Effects of Clostridium butyricum and inulin supplementation on intestinal microbial composition in high-fat diet fed mice

Obesity has become a serious epidemic problem in the world, and probiotics and prebiotics have been used to treat obesity. The effectiveness of diet therapy such as Clostridium butyricum (CB) and inulin supplementation in obesity and whether they can cooperate to produce better effects are still unclear. And during this process, intestinal flora play an important role, while the bacteria involved and the metabolic mechanism need to be explored. In this study, we successfully established a mouse obesity model with a high-fat diet (HFD) and divided it into three experimental groups: 7% CB (CB7), 7% CB + 1% inulin (C7G1), and 10% CB + 1% inulin (C10G). Dietary supplementation with CB and inulin could improve the glucose tolerance and intestinal microbial composition of obese mice, among which the simultaneous supplementation with 7% CB and 1% inulin (C7G1) has the most significant effect on obese mice fed with a HFD. It could significantly reduce the amount of total cholesterol, triglyceride, and low-density lipoprotein, improve abnormal glucose tolerance, and reduce abnormal blood glucose in obese mice. The intestinal flora of obese mice changed significantly, among which Lachnospiraceae_unclassified, Porphyromonaceae_unclassified, Olsenella, Bacteria_unclassified and Clostridiales_unclassified decreased due to the HFD, while Megamonas and Clostridium XIVa increased. After the supplementation with CB and inulin, the enrichment of three kinds of beneficial bacteria, Parabacteroides, Bacteroides, and Ruminococcaceae unclassified increased. The high-fat diet could upregulate the expression of FGF21, and the Clostridium butyricum and inulin supplemented diet could decrease the upregulation.