The Positive Effects of Grifola frondosa Heteropolysaccharide on NAFLD and Regulation of the Gut Microbiota

Abstract

Non-alcoholic fatty liver disease (NAFLD) is a major public health problem in many countries. In this study, the ability of Grifola frondosa heteropolysaccharide (GFP) to ameliorate NAFLD was investigated in rats fed a high-fat diet (HFD). The molecular mechanisms modulating the expression of specific gene members related to lipid synthesis and conversion, cholesterol metabolism, and inflammation pathways were determined. The components of the intestinal microflora in rats were analyzed by high-throughput next-generation 16S rRNA gene sequencing. Supplementation with GFP significantly increased the proportions of Allobaculum, Bacteroides, and Bifidobacterium and decreased the proportions of Acetatifactor, Alistipes, Flavonifractor, Paraprevotella, and Oscillibacter. In addition, Alistipes, Flavonifractor, and Oscillibacter were shown to be significant cecal microbiota according to the Spearman’s correlation test between the gut microbiota and biomedical assays (|r| > 0.7). Histological analysis and biomedical assays showed that GFP treatments could significantly protect against NAFLD. In addition, Alistipes, Flavonifractor, and Oscillibacter may play vital roles in the prevention of NAFLD. These results suggest that GFP could be used as a functional material to regulate the gut microbiota of NAFLD individuals.

Resveratrol Improves Liver Steatosis and Insulin Resistance in Non-alcoholic Fatty Liver Disease in Association With the Gut Microbiota

“…RSV could increase the proportion of Allobaculum . Previous studies have proven that increases in Allobaculum are beneficial to HFD mice ( Raza et al, 2017 ; Li et al, 2019 ). Allobaculum shows increases when dietary fiber is taken and is negatively related to the concentration of leptin ( Ravussin et al, 2012 ).…”

Bioactive Ingredients and Medicinal Values of Grifola frondosa (Maitake)

“…Additionally, GFP has also been found to regulate the gut microbiota of rats with non-alcoholic fatty liver disease (NAFLD). Li and coworkers found that GFP could partly recover the HFD-induced alteration of cecal microbiota structure [ 30 ]. GFP treatment could decrease the Firmicutes to Bacteroidetes ratio, indicating a lower possibility of lipid production from undigested carbohydrates [ 108 ].…”

“…Friedman also suggested in his review that the ratio decrease of the two major classes of gut bacteria, namely, Firmicutes and Bacteroides , could have fat-lowering effects in obesity treatment [ 106 ]. In addition, GFP supplementation significantly increased the proportion of Allobaculum , Bacteroides , Bifidobacterium and some other microbial groups in the cecal microbiota, which might boost the immune system of the host and the defense against NAFLD [ 30 ]. The boosting of the immune system may contribute to the anti-tumor and anti-inflammatory effect of GFP as well [ 29 , 111 ].…”

“…In particular, gut microbiota play a role in maintaining immune homeostasis, which may have a connection to the antitumor effects of polysaccharides [ 29 ]. The regulation of gut microbiota composition by G. frondosa polysaccharides has also been suggested to contribute to the treatment of metabolic disorders such as non-alcoholic fatty liver disease (NAFLD) [ 30 ] and diabetes [ 31 ], indicating their potential for preventing or treating hyperglycemia and hyperlipidemia. Apart from polysaccharides, other molecular fractions isolated from G. frondosa fruiting bodies or mycelial biomass have shown promising medicinal values as well.…”

Antitumor, Anti-inflammatory and Antiallergic Effects of Agaricus blazei Mushroom Extract and the Related Medicinal Basidiomycetes Mushrooms, Hericium erinaceus and Grifola frondosa: A Review of Preclinical and Clinical Studies

“…Regarding GF, it has been shown that a polysaccharide given orally had a similar protective effect on non-alcoholic steato-hepatitis in rats as AbM had in mice above [66]. The mechanism was a beneficial regulation of gut microbiota [79]. Moreover, a fermented GF extract had anti-inflammatory effect in an endotoxin-induced uveitis model in rats [80], and a GF extract reduced colon ulceration in an IBD rat model through an antioxidative and anti-inflammatory mechanism [81].…”