scholarly journals Probiotics in Irritable Bowel Syndrome: An Up-to-Date Systematic Review

Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 2048 ◽  
Author(s):  
Hanna Fjeldheim Dale ◽  
Stella Hellgren Rasmussen ◽  
Özgün Ömer Asiller ◽  
Gülen Arslan Lied
Keyword(s):  
Systematic Review ◽  
Irritable Bowel Syndrome ◽  
Gut Microbiota ◽  
Gastrointestinal Disorder ◽  
Inclusion Criteria ◽  
Probiotic Supplementation ◽  
Beneficial Effects ◽  
Randomized Controlled ◽  
Irritable Bowel ◽  
Gut Microbiota Composition

Irritable bowel syndrome (IBS) is a frequent functional gastrointestinal disorder, and alterations in the gut microbiota composition contributes to symptom generation. The exact mechanisms of probiotics in the human body are not fully understood, but probiotic supplements are thought to improve IBS symptoms through manipulation of the gut microbiota. The aim of this systematic review was to assess the latest randomized controlled trials (RCTs) evaluating the effect of probiotic supplementation on symptoms in IBS patients. A literature search was conducted in Medline (PubMed) until March 2019. RCTs published within the last five years evaluating effects of probiotic supplements on IBS symptoms were eligible. The search identified in total 35 studies, of which 11 met the inclusion criteria and were included in the systematic review. Seven studies (63.6%) reported that supplementation with probiotics in IBS patients significantly improved symptoms compared to placebo, whereas the remaining four studies (36.4%) did not report any significant improvement in symptoms after probiotic supplementation. Of note, three studies evaluated the effect of a mono-strain supplement, whereas the remaining eight trials used a multi-strain probiotic. Overall, the beneficial effects were more distinct in the trials using multi-strain supplements with an intervention of 8 weeks or more, suggesting that multi-strain probiotics supplemented over a period of time have the potential to improve IBS symptoms.

The Effects of Increasing Intake of Intact Wheat Fibre or Wheat Bran on Gut Microbiota Diversity: a Systematic Review

2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Angie Jefferson ◽  
Katie Adolphus
Keyword(s):  
Systematic Review ◽  
Gut Microbiota ◽  
Wheat Bran ◽  
Bacterial Species ◽  
Microbiota Composition ◽  
Inclusion Criteria ◽  
Breakfast Cereal ◽  
High Fibre ◽  
Microbiota Diversity ◽  
Gut Microbiota Composition

AbstractThe influence on health of the human gut microbiota is increasingly recognised, however wheat fibre, consumed frequently in Western diets has traditionally been considered inert with regard to gut microbiota composition and metabolic activity. We undertook a systematic review (PRISMA methodology) of human intervention studies examining the effects of intact cereal fibres on gut microbiota composition among healthy adults.(1) Studies published in the past 20 years were identified on PubMed and Cochrane electronic databases. Inclusion criteria were: healthy adult participants, at least one intact cereal fibre (or its sub-fraction) and measurement of faecal microbiota related outcomes. Out of forty studies meeting inclusion criteria, seventeen manipulated wheat fibre/bran or its key constituent arabinoxylans (AXOS), and ten used a whole diet approach with predominantly wheat fibre. Results from these twenty seven wheat fibre papers are presented here. Eight studies provided wheat bran/fibre (ranging from 5.7g-21g/day wheat fibre or 13g-28g/day wheat bran). Three reported significant effects on gut microbiota abundance and/or diversity (both at phyla and species level) and one showed no effect. Six reported significant increases in fermentation metabolites and one reported no significant change. Ten studies manipulated whole day fibre intake (predominantly wheat but also permitting some oats, rye and rice). Wholegrain intake ranged from 80g-150 g per day and fibre from 13.7g–40 g per day. Six found significant increases in bacterial diversity and/or abundance and five showed significant increases in fermentation metabolites. Two identified that response to high fibre intervention is dependent on baseline gut microbiota richness - those with limited richness exhibiting greater microbiota change over time in response to fibre increase. Two reported no significant effects. Nine studies utilised manipulation of AXOS (2.2g–18.8 g per day) with five demonstrating significant increases in target bacterial species and six significant increases in fermentation metabolites. One reported no significant effect to faecal metabolites. This review supports a role for the wheat fibre found in everyday foods (such as bran breakfast cereal of high fibre breads) promoting both microbiota diversity and abundance. While the healthy microbiome is yet to be defined, consumption of a single daily serving of wheat bran fibre appears sufficient to effect gut microbiota fermentation (with demonstrable effects arising from as low as 6g/day), and promote species diversity, with potential benefit to health.However exploration of stability over longer time frames (> 12 weeks) is now required.

scholarly journals Mechanism of action and therapeutic benefit of rifaximin in patients with irritable bowel syndrome: a narrative review

2020 ◽  
Vol 13 ◽  
pp. 175628481989753 ◽  
Author(s):  
William D. Chey ◽  
Eric D. Shah ◽  
Herbert L. DuPont
Keyword(s):  
Irritable Bowel Syndrome ◽  
Gut Microbiota ◽  
Mechanism Of Action ◽  
Bacterial Overgrowth ◽  
Gastrointestinal Disorder ◽  
Small Intestinal Bacterial Overgrowth ◽  
The United States ◽  
Clinical Effects ◽  
Healthy Individuals ◽  
Irritable Bowel

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder with a multifactorial pathophysiology. The gut microbiota differs between patients with IBS and healthy individuals. After a bout of acute gastroenteritis, postinfection IBS may result in up to approximately 10% of those affected. Small intestinal bacterial overgrowth (SIBO) is more common in patients with IBS than in healthy individuals, and eradication of SIBO with systemic antibiotics has decreased symptoms of IBS in some patients with IBS and SIBO. The nonsystemic (i.e. low oral bioavailability) antibiotic rifaximin is indicated in the United States and Canada for the treatment of adults with IBS with diarrhea (IBS-D). The efficacy and safety of 2-week single and repeat courses of rifaximin have been demonstrated in randomized, placebo-controlled studies of adults with IBS. Rifaximin is widely thought to exert its beneficial clinical effects in IBS-D through manipulation of the gut microbiota. However, current studies indicate that rifaximin induces only modest effects on the gut microbiota of patients with IBS-D, suggesting that the efficacy of rifaximin may involve other mechanisms. Indeed, preclinical data reveal a potential role for rifaximin in the modulation of inflammatory cytokines and intestinal permeability, but these two findings have not yet been examined in the context of clinical studies. The mechanism of action of rifaximin in IBS is likely multifactorial, and further study is needed.

scholarly journals The Effects of Human Milk Oligosaccharides on Gut Microbiota, Metabolite Profiles and Host Mucosal Response in Patients with Irritable Bowel Syndrome

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3836
Author(s):  
Cristina Iribarren ◽  
Maria K. Magnusson ◽  
Louise K. Vigsnæs ◽  
Imran Aziz ◽  
Ingvild Dybdrodt Amundsen ◽  
...  
Keyword(s):  
Irritable Bowel Syndrome ◽  
Gut Microbiota ◽  
Human Milk ◽  
Microbiota Composition ◽  
Bifidobacterium Adolescentis ◽  
Metabolite Profiles ◽  
Mucosal Response ◽  
Irritable Bowel ◽  
Plasma Metabolite ◽  
Gut Microbiota Composition

Background: Human milk oligosaccharide supplementation safely modulates fecal bifidobacteria abundance and holds the potential to manage symptoms in irritable bowel syndrome (IBS). Here, we aimed to determine the role of a 4:1 mix of 2′-O-fucosyllactose and lacto-N-neotetraose (2′FL/LNnT) on the modulation of the gut microbiota composition and host mucosal response, as well as the link between the bifidobacteria abundance and metabolite modulation, in IBS patients. Methods: Biological samples were collected from IBS patients (n = 58) at baseline and week 4 post-supplementation with placebo, 5 g or 10 g doses of 2′FL/LNnT. The gut microbiota composition, metabolite profiles and expression of genes related to host mucosal response were determined. Results: Moderate changes in fecal, but not mucosal, microbial composition (β-diversity) was observed during the intervention with higher dissimilarity observed within individuals receiving 10g 2′FL/LNnT compared to placebo. Both fecal and mucosal Bifidobacterium spp. increased after 2′FL/LNnT intake, with increased proportions of Bifidobacterium adolescentis and Bifidobacterium longum. Moreover, the intervention modulated the fecal and plasma metabolite profiles, but not the urine metabolite profile or the host mucosal response. Changes in the metabolite profiles were associated to changes in bifidobacteria abundance. Conclusion: Supplementation with 2′FL/LNnT modulated the gut microbiota, fecal and plasma metabolite profiles, but not the host mucosal response in IBS. Furthermore, the bifidogenic effect was associated with metabolite modulation. Overall, these findings support the assertion that 2′FL/LNnT supplementation modulate the intestinal microenvironment of patients with IBS, potentially related to health.

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