Combined treatment with probiotics and fructooligosaccharides in a mouse model of nonalcoholic fatty liver disease and its possible mechanism

Abstract

Objective To investigate the effectiveness of Lactobacillus paracasei N1115 combined with fructooligosaccharides (FOS) in the treatment of nonalcoholic fatty liver disease(NAFLD) in a mouse model and to analyze the possible mechanism. Methods Fifty male C57BL/6 mice were randomly divided into five groups and respectively given normal diet (ND group), high-fat diet (HFD group), HFD containing Lactobacillus paracasei N1115 (HFD+ L) (2.2×109 CFU/ml), HFD containing FOS (HFD+ FOS) (4 g/kg per day) and HFD containing Lactobacillus paracasei N1115 and FOS for 16 consecutive weeks. Levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), lipopolysaccharide (LPS) and diamine oxidase (DAO) in serum samples from each group were measured. Expression of tight-junction proteins (Claudin-1 and Occludin), p38 and phosphorylated p38 (p-p38) in intestinal tissues were analyzed. Results Compared with the HFD group, the HFD+ FOS+ L group showed decreased levels of TC, TG, LDL, LPS and DAO in serum samples, but increased serum HDL level (P<0.05). Moreover, combined treatment with Lactobacillus paracasei N1115 and FOS alleviated liver lipid deposition, significantly increased the expression of Claudin-1 and Occludin in intestine and inhibited the phosphorylation of p38 (P<0.05). Conclusion Lactobacillus paracasei N1115 combined with FOS may increase the expression of Claudin-1 and Occludin through inhibiting the phosphorylation of intestinal p38, which is conducive to maintaining the intestinal mucosal barrier integrity and alleviating NAFLD. Key words: NAFLD; Lactobacillus paracasei N1115; Fructooligosaccharides; Intestinal mucosal barrier