Phellinus linteus polysaccharide extract improves insulin resistance by regulating gut microbiota composition

Abstract

The hypoglycemic effect of Phellinus linteus polysaccharide extract (PLPE) has been documented in several previous studies, but the functional interactions among PLPE, gut microbiota, and the hypoglycemic effect remain unclear. We examined the regulatory effect of PLPE on gut microbiota, and the molecular mechanism underlying improvement of insulin resistance, using a type 2 diabetic rat model. Here, 24 male Sprague‐Dawley rats were randomly divided into four groups that were subjected to intervention of saline (normal and model control group), metformin (120 mg/kg.bw), and PLPE (600 mg/kg.bw) by oral administration. After 8 weeks of treatment, PLPE increased levels of short‐chain fatty acids (SCFAs) by enhancing abundance of SCFA‐producing bacteria. SCFAs maintained intestinal barrier function and reduced lipopolysaccharides content in blood, thereby helping to reduce systemic inflammation and reverse insulin resistance. Our findings suggest that PLPE (in which polysaccharides are the major component) has potential application as a prebiotic for regulating gut microbiota composition in diabetic patients.

The impact of the gut microbiota on the reproductive and metabolic endocrine system

“…85 The administration of Phellinus linteus polysaccharide extract (PLPE) to mice was found to change the gut microbiota composition and increase SCFA levels, which reduces LPS content and systemic inflammation and improves insulin resistance by inhibiting JNK and NFκB activation. 86 SCFAs, which are the main fermentation products of the intestinal microbiota and include propionate, acetate, and butyrate, affect metabolic processes of the host, especially insulin resistance. 87 Human and animal studies have suggested that acetate beneficially affects host metabolism and improves insulin resistance through the gut hormone GLP-1 secreted from colonic L cells, which inhibits appetite and reduces lipolysis and systemic proinflammatory cytokine levels.…”

<p>Effects of Metformin on the Gut Microbiota in Obesity and Type 2 Diabetes Mellitus</p>

“…A total of 9 studies conducted in Wistar rats (five papers), Sprague-Dawley rats (two papers), Otsuka Long-Evans Tokushima fatty rats (one paper), and Zucker diabetic fatty rats (one paper) were included ( Table 2). Two studies gave the rats HFD for 2 or 10 weeks to induce an obese rat model, 41,42 five studies treated rats with HFD for 2-12 weeks followed by injection of streptozotocin (STZ) to induce diabetes, [43][44][45][46][47] and two studies used spontaneously diabetic rat models. 48,49 The dose of metformin ranged from 30 to 215.12 mg/kg/d, and the treatment period ranged from 4 weeks to 12 weeks.…”

Protective Effects of Almond Oil on Streptozotocin-Induced Diabetic Rats via Regulating Nrf2/HO-1 Pathway and Gut Microbiota

“…Release of LPS by pathogenic bacteria in the intestine can enter the bloodstream and trigger low-level inflammation and oxidative damage in rats with high intestinal permeability. Reducing the levels of LPSproducing bacteria in diabetic rats might contribute to reducing systemic inflammation and promoting normal liver insulin signaling [17]. erefore, regulation of the gut microflora may be beneficial for reversing the inflammatory and maintaining the balance of glucose metabolism.…”