 2021 Mar 10.

College of Animal Sciences, Zhejiang University, Hangzhou, China.

Background: Microbiota-accessible carbohydrates (MACs) are critical substrates for intestinal microbes; the subsequent production of SCFAs may have some potential benefits for patients with type 2 diabetes mellitus (T2DM).

Objectives: We conducted a meta-analysis of randomized controlled trials (RCTs) to assess the effects of higher compared with lower MAC intakes on cardiovascular risk factors in T2DM patients and performed an umbrella review of RCTs to evaluate the evidence quality concerning existing dietary T2DM interventions.

Methods: Publications were identified by searching MEDLINE, EMBASE, and CINAHL. In the meta-analysis, random-effects models were used to calculate pooled estimates, and sensitivity analyses, meta-regression, subgroup analyses, and Egger's test were performed. For the umbrella review, we summarized pooled estimates, 95% CIs, heterogeneity, and publication bias. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) and modified NutriGrade were used to assess the quality of evidence in the meta-analysis and umbrella review, respectively.

Results: Forty-five RCTs with 1995 participants were included in the meta-analysis. High MAC intake significantly reduced glycated hemoglobin (HbA1c) (weighted mean difference [WMD] -0.436% [-0.556, -0.315]), fasting glucose (WMD -0.835 mmol/L [-1.048, -0.622]), total cholesterol (WMD -0.293 mmol/L [-0.397, -0.190]), triglycerides (WMD -0.118 mmol/L [-0.308, -0.058]), BMI (WMD -0.476 [-0.641, -0.312]), and systolic blood pressure (WMD -3.066 mmHg [-5.653, -0.478]), with a moderate-to-high quality of evidence, compared with low intake. Region, dose, and MAC type were key variables. The umbrella review of all dietary interventions for cardiovascular risk factors in patients with T2DM included 26 meta-analyses with 158 pooled estimates. The evidence quality of MACs, dietary fiber, high-protein diet, ω-3 (n-3), viscous fiber, vitamin D, and vitamin E intake was moderate to high.

Conclusions: When compared with lower intake, increased MAC intake improved glycemic control, blood lipid, body weight, and inflammatory markers for people with T2DM. This trial was registered at PROSPERO (https://www.crd.york.ac.uk/PROSPERO/#recordDetails) as CRD42019120531.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ajcn/nqaa435DOI Listing
March 2021

Efficacy of metformin and fermentable fiber combination therapy in adolescents with severe obesity and insulin resistance: study protocol for a double-blind randomized controlled trial.

Trials 2021 Feb 17;22(1):148. Epub 2021 Feb 17.

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

Background: Accumulating evidence suggests that the metabolic effects of metformin and fermentable fibers are mediated, in part, through diverging or overlapping effects on the composition and metabolic functions of the gut microbiome. Pre-clinical animal models have established that the addition of fiber to metformin monotherapy improves glucose tolerance. However, possible synergistic effects of combination therapy (metformin plus fiber) have not been investigated in humans. Moreover, the underlying mechanisms of synergy have yet to be elucidated. The aim of this study is to compare in adolescents with obesity the metabolic effects of metformin and fermentable fibers in combination with those of metformin or fiber alone. We will also determine if therapeutic responses correlate with compositional and functional features of the gut microbiome.

Methods: This is a parallel three-armed, double-blinded, randomized controlled trial. Adolescents (aged 12-18 years) with obesity, insulin resistance (IR), and a family history of type 2 diabetes mellitus (T2DM) will receive either metformin (850 mg p.o. twice/day), fermentable fibers (35 g/day), or a combination of metformin plus fiber for 12 months. Participants will be seen at baseline, 3, 6, and 12 months, with a phone follow-up at 1 and 9 months. Primary and secondary outcomes will be assessed at baseline, 6, and 12 months. The primary outcome is change in IR estimated by homeostatic model assessment of IR; key secondary outcomes include changes in the Matsuda index, oral disposition index, body mass index z-score, and fat mass to fat-free mass ratio. To gain mechanistic insight, endpoints that reflect host-microbiota interactions will also be assessed: obesity-related immune, metabolic, and satiety markers; humoral metabolites; and fecal microbiota composition, short-chain fatty acids, and bile acids.

Discussion: This study will compare the potential metabolic benefits of fiber with those of metformin in adolescents with obesity, determine if metformin and fiber act synergistically to improve IR, and elucidate whether the metabolic benefits of metformin and fiber associate with changes in fecal microbiota composition and the output of health-related metabolites. This study will provide insight into the potential role of the gut microbiome as a target for enhancing the therapeutic efficacy of emerging treatments for T2DM prevention.

Trial Registration: ClinicalTrials.gov NCT04578652 . Registered on 8 October 2020.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13063-021-05060-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7890810PMC
February 2021

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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s40168-020-00887-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7439537PMC
August 2020

The Gut Microbiota Profile in Children with Prader-Willi Syndrome.

Genes (Basel) 2020 08 7;11(8). Epub 2020 Aug 7.

Department of Pediatrics, University of Alberta, Edmonton, AB T6G 2R3, Canada.

Although gut microbiota has been suggested to play a role in disease phenotypes of Prader-Willi syndrome (PWS), little is known about its composition in affected children and how it relates to hyperphagia. This cross-sectional study aimed to characterize the gut bacterial and fungal communities of children with PWS, and to determine associations with hyperphagia. Fecal samples were collected from 25 children with PWS and 25 age-, sex-, and body mass index-matched controls. Dietary intake data, hyperphagia scores, and relevant clinical information were also obtained. Fecal bacterial and fungal communities were characterized by 16S rRNA and ITS2 sequencing, respectively. Overall bacterial α-diversity and compositions of PWS were not different from those of the controls, but 13 bacterial genera were identified to be differentially abundant. Interestingly, the fungal community, as well as specific genera, were different between PWS and controls. The majority of the variation in the gut microbiota was not attributed to differences in dietary intake or the impact of genotype. Hyperphagia scores were associated with fungal α-diversity and relative abundance of several taxa, such as , , , and . Further longitudinal studies correlating changes in the microbiome with the degree of hyperphagia and studies integrating multi-omics data are warranted.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/genes11080904DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7463799PMC
August 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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ecco-jcc/jjaa084DOI Listing
November 2020

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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chom.2020.01.006DOI Listing
March 2020

Current and emerging therapies for managing hyperphagia and obesity in Prader-Willi syndrome: A narrative review.

Obes Rev 2020 05 30;21(5):e12992. Epub 2019 Dec 30.

Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada.

In early childhood, individuals with Prader-Willi syndrome (PWS) experience excess weight gain and severe hyperphagia with food compulsivity, which often leads to early onset morbid obesity. Effective treatments for appetite suppression and weight control are currently unavailable for PWS. Our aim to further understand the pathogenesis of PWS led us to carry out a comprehensive search of the current and emerging therapies for managing hyperphagia and extreme weight gain in PWS. A literature search was performed using PubMed and the following keywords: "PWS" AND "therapy" OR "[drug name]"; reference lists, pharmaceutical websites, and the ClinicalTrials.gov registry were also reviewed. Articles presenting data from current standard treatments in PWS and also clinical trials of pharmacological agents in the pipeline were selected. Current standard treatments include dietary restriction/modifications, exercise, and growth hormone replacement, which appear to have limited efficacy for appetite and weight control in patients with PWS. The long-term safety and effectiveness of bariatric surgery in PWS remains unknown. However, many promising pharmacotherapies are in development and, if approved, will bring much needed choices into the PWS pharmacological armamentarium. With the progress that is currently being made in our understanding of PWS, an effective treatment may not be far off.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/obr.12992DOI Listing
May 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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/nu11102291DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6835402PMC
September 2019

The Effect of Isolated and Synthetic Dietary Fibers on Markers of Metabolic Diseases in Human Intervention Studies: A Systematic Review.

Adv Nutr 2020 03;11(2):420-438

Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.

Observational studies provide strong evidence for the health benefits of dietary fiber (DF) intake; however, human intervention studies that supplement isolated and synthetic DFs have shown inconsistent results. Therefore, we conducted a systematic review to summarize the effects of DF supplementation on immunometabolic disease markers in intervention studies in healthy adults, and considered the role of DF dose, DF physicochemical properties, intervention duration, and the placebo used. Five databases were searched for studies published from 1990 to 2018 that assessed the effect of DF on immunometabolic markers. Eligible studies were those that supplemented isolated or synthetic DFs for ≥2 wk and reported baseline data to assess the effect of the placebo. In total, 77 publications were included. DF supplementation reduced total cholesterol (TC), LDL cholesterol, HOMA-IR, and insulin AUC in 36-49% of interventions. In contrast, <20% of the interventions reduced C-reactive protein (CRP), IL-6, glucose, glucose AUC, insulin, HDL cholesterol, and triglycerides. A higher proportion of interventions showed an effect if they used higher DF doses for CRP, TC, and LDL cholesterol (40-63%), viscous and mixed plant cell wall DFs for TC and LDL cholesterol (>50%), and longer intervention durations for CRP and glucose (50%). Half of the placebo-controlled studies used digestible carbohydrates as the placebo, which confounded findings for IL-6, glucose AUC, and insulin AUC. In conclusion, interventions with isolated and synthetic DFs resulted mainly in improved cholesterol concentrations and an attenuation of insulin resistance, whereas markers of dysglycemia and inflammation were largely unaffected. Although more research is needed to make reliable recommendations, a more targeted supplementation of DF with specific physicochemical properties at higher doses and for longer durations shows promise in enhancing several of its health effects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/advances/nmz074DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7442353PMC
March 2020

Faecal microbiota from patients with cirrhosis has a low capacity to ferment non-digestible carbohydrates into short-chain fatty acids.

Liver Int 2019 08 10;39(8):1437-1447. Epub 2019 Apr 10.

Division of Gastroenterology (Liver Unit), University of Alberta, Edmonton, Alberta, Canada.

Background And Aims: Cirrhosis is associated with dysbiosis, but its functional consequences are still largely unknown. Short-chain fatty acids (SCFAs) account for physiological interactions between the gut microbiota and host. Our aim was to assess the impact of cirrhotic dysbiosis on the production of SCFAs.

Methods: Seventeen patients with cirrhosis and 17 controls were selected. Microbiota composition in faecal samples was assessed by next-generation 16S rRNA gene sequencing. SCFAs were measured with GC-MS in faecal samples and after in vitro batch fermentations using arabinoxylan, resistant starch, pectin, and lactulose as substrates.

Results: Among the 17 cirrhotic patients (mean age 58, eight males), six, nine and two were, respectively, Child-Pugh class A, B and C. Eleven patients were on oral antibiotics, 11 on lactulose and 13 on proton pump inhibitors. Cirrhotic patients showed marked differences in the composition and diversity of gut microbiome when compared to controls, that were more pronounced with increased severity. Stool samples from cirrhotic patients showed lower SCFAs content and reduced capacity to produce SCFAs in batch fermentations, with butyrate production being the most abnormal. These functional aberrancies were more pronounced with greater liver disease severity. Abundance of Ruminococcus faecis (in family Ruminococcaceae), Faecalicatena fissicatena and Fusicatenibacter saccharivorans (in family Lachnospiraceae) was positively correlated with the SCFAs production.

Conclusion: Cirrhotic dysbiosis is associated with a decreased capacity to ferment non-digestible carbohydrates into SCFAs, especially into butyrate. These functional abnormalities are more pronounced as disease progresses. These results might inform the design of gut-targeted therapies for cirrhosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/liv.14106DOI Listing
August 2019

The Impact of Dietary Fiber on Gut Microbiota in Host Health and Disease.

Cell Host Microbe 2018 06;23(6):705-715

Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden; Novo Nordisk Foundation Center for Basic Metabolic Research, Section for Metabolic Receptology and Enteroendocrinology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. Electronic address:

Food is a primordial need for our survival and well-being. However, diet is not only essential to maintain human growth, reproduction, and health, but it also modulates and supports the symbiotic microbial communities that colonize the digestive tract-the gut microbiota. Type, quality, and origin of our food shape our gut microbes and affect their composition and function, impacting host-microbe interactions. In this review, we will focus on dietary fibers, which interact directly with gut microbes and lead to the production of key metabolites such as short-chain fatty acids, and discuss how dietary fiber impacts gut microbial ecology, host physiology, and health. Hippocrates' notion "Let food be thy medicine and medicine be thy food" remains highly relevant millennia later, but requires consideration of how diet can be used for modulation of gut microbial ecology to promote health.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chom.2018.05.012DOI Listing
June 2018

Modulation of the Gastrointestinal Microbiome with Nondigestible Fermentable Carbohydrates To Improve Human Health.

Microbiol Spectr 2017 09;5(5)

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

There is a clear association between the gastrointestinal (GI) microbiome and the development of chronic noncommunicable diseases, providing a rationale for the development of strategies that target the GI microbiota to improve human health. In this article, we discuss the potential of supplementing the human diet with nondigestible fermentable carbohydrates (NDFCs) to modulate the composition, structure, diversity, and metabolic potential of the GI microbiome in an attempt to prevent or treat human disease. The current concepts by which NDFCs can be administered to humans, including prebiotics, fermentable dietary fibers, and microbiota-accessible carbohydrates, as well as the mechanisms by which these carbohydrates exert their health benefits, are discussed. Epidemiological research presents compelling evidence for the health effects of NDFCs, with clinical studies providing further support for some of these benefits. However, rigorously designed human intervention studies with well-established clinical markers and microbial endpoints are still essential to establish (i) the clinical efficiency of specific NDFCs, (ii) the causal role of the GI microbiota in these effects, (iii) the underlying mechanisms involved, and (iv) the degree by which inter-individual differences between GI microbiomes influence these effects. Such studies would provide the mechanistic understanding needed for a systematic application of NDFCs to improve human health via GI microbiota modulation while also allowing the personalization of these dietary strategies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/microbiolspec.BAD-0019-2017DOI Listing
September 2017

The Fiber Gap and the Disappearing Gut Microbiome: Implications for Human Nutrition.

Trends Endocrinol Metab 2016 05 11;27(5):239-242. Epub 2016 Apr 11.

Department of Agricultural, Food, and Nutritional Science, University of Alberta, 4-126A Li Ka Shing Centre for Health Research Innovation and 7-142 Katz Group Center, Edmonton, Alberta, T6G 2E1, Canada; Department of Biological Sciences, University of Alberta, 4-126A Li Ka Shing Centre for Health Research Innovation and 7-142 Katz Group Center, Edmonton, Alberta, T6G 2E1, Canada. Electronic address:

Increasing evidence indicates that modern lifestyle, and specifically a Western diet, has led to a substantial depletion of the human gut microbiome. This loss is implicated in the rampant increase of chronic diseases, providing an incentive to fundamentally transform human nutrition towards being more holistic and microbiome-focused.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tem.2016.03.001DOI Listing
May 2016