Lactobacillus fermentum promotes adipose tissue oxidative phosphorylation to protect against diet-induced obesity
Gut microbiota has an important role in maintaining metabolic homeostasis. In conditions such as obesity, alterations in the gut microbiota are observed. Recent studies have shown a protective effect of the administration of Lactobacillus fermentum in obese humans and mice. However, the underlying mechanism is unclear.
The author Youngmin Yoon and colleagues (2020) attempted to understand the mechanism in the study entitled, “Lactobacillus fermentum promotes adipose tissue oxidative phosphorylation to protect against diet-induced obesity”, published in the journal “Experimental & Molecular Medicine”. The summary of the article is provided below.
Objective:
To evaluate the protective role of Lactobacillus fermentum LM1016 against diet-induced obesity.
Method:
For one week, 6-week-old mice were fed with either a normal diet with phosphate-buffered saline or a High-fat diet. 1 × 109 CFU of bacteria was administered orally, once. After administration, stool samples were collected at 4, 8, 12, and 24 h. On mice, the analysis was conducted of tissue histology, liver triglyceride levels, RNA extraction, and isolation and real-time polymerase chain reaction (PCR). Biochemical analysis of serum insulin, serum C-reactive protein, serum total cholesterol, serum leptin, and glucose tolerance tests were performed on the mice. On bacteria, the analysis was conducted of bacterial transcriptome sequencing and annotation.
Results:
The authors were able to demonstrate that L. fermentum-potentiated oxidative phosphorylation in adipose tissue. This action resulted in increased energy expenditure. Thus, protects against diet-induced obesity. To identify the strain of L. fermentum with protective effects on HFD, seven L. fermentum strains were tested. Lactobacillus fermentum strain LM1016 showed 6 significantly reduced diet-induced body weight gain. The said effect arises as oral administration of L. fermentum:
1. Ameliorated glucose clearance and hepatic steatosis in high-fat diet-fed mice.
2. Transcriptome analysis demonstrated decreased inflammation and increased oxidative phosphorylation in gonadal white adipose tissue.
3. Metabolome analysis demonstrated that metabolites reduced adipocyte differentiation and inflammation in 3T3-L1 preadipocytes.