A protective mechanism of probiotic Lactobacillus against hepatic steatosis via reducing host intestinal fatty acid absorption

Abstract

The gut microbiome has been known to contribute up to ~30% of the energy absorption of the host. Although various beneficial mechanisms of probiotics have been suggested for non-alcoholic fatty liver disease (NAFLD), whether and which probiotics impact the host’s intestinal energy absorption have not yet been quantitatively studied. Here, we suggest a novel mechanism of probiotics against NAFLD, in which Lactobacillus rhamnosus GG, the most common probiotic, shares intestinal fatty acids and prevents the development of diet-induced hepatic steatosis. By using quantitative methods (radioactive tracers and LC–MS) under both in vitro and in vivo conditions, we found that bacteria and hosts competed for fatty acid absorption in the intestine, resulting in decreased weight gain, body fat mass, and hepatic lipid accumulation without differences in calorie intake and excretion in mice fed the probiotic bacteria.

Revisiting the Bacterial Phylum Composition in Metabolic Diseases Focused on Host Energy Metabolism

“…Chronic oral administration of Lactobacillus reduced weight gain, body fat mass, and hepatic lipid accumulation during high-fat diet feeding, without altering dietary calorie intake or fecal calorie excretion [71]. Pyrosequencing data show that the ratio of Firmicutes to Bacteroidetes is unchanged by LGG treatment, despite the dramatic changes in metabolic phenotypes [71]. Another study also suggests a similar result and shows that Lactobacillus strains reduce intestinal free fatty acids, resulting in a loss of body weight [72].…”

“…Furthermore, the increase of these specific gut bacteria, which consume dietary substrates results in a decrease in the remaining nutrients in which, in turn, can reduce the amount of nutrients that can be absorbed by the host. Lactobacillus bacteria consume fatty acids during cultivation and delay the intestinal absorption of oleic acids in high-fat diet-fed mice [71]. Chronic oral administration of Lactobacillus reduced weight gain, body fat mass, and hepatic lipid accumulation during high-fat diet feeding, without altering dietary calorie intake or fecal calorie excretion [71].…”

“…Lactobacillus bacteria consume fatty acids during cultivation and delay the intestinal absorption of oleic acids in high-fat diet-fed mice [71]. Chronic oral administration of Lactobacillus reduced weight gain, body fat mass, and hepatic lipid accumulation during high-fat diet feeding, without altering dietary calorie intake or fecal calorie excretion [71]. Pyrosequencing data show that the ratio of Firmicutes to Bacteroidetes is unchanged by LGG treatment, despite the dramatic changes in metabolic phenotypes [71].…”

The Molecular and Mechanistic Insights Based on Gut–Liver Axis: Nutritional Target for Non-Alcoholic Fatty Liver Disease (NAFLD) Improvement

“…Plentiful studies have shown the extensive salubrious effects of probiotics (e.g., Lactobacillus and Bifidobacterium) on liver disease. As shown in high-fructose or high-fat diet-induced experimental NAFLD models, Lactobacillus rhamnosus GG ameliorated NAFLD by (1) control of gut microbiome; (2) repair of intestinal barrier; and (3) suppression of hepatic steatosis, inflammation, and lipid accumulation [83,84]. Bifidobacterium serves to protect against secretion of pro-inflammatory cytokines and dysfunction in intestinal barrier both in vitro and in vivo [85].…”

Lactobacillus fermentum CECT5716 Supplementation in Rats during Pregnancy and Lactation Impacts Maternal and Offspring Lipid Profile, Immune System and Microbiota

“…Recent studies suggest that probiotic administration may impact the lipid profile by affecting their absorption or metabolism [76][77][78]. With this in mind, we also quantified the plasmatic FA profile of the dams and pups.…”