Gut microbiota: A new target for T2DM prevention and treatment

Molecular Mechanism of Pasteurized Akkermansia muciniphila in Alleviating Type 2 Diabetes Symptoms

Type 2 diabetes (T2DM) significantly diminishes people's quality of life and imposes a substantial economic burden. This pathological progression is intimately linked with specific gut microbiota, such as Akkermansia muciniphila. Pasteurized A. muciniphila (P-AKK) has been defined as a novel food by the European Food Safety Authority and exhibited significant hypoglycemic activity. However, current research on the hypoglycemic activity of P-AKK is limited to the metabolic level, neglecting systematic exploration at the pathological level. Consequently, its material basis and mechanism of action for hypoglycemia remain unclear. Drawing upon this foundation, we utilized high-temperature killed A. muciniphila (H-K-AKK) with insignificant hypoglycemic activity as the control research object. Assessments were conducted at pathological levels to evaluate the hypoglycemic functions of both P-AKK and H-K-AKK separately. Our study unveiled for the first time that P-AKK ameliorated symptoms of T2DM by enhancing the generation of glucagon-Like Peptide 1 (GLP-1), with pasteurized A. muciniphila total proteins (PP) being a pivotal component responsible for this activity. Utilizing SDS-PAGE, proteomics, and molecular docking techniques, we deeply analyzed the material foundation of PP. We scientifically screened and identified a protein weighing 77.85 kDa, designated as P5. P5 enhanced GLP-1 synthesis and secretion by activating the G protein-coupled receptor (GPCR) signaling pathway, with free fatty acid receptor 2 (FFAR-2) being identified as the pivotal target protein for P5's physiological activity. These findings further promote the widespread application of P-AKK in the food industry, laying a solid theoretical foundation for its utilization as a beneficial food ingredient or functional component.

Global research trends in regulating gut microbiome to improve type 2 diabetes mellitus: bibliometrics and visual analysis

Background

Gut microbiome (GM) and type 2 diabetes mellitus (T2DM) have two-way effects. Improving T2DM by modulating GM in various ways, such as diet, exercise, and medication, is gradually becoming popular, and related studies have yielded positive results. However, there is still a lack of high-quality bibliometric analyses of research in this area. This study aims to systematize and comprehensively summarize the knowledge structure, research tropics, and research trends of GM and T2DM through bibliometric analysis.

Methods

Publications related to GM and T2DM before January 9, 2024, in the Web of Science Core Collection (WOSCC) were searched in this study. Microsoft Excel 2019 was used to analyze publishing trends and CiteSpace (v.6.1.R6 Advanced) was used to analyze institutions, cited journals, references, and keywords.SCImago Graphica (v.1.0.39) was used to analyze countries/regions, institutions' collaborations, cited authors, and published journals.

Results

We finally included 1004 articles published from 2008 to 2023. The number of published articles showed an upward trend and reached its peak in 2022. China is the country with the largest number of articles, Univ Copenhagen is the institution with the largest number of articles, Fukui, Michiaki, Hamaguchi, Masahide are the scholars with the largest number of articles, and Cani and Patrice D. are the scholars with the largest number of citations. NUTRIENTS(Q1/5.9) published the most publications, while Nature (Q1/64.8; Cited 804 times) is the most frequently cited journal. Gut microbiota, Obesity, and insulin resistance are the most frequently used keywords. This study found that current researches focus on the effects of diet, exercise, and pharmacological modification of GM to improve T2DM and explores specific mechanisms. Future researches will focus on three areas: complications of T2DM and specific physiological processes, methods and measures to regulate GM, and new experimental techniques and assays.

Conclusion

The current researches confirmed the effects and specific mechanisms of modulating GM to improve T2DM. Further exploration of the effects of modulating GM on T2DM complications and specific physiologic processes is a future trend of research. Exploring specific methods for regulating GM and developing new experimental techniques and assays are important for future research.

Pravastatin promotes type 2 diabetes vascular calcification through activating intestinal Bacteroides fragilis to induce macrophage M1 polarization

BACKGROUND

Pravastatin is an oral lipid-lowering drug, commonly used by patients with diabetes that is positively correlated with the occurrence of vascular calcification (VC), but the mechanism is unclear.

METHODS

In this study, 16S rRNA sequencing and qRT-PCR wereused to detect the differential gut bacteria. Metabolomics and ELISA were used to analyze the differential metabolites. qRT-PCR and western blotting (WB) were used to detect genes expression. Flow cytometry was used to analyze macrophage phenotype. Immunohistochemistry was used to analyze aortic calcification.

RESULTS

We found that gut Bacteroides fragilis (BF) increased significantly in patients who took pravastatin or type 2 diabetes (T2D) mice treated with pravastatin. In vitro experiments showed that pravastatin had little effect on BF but significantly promoted BF proliferation in vivo. Further analysis showed that ArsR was an important gene for pravastatin to regulate the activation of BF, and overexpression of ArsR significantly promoted the secretion of 3,4,5-trimethoxycinnamic acid (TMCA). Importantly, pravastatin significantly promoted BF secretion of TMCA and significantly increased TMCA secretion in T2D patients or T2D mice. TMCA had little effect on vascular smooth muscle cell calcification but significantly promoted macrophage M1 polarization, which we had demonstrated that M1 macrophages promoted T2D VC. In vivo studies found that pravastatin significantly upregulated TMCA levels in the feces and serum of T2D mice transplanted with BF and promoted the macrophage M1 polarization in bone marrow and the osteoblastic differentiation of aortic cells. Similar results were obtained in T2D mice after intravenous infusion of TMCA.

CONCLUSIONS

Promoting intestinal BF to secrete TMCA, which leads to macrophage M1 polarization, is an important mechanism by which pravastatin promotes calcification, and the result will be used for the optimization of clinical medication strategies of pravastatin supplying a theoretical basis and experimental basis.

Gut Microbiota Targeted Approach by Natural Products in Diabetes Management: An Overview

PURPOSE OF REVIEW

This review delves into the complex interplay between obesity-induced gut microbiota dysbiosis and the progression of type 2 diabetes mellitus (T2DM), highlighting the potential of natural products in mitigating these effects. By integrating recent epidemiological data, we aim to provide a nuanced understanding of how obesity exacerbates T2DM through gut flora alterations.

RECENT FINDINGS

Advances in research have underscored the significance of bioactive ingredients in natural foods, capable of restoring gut microbiota balance, thus offering a promising approach to manage diabetes in the context of obesity. These findings build upon the traditional use of medicinal plants in diabetes treatment, suggesting a deeper exploration of their mechanisms of action. This comprehensive manuscript underscores the critical role of targeting gut microbiota dysbiosis in obesity-related T2DM management and by bridging traditional knowledge with current scientific evidence; we highlighted the need for continued research into natural products as a complementary strategy for comprehensive diabetes care.

The Effect of Bifidobacterium animalis subsp. lactis MN-Gup on Glucose Metabolism, Gut Microbiota, and Their Metabolites in Type 2 Diabetic Mice

Probiotics have garnered increasing attention as a potential therapeutic approach for type 2 diabetes mellitus (T2DM). Previous studies have confirmed that Bifidobacterium animalis subsp. lactis MN-Gup (MN-Gup) could stimulate the secretion of glucagon-like peptide-1 (GLP-1) in NCI-H716 cells, but whether MN-Gup has a hypoglycemic effect on T2DM in vivo remains unclear. In this study, a T2DM mouse model was constructed, with a high-fat diet and streptozotocin in mice, to investigate the effect of MN-Gup on diabetes. Then, different doses of MN-Gup (2 × 109 CFU/kg, 1 × 1010 CFU/kg) were gavaged for 6 weeks to investigate the effect of MN-Gup on glucose metabolism and its potential mechanisms. The results showed that a high-dose of MN-Gup significantly reduced the fasting blood glucose (FBG) levels and homeostasis model assessment-insulin resistance (HOMA-IR) of T2DM mice compared to the other groups. In addition, there were significant increases in the short-chain fatty acids (SCFAs), especially acetate, and GLP-1 levels in the MN-Gup group. MN-Gup increased the relative abundance of Bifidobacterium and decreased the number of Escherichia-Shigella and Staphylococcus. Moreover, the correlation analysis revealed that Bifidobacterium demonstrated a significant positive correlation with GLP-1 and a negative correlation with the incremental AUC. In summary, this study demonstrates that Bifidobacterium animalis subsp. lactis MN-Gup has significant hypoglycemic effects in T2DM mice and can modulate the gut microbiota, promoting the secretion of SCFAs and GLP-1.

Effects of metformin on the glucose regulation, lipid levels and gut microbiota in high-fat diet with streptozotocin induced type 2 diabetes mellitus rats

OBJECTIVE

Metformin, an anti-diabetic drug, regulates blood glucose by affecting gut microbiotas. However, the potential mechanism underlying this effect remains unclear. This study aimed to evaluate the effect of metformin on glucose regulation, lipid levels, and the gut microbiota in rats with type 2 diabetes mellitus induced by a high-fat diet with streptozotocin.

RESEARCH DESIGN METHODS

Thirty Wistar rats was using in this experiment. T2DM rats were administered 300 mg/kg metformin for 8 weeks. The glucose regulation, lipid levels, organ coefficients, and gut microbiotawere measured by 16S rDNA.

RESULT

The metformin-gavaged rats exhibited significant improvements in blood glucose and serum lipid levels, accompanied by alterations in short-chain fatty acid levels and the intestinal microbiota (p < 0.05). In the diabetic rats, metformin potentially increased specific probiotics, thus improving the hypoglycaemic effects of the oral anti-diabetic drug. Further, damage to the liver and kidney was effectively alleviated in the metformin-gavaged rats.

CONCLUSION

This study's findings demonstrate that metformin exerts a positive anti-diabetic effect in HFD- and STZ-induced T2DM rats. These findings potentially provide a basis for the recommended use of metformin as a reliable oral drug for T2DM owing to its positive effect on the intestinal microbiota.

Advances in fecal microbiota transplantation for the treatment of diabetes mellitus

Diabetes mellitus (DM) refers to a group of chronic diseases with global prevalence, characterized by persistent hyperglycemia resulting from various etiologies. DM can harm various organ systems and lead to acute or chronic complications, which severely endanger human well-being. Traditional treatment mainly involves controlling blood sugar levels through replacement therapy with drugs and insulin; however, some patients still find a satisfactory curative effect difficult to achieve. Extensive research has demonstrated a close correlation between enteric dysbacteriosis and the pathogenesis of various types of DM, paving the way for novel therapeutic approaches targeting the gut microbiota to manage DM. Fecal microbiota transplantation (FMT), a method for re-establishing the intestinal microbiome balance, offers new possibilities for treating diabetes. This article provides a comprehensive review of the correlation between DM and the gut microbiota, as well as the current advancements in FMT treatment for DM, using FMT as an illustrative example. This study aims to offer novel perspectives and establish a theoretical foundation for the clinical diagnosis and management of DM.

Gut microbiota in relationship to diabetes mellitus and its late complications with a focus on diabetic foot syndrome: A review

Diabetes mellitus is a chronic disease affecting glucose metabolism. The pathophysiological reactions underpinning the disease can lead to the development of late diabetes complications. The gut microbiota plays important roles in weight regulation and the maintenance of a healthy digestive system. Obesity, diabetes mellitus, diabetic retinopathy, diabetic nephropathy and diabetic neuropathy are all associated with a microbial imbalance in the gut. Modern technical equipment and advanced diagnostic procedures, including xmolecular methods, are commonly used to detect both quantitative and qualitative changes in the gut microbiota. This review summarises collective knowledge on the role of the gut microbiota in both types of diabetes mellitus and their late complications, with a particular focus on diabetic foot syndrome.

Edible traditional Chinese medicines improve type 2 diabetes by modulating gut microbiotal metabolites

Type 2 diabetes mellitus (T2DM) is a metabolic disorder with intricate pathogenic mechanisms. Despite the availability of various oral medications for controlling the condition, reports of poor glycemic control in type 2 diabetes persist, possibly involving unknown pathogenic mechanisms. In recent years, the gut microbiota have emerged as a highly promising target for T2DM treatment, with the metabolites produced by gut microbiota serving as crucial intermediaries connecting gut microbiota and strongly related to T2DM. Increasingly, traditional Chinese medicine is being considered to target the gut microbiota for T2DM treatment, and many of them are edible. In studies conducted on animal models, edible traditional Chinese medicine have been shown to primarily alter three significant gut microbiotal metabolites: short-chain fatty acids, bile acids, and branched-chain amino acids. These metabolites play crucial roles in alleviating T2DM by improving glucose metabolism and reducing inflammation. This review primarily summarizes twelve edible traditional Chinese medicines that improve T2DM by modulating the aforementioned three gut microbiotal metabolites, along with potential underlying molecular mechanisms, and also incorporation of edible traditional Chinese medicines into the diets of T2DM patients and combined use with probiotics for treating T2DM are discussed.

Research progress on the mechanism of TCM regulating intestinal microbiota in the treatment of DM mellitus

In recent years, with the improvement of people's living standards, the incidence of DM has increased year by year in China. DM is a common metabolic syndrome characterized by hyperglycemia caused by genetic, environmental and other factors. At the same time, long-term suffering from DM will also have an impact on the heart, blood vessels, eyes, kidneys and nerves, and associated serious diseases. The human body has a large and complex gut microbiota, which has a significant impact on the body's metabolism. Research shows that the occurrence and development of DM and its complications are closely related to intestinal microbiota. At present, western medicine generally treats DM with drugs. The hypoglycemic effect is fast and strong, but it can have a series of side effects on the human body. Compared with western medicine, Chinese medicine has its unique views and methods in treating DM. TCM can improve symptoms and treat complications by improving the imbalance of microbiota in patients with DM. Its characteristics of health, safety, and reliability are widely accepted by the general public. This article reviews the relationship between intestinal microbiota and DM, as well as the mechanism of TCM intervention in DM by regulating intestinal microbiota.

Exploration of hypoglycemic peptides from porcine collagen based on network pharmacology and molecular docking

In recent years, the extraction of hypoglycemic peptides from food proteins has gained increasing attention. Neuropeptides, hormone peptides, antimicrobial peptides, immune peptides, antioxidant peptides, hypoglycemic peptides and antihypertensive peptides have become research hotspots. In this study, bioinformatic methods were used to screen and predict the properties of pig collagen-derived hypoglycemic peptides, and their inhibitory effects on α-glucosidase were determined in vitro. Two peptides (RL and NWYR) were found to exhibit good water solubility, adequate ADMET (absorption, distribution, metabolism, elimination, and toxicity) properties, potentially high biological activity, and non-toxic. After synthesizing these peptides, NWYR showed the best inhibitory effect on α-glucosidase with IC50 = 0.200±0.040 mg/mL, and it can regulate a variety of biological processes, play a variety of molecular functions in different cellular components, and play a hypoglycemic role by participating in diabetic cardiomyopathy and IL-17 signaling pathway. Molecular docking results showed that NWYR had the best binding effect with the core target DPP4 (4n8d), with binding energy of -8.8 kcal/mol. NWYR mainly bonded with the target protein through hydrogen bonding, and bound with various amino acid residues such as Asp-729, Gln-731, Leu-765, etc., thus affecting the role of the target in each pathway. It is the best core target for adjuvant treatment of T2DM. In short, NWYR has the potential to reduce type 2 diabetes, providing a basis for further research or food applications as well as improved utilization of pig by-products. However, in subsequent studies, it is necessary to further verify the hypoglycemic ability of porcine collagen active peptide (NWYR), and explore the hypoglycemic mechanism of NWYR from multiple perspectives such as key target genes, protein expression levels and differences in metabolites in animal models of hyperglycemia, which will provide further theoretical support for its improvement in the treatment of T2DM.

Fecal Microbiota Transplantation: A Prospective Treatment for Type 2 Diabetes Mellitus

Purpose of Review

The aim of this review is to summarize the role of gastrointestinal microbiome (GM) in the development of type 2 diabetes mellitus (T2DM). Besides, we discuss the feasibility of applying FMT in the treatment of T2DM and propose a series of processes to refine the use of FMT in the treatment of T2DM.

Recent Findings

T2DM is a metabolic disease which is connected with the GM. According to many researches, GM can produce a variety of metabolites such as bile acid, short chain fatty acids, lipopolysaccharides and trimethylamine oxide which play an important role in metabolism. FMT is a method to regulate GM and has been observed to be effective in the treatment of metabolic diseases such as T2DM in some mouse models and people. However, there is still a lack of direct evidence for the use of FMT in the treatment of T2DM, and the process of FMT is not standardized.

Summary

Dysregulation of GM is closely related to the development of T2DM. Promoting the conversion of GM in T2DM patients to normal population through FMT can reduce insulin resistance and lower their blood glucose level, which is an optional treatment for T2DM patients in the future. At present, the feasibility and limitations of applying FMT to the treatment of T2DM need to be further studied.

Nutrition at the Intersection between Gut Microbiota Eubiosis and Effective Management of Type 2 Diabetes

Nutrition is one of the most influential environmental factors in both taxonomical shifts in gut microbiota as well as in the development of type 2 diabetes mellitus (T2DM). Emerging evidence has shown that the effects of nutrition on both these parameters is not mutually exclusive and that changes in gut microbiota and related metabolites such as short-chain fatty acids (SCFAs) and branched-chain amino acids (BCAAs) may influence systemic inflammation and signaling pathways that contribute to pathophysiological processes associated with T2DM. With this background, our review highlights the effects of macronutrients, carbohydrates, proteins, and lipids, as well as micronutrients, vitamins, and minerals, on T2DM, specifically through their alterations in gut microbiota and the metabolites they produce. Additionally, we describe the influences of common food groups, which incorporate varying combinations of these macronutrients and micronutrients, on both microbiota and metabolic parameters in the context of diabetes mellitus. Overall, nutrition is one of the first line modifiable therapies in the management of T2DM and a better understanding of the mechanisms by which gut microbiota influence its pathophysiology provides opportunities for optimizing dietary interventions.

Communal interaction of glycation and gut microbes in diabetes mellitus, Alzheimer's disease, and Parkinson's disease pathogenesis

Diabetes and its complications, Alzheimer's disease (AD), and Parkinson's disease (PD) are increasing gradually, reflecting a global threat vis-à-vis expressing the essentiality of a substantial paradigm shift in research and remedial actions. Protein glycation is influenced by several factors, like time, temperature, pH, metal ions, and the half-life of the protein. Surprisingly, most proteins associated with metabolic and neurodegenerative disorders are generally long-lived and hence susceptible to glycation. Remarkably, proteins linked with diabetes, AD, and PD share this characteristic. This modulates protein's structure, aggregation tendency, and toxicity, highlighting renovated attention. Gut microbes and microbial metabolites marked their importance in human health and diseases. Though many scientific shreds of evidence are proposed for possible change and dysbiosis in gut flora in these diseases, very little is known about the mechanisms. Screening and unfolding their functionality in metabolic and neurodegenerative disorders is essential in hunting the gut treasure. Therefore, it is imperative to evaluate the role of glycation as a common link in diabetes and neurodegenerative diseases, which helps to clarify if modulation of nonenzymatic glycation may act as a beneficial therapeutic strategy and gut microbes/metabolites may answer some of the crucial questions. This review briefly emphasizes the common functional attributes of glycation and gut microbes, the possible linkages, and discusses current treatment options and therapeutic challenges.

Effect of beinaglutide combined with metformin versus aspart 30 with metformin on metabolic profiles and antidrug antibodies in patients with type 2 diabetes: a randomized clinical trial

Objective

This prospective study aimed to evaluate the effect of beinaglutide combined with metformin versus aspart 30 with metformin on metabolic profiles and antidrug antibodies (ADAs) in patients with type 2 diabetes (T2D).

Methods

A total of 134 eligible participants were randomly assigned to the test group and the control group. Patients in the test group were treated with beinaglutide and metformin, whereas patients in the control group were randomly treated with aspart 30 and metformin, with a follow-up period of 6 months. The metabolic profiles and ADAs over 6 months were evaluated.

Results

After 6 months, 101 (75.37%) patients completed the study. Compared with the control group, the beinaglutide group had significant reductions in 2-h postprandial blood glucose (2hBG) and low blood glucose index (LBGI). Glycated hemoglobin (HbA1c) decreased in both groups relative to baseline. In the test group, one had treatment-emergent beinaglutide ADAs. Significant reductions in triglycerides (TG), non-fasting TG, weight, waist circumference (WC), and body mass index (BMI) were observed. The values of insulin sensitivity index (HOMA-IR) were decreased to a statistically higher degree with beinaglutide treatment.

Conclusion

Beinaglutide reduces metabolic dysfunction, LBGI, and weight in patients of T2D with a low risk of ADAs. Beinaglutide may offer the potential for a disease-modifying intervention in cardiovascular disease (CVD).

Clinical trial registration

www.chictr.org.cn, identifier ChiCTR2200061003.

Parabacteroides distasonis ameliorates insulin resistance via activation of intestinal GPR109a

Gut microbiota plays a key role in insulin resistance (IR). Here we perform a case-control study of Chinese adults (ChiCTR2200065715) and identify that Parabacteroides distasonis is inversely correlated with IR. Treatment with P. distasonis improves IR, strengthens intestinal integrity, and reduces systemic inflammation in mice. We further demonstrate that P. distasonis-derived nicotinic acid (NA) is a vital bioactive molecule that fortifies intestinal barrier function via activating intestinal G-protein-coupled receptor 109a (GPR109a), leading to ameliorating IR. We also conduct a bioactive dietary fiber screening to induce P. distasonis growth. Dendrobium officinale polysaccharide (DOP) shows favorable growth-promoting effects on P. distasonis and protects against IR in mice simultaneously. Finally, the reduced P. distasonis and NA levels were also validated in another human type 2 diabetes mellitus cohort. These findings reveal the unique mechanisms of P. distasonis on IR and provide viable strategies for the treatment and prevention of IR by bioactive dietary fiber.

Microbiota-derived imidazole propionate inhibits type 2 diabetic skin wound healing by targeting SPNS2-mediated S1P transport

Imidazole propionate (ImP) is a recently discovered metabolite of T2DM-related gut microbiota. The effect of ImP on T2DM wound healing has not been studied yet. In this research, the changes of ImP-producing bacteria on the skin are firstly evaluated. 16sRNA sequencing results showed that the abundance of ImP-producing bacteria-Streptococcus in the intestine and skin of T2DM mice is significantly increased. Animal experiments show that ImP can inhibit the process of wound healing and inhibit the formation of blood vessels in the process of wound healing. Molecular mechanism research results show that ImP can inhibit S1P secretion mediated by SPNS2, and inhibit the activation of Rho signaling pathway, thereby affecting the angiogenesis process of HUVEC cells. This work also provides a potential drug HMPA that promotes T2DM wound healing.

Apple consumption affects cecal health by regulating 12S-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid (12(S)-HETE) levels through modifying the microbiota in rats

Apples are rich in many nutrients and functional components. However, the mechanism of the effect of fresh apple consumption on rats remains unclear. In the present study, fresh apples (10 g kg-1) were added to the diet of Wistar rats, and changes in the microbiota and metabolite content of the cecum were analyzed after 28 days of feeding, and changes in the 12S-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid (12(S)-HETE) content and indicators related to inflammation, oxidative stress, and apoptosis were detected. Subsequently, a fecal microbiota transplantation (FMT) protocol was designed and carried out to verify the relationship between the microbiota and 12(S)-HETE, the cecal structure, and inflammatory factors. The results show that apple consumption significantly reduced the serum levels of alanine aminotransferase (ALT) and immunoglobulin G (IgG), altered the cecal histomorphology, and significantly upregulated the gene expression of claudin-1 and zonula occludens-1 (ZO-1), which encode tight junction proteins. Apple consumption also changed the structure of the cecal microbiota, increasing the abundance of some species (such as Shuttleworthia) and decreasing the abundance of others (such as Alphaproteobacteria). Metabolomic screening identified 64 significantly different metabolites. The FMT results showed that apple consumption reduced 12(S)-HETE metabolite levels in the cecal contents, improved the intestinal structure, and reduced the levels of proinflammatory factor expression by altering the cecal microbiota. In conclusion, this study provides further insight into the effects of apples on animals using rats as experimental animals. It provides basic data for future exploration of the mechanisms of the effect of apple consumption on humans.

Effects of lipid extract from blue mussel (Mytilus edulis) on gut microbiota, and its relationship with glycemic traits in type 2 diabetes mellitus patients: a double-blind randomized controlled trial

Studies have shown that blue mussel lipid extract (BMLE) can improve the glycemic traits, inflammatory cytokines, and lipid profile of patients with type 2 diabetes mellitus (T2DM) in China. Gut microbiota is closely related to T2DM. This study aims to explore whether BMLE can improve the glycemic status of T2DM patients by regulating gut microbiota in a 60-day double-blind randomized controlled trial. A total of 133 T2DM subjects were randomized into BMLE (n = 44), fish oil (FO) (n = 44), and corn oil (CO) (n = 45) groups. The participants were asked to take two corresponding oil capsules (0.8 g per capsule each) every day. The faecal microbiota, glycemic traits, and other cardiometabolic factors were analyzed at baseline and endpoint. The α diversity estimators of Ace and Chao1 decreased significantly in all three groups, but there was no significant difference between the groups. Eight bacteria decreased significantly in the BMLE group but not in the FO and CO groups: unclassified_Clostridia_UCG_014, unclassified_Bacteroidia, Erysipelotrichaceae, and uncultured_Ruminococcaceae_bacterium at the family level and unclassified_Bacteroidia, uncultured_Ruminococcaceae_bacterium, unclassified_Clostridia_UCG_014, and Turicibacter at genus level. In the BMLE group, the change in the relative abundance of Erysipelotrichaceae was positively correlated with the changes in the homeostatic model assessment of insulin resistance (HOMA-IR) (r = 0.454, p < 0.01) and fasting insulin (r = 0.414, p < 0.01). The change in the relative abundance of Turicibacter was positively correlated with the changes in HOMA-IR (r = 0.431, p < 0.01), fasting insulin (r = 0.414, p < 0.01), total cholesterol (TC) (r = 0.358, p < 0.05), and triacylglycerol (TG) (r = 0.393 p = 0.013). In conclusion, BMLE might improve glycemic traits by modulating gut microbiota in T2DM patients.

Causal relationship between gut microbiota and type 2 diabetes: a two-sample Mendelian randomization study

Background

Studies showed that development of gut microbial dysbiosis has a close association with type 2 diabetes (T2D). It is not yet clear if there is a causal relationship between gut microbiota and T2D.

Methods

The data collected from the published genome-wide association studies (GWASs) on gut microbiota and T2D were analyzed. Two-sample Mendelian randomization (MR) analyses were performed to identify causal relationship between bacterial taxa and T2D. Significant bacterial taxa were further analyzed. To confirm the findings' robustness, we performed sensitivity, heterogeneity, and pleiotropy analyses. A reverse MR analysis was also performed to check for potential reverse causation.

Results

By combining the findings of all the MR steps, we identified six causal bacterial taxa, namely, Lachnoclostridium, Oscillospira, Roseburia, Ruminococcaceae UCG003, Ruminococcaceae UCG010 and Streptococcus. The risk of T2D might be positively associated with a high relative abundance of Lachnoclostridium, Roseburia and Streptococcus but negatively associated with Oscillospira, Ruminococcaceae UCG003 and Ruminococcaceae UCG010. The results of MR analyses revealed that there were causal relationships between the six different genera and T2D. And the reverse MR analysis did not reveal any evidence of a reverse causality.

Conclusion

This study implied that Lachnoclostridium, Roseburia and Streptococcus might have anti-protective effect on T2D, whereas Oscillospira, Ruminococcaceae UCG003 and Ruminococcaceae UCG010 genera might have protective effect on T2D. Our study revealed that there was a causal relationship between specific gut microbiota genera and T2D.

Ameliorative Effects of Lactobacillus paracasei L14 on Oxidative Stress and Gut Microbiota in Type 2 Diabetes Mellitus Rats

Bioprospecting of more novel probiotic strains has attained continuous interest. This study aimed to investigate the beneficial effects of Lactobacillus paracasei strain L14, an isolate from a traditional Chinese dairy product, on type 2 diabetes mellitus (T2DM) rats. Preventive supplementation of strain L14 showed excellent anti-diabetic effects on high-fat diet/low-dose streptozotocin (HFD/STZ)-induced T2DM rats. It significantly reduced hyperglycemia, protected pancreatic β-cell and liver function, and ameliorated oxidative stress while considerably improving dyslipidemia and inflammation. Furthermore, the strain modulated the gut microbiota to alleviate gut dysbiosis. Interestingly, most of these biochemical parameters could even restore to normal levels by the intervention of strain L14. The whole-genome sequencing of L14 was performed to provide a critical molecular basis for its probiotic activities. Genes related to antioxidant systems and other beneficial microbial metabolites like exopolysaccharides (EPS) biosynthesis were found. This study demonstrates that probiotic L. paracasei L14 has good potential for applications in functional food and pharmaceutical industries.

Fecal Microbiota Composition, Their Interactions, and Metagenome Function in US Adults with Type 2 Diabetes According to Enterotypes

T2DM etiology differs among Asians and Caucasians and may be associated with gut microbiota influenced by different diet patterns. However, the association between fecal bacterial composition, enterotypes, and T2DM susceptibility remained controversial. We investigated the fecal bacterial composition, co-abundance network, and metagenome function in US adults with T2DM compared to healthy adults based on enterotypes. We analyzed 1911 fecal bacterial files of 1039 T2DM and 872 healthy US adults from the Human Microbiome Projects. Operational taxonomic units were obtained after filtering and cleaning the files using Qiime2 tools. Machine learning and network analysis identified primary bacteria and their interactions influencing T2DM incidence, clustered into enterotypes, Bacteroidaceae (ET-B), Lachnospiraceae (ET-L), and Prevotellaceae (ET-P). ET-B showed higher T2DM incidence. Alpha-diversity was significantly lower in T2DM in ET-L and ET-P (p < 0.0001), but not in ET-B. Beta-diversity revealed a distinct separation between T2DM and healthy groups across all enterotypes (p < 0.0001). The XGBoost model exhibited high accuracy and sensitivity. Enterocloster bolteae, Facalicatena fissicatena, Clostridium symbiosum, and Facalibacterium prausnitizii were more abundant in the T2DM group than in the healthy group. Bacteroides koreensis, Oscillibacter ruminantium, Bacteroides uniformis, and Blautia wexlerae were lower in the T2DM than in the healthy group regardless of the enterotypes in the XGBoost model (p < 0.0001). However, the patterns of microbial interactions varied among different enterotypes affecting T2DM risk. The interaction between fecal bacteria was more tightly regulated in the ET-L than in the ET-B and ET-P groups (p < 0.001). Metagenomic analysis revealed an inverse association between bacteria abundance in T2DM, energy utility, butanoate and propanoate metabolism, and the insulin signaling pathway (p < 0.0001). In conclusion, fecal bacteria play a role in T2DM pathogenesis, particularly within different enterotypes, providing valuable insights into the link between gut microbiota and T2DM in the US population.

The Black Box Orchestra of Gut Bacteria and Bile Acids: Who Is the Conductor?

Over the past decades the potential role of the gut microbiome and bile acids in type 2 diabetes mellitus (T2DM) has been revealed, with a special reference to low bacterial alpha diversity. Certain bile acid effects on gut bacteria concern cytotoxicity, or in the case of the microbiome, bacteriotoxicity. Reciprocally, the gut microbiome plays a key role in regulating the bile acid pool by influencing the conversion and (de)conjugation of primary bile acids into secondary bile acids. Three main groups of bacterial enzymes responsible for the conversion of bile acids are bile salt hydrolases (BSHs), hydroxysteroid dehydrogenases (HSDHs) and enzymes encoded in the bile acid inducible (Bai) operon genes. Interventions such as probiotics, antibiotics and fecal microbiome transplantation can impact bile acids levels. Further evidence of the reciprocal interaction between gut microbiota and bile acids comes from a multitude of nutritional interventions including macronutrients, fibers, prebiotics, specific individual products or diets. Finally, anatomical changes after bariatric surgery are important because of their metabolic effects. The heterogeneity of studies, diseases, bacterial species and (epi)genetic influences such as nutrition may challenge establishing specific and detailed interventions that aim to tackle the gut microbiome and bile acids.

Intestinal Region-Dependent Alterations of Toll-Like Receptor 4 Expression in Myenteric Neurons of Type 1 Diabetic Rats

Toll-like receptor 4 (TLR4) can activate pro-inflammatory cascades in the gastrointestinal tract. Our aim was to determine TLR4 expression in myenteric neurons of different gut regions using a type 1 diabetic model. Ten weeks after the onset of hyperglycemia, myenteric whole-mount preparations from the duodenum, ileum and colon of streptozotocin-induced diabetic, insulin-treated diabetic and control rats were prepared for TLR4/peripherin double-labelling fluorescent immunohistochemistry. Immunogold electron microscopy was applied to evaluate TLR4 expression in the myenteric perikaryon and neuropil. Tissue TLR4 levels were measured by enzyme-linked immunosorbent assay. In controls, the number and proportion of the TLR4-immunoreactive myenteric neurons showed an increasing tendency to aboral direction. These values were significantly higher in diabetics compared to controls in the duodenum and ileum, but were significantly lower in the colon. In diabetics, the distribution of TLR4-labelling gold particles between the perikaryon and neuropil of myenteric neurons varied in a different way by intestinal segment. TLR4 tissue concentration changed only in the diabetic duodenum, and it decreased in muscle/myenteric plexus-containing homogenates, while it increased in mucosa/submucosa/submucous plexus-containing samples relative to controls. Insulin had beneficial effects on TLR4 expression. These findings support that chronic hyperglycemia has segment-specific effects on TLR4 expression, contributing to gastrointestinal disorders in diabetic patients.

Turicibacter and Acidaminococcus predict immune-related adverse events and efficacy of immune checkpoint inhibitor

Introduction

Immune checkpoint inhibitors have had a major impact on cancer treatment. Gut microbiota plays a major role in the cancer microenvironment, affecting treatment response. The gut microbiota is highly individual, and varies with factors, such as age and race. Gut microbiota composition in Japanese cancer patients and the efficacy of immunotherapy remain unknown.

Methods

We investigated the gut microbiota of 26 patients with solid tumors prior to immune checkpoint inhibitor monotherapy to identify bacteria involved in the efficacy of these drugs and immune-related adverse events (irAEs).

Results

The genera Prevotella and Parabacteroides were relatively common in the group showing efficacy towards the anti-PD-1 antibody treatment (effective group). The proportions of Catenibacterium (P = 0.022) and Turicibacter (P = 0.049) were significantly higher in the effective group than in the ineffective group. In addition, the proportion of Desulfovibrion (P = 0.033) was significantly higher in the ineffective group. Next, they were divided into irAE and non-irAE groups. The proportions of Turicibacter (P = 0.001) and Acidaminococcus (P = 0.001) were significantly higher in the group with irAEs than in those without, while the proportions of Blautia (P = 0.013) and the unclassified Clostridiales (P = 0.027) were significantly higher in the group without irAEs than those with. Furthermore, within the Effective group, Acidaminococcus and Turicibacter (both P = 0.001) were more abundant in the subgroup with irAEs than in those without them. In contrast, Blautia (P = 0.021) and Bilophila (P= 0.033) were statistically significantly more common in those without irAEs.

Discussion

Our Study suggests that the analysis of the gut microbiota may provide future predictive markers for the efficacy of cancer immunotherapy or the selection of candidates for fecal transplantation for cancer immunotherapy.

Relationships between Diabetes and the Intestinal Microbial Population

Diabetes is a metabolic disorder characterized by lower responsiveness of tissues to insulin and consequent large variations in circulating levels of glucose. This fluctuation has harmful effects as both hyperglycemia and hypoglycemia can be very injurious. The causes of diabetes are varied but the consequences are rather uniform. Dietary factors are important especially in adult onset type 2 diabetes (T2D) while type 1 diabetes (T1D) is characterized by having a stronger heritable component and involving autoimmune attach on pancreatic beta cells. This review is focused on the relation of the bacterial components found within the intestine, to the establishment and maintenance of diabetes. The precise composition of the gut microbiome is increasingly recognized as a factor in organismic health and its interaction with a variety of disease states has been described. This is especially marked in the case of diabetes since the nature of the diet is an important factor in establishing both the microbiome and the incidence of diabetes. The bidirectional nature of this relationship is discussed. The effects of disease that lead to altered microbiomal composition together with aberrant metabolic changes are also included. Emphasis is given to the important role of short chain fatty acids (SCFAs) as mediators of the microbiome-diabetes relation.

Association between diabetes and cancer. Current mechanistic insights into the association and future challenges

Compelling pieces of epidemiological, clinical, and experimental research have demonstrated that Diabetes mellitus (DM) is a major risk factor associated with increased cancer incidence and mortality in many human neoplasms. In the pathophysiology context of DM, many of the main classical actors are relevant elements that can fuel the different steps of the carcinogenesis process. Hyperglycemia, hyperinsulinemia, metabolic inflammation, and dyslipidemia are among the classic contributors to this association. Furthermore, new emerging actors have received particular attention in the last few years, and compelling data support that the microbiome, the epigenetic changes, the reticulum endoplasmic stress, and the increased glycolytic influx also play important roles in promoting the development of many cancer types. The arsenal of glucose-lowering therapeutic agents used for treating diabetes is wide and diverse, and a growing body of data raised during the last two decades has tried to clarify the contribution of therapeutic agents to this association. However, this research area remains controversial, because some anti-diabetic drugs are now considered as either promotors or protecting elements. In the present review, we intend to highlight the compelling epidemiological shreds of evidence that support this association, as well as the mechanistic contributions of many of these potential pathological mechanisms, some controversial points as well as future challenges.

Gut microbiota: The key to the treatment of metabolic syndrome in traditional Chinese medicine - a case study of diabetes and nonalcoholic fatty liver disease

Metabolic syndrome mainly includes obesity, type 2 diabetes (T2DM), alcoholic fatty liver (NAFLD) and cardiovascular diseases. According to the ancient experience philosophy of Yin-Yang, monarch-minister compatibility of traditional Chinese medicine, prescription is given to treat diseases, which has the advantages of small toxic and side effects and quick effect. However, due to the diversity of traditional Chinese medicine ingredients and doubts about the treatment theory of traditional Chinese medicine, the mechanism of traditional Chinese medicine is still in doubt. Gastrointestinal tract is an important part of human environment, and participates in the occurrence and development of diseases. In recent years, more and more TCM researches have made intestinal microbiome a new frontier for understanding and treating diseases. Clinically, nonalcoholic fatty liver disease (NAFLD) and diabetes mellitus (DM) often co-occur. Our aim is to explain the mechanism of interaction between gastrointestinal microbiome and traditional Chinese medicine (TCM) or traditional Chinese medicine formula to treat DM and NAFLD. Traditional Chinese medicine may treat these two diseases by influencing the composition of intestinal microorganisms, regulating the metabolism of intestinal microorganisms and transforming Chinese medicinal compounds.

Mushroom polysaccharides with potential in anti-diabetes: Biological mechanisms, extraction, and future perspectives: A review

Diabetes mellitus (DM) is a global health threat. Searching for anti-diabetic components from natural resources is of intense interest to scientists. Mushroom polysaccharides have received growing attention in anti-diabetes fields due to their advantages in broad resources, structure diversity, and multiple bioactivities, which are considered an unlimited source of healthy active components potentially applied in functional foods and nutraceuticals. In this review, the current knowledge about the roles of oxidative stress in the pathogenesis of DM, the extraction method of mushroom polysaccharides, and their potential biological mechanisms associated with anti-diabetes, including antioxidant, hypolipidemic, anti-inflammatory, and gut microbiota modulatory actions, were summarized based on a variety of in vitro and in vivo studies, with aiming at better understanding the roles of mushroom polysaccharides in the prevention and management of DM and its complications. Finally, future perspectives including bridging the gap between the intervention of mushroom polysaccharides and the modulation of insulin signaling pathway, revealing structure-bioactivity of mushroom polysaccharides, developing synergistic foods, conducting well-controlled clinical trials that may be very helpful in discovering valuable mushroom polysaccharides and better applications of mushroom polysaccharides in diabetic control were proposed.

The Therapeutic Potential of Plant Polysaccharides in Metabolic Diseases

Plant polysaccharides (PPS) composed of more than 10 monosaccharides show high safety and various pharmacological activities, including immunoregulatory, antitumor, antioxidative, antiaging, and other effects. In recent years, emerging evidence has indicated that many PPS are beneficial for metabolic diseases, such as cardiovascular disease (CVD), diabetes, obesity, and neurological diseases, which are usually caused by the metabolic disorder of fat, sugar, and protein. In this review, we introduce the common characteristics and functional activity of many representative PPS, emphasize the common risks and molecular mechanism of metabolic diseases, and discuss the pharmacological activity and mechanism of action of representative PPS obtained from plants including Aloe vera, Angelica sinensis, pumpkin, Lycium barbarum, Ginseng, Schisandra chinensis, Dioscorea pposite, Poria cocos, and tea in metabolic diseases. Finally, this review will provide directions and a reference for future research and for the development of PPS into potential drugs for the treatment of metabolic diseases.