Similar bacterial signatures in the gut microbiota of type 1 and type 2 diabetes patients and its association with G protein-coupled receptor 41 and 43 gene expression.

Purpose: There are conflicting reports regarding the abundance of short-chain fatty acids producing bacteria in the gut microbiota in patients with type 1 and type 2 diabetes. We aimed to determine the amount of Akkermansia muciniphila, Anaerobutyricum hallii, Bifidobacterium adolescentis, Bifidobacterium longum, Collinsella aerofaciens, Faecalibacterium prausnitzii, Lacticaseibacillus rhamnosus, and Parabacteroides distasonis in the gut microbiota in patients with type1 and type2 diabetes, compared with the healthy controls and analyze the correlation between the gene expression levels of two short-chain fatty acids receptors GPR41 and GPR43. Methods: Forty type 1, 40 type 2 stool and blood samples of diabetes patients, and 40 healthy control samples were studied. DNA and RNA were extracted, and bacteria were detected using a Microbial DNA qPCR Assay kit. Gene expressions were detected with GPR41 and GPR43 primers via in-house qPCR. Results: Compared with healthy controls, B.longum and F.prausnitzii abundance were significantly decreased in patients with type1 and type2 diabetes, A.hallii abundance was increased in patients with type1 and decreased in type2 diabetes contrarily A.muciniphila abundance was decreased in patients with type1 and increased in type2 diabetes. GPR43 gene expression was upregulated in both patients group, however GPR41 was upregulated only in patients with type2 diabetes. Conclusions: Elevated B. longum and F. prausnitzii abundances were detected in the gut microbiota of patients with type1 and type2 diabetes and compared with healthy controls. B. longum and F.prausnitzii abundances were also correlated with the GPR43 gene expression level in type1 diabetes patients. Extensive studies determining bacteria producing short-chain fatty acids in gut microbiota, and their contribution in the pathogenesis of diabetes, are needed to understand better the mechanism of these diseases.

Firmicutes/Bacteroidetes Ratio in the Gut Microbiota and IL-1ß, IL-6, IL-8, TLR2, TLR4, TLR5 Gene Expressions in Type 2 Diabetes.

BACKGROUND: The aim of this study was to determine the Firmicutes/Bacteroidetes ratio in the gut microbiota and IL-1ß, IL-6, IL-8, TLR2, TLR4 and TLR5 gene expression levels in the blood of adult type 2 diabetes (T2D) patients and compare it with that of adult nondiabetic healthy controls (HC). METHODS: Between May 2016 and April 2017, 99 T2D patients and 99 HCs were enrolled in the study. Bacteroidetes and Firmicutes levels were assessed from stool sample DNA and IL-1ß, IL-6, IL-8, TLR2, TLR4, and TLR5 gene expression levels assesed from blood sample RNA via qPCR from both T2D patients and healthy controls. RESULTS: The Firmicutes/Bacteroidetes ratio detected in the stool of type 2 diabetes patients was found to be higher with a statistically significant difference (p < 0.0001). Gene expression levels of IL-1ß, IL-6, IL-8, TLR2, TLR4, and TLR5 were found to be upregulated. CONCLUSIONS: The highest upregulation was detected in IL-6 with 11 fold in T2D patients comparing with HCs. F/B ratio and gene expression levels were elevated in T2D patients. Firmicutes were positively correlated with studied gene expressions. A better understanding of the complex interaction between gut microbiota, environment, and diabetes will allow for more effective prevention and treatment strategies for T2D.

Bacteroidetes and Firmicutes levels in gut microbiota and effects of hosts TLR2/TLR4 gene expression levels in adult type 1 diabetes patients in Istanbul, Turkey.

AIM: The aim of this study was to determine and compare the levels of both Bacteroidetes and Firmicutes in the gut microbiota and TLR2/TLR4 gene expression in the blood of patients with type 1 diabetes mellitus (T1DM) and healthy individuals. These results may serve as a preliminary assessment to guide future research. METHOD: Between January and October 2014, stool and blood samples were collected from 53 adult T1DM patients and 53 age- and gender-matched healthy individuals. Bacteroidetes and Firmicutes levels were assessed from stool sample DNA and TLR2 and TLR4 expression levels were analyzed via qPCR using RNA from EDTA blood samples from both patients and healthy controls. RESULTS: The amounts of Bacteroidetes and Firmicutes were statistically significantly higher and lower, respectively, in the T1DM group than in the healthy control group (p < 0.001 and p < 0.001, respectively). In addition, the Firmicutes/Bacteroidetes ratios in patients with T1DM were significantly lower than in healthy controls. The TLR4 and TLR2 gene expression levels in T1DM patients were significantly upregulated and downregulated, respectively, compared to those in the control group. CONCLUSION: Our data are the first to show a relationship between T1DM and gut microbiota in our country. In addition, our results provide information about the connections between T1DM, gut microbiota, and TLR2 and TLR4 expression. We believe that Bacteroidetes and Firmicutes in the gut microbiota may play a role in the autoimmune process of T1DM and that these findings should be further investigated in the future.

Orlistat augments postprandial increases in glucagon-like peptide 1 in obese type 2 diabetic patients.

OBJECTIVE: Orlistat leads to improved glycemic control in obese type 2 diabetic patients, which is attributed to decreased insulin resistance associated with weight loss. Glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) are gut hormones that are secreted in response to food intake, and they both stimulate insulin secretion. Orlistat decreases fat absorption and increases intestinal fat content, which may lead to increased secretion of these peptides. In this pilot study, we tested the hypothesis that increased levels of these intestinal hormones may be involved in the improvement of postprandial hyperglycemia observed previously with orlistat in type 2 diabetic patients. RESEARCH DESIGN AND METHODS: A total of 29 type 2 diabetic patients, who were not taking insulin or alpha-glucosidase inhibitors, were enrolled in the study. On a crossover and single-blind design, after an overnight fasting, the patients received 120-mg orlistat or placebo capsules, followed by a standard 600-kcal mixed meal that contained 38% fat. At baseline and 60 min after the meal, blood samples were obtained for the measurement of GLP-1, GIP, insulin, C-peptide, triglycerides, free fatty acids, and glucose. RESULTS: All measured parameters increased significantly in response to the mixed meal compared with baseline, both with orlistat or placebo. When compared with the placebo, the orlistat administration resulted in a significantly enhanced postprandial increase in GLP-1 and C-peptide levels and attenuated the postprandial rise in glucose and triglycerides. CONCLUSIONS: The results of this study suggest that apart from decreasing insulin resistance as a result of weight loss, orlistat may increase postprandial GLP-1 levels, thereby enhancing the insulin secretory response to the meal and blunting the postprandial rise in glucose in type 2 diabetic patients. Increased GLP-1 levels, which lead to decreased food intake, may also contribute to the weight loss that is associated with the use of this drug.