Dietary Supplementation with Lactobacillus casei Alleviates Lipopolysaccharide-Induced Liver Injury in a Porcine Model

Abstract

This study aims to determine whether Lactobacillus casei (L. casei) could relieve liver injury in piglets challenged with lipopolysaccharide (LPS). Piglets were randomly allocated into one of the three groups: control, LPS, and L. casei. The control and LPS groups were fed a corn- and soybean meal-based diet, whereas the L. casei group was fed the basal diet supplemented with 6 × 10⁶ cfu/g L. casei. On Day 31 of the trial, piglets in the LPS and L. casei groups received intraperitoneal administration of LPS (100 µg/kg body weight), while the control group received the same volume of saline. Blood and liver samples were collected for analysis. Results showed that L. casei supplementation decreased the feed/gain ratio (p = 0.027) and diarrhea incidence (p < 0.001), and attenuated LPS-induced liver histomorphological abnormalities. Compared with the control group, LPS challenge dramatically increased glutamyl transpeptidase activity (p = 0.001) in plasma as well as the concentrations of Interleukin 6 (IL-6) (p = 0.048), Tumor necrosis factor-alpha (TNF-α) (p = 0.041), and Malondialdehyde (MDA) (p = 0.001) in the liver, while decreasing the hepatic SOD activity. LPS also increased (p < 0.05) the mRNA levels for IL-6, IL-8, TNF-α, Toll-like receptors 4 (TLR4), Nuclear factor κB (NF-κB) and Heat shock protein 70 (HSP70) in the liver. The adverse effects of LPS challenge were ameliorated by L. casei supplementation. In conclusion, dietary L. casei alleviates LPS-induced liver injury via reducing pro-inflammatory cytokines and increasing anti-oxidative capacity.

Keywords: Lactobacillus casei; lipopolysaccharide; liver; piglets.

Figure 1

Effects of dietary supplementation with L. casei on liver morphology. Representative photomicrographs of liver sections stained with hematoxylin and eosin are shown (×400): (I) piglets fed the basal diet and received intraperitoneal administration of sterile saline; (II) piglets fed the basal diet and received intraperitoneal administration of Escherichia coli lipopolysaccharide (LPS); and (III) piglets fed the basal diet supplemented with 6 × 10⁶ cfu/g L. casei and received intraperitoneal administration of LPS, as described in the Material and Methods Section. Histological analysis revealed abnormalities in hepatic structure, including: caryolysis (A); karyopycnosis (B); infiltration of inflammatory cells (C); injury to hepatic sinusoids (D); and the disordered arrangement of hepatic cell cords.