Bacteroides uniformis CECT 7771 and wheat-bran extract (WBE)-based fiber used as an innovative synbiotic product reducing diet-induced obesity in mice.

An 18-weeks long interventional study was conducted in an animal model of DIO receiving either B. uniformis CECT 7771, at a lower dose as that used in our previous study, WBE or the combination of both. Metabolic phenotype, as well as intestinal immunity, were compared between groups to evaluate the anti-obesity efficacy of each intervention.This study shows that, while separately B. uniformis CECT 7771 or WBE exhibited modest metabolic benefits independently of weight loss in DIO mice, B. uniformis CECT 7771 together with WBE was the most effective anti-obesity intervention showing synergism reducing body weight gain and adiposity. We have also identified that the combination of B. uniformis CECT 7771 with WBE restores insulin-dependent metabolic routes in visceral fat and liver contributing to improving whole-body glucose disposal and limiting ectopic lipid accumulation. This intervention also enhanced intestinal barrier integrity coupled with a restoration of the intestinal abundance of induced intraepithelial lymphocytes (IEL) and innate lymphoid cells type 3 (ILC3), immune cells populations that provide the first line of specific immune defence against microbes in the gut. B.uniformis and WBE showed a different impact on caecal content microbiota boosting multiple fiber-degrading and SCFAs-producing bacteria when administrated individually and in combination.