Study On The Effects And Mechanism Of Dietary Fiber Inulin On Type 2 Diabetes Mellitus And Polycystic Ovary Syndrome In Mice

Objective To evaluate the effects and associated mechanism of inulin on different stages of type 2 diabetes mellitus?T2DM?mice;To evaluate the effects and mechanism of inulin on polycystic ovary syndrome?PCOS?mice.Methods 1.Modeling and grouping:?1?According to fasting blood glucose?FBG?,oral glucose tolerance tests?OGTT?and whether or not to give inulin intervention,90 db/db mice were divided into pre-diabetes group?PDM group?,early diabetic group?EDM group?,diabetic group?DM group?,PDM inulin intervention group?INU/PDM group?,EDM inulin intervention group?INU/EDM group?and DM inulin intervention group?INU/DM group?.Mice in intervention groups were continuously intervened with inulin for 6 weeks.?2?Forty female C57BL/6J mice were randomly divided into 4 groups: control group?CON group?,model group?MOD group?,inulin group?INU group?,metformin group?MET group?,and the last three groups were given 6mg/100 g dehydroepiandrosterone and 60% high-fat diet for 20 days to form PCOS mouse model,inulin and metformin were respectively administered to INU and MET group for 21 days.2.Experimental method:?1?After inulin intervention,body weight?BW?of db/db mice and C57BL/6J mice were monitored once a week.FBG levels were also monitored once a week and OGTT was monitored twice a week in db/db mice after inulin intervention.?2?Insulin tolerance test?ITT?were measured for insulin resistance after 21 days of intervention in C57BL/6J mice.?3?Glycated hemoglobin?GHb?in db/db mice and serum six hormones in C57BL/6J mice were detected by ELISA.?4?Serum triglyceride?TG?and total cholesterol?TC?in db/db mice were detected by AU400 automatic biochemical analyzer;?5?Morphology and structure of ovary in C57BL/6J mice were observed via HE staining.?6?Plasma LPS in db/db and C57BL/6J mice were measured using limulus amebocyte lysate kit.?7?Inflammatory factors of plasma in db/db and C57BL/6J mice were measured by Cytometric Bead Array?CBA?;?8?Immunohistochemistry was used to detect macrophage in liver of db/db mice.?9?Gut microbiota of db/db and C57BL/6J mice were detected by 16 S rRNA sequencing.?10?Spearman correlated analysis was performed to detect the correlation between plasma inflammatory factors and gut microbiota in db/db and C57BL/6J mice.Results First part: Inulin significantly reduced the levels of BW,FBG,GHb,TG,TC,LPS,IL-6,TNF-? and IL-17 A in different stages of T2 DM mice.But IL-17 A showed no significant difference between PDM and INU/PDM groups.In addition,IL-10 was significantly elevated in INU/PDM and INU/EDM groups compared with corresponding untreated group,while there was no significant difference in INU/DM group.Liver immunohistochemistry showed that inulin reduced the number of macrophages and fat vacuoles in the liver of T2 DM mice at different stages.Sequencing of 16 S rRNA gut microbiota showed that inulin could significantly increase Cyanobacteria,Bacteroides and decrease significantly Ruminiclostridium₆ in different stages of T2 DM mice.Compared with corresponding untreated group,Deferribacteres and Tenericutes were decreased significantly in INU/DM group,While Mucispirillum was significantly reduced in INU/PDM and INU/EDM groups.Spearman correlation analysis showed that positive correlation was found between Cyanobacteria,Bacteroides and IL-10,or between Deferribacteres,Tenericumutes,Mucispirillum and IL-6,TNF-?,or between Mucispirillum,Ruminococcaceae₆ and IL-17 A,LPS,or between Ruminococcaceae₆ and TNF-?.The negative correlation was found between Cyanobacteria,Bacteroides and IL-6,TNF-?,or between Cyanobacteria and IL-17 A,or between Ruminococcaceae₆ and IL-10.Second part: Dietary inulin significantly reduced BW,testosterone?T?,TNF-?,IL-6,IL-17 A.Serum estradiol?E2?was increased and insulin resistance was improved in PCOS mice after inulin treatment,But IL-10 showed no significant difference between INU and MOD groups.Ovarian HE staining showed that inulin increased formation of granulosa layer and corpora lutea.Sequencing of 16 S rRNA gut microbiota showed that Bifidobacterium was significantly elevated in INU group.Proteobacteria,Helicobacter and Parasutterella in INU group were significantly reduced compared with MOD group.Spearman correlation analysis showed that Bifidobacterium was negatively correlated with TNF-?,IL-6 and IL-17 A,while Helicobacter was positively correlated with plasma inflammatory factors?TNF-?,IL-6,IL-17A?.Conclusion?1?Inulin can alleviate T2 DM at different stages by anti-inflammation and regulating the gut microbiota.?2?Inulin can ameliorates PCOS by anti-inflammatory and regulating gut microbiota.