Impact of a Plant Sterol- and Galactooligosaccharide-EnrichedBeverage on Colonic Metabolism and Gut Microbiota Composition Usingan In Vitro Dynamic Model

A beverage enriched with plant sterols (1 g/100 mL) and galactooligosaccharides (1.8 g/100 mL) was subjected to a dynamic gastrointestinal and colonic fermentation process to evaluate the effect on sterol metabolism, organic acid production and microbiota composition. Production of sterol metabolites (coprostanol, methylcoprostanol, ethylcoprostenol, ethylcoprostanol and sitostenone) was observed in the transverse (TC) and descending colon vessels (DC) in general, from 24 and 48 h, respectively. Microbial activity was assessed through the production of organic acids, mainly acetate in all colon vessels, lactate in the AC and butyrate and propionate in the TC and DC. A higher diversity in the microbial community was found in the TC and DC, in accordance with a higher sterol metabolism and organic acid production. Although the prebiotic effect of galactooligosaccharides was not detected, changes in microbiota composition (an increase in Parabacteroides genus and the Synergistaceae and Lachnospiraceae famili...