In Vitro Digestion and Fecal Fermentation of Arecanut Polysaccharides: Effects on Gut Microbiota and Metabolites

Recent studies have increasingly emphasized the regulatory potential of plant-derived polysaccharides on gut microbial composition and metabolic function. Despite this growing interest, investigations focusing specifically on the simulated digestion and fermentation properties of arecanut polysaccharide (PAP1b) remain limited. In this work, we employed the standardized INFOGEST 2.0 protocol to mimic the oral, gastric, and intestinal digestion of PAP1b, followed by 48 h anaerobic fermentation using pooled human fecal samples from healthy adult donors. PAP1b treatment led to a progressive decrease in pH and a substantial elevation in SCFAs levels, notably acetic, propionic, and butyric acids. Simultaneously, PAP1b significantly promoted the growth of SCFA-producing microbial taxa, particularly members of the <i>Firmicutes</i> phylum such as <i>Lachnospiraceae</i>, <i>Lachnoclostridium</i>, <i>Bilophila</i>, and <i>Phascolarctobacterium</i>, while markedly suppressing <i>Bacteroidota</i> populations. Metabolomic analysis further indicated that PAP1b intake enhanced bile acid metabolism, suggesting its potential as a prebiotic candidate for improving intestinal health.