Biomarkers of Diet-microbiota Interactions in Irritable Bowel Syndrome

Summary

Most patients suffering from the irritable bowel syndrome (IBS) report that ingestion of certain foods is a major trigger of symptoms, but the reason is unclear. Previous studies have shown that foods containing poorly absorbed carbohydrates (FODMAPs) are fermented by the bacteria in our bowels and these cause symptoms in some but not all patients. Gut bacteria are capable of producing various products, such as neuroimmune mediator histamine, that may be related to IBS symptoms. Our recent data suggest that consumption of FODMAPs promotes production of bacterial histamine.

The main objective of this study is to investigate bacterial production of histamine and its relationship to IBS symptoms. The study will involve 6 weeks on a low-FODMAP diet with three three-day interventions consisting of High- or Low-FODMAP drinks along with probiotics or placebo capsules. The patient's bacteria and metabolites will be analyzed at various time points.

Conditions

• Irritable Bowel Syndrome

Interventions

DIETARY_SUPPLEMENT

L-Histidine

1 capsule (0.6g) twice daily

DIETARY_SUPPLEMENT

High-FODMAP beverage

High-FODMAP beverage (10g of fermentable carbohydrates) consumed twice daily.

DIETARY_SUPPLEMENT

Low-FODMAP beverage

Low-FODMAP beverage (10g glucose) consumed twice daily.

DIETARY_SUPPLEMENT

Lactobacillus acidophilus CL1285, L. casei LBC80R and L. rhamnosus CLR2.

Total of 50 billion CFU/capsule taken twice daily.

OTHER

Placebo

Enteric coated capsule with no active ingredient, taken twice daily

Sponsors & Collaborators

• McMaster University

  lead OTHER

Principal Investigators

• Premysl Bercik, MD · McMaster University

• Stephen Vanner, MD · Queens University

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

QUADRUPLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2021-07-15

Primary Completion

2026-02-10

Completion

2026-02-10

Countries

• Canada

Study Locations