Microbial fermentation of Fossence™, a short-chain fructo-oligosaccharide, under simulated human proximal colonic condition and assessment of its prebiotic effects-a pilot study.

Abstract

A short-chain fructo-oligosaccharide (sc-FOS) was tested in a simulator of the human gut microbial ecosystem (SHIME) in vitro model to quantify its prebiotic effects according to Prebiotic Index (PI) and Measure of prebiotic effect (MPE) equations. FossenceTM, (sc-FOS, 0.5%) was fermented in a simulated human proximal colonic condition, using a fecal inoculum from a healthy individual. We analysed the pH reduction, substrate utilization, lactate and short-chain fatty acid (SCFA) production and microbial community modulation. Microbial fermentation of sc-FOS strongly reduced the media pH indicating the production of lactate and SCFA with accumulation of lactate and enhanced levels of acetate (34.38±0.38 mM),propionate(20.93±0.56 mM)andbutyrate(4.93±0.03 mM)comparedto18.46±0.20 mM,6.24±0.10 mMand3.3±0.06 mMintheblank, respectively. Total SCFA production in test media was 61.91±0.87 mMcompared to 33.65±0.36 mMin blank and the contribution of free-sugars present in sc-FOS to SCFAs was negligible. Modulation of the microbial community was analysed through 16S rRNA sequencing and we found that sc-FOS greatly stimulated the beneficial bacteria such as Bifidobacteria and Lactobacillus. We report the PI and MPE values for FossenceTM, as 14.9 and 0.01 respectively at the end of 24 h,whichisanindicator of a strong prebiotic effect.