Complex Dietary Fiber Improves Glucolipid Metabolism In Mice With Type 2 Diabetes

The aim of this thesis is to investigate the effect of complex dietary fibre on the improvement of glucolipid metabolism in type 2 diabetic mice and to provide an idea for the development of functional dietary fibre products.Mice were moulded by high-fat feeding for 8 weeks followed by STZ injection to establish a type 2 diabetic mouse model,and the success of the moulding was confirmed by fasting blood glucose and glucose tolerance measurements.After successful moulding,the mice were grouped and the blank control group(CON,n = 10)continued to be fed a maintenance diet for 12 weeks,the model control group(HFD,n = 6)continued to be fed a high-fat diet for 12 weeks and the diet improvement group(HFD + LFD,n = 6)was fed a high-fat diet for 8 weeks before being switched to a maintenance diet for 4 weeks.he dietary fibre intervention groups were divided into low(L-DF,n=6),medium(M-DF,n=6)and high(H-DF,n=6)dose groups and the mice were fed three doses of combined dietary fibre,low,medium and high,also on high-fat chow for 8 weeks and then switched to maintenance chow for 4 weeks.During this period,fasting blood glucose was measured every 2 weeks to observe the hypoglycaemic effect of dietary fibre on the mice.At the end of the experiment,serum and faeces were collected from each group of mice.The serum was used to test biochemical parameters such as blood glucose and blood lipids;the faeces was used to test short-chain fatty acids and intestinal flora to investigate the effect of dietary fibre on the diversity of short-chain fatty acids and flora in the intestine of mice.The results showed that fasting blood glucose,glucose tolerance and some serum indexes were increased in the HFD group compared with the CON group,the coefficients of each organ were significantly higher and the overall content of short-chain fatty acids decreased.The high dose of complex dietary fibre was effective in improving glucolipid metabolism and reducing fasting blood glucose,insulin resistance,LDL-C,TC and TG in diabetic mice.Analysis of faecal content of short-chain fatty acids showed a significant increase in propionic acid and butyric acid(p<0.05)and a significant but not significant increase in acetic acid content in the faeces of the high dose group compared to the HFD group.Some mice in the diet-improved group(HFD + LFD)showed improvement in lipids,although the improvement in other indicators was not significant.The intestinal flora was found to be disrupted in the HFD group,with a reduction in the number and diversity of species.The observed＿otus index and Chao1 index were significantly lower in the HFD group compared to the CON group(p<0.05)and the Shannon index was significantly higher in the M-DF group compared to the HFD group(p<0.05).Compound dietary fibre significantly increased the abundance of the phylum Aerobacteriaceae in the intestine and decreased the abundance of the phylum Thick-walled＿Enterobacteriaceae with unidentified＿Enterobacteria.The increased Bacillus mimicus promotes the breakdown of polysaccharides in the body to produce short-chain fatty acids.