AUTHOR=Ma Qingyu , Zhai Ruohan , Xie Xiaoqing , Chen Tao , Zhang Ziqi , Liu Huicui , Nie Chenxi , Yuan Xiaojin , Tu Aobai , Tian Baoming , Zhang Min , Chen Zhifei , Li Juxiu 

TITLE=Hypoglycemic Effects of Lycium barbarum Polysaccharide in Type 2 Diabetes Mellitus Mice via Modulating Gut Microbiota

JOURNAL=Frontiers in Nutrition

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.916271

DOI=10.3389/fnut.2022.916271

ISSN=2296-861X

ABSTRACT=<p>This study aims to explore the molecular mechanisms of <italic>Lycium barbarum</italic> polysaccharide (LBP) in alleviating type 2 diabetes through intestinal flora modulation. A high-fat diet (HFD) combined with streptozotocin (STZ) was applied to create a diabetic model. The results indicated that LBP effectively alleviated the symptoms of hyperglycemia, hyperlipidemia, and insulin resistance in diabetic mice. A high dosage of LBP exerted better hypoglycemic effects than low and medium dosages. In diabetic mice, LBP significantly boosted the activities of CAT, SOD, and GSH-Px and reduced inflammation. The analysis of 16S rDNA disclosed that LBP notably improved the composition of intestinal flora, increasing the relative abundance of <italic>Bacteroides</italic>, <italic>Ruminococcaceae_UCG-014</italic>, <italic>Intestinimonas</italic>, <italic>Mucispirillum</italic>, <italic>Ruminococcaceae_UCG-009</italic> and decreasing the relative abundance of <italic>Allobaculum</italic>, <italic>Dubosiella</italic>, <italic>Romboutsia</italic>. LBP significantly improved the production of short-chain fatty acids (SCFAs) in diabetic mice, which corresponded to the increase in the beneficial genus. According to Spearman’s correlation analysis, <italic>Cetobacterium</italic>, <italic>Streptococcus</italic>, <italic>Ralstonia</italic>. <italic>Cetobacterium</italic>, <italic>Ruminiclostridium</italic>, and <italic>Bifidobacterium</italic> correlated positively with insulin, whereas <italic>Cetobacterium</italic>, <italic>Millionella</italic>, <italic>Clostridium_sensu_stricto_1</italic>, <italic>Streptococcus</italic>, and <italic>Ruminococcaceae_UCG_009</italic> correlated negatively with HOMA-IR, HDL-C, ALT, AST, TC, and lipopolysaccharide (LPS). These findings suggested that the mentioned genus may be beneficial to diabetic mice’s hypoglycemia and hypolipidemia. The up-regulation of peptide YY (PYY), glucagon-like peptide-1 (GLP-1), and insulin were remarkably reversed by LBP in diabetic mice. The real-time PCR (RT-PCR) analysis illustrated that LBP distinctly regulated the glucose metabolism of diabetic mice by activating the IRS/PI3K/Akt signal pathway. These results indicated that LBP effectively alleviated the hyperglycemia and hyperlipidemia of diabetic mice by modulating intestinal flora.</p>