Effects of prebiotics from diverse sources on dysbiotic gut microbiota associated to western diet: Insights from the human Mucosal ARtificial COLon (M-ARCOL)

Associated to various illnesses, Western Diet (WD) is acknowledged to have deleterious effects on human gut microbiota, decreasing bacterial diversity, lowering gut bacteria associated to health (such as <i>Akkermansia muciniphila)</i>, while increasing those linked to diseases (e.g., <i>Proteobacteria</i>). In this study, we evaluated the potential of two new prebiotics to counteract the negative effect of WD on gut microbiota, namely raffinose family oligosaccharides (RFO) from chickpeas and laminarin (LAM) from algae, when compared to the well-known inulin (INU). The effects of prebiotics on gut microbiota composition and metabolic activities were investigated in the Mucosal-Artificial Colon, set-up to reproduce WD condition, as compared to healthy control (n = 3). None of the prebiotics was able to efficiently offset the shift in microbiota induced by WD. Nevertheless, when compared to non-supplemented WD, all prebiotics showed significant impacts on microbiota composition, that were both prebiotic and donor-dependant. RFO was the only prebiotic to enhance α-diversity, while it led to an increase in <i>Blautia</i> and <i>Butyricicoccaceae</i>, associated with higher amounts of gas and butyrate. LAM and INU did not strongly impact microbial metabolic activities but were associated with a rise in <i>Prevotella_9</i>/<i>Agathobacter</i> and <i>Faecalibacterium,</i> respectively. To conclude, this study showed that all tested prebiotics had different impacts on human gut microbiota structure and activities, which was further donor-dependent. M-ARCOL appears as a suitable <i>in vitro</i> tool to better understand the mechanisms of action of prebiotic compounds in relation to gut microbes and define responders and non-responders to prebiotic supplementation, opening the possibility of customized nutritional strategies.