Lemon fermented products prevent obesity in high-fat diet-fed rats by modulating lipid metabolism and gut microbiota

Citrus limon (lemon) possesses immunoregulatory, antioxidant, and lipid-lowering effects. Our previous study showed that lemon fermented products (LFP) which were lemon fermented with Lactobacillus OPC1 had the ability to avert obesity. However, the LFP effects on the pathway of lipid metabolism by gut microbiota were still unclear. This study was aimed to investigate the LFP effects on liver lipid metabolism and gut microbiota in a rat model of obesity caused by a high-calorie diet. LFP effectively reduced the total triglyceride (49.7%) and total cholesterol (53.3%) contents of the liver. Additionally, the mRNA levels of genes related to triglyceride metabolism (SREBP-1c, PPAR gamma, and ACC), cholesterol metabolism (HMG-CoA reductase, ACAT, and LCAT), and lipid beta-oxidation (PPAR alpha, and CPT-1) were regulated by LFP. Furthermore, LFP reduced the ratio of Firmicutes/Bacteroidetes and enhanced the ratio of Firmicutes Clostridia. Overall, these findings suggested that LFP might use as a potential dietary supplement for preventing obesity by modulating the lipid metabolism and improving the gut microbiota.