Anti-Obesity Effects and Changes of Fecal Microbiome by Lactic Acid Bacteria from Grains in a High-Fat Diet Mouse Model

Single three-lactic acid bacterial strains with anti-adipogenic effects in C3H10T1/2 cells and possessing beneficial probiotic properties were administered to mice fed a high-fat diet. Of the three strains, Lactiplantibacillus plantarum RP12, which had the lowest weight gain, was utilized for further studies, including a second mouse experiment lasting 10 weeks. Oral administration of Lactiplantibacillus plantarum RP12 resulted in reduced body weight gain and epididymal fat mass. Significant reductions in serum total cholesterol, triglycerides, and blood glucose were observed in the group treated with Lactiplantibacillus plantarum RP12. This strain was found to regulate the expression of genes associated with lipid metabolism in epididymal adipose tissue and liver. It induced changes in the composition of fecal microbiota. Although there is no difference in the Bacillota to Bacteroidota ratio between the HFD and RP12 groups, notable differences in the compositions at the family, genus, and species levels were evident. Specifically, differences in the proportions of some taxa reported to have an association with obesity were observed between the HFD and RP12 groups. Fecal analyses demonstrated that Lactiplantibacillus plantarum RP12 diminishes lipid absorption and augments the production of short-chain fatty acids in the intestine. Lactiplantibacillus plantarum RP12 also mitigated damage to the morphology of the ileum and colon caused by a high-fat diet and promoted the expression of Claudin-1 and Muc2. Overall, Lactiplantibacillus plantarum RP12 has potential as a useful probiotic to address metabolic disorders as well as obesity, substantiating the positive in vivo indicators and modulation of gut microbiota in a high-fat diet-induced obese mouse model.