Active phase prebiotic feeding alters gut microbiota, induces weight-independent alleviation of hepatic steatosis and serum cholesterol in high-fat diet-fed mice

Growing evidence suggests that prebiotics may induce weight loss and alleviate non-alcoholic fatty liver disease (NAFLD) via modulation of the gut microbiota. However, key members of the gut microbiota that may mediate the beneficial effects of prebiotics remain elusive. Here, we find that restricted prebiotic feeding during active phase (HF-ARP) induced weight-independent alleviation of liver steatosis and reduced serum cholesterol in high-fat diet (HF) fed mice more significantly than unrestricted feeding (HF-UP). HF-ARP mice also showed concomitantly altered gut microbiota structure that was different from HF-UP group along with significantly increased production of total short-chain fatty-acids (SCFAs). Amplicon sequence variants (ASVs) were clustered into co-abundant groups (CAGs) as potential functional groups that may respond distinctively to prebiotic consumption and prebiotic feeding regime. Prebiotic feeding induces significant alterations in CAG abundances by day 7. Eight of 32 CAGs were promoted by prebiotics, including CAG17 with the most abundant ASV from Parabacteroides, CAG22 with Bacteroides thetaiotamicron and CAG32 with Fecalibaculum and Akkermansia. Among the prebiotic-promoted CAGs, CAG20 with ASVs from Lachnospiraceae and CAG21 with ASVs from Bifidobacterium and Lachnospiraceae were significantly enhanced in HF-ARP compared to HF-UP. Moreover, most of the prebiotic-promoted CAGs were also significantly associated with improvements in hepatic steatosis, reduction in serum cholesterol and increased cecal propionate production. Together, these results suggest that the impact of prebiotics on weight-independent alleviation of liver steatosis and cholesterol-lowering effect can be optimized by restricting prebiotic intake to active phase and is associated with a distinct change of gut microbiota with increased SCFA production.