Effects of varying dietary content of fermentable short-chain carbohydrates on symptoms, fecal microenvironment, and cytokine profiles in patients with irritable bowel syndrome.
Study Goal
The researchers aimed to investigate the effects of a blinded low-FODMAP diet versus high-fructo-oligosaccharides (FOS) on IBS symptoms, immune activation, gut microbiota composition, and short-chain fatty acids (SCFAs).
Results Summary
The study found that a low-FODMAP diet (LFD) significantly improved IBS symptoms, with 80% of participants reporting relief on placebo compared to 30% on FOS. The LFD also reduced proinflammatory cytokines and altered gut microbiota and SCFA levels, while FOS supplementation increased certain bacteria without affecting cytokines or SCFAs.
Population
Twenty patients with diarrhea-predominant or mixed irritable bowel syndrome (IBS).
Effective Dosage
Not specified (supplementation duration was 10 days for FOS or placebo).
Duration
9-week study period (3 weeks LFD, 10 days supplementation, 3-week washout, crossover).
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
low-FODMAP diet | decrease | Irritable bowel syndrome symptoms | patients with diarrhea-predominant or mixed IBS | - | improved | #1 |
placebo | decrease | symptoms | patients with diarrhea-predominant or mixed IBS | 80% | significantly more participants reported symptom relief in response to | #2 |
FOS | decrease | symptoms | patients with diarrhea-predominant or mixed IBS | 30% | reported symptom relief in response to | #3 |
low-FODMAP diet | decrease | Serum levels of proinflammatory IL-6 | patients with diarrhea-predominant or mixed IBS | - | decreased significantly | #4 |
low-FODMAP diet | decrease | Serum levels of proinflammatory IL-8 | patients with diarrhea-predominant or mixed IBS | - | decreased significantly | #5 |
low-FODMAP diet | decrease | levels of fecal bacteria (Actinobacteria, Bifidobacterium, and Faecalibacterium prausnitzii) | patients with diarrhea-predominant or mixed IBS | - | decreased significantly | #6 |
low-FODMAP diet | decrease | total SCFAs | patients with diarrhea-predominant or mixed IBS | - | decreased significantly | #7 |
low-FODMAP diet | decrease | n-butyric acid | patients with diarrhea-predominant or mixed IBS | - | decreased significantly | #8 |
FOS supplementation | increase | level of these bacteria | patients with diarrhea-predominant or mixed IBS | - | increased | #9 |
FOS supplementation | no change | levels of cytokines | patients with diarrhea-predominant or mixed IBS | - | remained unchanged | #10 |
FOS supplementation | no change | levels of SCFAs | patients with diarrhea-predominant or mixed IBS | - | remained unchanged | #11 |
BACKGROUND: A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) is increasingly recommended for patients with irritable bowel syndrome (IBS). We aimed to investigate the effects of a blinded low-FODMAP vs high-fructo-oligosaccharides (FOS) diet on symptoms, immune activation, gut microbiota composition, and short-chain fatty acids (SCFAs). METHODS: Twenty patients with diarrhea-predominant or mixed IBS were instructed to follow a low-FODMAP diet (LFD) throughout a 9-week study period. After 3 weeks, they were randomized and double-blindly assigned to receive a supplement of either FOS (FODMAP) or maltodextrin (placebo) for the next 10 days, followed by a 3-week washout period before crossover. Irritable bowel syndrome severity scoring system (IBS-SSS) was used to evaluate symptoms. Cytokines (interleukin [IL]-6, IL-8, and tumor necrosis factor alpha) were analyzed in blood samples, and gut microbiota composition (16S rRNA) and SCFAs were analyzed in fecal samples. KEY RESULTS: Irritable bowel syndrome symptoms consistently improved after 3 weeks of LFD, and significantly more participants reported symptom relief in response to placebo (80%) than FOS (30%). Serum levels of proinflammatory IL-6 and IL-8, as well as levels of fecal bacteria (Actinobacteria, Bifidobacterium, and Faecalibacterium prausnitzii), total SCFAs, and n-butyric acid, decreased significantly on the LFD as compared to baseline. Ten days of FOS supplementation increased the level of these bacteria, whereas levels of cytokines and SCFAs remained unchanged. CONCLUSIONS AND INFERENCES: Our findings support the efficacy of a LFD in alleviating IBS symptoms, and show changes in inflammatory cytokines, microbiota profile, and SCFAs, which may have consequences for gut health.