Limosilactobacillus fermentum HNU312 alleviates lipid accumulation and inflammation induced by a high-fat diet: improves lipid metabolism pathways and increases short-chain fatty acids in the gut microbiome.

A high-fat diet can cause health problems, such as hyperlipidemia, obesity, cardiovascular disease, and metabolic disorders. Dietary supplementation with beneficial microbes might reduce the detrimental effects of a high-fat diet by modulating the gut microbiome, metabolic pathways and metabolites. This study assessed the effects of Limosilactobacillus fermentum HNU312 ( L. fermentum HNU312) on blood lipid levels, fat accumulation, inflammation and the gut microbiome in mice on a high-fat diet. The results indicate that L. fermentum HNU312 supplementation to high-fat diet-fed mice led to decreases of 7.52% in the final body weight, 22.30% in total triglyceride, 24.87% in total cholesterol, and 27.3% in low-density lipoprotein cholesterol. Furthermore, the addition of L. fermentum HNU312 significantly reduced the fat accumulation in the liver and adipose tissue by 18.99% and 32.55%, respectively, and decreased chronic inflammation induced by a high-fat diet. Further analysis of the gut microbiome revealed that on the one hand, L. fermentum HNU312 changed the structure of the intestinal microbiota, increased the abundance of beneficial intestinal bacteria related to lipid metabolism, and reversed the enrichment of lipid-related metabolic pathways. On the other hand, L. fermentum HNU312 increased the production of short-chain fatty acids, which can reduce liver inflammation and chronic inflammation induced by a high-fat diet. In summary, by regulating gut microbiota, L. fermentum HNU312 improved lipid metabolism pathways and increased short-chain fatty acids, which reduced body weight, blood lipids, fat accumulation and chronic inflammation caused by high-fat diets. Therefore, L. fermentum HNU312 could be a good candidate probiotic for ameliorating metabolic syndrome.