Fasting breath H2 and gut microbiota metabolic potential are associated with the response to a fermented milk product in irritable bowel syndrome

Abstract

Objectives: Aim of this study was to assess the effect of a fermented milk product containing Bifidobacterium lactis CNCM I-2494 (FMP) on gastrointestinal (GI) symptoms and exhaled H2 and CH4 during a nutrient and lactulose challenge in patients with irritable bowel syndrome (IBS).

Methods: We included 125 patients with IBS (Rome III). Fasted subjects were served a 400ml liquid test meal containing 25g lactulose. The intensity of eight GI symptoms and the amount of exhaled H2 and CH4 were assessed before and during 4h after meal intake. The challenge was repeated after 14 days consumption of FMP or a control product in a double-blind, randomized, parallel design. The metabolic potential of fecal microbiota was profiled using 16S MiSeq analysis of samples obtained before and after the intervention.

Results: 106 patients with IBS were randomized. No difference between FMP or control groups was found on GI symptoms or breath H2 and CH4 in the whole cohort. A post-hoc analysis in patients stratified according to their fasting H2 levels showed that in high H2 producers (fasting H2 level≥10ppm, n = 35), FMP consumption reduced fasting H2 levels (p = 0.003) and H2 production during the challenge (p = 0.002) and tended to decrease GI discomfort (p = 0.05) vs. control product. The Prevotella/Bacteroides metabolic potential at baseline was higher in high H2 producers (p<0.05) vs. low H2 producers and FMP consumption reduced this ratio (p<0.05) vs. control product.

Conclusions: The response to a fermented milk product containing Bifidobacterium lactis CNCM I-2494 (FMP) in patients with IBS seems to be associated with the metabolic potential of the gut microbiota.

Trial registration: ClinicalTrial.gov NCT01252550. These results were presented as congress posters at Digestive Disease Week 2016 in San Diego, USA and United European Gastroenterology Week 2016 in Vienna, Austria.

Conflict of interest statement

Funding by Danone Nutricia Research. This does not alter our adherence to PLOS ONE policies on sharing data and materials. B Le Nevé, J Tap, M Derrien, R Brazeilles and S Cools- Portier are employees of Danone Nutricia Research. D Guyonnet is employee of Diana Nova and was employee of Danone Nutricia Research when this work was performed. H Törnblom has received an unrestricted research grant from Tillotts Pharma and served as a consultant/advisory board member for Allergan, Almirall Nordic and Shire. M Simrén has received unrestricted research grants from Danone and Ferring and served as a Consultant/Advisory Board member for AstraZeneca, Danone, Novartis, Almirall, Allergan, Glycom, Nestlé and Shire/Movetis. L Ohman and S Störsrud have nothing to disclose.

Figures

Fig 1

A) Study design B) Flow chart demonstrating the number of patients in the different phases of the study.

Fig 2. Effect of intervention on breath hydrogen in IBS patients stratified according to fasting H2 levels.

A) Distribution of subjects in % according to H2 fasting value B) Effect of the intervention on the 4h mean change in AUC levels of H2C) Effect of the intervention on the mean change in fasting H2 levels (T0); FMP: fermented milk product; Control: non-fermented milk product; High H2: fasting H2 level≥10ppm (n = 33); Low H2: fasting H2 level<10ppm (n = 67); ppm: parts per million; H2: hydrogen; T0: fasting value; statistical analyses for B) and C) are covariance analyses of the mean change (Δ) of the measured endpoints from 1st to 2nd nutrient-lactulose challenge between the two study arms adjusted for first challenge values; all significance tests were two-sided and conducted at the 5% significance level. Interaction was evaluated at 10% significance level; NS for p value >0.05, * <0.05, ** <0.01, *** <0.001.

Fig 3. Impact of the intervention on the metabolic potential of the gut microbiota in subjects consuming FMP (n = 32) or control product (n = 30).

Effect of the intervention on microbial OTUs. Each dot corresponds to an OTU colored according to their taxonomical affiliation (Phylum).

Fig 4. Gut microbiota of IBS patients according to their fasting H2 levels.

Metabolic potential of the Prevotella/Bacteroides ratio in low (n = 40) and high (n = 22) H2 producers; Statistical significance was determined by Wilcoxon test; *P < 0.05.

Fig 5. Response of gut microbiota to intervention according to fasting H2 levels in IBS patients.

A) Metabolic potential of the Prevotella / Bacteroides ratio. Each line represents a subject before and after intervention. The red line represents the median evolution. B) Effect of the intervention (FMP vs. control) on microbial OTUs in high and low H2 producers. Each dot corresponds to an OTU with its associated family depicted on the x axis. OTUs are colored according to their taxonomical affiliation (Phylum). C) Proportion (showed in %) of whole microbiota metabolic potential regulated in high H2 versus low H2 producers upon intervention. High H2/control n = 8; High H2/FMP n = 14; Low H2/control n = 22; Low H2 FMP n = 18.