T2027 Lactobacillus casei Dn-114 Oo1 Strain in the Prevention of Postoperative Recurrence of Crohn's Disease: A Randomised, Double-Blind Placebo-Controlled Trial

Abstract

Background The addition of prebiotics to the diet may improve host health by modulation of the colonicmetabolism. The effect of a new candidate prebiotic, arabinoxylan oligosaccharides (AXOS), on the colonic metabolism was evaluated by characterization of the metabolite profile in faeces. Methods AXOS was administered for 3 weeks at 10 g/day to 20 healthy volunteers (30% male; age 23(20-45); BMI 21(18-26)). Faecal samples were collected before and after the intervention with AXOS. To determine a broad range of fermentation metabolites, metabolic fingerprinting was applied using a purge-and-trap system coupled on-line to a gas chromatograph time-of-flight mass spectrometer (GC-TOF-MS). Cluster analysis, based on relative indices of all identified volatile organic compounds (VOCs) versus 2ethylbutyric acid as internal standard, was used to compare the metabolite profiles. Results A total of 179 different VOCs were identified in the faecal samples, 24 VOCs were present in more than 70% of the samples. The compounds acetaldehyde, butanoic acid, dimethyl disulfide, dimethyl trisulphide and limonene were present in all samples. Cluster analysis of the VOC fingerprints allowed to discriminate baseline samples from the samples after the intervention with AXOS, suggesting that the impact of the intervention exceeded the interindividual variability (Figure). This discrimination was mainly due to protein fermentation metabolites such as p-cresol, branched-chain fatty acids (4-methyl pentanoic acid, 2-methyl propanoic acid and 3methyl butanoic acid) and sulphur containing compounds (hydrogen sulphide, carbon disulfide, dimethyl tetrasulfide). Faecal short-chain fatty acids did not contribute to discrimination between both groups, although this does not preclude an increased SCFA production in the proximal colon. Conclusion Dietary intervention with AXOS has a considerable impact on the colonic metabolism mainly by decreasing proteolytic activity.