Protective Effects of Mannan Oligosaccharides and Partially Hydrolyzed Guar Gum on Chronic Alcoholic Liver Injury in Mice

Objective: To investigate the protective effects of mannan oligosaccharide (MOS) and partially hydrolyzed guar gum (PHGG) on liver injury induced by long-term alcohol intake in mice. Methods: Mice were randomly divided into control (Ctrl), model (EtOH), positive control (PC, silymarin at 86 mg/(kg·d)), MOS intervention (2 000 mg/(kg·d)) and PHGG intervention (2 000 mg/(kg·d)) groups. A Lieber-DeCarli model of chronic alcoholic liver injury (ALD) was established in this study. After five weeks of feeding, the levels of liver function, oxidative stress and inflammatory factors were measured. Hematoxylin-eosin (HE) staining and oil red O (ORO) staining were used to observe hepatic histopathological alterations. The mRNA and protein expression levels of ileal tight junction proteins (zonula occludens-1 and occludin) were detected by real-time fluorescence quantitative polymerase chain reaction (qPCR) and immunofluorescence staining, respectively. The hepatic lipopolysaccharide (LPS) level was quantitatively determined by enzyme-linked immunosorbent assay (ELISA). Besides, the contents of acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid and caproic acid in fecal samples were quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS). Results: Supplementation of MOS and PHGG could significantly attenuate hepatic steatosis, lipid accumulation, oxidative stress and inflammation induced by long-term ethanol exposure. Additionally, compared with the EtOH group, MOS and PHGG intake markedly improved liver function and intestinal barrier function, inhibited intestinal LPS leakage, and increased intestinal short-chain fatty acids (SCFAs) levels. Conclusion: Guar gum-derived MOS and PHGG could effectively alleviate chronic ALD in mice by enhancing intestinal integrity and regulating intestinal SCFA levels.