Single and mixed strains of probiotics attenuated inflammation and oxidative stress in rat model of non-alcoholic steatohepatitis

Abstract

The development of non-alcoholic steatohepatitis (NASH) involves complex pathophysiological processes. The aim of this study was to determine whether single and mixed strains of probiotics could reduce the severity of NASH induced by high-fat-high-fructose (HFHF) diet through the alleviation of inflammatory cytokines and oxidative stress in rats. Twenty-eight male Sprague-Dawley rats were divided into 4 groups (n=7 each group), control; NASH group fed with HFHF diet; NASH+single strain (1.8×109 CFUs/ml of Lactobacillus plantarum B7) 1 ml by gavage once daily; NASH + mixed strains (1.8×109 CFUs/ml of Lactobacillus rhamnosus L34 and 1.8×109 CFUs/ml of Lactobacillus casei B13) 1 ml by gavage once daily for 6 weeks. Liver histology was used to determine NASH severity. The oxidative stress marker (i.e. hepatic malondialdehyde (MDA) levels), natural antioxidant (i.e. hepatic glutathione (GSH)), and inflammatory marker (i.e. serum interleukin-6 (IL-6) levels) were measured. Gross liver appearance in the NASH group showed enlarged and yellowish livers. Histopathology demonstrated a moderate to severe degree of steatosis, hepatocyte ballooning, and lobular inflammation in the NASH group. In both treatment groups, the improvement of liver histology was noted compared with the NASH group.  Serum IL-6 and hepatic MDA levels were significantly increased in the NASH group, while GSH levels were significantly decreased compared with the control group. Moreover, in both treatment groups, serum IL-6 and hepatic MDA levels
were significantly decreased, while GSH levels were significantly increased compared with the NASH group. In conclusion, single and mixed strains of probiotics were effective in the prevention of NASH, likely through the alleviation of inflammatory cytokines and reduction of oxidative stress. Probiotics could potentially be used for the management of NASH. Clinical studies are needed to confirm their therapeutic effects in human.