Farsi, DN 
ORCID: 0000-0002-8077-8140, Cotillard, A ORCID: 0009-0004-7409-7703, Wilson, B ORCID: 0000-0003-4755-8872, So, D, Gibson, PS, Slater, R ORCID: 0000-0001-9765-6978, Probert, C ORCID: 0000-0003-0477-6714, Morris, S ORCID: 0000-0003-4125-7024, Scott, SM ORCID: 0000-0002-7997-1533, Quinquis, L et al (show 6 more authors)
(2026)
Gut Microbiome Composition and Function, Diet and Clinical Factors in Relation to Fermentable Carbohydrate-Induced Bloating: A Double-Blind, Randomized, Crossover Trial
American Journal of Gastroenterology.
ISSN 0002-9270, 1572-0241
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Farsi gut_microbiome_composition_and_function,_diet2142.pdf - Open Access published version Available under License Creative Commons Attribution. Download (2MB) | Preview |
Abstract
Background: – Specific foods are associated with abdominal bloating, which can significantly impact quality of life.Objective: – To identify responders to fiber-induced bloating and the mechanisms underpinning clinical and microbial responses.Design: – Double-blind, placebo-controlled, randomized, 2-period, 2-challenge crossover trial in 41 individuals with functional bloating. Participants were randomized to 8 g/d of fructan or α-galacto-oligosaccharides (α-GOS) for 7 days with a 21-day washout. Clinical, nutritional, microbial (shotgun sequencing, metatranscriptomics) and fermentation (short-chain fatty acids, volatile organic compounds, breath hydrogen) profiles were characterized prior to each challenge to identify factors predicting response, and after the challenge to elucidate mechanisms underpinning food-induced bloating.Results: – Thirty-nine participants completed both challenges (39 fructan, 40 α-GOS). Overall, seven (7/39, 17.9%) participants were fructan responders and eight (8/40, 20%) were α-GOS responders (experienced fiber-related symptom induction). Clinical metrics indicative of bloating distinguished responders and non-responders to both challenges, including greater abdominal girth (fructan, p = 0.009; α-GOS, p = 0.030). α-GOS responders had higher breath hydrogen (H<inf>2</inf>) pre-challenge than α-GOS non-responders (p = 0.011). Trends were identified within metagenomic and metatranscriptomic gut microbial analyses, with higher carbohydrate active enzyme (CAZyme) diversity in fructan responders (pre-challenge, adjusted p-value (padj) = 0.024; post-challenge, padj = 0.042), and greater increase in gene expression for gamma-aminobutyric acid (GABA) degradation in α-GOS responders (padj = 0.041).Conclusion: – A higher burden of GI symptoms predicts clinical response to fermentable fibers in functional bloating, while for α-GOS, higher repeated fasting breath H<inf>2</inf> is also a predictor. Gut microbiome function and fermentation is associated with functional bloating; however, further investigations are required to draw firm conclusions for the microbial influence in this interplay.ClinicalTrials.gov (Identifier: NCT04802798).
| Item Type: | Article |
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| Uncontrolled Keywords: | fermentable carbohydrates, fiber, functional bloating, gut microbiome |
| Divisions: | Faculty of Health & Life Sciences Faculty of Health & Life Sciences > Inst. Systems, Molec & Integrative Biology Faculty of Health & Life Sciences > Inst. Systems, Molec & Integrative Biology > Inst. Systems, Molec & Integrative Biology (T&R Staff) Faculty of Health & Life Sciences > Inst. Systems, Molec & Integrative Biology > Molecular & Clinical Cancer Medicine |
| Depositing User: | Symplectic Admin |
| Date Deposited: | 15 May 2026 09:52 |
| Last Modified: | 28 May 2026 10:37 |
| DOI: | 10.14309/ajg.0000000000003997 |
| Related Websites: | |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3198484 |
| Disclaimer: | The University of Liverpool is not responsible for content contained on other websites from links within repository metadata. Please contact us if you notice anything that appears incorrect or inappropriate. |
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