Considering gut microbiota in treatment of type 2 diabetes mellitus

GEMimp: An accurate and robust imputation method for microbiome data using graph embedding neural network

Microbiome research has increasingly underscored the profound link between microbial compositions and human health, with numerous studies establishing a strong correlation between microbiome characteristics and various diseases. However, the analysis of microbiome data is frequently compromised by inherent sparsity issues, characterized by a substantial presence of observed zeros. These zeros not only skew the abundance distribution of microbial species but also undermine the reliability of scientific conclusions drawn from such data. Addressing this challenge, we introduce GEMimp, an innovative imputation method designed to infuse robustness into microbiome data analysis. GEMimp leverages the node2vec algorithm, which incorporates both Breadth-First Search (BFS) and Depth-First Search (DFS) strategies in its random walks sampling process. This approach enables GEMimp to learn nuanced, low-dimensional representations of each taxonomic unit, facilitating the reconstruction of their similarity networks with unprecedented accuracy. Our comparative analysis pits GEMimp against state-of-the-art imputation methods including SAVER, MAGIC and mbImpute. The results unequivocally demonstrate that GEMimp outperforms its counterparts by achieving the highest Pearson correlation coefficient when compared to the original raw dataset. Furthermore, GEMimp shows notable proficiency in identifying significant taxa, enhancing the detection of disease-related taxa and effectively mitigating the impact of sparsity on both simulated and real-world datasets, such as those pertaining to Type 2 Diabetes (T2D) and Colorectal Cancer (CRC). These findings collectively highlight the strong effectiveness of GEMimp, allowing for better analysis on microbial data. With alleviation of sparsity issues, it could be greatly facilitated in downstream analyses and even in the field of microbiology.

Effects of traditional Chinese medicine polysaccharides on chronic diseases by modulating gut microbiota: A review

Intestinal tract is the largest immune system of human body. Gut microbiota (GM) can produce a large number of metabolites, such as short-chain fatty acids and bile acids, which regulate the physiological health of the host and affect the development of disease. In recent years, traditional Chinese medicine (TCM) polysaccharides have attracted extensive attention with multiple biological activities and low toxicity. TCM polysaccharides can promote the growth of intestinal beneficial bacteria and inhibit the growth of harmful bacteria by regulating the structure and function of GM, thus playing a crucial role in preventing or treating chronic diseases such as inflammatory bowel disease (IBD), obesity, type 2 diabetes mellitus (T2DM), liver diseases, cancer, etc. In this paper, the research progress of TCM polysaccharides in the treatment of chronic diseases such as inflammatory bowel disease, obesity, T2DM, liver diseases, cancer, etc. by modulating GM was reviewed. Meanwhile, this review makes an in-depth discussion on the shortcomings of the research of TCM polysaccharides on chronic diseases by modulating GM, and new valuable prospection for the future researches of TCM polysaccharides are proposed, which will provide new ideas for the further study of TCM polysaccharides.

Exploring the Gut Microbiota: Key Insights Into Its Role in Obesity, Metabolic Syndrome, and Type 2 Diabetes

The gut microbiota (GM), comprising trillions of microorganisms in the gastrointestinal tract, is a key player in the development of obesity and related metabolic disorders, such as type 2 diabetes (T2D), metabolic syndrome (MS), and cardiovascular diseases. This mini-review delves into the intricate roles and mechanisms of the GM in these conditions, offering insights into potential therapeutic strategies targeting the microbiota. The review elucidates the diversity and development of the human GM, highlighting its pivotal functions in host physiology, including nutrient absorption, immune regulation, and energy metabolism. Studies show that GM dysbiosis is linked to increased energy extraction, altered metabolic pathways, and inflammation, contributing to obesity, MS, and T2D. The interplay between dietary habits and GM composition is explored, underscoring the influence of diet on microbial diversity and metabolic functions. Additionally, the review addresses the impact of common medications and therapeutic interventions like fecal microbiota transplantation on GM composition. The evidence so far advocates for further research to delineate the therapeutic potential of GM modulation in mitigating obesity and metabolic diseases, emphasizing the necessity of clinical trials to establish effective and sustainable treatment protocols.

Porous starch microspheres loaded with luteolin exhibit hypoglycemic activities and alter gut microbial communities in type 2 diabetes mellitus mice

Luteolin (LUT), a natural flavonoid known for its hypoglycemic properties, is primarily sourced from vegetables such as celery and broccoli. However, its poor stability and low bioavailability in the upper digestive tract hinder its application in the functional food industry. To address these challenges, this study employed porous starch (PS) as a carrier to develop PS microspheres loaded with luteolin (PSLUT), simulating its release in vitro. The research assessed the hypoglycemic effects of LUT in type 2 diabetes mellitus (T2DM) mice both before and after PS treatment. In vitro findings demonstrated that PS improved LUT's stability in simulated gastric fluids and enhanced its in vivo bioavailability, aligning with experimental outcomes. PSLUT administration significantly improved body weight, fasting blood glucose (FBG), oral glucose tolerance test (OGTT), pancreatic islet function, and other relevant indicators in T2DM mice. Moreover, PSLUT alleviated abnormal liver biochemical indicators and liver tissue injury caused by T2DM. The underlying hypoglycemic mechanism of PSLUT is thought to involve the regulation of protein kinase B (AKT-1) and glucose transporter 2 (GLUT-2). After four weeks of intervention, various PSLUT doses significantly reduced the Firmicutes to Bacteroidetes ratio at the phylum level and decreased the relative abundance of harmful bacteria at the genus level, including Acetatifactor, Candidatus-Arthromitus, and Turicibacter. This microbial shift was associated with improvements in hyperglycemia-related indicators such as FBG, the area under the curve (AUC) of OGTT, and homeostasis model assessment of insulin resistance (HOMA-IR), which are closely linked to these bacterial genera. Additionally, Lachnoclostridium, Parasutterella, Turicibacter, and Papillibacter were identified as key intestinal marker genera involved in T2DM progression through Spearman correlation analysis. In conclusion, PS enhanced LUT's hypoglycemic efficacy by modulating the transcription and protein expression levels of AKT-1 and GLUT-2, as well as the relative abundance of potential gut pathogens in T2DM mice. These results provide a theoretical foundation for advancing luteolin's application in the functional food industry and further investigating its hypoglycemic potential.

Study on the protective effect of Aronia melanocarpa extract on type 2 diabetes by regulating glucose and lipid metabolism through intestinal flora

Aronia melanocarpa, a plant rich in anthocyanins, has been studied for its potential to regulate blood sugar and blood lipids, although the specific mechanism is not yet understood. This research aims to identify the differential bacterial flora and elucidate the mechanism by which it improves glucose and lipid metabolism disorders through 16S rDNA gene sequencing. The study reveals the protective effect of Aronia melanocarpa extract (AME) on liver damage in type 2 diabetic rats. Experimental results demonstrate that AME can effectively modulate the abundance of intestinal flora, reduce colon tissue damage, enhance the weight of diabetic rats, and lower levels of fasting blood sugar, low-density lipoprotein (LDL), and triglycerides (TG). Additionally, liver morphology analysis shows that AME can effectively mitigate liver tissue structural damage in type 2 diabetic rats. In conclusion, AME regulates glucose and lipid metabolism by influencing intestinal flora, ultimately regulating glucose and lipid metabolism in type 2 diabetic rats.

Mechanism of action of FoxiangSan in diabetic gastroparesis: Gut microbiota and cAMP/PKA pathway

Diabetic gastroparesis, a common complication of type 2 diabetes (T2DM), presents a significant treatment challenge. FoxiangSan is emerging as a potential therapy. FoxiangSan is a traditional Chinese medicine formula with the potential for treating diabetic gastroparesis by modulating gut microbiota and cAMP/PKA signaling pathways. This study explores the mechanisms behind FoxiangSan's effects on T2DM-induced gastroparesis, focusing on its impact on gut microbiota and the cAMP/PKA pathway. A rat model of type 2 diabetic gastroparesis was established through a high-fat diet and streptozotocin (STZ) injection, and the effects of FoxiangSan were assessed. Additionally, protein expression related to the cAMP/PKA pathway was examined, and FoxiangSan's influence on gut microbiota was studied using 16S rRNA sequencing. FoxiangSan significantly alleviated hyperglycemia, improved gastric pathology in rats with gastroparesis, enhanced the expression of 5-HT4, cAMP, PKA, and pPKA in the gastric antrum, and rebalanced gut microbiota. FoxiangSan demonstrates the therapeutic potential for T2DM-associated gastroparesis by modulating the cAMP/PKA pathway and gut microbiota.

Acute Pre- and Post-administration of Lactiplantibacillus plantarum 2034 and Its Secretory Metabolites Ameliorates Hyperglycaemia, Hyperlipidaemia, and Oxidative Stress in Diabetic Rats

The global prevalence rate of diabetes in 2021 was 6.1% making diabetes one of the top 10 causes of death. Prolonged use of antidiabetic medications is associated with various side effects; therefore, alternative treatment strategies for diabetes need exploration. The antidiabetic properties of Lactiplantibacillus plantarum 2034 was explored both in in vitro and in vivo studies. Secretory metabolites of probiotic L. plantarum 2034 exhibited alpha-glucosidase, alpha-amylase, and lipase inhibitory activities, in vitro. Further, the antidiabetic efficacy of 2034 was evaluated in streptozotocin-nicotinamide-induced diabetic rats. In the therapeutic model, oral administration of L. plantarum resulted in normalization of body weight, fasting blood glucose, total cholesterol (TC), and liver enzymes, and significant (p < 0.05) reduction in insulin and triglyceride (TG) levels. Histological evaluation of pancreas, liver, and kidney showed restoration of normal architecture in probiotic-treated group. Similarly, in a preventive + therapeutic model, 14 days of pre-administration of 2034 in pre, pre + post, and cell-free supernatant resulted in significant reduction in glucose, TG, TC, and liver biochemistry of diabetic rats as compared to untreated diabetic rats. An oral glucose tolerance test showed that the glucose levels normalized within 90 min in all the treated groups. Further, the oxidative stress parameters were also studied that showed that in all the treated groups, the concentration of antioxidant enzymes significantly (p < 0.05) increased as compared to diabetic untreated rats. Thus, administration of L. plantarum 2034 and its metabolites successfully ameliorated hyperglycaemia and hypercholesterolemia in both the models probably due to inhibition of gut enzymes and by increasing the concentration of liver antioxidant enzymes.

Gut Microbiota in the Progression of Type 2 Diabetes and the Potential Role of Exercise: A Critical Review

Type 2 diabetes (T2D) is the predominant metabolic epidemic posing a major threat to global health. Growing evidence indicates that gut microbiota (GM) may critically influence the progression from normal glucose tolerance, to pre-diabetes, to T2D. On the other hand, regular exercise contributes to the prevention and/or treatment of the disease, and evidence suggests that a possible way regular exercise favorably affects T2D is by altering GM composition toward health-promoting bacteria. However, research regarding this potential effect of exercise-induced changes of GM on T2D and the associated mechanisms through which these effects are accomplished is limited. This review presents current data regarding the association of GM composition and T2D and the possible critical GM differentiation in the progression from normal glucose, to pre-diabetes, to T2D. Additionally, potential mechanisms through which GM may affect T2D are presented. The effect of exercise on GM composition and function on T2D progression is also discussed.

Liraglutide combined with routine therapy improves renal function, renal fibrosis, immune status, and prognosis of type 2 diabetes patients

OBJECTIVE

To investigate the effect of Liraglutide in conjunction with routine therapy on renal function, renal fibrosis, immune status, and prognosis in patients with diabetes mellitus.

METHODS

The clinical data of patients with Type 2 diabetes mellitus (T2DM) treated at the First Affiliated Hospital of Jishou University from March 2021 to March 2022 were retrospectively analyzed. Patients were assigned into a control group (n=42) and a study group (n=42) according to their treatment regimen. The control group received routine treatment, and the study group received Liraglutide in addition to routine treatment. The therapeutic effects, blood glucose levels, renal function, renal fibrosis, and Immunoglobulin (Ig) levels as well as the incidence of adverse reactions, were compared between the two groups.

RESULTS

The effective rate was higher in study group (97.62%) than that of the control group (78.57%) (P<0.05). After treatment, the fasting blood-glucose (FBG), 2-hour postprandial plasma glucose (2hPG), and glycosylated hemoglobin (HbA1c) levels were decreased; and the study group displayed a significantly lower blood glucose level than the control group (all P<0.05). Also, the serum creatinine (Scr), blood urea nitrogen (BUN), and 24-hour urinary protein quantification (24h-UPor) were decreased after treatment; and the study group showed more pronounced improvement in renal function index than did the control group (all P<0.05). The levels of IgA, IgM, and IgG were increased after treatment compared to pre-treatment; and the study group exhibited significantly better improvement than the control group (all P<0.05). However, the study group reported a notably higher incidence of adverse reactions than the control group (19.05% vs 2.38%; P<0.05).

CONCLUSION

Liraglutide combined with routine therapy is effective in treating patients with diabetes, which can effectively reduce the levels of blood glucose andurinary protein, and the degree of renal fibrosis, while improving renal and immune functions and the clinical prognosis of diabetic patients.

Interactions between toll-like receptors signaling pathway and gut microbiota in host homeostasis

BACKGROUND

Toll-like receptors (TLRs) are a family of fundamental pattern recognition receptors in the innate immune system, constituting the first line of defense against endogenous and exogenous antigens. The gut microbiota, a collection of commensal microorganisms in the intestine, is a major source of exogenous antigens. The components and metabolites of the gut microbiota interact with specific TLRs to contribute to whole-body immune and metabolic homeostasis.

OBJECTIVE

This review aims to summarize the interaction between the gut microbiota and TLR signaling pathways and to enumerate the role of microbiota dysbiosis-induced TLR signaling pathways in obesity, inflammatory bowel disease (IBD), and colorectal cancer (CRC).

RESULTS

Through the recognition of TLRs, the microbiota facilitates the development of both the innate and adaptive immune systems, while the immune system monitors dynamic changes in the commensal bacteria to maintain the balance of the host-microorganism symbiosis. Dysbiosis of the gut microbiota can induce a cascade of inflammatory and metabolic responses mediated by TLR signaling pathways, potentially resulting in various metabolic and inflammatory diseases.

CONCLUSION

Understanding the crosstalk between TLRs and the gut microbiota contributes to potential therapeutic applications in related diseases, offering new avenues for treatment strategies in conditions like obesity, IBD, and CRC.

Correlation between intestinal flora and GLP-1 receptor agonist dulaglutide in type 2 diabetes mellitus treatment-A preliminary longitudinal study

GLP-1 receptor agonists (GLP-1 RA) are presently used as the first-line drugs for the clinical treatment of type 2 diabetes mellitus (T2DM). It can regulate blood glucose by stimulating insulin secretion and lowering glucagon levels. We used 16S rRNA amplicon sequencing to detect structural changes in the composition of the intestinal flora of newly diagnosed T2DM after 1 and 48 weeks of dulaglutide administration. Our research found no significant changes in the intestinal flora after the administration of dulaglutide for 1 week to subjects with newly diagnosed T2DM. Nevertheless, after 48 weeks of dulaglutide administration, the composition of the intestinal flora changed significantly, with a significant reduction in the abundance of intestinal flora. Furthermore, we found that fasting glucose levels, fasting c-peptide levels, HbA1c levels, and BMI are also closely associated with intestinal flora. This reveals that intestinal flora may be one of the mechanisms by which dulaglutide treats T2DM.

Advances in Gut Microbiota-Targeted Therapeutics for Metabolic Syndrome

Previous investigations have illuminated the significant association between the gut microbiome and a broad spectrum of health conditions, including obesity, diabetes, cardiovascular diseases, and psychiatric disorders. Evidence from certain studies suggests that dysbiosis of the gut microbiota may play a role in the etiology of obesity and diabetes. Moreover, it is acknowledged that dietary habits, pharmacological interventions, psychological stress, and other exogenous factors can substantially influence the gut microbial composition. For instance, a diet rich in fiber has been demonstrated to increase the population of beneficial bacteria, whereas the consumption of antibiotics can reduce these advantageous microbial communities. In light of the established correlation between the gut microbiome and various pathologies, strategically altering the gut microbial profile represents an emerging therapeutic approach. This can be accomplished through the administration of probiotics or prebiotics, which aim to refine the gut microbiota and, consequently, mitigate the manifestations of associated diseases. The present manuscript evaluates the recent literature on the relationship between gut microbiota and metabolic syndrome published over the past three years and anticipates future directions in this evolving field.

Polysaccharides from Phellinus linteus attenuate type 2 diabetes mellitus in rats via modulation of gut microbiota and bile acid metabolism

Type 2 diabetes mellitus (T2DM) is the most prevalent metabolic disorder. Polysaccharides from Phellinus linteus (PLP) have been found to have anti-diabetes effects, but the mechanism has not been elucidated. The purpose of this study was to investigate the mechanism of PLP on T2DM through the gut microbiota and bile acids metabolism. The T2DM rat model was induced by a high-fat high-carbohydrate (HFHC) diet and streptozocin (30 mg/kg). We found that PLP ameliorated diabetes symptoms. Besides, PLP intervention increased the abundance of g_Bacteroides, g_Parabacteroides, and g_Alistioes, which are associated with the biosynthesis of short-chain fatty acids (SCFAs) and bile acids (BAs) metabolism. Meanwhile, untargeted and targeted metabolomics indicated that PLP could regulate the composition of BAs and increase the levels of SCFAs. Real-time quantitative PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) were performed to analyze the expression levels of BAs metabolism enzymes in the liver. Finally, the results of correlation analysis and Glucagon-like peptide-1 (GLP-1) showed that PLP stimulated the release of GLP-1 by regulating SCFAs and BAs. In conclusion, this study demonstrated that PLP can regulate gut microbiota and BAs metabolism to promote GLP-1 secretion, thereby increasing insulin release, decreasing blood glucose and attenuating T2DM.

Comparative efficacy and safety of probiotics, prebiotics, and synbiotics for type 2 diabetes management: A systematic review and network meta-analysis

AIMS

To compare the effects of probiotics, prebiotics, and synbiotics for type 2 diabetes (T2D) management.

METHODS

We searched PubMed, Scopus, CENTRAL, and grey literature sources to December 2022 for randomized trials of the impacts of probiotics, prebiotics, or synbiotics in patients with T2D. We performed network meta-analyses with a Bayesian framework to calculate mean difference [MD] and 95 % credible interval [CrI] and rated the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

68 randomised trials were included. All results are presented in comparison to the placebo. Supplementation with probiotics (MD: -0.25 %, 95%CrI: -0.42, -0.08; GRADE = moderate) and synbiotics (MD: -0.31 %, 95%CrI: -0.61, -0.04; GRADE = very low) resulted in a trivial/unimportant decrease in glycated hemoglobin. Supplementation with probiotics (MD: -0.69 mmol/L, 95%CrI: -0.98, -0.40; GRADE = very low) and synbiotics (MD: -0.82 mmol/L, 95%CrI: -1.22, -0.43; GRADE = very low) resulted in a trivial/unimportant decrease in fasting plasma glucose. Supplementation with probiotics resulted in a small but important decrease in low-density lipoprotein cholesterol (MD: -0.19 mmol/L; 95%CrI: -0.34, -0.05; GRADE = very low). Supplementations had moderate effects on serum triglyceride (GRADE = low).

CONCLUSIONS

Existing evidence is uncertain and does not support supplementation with probiotics, prebiotics, and synbiotics for T2D management.

Comparison of Lactiplantibacillus plantarum isolates from the gut of mice supplemented with different types of nutrients: a genomic and metabolomic study

Many studies have focused on the influence of dietary supplements on gut microbiota composition, but limited research have reported their effects on specific bacterial species in the gut. Lactiplantibacillus plantarum is one of the most widely studied probiotics, with a wide range of sources and good environmental adaptability. In this study, in order to elucidate the adaptation strategies of L. plantarum to the gut of mice supplemented with carbohydrates, peptides and minerals, whole genome resequencing and intracellular metabolites detection were performed, and high-frequency mutant genes and differential metabolites were screened. The results suggested different types of dietary supplements do have different effects on L. plantarum from the gut of mice. Additionally, KEGG annotation unveiled that the effects of these dietary supplements on the gene level of L. plantarum primarily pertained to environmental information processing, while the differential metabolites were predominantly associated with metabolism. This study provided new perspectives on the adaptive mechanism of L. plantarum in response to the host's gut environment, suggesting that the diversity of the genome and metabolome of L. plantarum was correlated with dietary supplements. Furthermore, this study offered useful guidance in the effective utilization of dietary supplements.

Gut microbiota in the pathogenesis and therapeutic approaches of diabetes

The gut-liver axis plays a prominent role in the pathogenesis and therapy of metabolic diseases such as diabetes. The intestinal specific origin of several hormones that guide both inter- and post-prandial metabolism of carbohydrates and lipids, drives the attention of scientists and clinicians on the gut as a major site to intervene with novel diagnostic or prognostic markers. The role of intestinal ecology in the metabolic syndrome was postulated when gut microbiota was directly connected with inflammation, hyperinsulinemia, and diabetes. There have been several discoveries with the role of gut microbiota and gut-liver axis in diabetes. Also, there are several trials ongoing on the therapeutic efficacy of probiotic administration in diabetes and its complications. Here we point to the metabolic action of microbiota and discuss the actual state of the art on gut microbiota as a novel prognostic biomarker with a putative therapeutic role in diabetes.

Effects of metformin on the gut microbiota: A systematic review

BACKGROUND

The gut microbiota is increasingly recognized as a crucial factor in human health and disease. Metformin, a commonly prescribed medication for type 2 diabetes, has been studied for its potential impact on the gut microbiota in preclinical models. However, the effects of metformin on the gut microbiota in humans remain uncertain.

SCOPE OF REVIEW

We conducted a systematic review of clinical trials and observational studies to assess the existing knowledge on the impact of metformin on the gut microbiota in humans. The review focused on changes in bacterial composition and diversity following metformin treatment.

MAJOR CONCLUSIONS

Thirteen studies were included in the analysis. The results revealed alterations in the abundance of bacterial genera from various phyla, suggesting that metformin may selectively influence certain groups of bacteria in the gut microbiota. However, the effects on gut microbiota diversity were inconsistent across populations, with conflicting findings on changes in alpha and beta diversity measures. Overall, the use of metformin was associated with changes in the abundance of specific bacterial genera within the gut microbiota of human populations. However, the effects on gut microbiota diversity were not consistent, highlighting the need for further research to understand the underlying mechanisms and clinical significance of these changes.

Positive interactions among Corynebacterium glutamicum and keystone bacteria producing SCFAs benefited T2D mice to rebuild gut eubiosis

Accumulating evidences strongly support the correlations between the compositions of gut microbiome and therapeutic effects on Type 2 diabetes (T2D). Notably, gut microbes such as Akkermansia muciniphila are found able to regulate microecological balance and alleviate dysmetabolism of mice bearing T2D. In order to search out similarly functional bacteria, bacteriophage MS2 with a good specificity to bacteria carrying fertility (F) factor were used to treat T2D mice. Based on multi-omics analysis of microbiome and global metabolism of mice, we observed that gavage of bacteriophage MS2 and metformin led to a significant increase in the abundance of Corynebacterium glutamicum and A. muciniphila, respectively. Consequently, the gut microbiota were remodeled, leading to variations in metabolites and a substantial increase in short-chain fatty acids (SCFAs). In which, the amount of acetate, propionate, and butyrate presented negative correlations to that of proinflammatory cytokines, which was beneficial to repairing the intestinal barriers and improving their functions. Moreover, main short fatty acid (SCFA) producers exhibited positive interactions, further facilitating the restoration of gut eubiosis. These findings revealed that C. glutamicum and its metabolites may be potential dietary supplements for the treatment of T2D. Moreover, our research contributes to a novel understanding of the underlying mechanism by which functional foods exert their anti-diabetic effects.

Metformin: update on mechanisms of action and repurposing potential

Currently, metformin is the first-line medication to treat type 2 diabetes mellitus (T2DM) in most guidelines and is used daily by >200 million patients. Surprisingly, the mechanisms underlying its therapeutic action are complex and are still not fully understood. Early evidence highlighted the liver as the major organ involved in the effect of metformin on reducing blood levels of glucose. However, increasing evidence points towards other sites of action that might also have an important role, including the gastrointestinal tract, the gut microbial communities and the tissue-resident immune cells. At the molecular level, it seems that the mechanisms of action vary depending on the dose of metformin used and duration of treatment. Initial studies have shown that metformin targets hepatic mitochondria; however, the identification of a novel target at low concentrations of metformin at the lysosome surface might reveal a new mechanism of action. Based on the efficacy and safety records in T2DM, attention has been given to the repurposing of metformin as part of adjunct therapy for the treatment of cancer, age-related diseases, inflammatory diseases and COVID-19. In this Review, we highlight the latest advances in our understanding of the mechanisms of action of metformin and discuss potential emerging novel therapeutic uses.

Potential Application of Marine Fucosyl-Polysaccharides in Regulating Blood Glucose and Hyperglycemic Complications

Diabetes mellitus (DM) has become the world's third major disease after tumors and cardiovascular disease. With the exploitation of marine biological resources, the efficacy of using polysaccharides isolated from marine organisms in blood glucose regulation has received widespread attention. Some marine polysaccharides can reduce blood glucose by inhibiting digestive enzyme activity, eliminating insulin resistance, and regulating gut microbiota. These polysaccharides are mainly fucose-containing sulphated polysaccharides from algae and sea cucumbers. It follows that the hypoglycemic activity of marine fucosyl-polysaccharides is closely related to their structure, such as their sulfate group, monosaccharide composition, molecular weight and glycosidic bond type. However, the structure of marine fucosyl-polysaccharides and the mechanism of their hypoglycemic activity are not yet clear. Therefore, this review comprehensively covers the effects of marine fucosyl-polysaccharides sources, mechanisms and the structure-activity relationship on hypoglycemic activity. Moreover, the potential regulatory effects of fucosyl-polysaccharides on vascular complications caused by hyperglycemia are also summarized in this review. This review provides rationales for the activity study of marine fucosyl-polysaccharides and new insights into the high-value utilization of marine biological resources.

MicroRNA-29a Compromises Hepatic Adiposis and Gut Dysbiosis in High Fat Diet-Fed Mice via Downregulating Inflammation

SCOPE

miR-29a expression patterns influence numerous physiological phenomena. Of note, upregulation of miR-29a ameliorates high-fat diet (HFD)-induced liver dysfunctions in mice. However, the miR-29a effect on gut microbiome composition and HFD-induced gut microbiota changes during metabolic disturbances remains unclear. The study provides compelling evidence for the protective role of miR-29a in gut barrier dysfunction and steatohepatitis.

METHODS AND RESULTS

miR-29a overexpressed mice (miR-29aTg) are bred to characterize intestinal, serum biochemical, and fecal microbiota profiling features compared to wild-type mice (WT). Mice are fed an HFD for 8 months to induce steatohepatitis, and intestinal dysfunction is determined via histopathological analysis. miR-29aTg has better lipid metabolism capability that decreases total cholesterol and triglyceride levels in serum than WT of the same age. The study further demonstrates that miR-29aTg contributes to intestinal integrity by maintaining periodic acid Schiff positive cell numbers and diversity of fecal microorganisms. HFD-induced bacterial community disturbance and steatohepatitis result in more severe WT than miR-29aTg. Gut microorganism profiling reveals Lactobacillus, Ruminiclostridium_9, and Lachnoclostridium enrichment in miR-29aTg and significantly decreases interleukin-6 expression in the liver and intestinal tract.

CONCLUSION

This study provides new evidence that sheds light on the host genetic background of miR-29a, which protects against steatohepatitis and other intestinal disorders.

Improvement in Zebrafish with Diabetes and Alzheimer's Disease Treated with Pasteurized Akkermansia muciniphila

Diabetes and Alzheimer's disease (AD) are associated with specific changes in the composition of the intestinal flora. Studies have shown that the supplementation with pasteurized Akkermansia muciniphila has therapeutic and preventive effects on diabetes. However, it is not clear whether there is any association with improvement in and prevention of Alzheimer's disease and diabetes with Alzheimer's disease. Here, we found that pasteurized Akkermansia muciniphila can significantly improve the blood glucose, body mass index, and diabetes indexes of zebrafish with diabetes mellitus complicated with Alzheimer's disease and also alleviate the related indexes of Alzheimer's disease. The memory, anxiety, aggression, and social preference behavior of zebrafish with combined type 2 diabetes mellitus (T2DM) and Alzheimer's disease (TA zebrafish) were significantly improved after pasteurized Akkermansia muciniphila treatment. Moreover, we examined the preventive effect of pasteurized Akkermansia muciniphila on diabetes mellitus complicated with Alzheimer's disease. The results showed that the zebrafish in the prevention group were better in terms of biochemical index and behavior than the zebrafish in the treatment group. These findings provide new ideas for the prevention and treatment of diabetes mellitus complicated with Alzheimer's disease. IMPORTANCE The interaction between intestinal microflora and host affects the progression of diabetes and Alzheimer's disease. As a recognized next-generation probiotic, Akkermansia muciniphila has been shown to play a key role in the progression of diabetes and Alzheimer's disease, but whether A. muciniphila can improve diabetes complicated with Alzheimer's disease and its potential mechanism are unclear. In this study, a new zebrafish model of diabetes mellitus complicated with Alzheimer's disease was established, and the effect of Akkermansia muciniphila on diabetes mellitus complicated with Alzheimer's disease is discussed. The results showed that Akkermansia muciniphila after pasteurization significantly improved and prevented diabetes mellitus complicated with Alzheimer's disease. Treatment with pasteurized Akkermansia muciniphila improved the memory, social preference, and aggressive and anxiety behavior of TA zebrafish and alleviated the pathological characteristics of T2DM and AD. These results provide a new prospect for probiotics in the treatment of diabetes and Alzheimer's disease.

Assessment of glucocorticoid and antibiotic exposure as risk factors for diabetes mellitus in selected dog breeds attending UK primary-care clinics

BACKGROUND

Diabetes mellitus (DM) is an important endocrine disorder in dogs. This study explored prior exposure to glucocorticoids or antibiotic treatment as risk factors for developing DM in dogs attending primary-care VetCompass clinics in the UK.

METHODS

A breed frequency matched case-control study nested in a cohort of dogs (n = 480,469) aged 3 years or over was used to explore associations between glucocorticoid and antibiotic exposure and the odds of developing DM.

RESULTS

A total of 565 cases and 2179 controls were included. Dogs with DM had over four times the odds of exposure to glucocorticoids within 6 weeks prior to diagnosis (odds ratio [OR] 4.07, 95% confidence interval [CI] 2.41-6.89, p < 0.001) compared to controls within 6 weeks prior to a randomly selected quasi-date of diagnosis. Dogs that had only one unique documented antibiotic course had a decreased odds of developing DM (OR 0.65, 95% CI 0.46-0.91, p = 0.012) compared to dogs that had no documented courses of antibiotics.

LIMITATIONS

This study only included selected breeds, so the results may not be generalisable to all dog breeds.

CONCLUSIONS

Exposure to glucocorticoids is associated with a substantial increase in the risk of developing DM for the dog breeds included in this analysis.

Exenatide improves hypogonadism and attenuates inflammation in diabetic mice by modulating gut microbiota

With the rising incidence of diabetes and its onset at a younger age, the impact on the male reproductive system has gradually gained attention. Exenatide is a glucagon-like peptide-1 receptor agonist effective in the treatment of diabetes. However, its role in diabetes-induced reproductive complications has rarely been reported. The study aimed to investigate the mechanism by which exenatide improved diabetic hypogonadism by regulating gut microbiota (GM) mediated inflammation. C57BL/6J mice were equally divided into normal control (NC), diabetic model control (DM) and exenatide-treated (Exe) groups. Testicular, pancreatic, colonic, and fecal samples were collected to assess microbiota, morphologic damage, and inflammation. Exenatide significantly reduced the fasting blood glucose (FBG) level in diabetic mice, increased the testosterone level, ameliorated the pathological morphological damage of islet, colon, and testes, and reduced the expression of pro-inflammatory factors, tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 in colon and testis. Furthermore, exenatide significantly reduced the abundance of some pathogenic bacteria, such as Streptococcaceae and Erysipelotrichaceae, and increased that of beneficial bacteria Akkermansia. Probiotics, such as Lactobacillus were negatively correlated with TNF-α, nuclear factor-kappa-B (NF-κB), IL-6, and FBG. Conditional pathogenic bacteria such as Escherichia/Shigella Streptococcus were positively correlated with TNF-α, NF-κB, IL-6, and FBG. The fecal bacteria transplantation experiment revealed that the abundance of pathogenic bacteria, Peptostreptococcaceae, significantly decreased from Exe group mice to pseudo-sterile diabetic mice, and the pathological damage to testes was also alleviated. These data suggested the protective effects of exenatide on male reproductive damage induced by diabetes by regulating GM.

Pediococcus acidilactici pA1c® Improves the Beneficial Effects of Metformin Treatment in Type 2 Diabetes by Controlling Glycaemia and Modulating Intestinal Microbiota

Type 2 diabetes (T2D) is a complex metabolic disease, which involves maintained hyperglycemia, mainly due to the development of an insulin resistance process. Metformin administration is the most prescribed treatment for diabetic patients. In a previously published study, we demonstrated that Pediococcus acidilactici pA1c^® (pA1c) protects from insulin resistance and body weight gain in HFD-induced diabetic mice. The present work aimed to evaluate the possible beneficial impact of a 16-week administration of pA1c, metformin, or the combination of pA1c and metformin in a T2D HFD-induced mice model. We found that the simultaneous administration of both products attenuated hyperglycemia, increased high-intensity insulin-positive areas in the pancreas and HOMA-β, decreased HOMA-IR and also provided more beneficial effects than metformin treatment (regarding HOMA-IR, serum C-peptide level, liver steatosis or hepatic Fasn expression), and pA1c treatment (regarding body weight or hepatic G6pase expression). The three treatments had a significant impact on fecal microbiota and led to differential composition of commensal bacterial populations. In conclusion, our findings suggest that P. acidilactici pA1c^® administration improved metformin beneficial effects as a T2D treatment, and it would be a valuable therapeutic strategy to treat T2D.

Lactobacillus paracasei IMC 502 ameliorates type 2 diabetes by mediating gut microbiota-SCFA-hormone/inflammation pathway in mice

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a complex and prevalent metabolic disease that seriously threatens human health. Numerous studies have shown that probiotics as dietary supplements have the potential to prevent and treat T2DM. However, the ability of various strains to improve diabetes symptoms and corresponding mechanisms are different. Thus, mechanistic investigation is required to validate the pharmacology of each probiotic strain for T2DM treatment. Lactobacillus paracasei IMC 502 was originally isolated from Italian elderly human feces and its probiotic attributes have been demonstrated. Here, the antidiabetic pharmacodynamics of L. paracasei IMC 502 on T2DM mice was explored.

RESULTS

Lactobacillus paracasei IMC 502 significantly decreased blood glucose, HbA1c and lipid levels, improved insulin resistance and glucose intolerance, regulated the mRNA/protein expression of key hepatic enzymes associated with gluconeogenesis, de novo lipogenesis and PI3K/Akt pathway, and repaired pancreatic and hepatic tissue damage. This probiotic conferred beneficial outcomes in the gut microbiome of diabetic mice, which induced transformation of short-chain fatty acids (SCFAs) and further enhanced the secretion of downstream hormones, and ultimately ameliorated the inflammatory response.

CONCLUSION

Lactobacillus paracasei IMC 502 prevents and alleviates T2DM by mediating the gut microbiota-SCFA-hormone/inflammation pathway. © 2022 Society of Chemical Industry.

Dysbiosis versus diabesity: pathological signaling and promising therapeutic strategies

A healthy life depends on the inseparable relationship between a host and the gut microbiota. A healthy gut microbiota regulates intestinal integrity, whereas an unbalanced gut microbiota contributes to junctional remodeling and leads to dysbiosis. Bacterial infiltration and dysbiosis are reported to activate a series of pathological cascades that trigger metabolic abnormalities, including diabesity. Conversely, recent studies revealed that the incidence of dysbiosis itself is fuelled by diabesity. In this review, we highlight the molecular aspects of multifaceted pathological signaling between dysbiosis and diabetes that could pave the way for new drug discovery. Moreover, to reinstate the gut microbiota and restrict the epidemic of dysbiosis and diabesity, we also scrutinize a promising therapeutic strategy that can challenge the pathological interlink. Teaser: Dysbiosis and diabesity are closely related and can influence each other. Dysbiosis can worsen diabesity, whereas diabesity can affect the gut microbiota. Thus, to prevent and treat diabesity, it is important to understand this complex interplay.

Identification of key genes, biological functions, and pathways of empagliflozin by network pharmacology and its significance in the treatment of type 2 diabetes mellitus

Background

To explore the key genes, biological functions, and pathways of empagliflozin in the treatment of type 2 diabetes mellitus (T2DM) through network pharmacology.

Methods

The TCMSP (a traditional Chinese medicine system pharmacology database and analysis platform) was used to screen empagliflozin's active components and targets. The target genes of T2DM were screened according to the GeneCards and OMIM databases, and a Venn diagram was constructed to obtain the target for T2DM treatment. Cytoscape 3.7.2 software was adopted to construct the drug-component-target-disease network. Functional annotation of Gene Ontology (GO) and enrichment analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were performed using R software.

Results

Target genes with a probability >0 were selected, among which Compound 012, Compound 060, Compound 093, Compound 111, and Compound 119 Swiss Target Prediction suggested that no similar active substances or predictable target genes were found. A "compound-target gene-disease" network was constructed, in which SLC5A2, SLC5A1, SLC5A4, SLC5A11, ADK, and ADORA2A were the core genes of T2DM. The key factors of the GO summary map included chemical reaction, membrane organelle, protein binding, and so on. The KEGG pathway summary map included the AMPK pathway, insulin resistance, the MAPK pathway, longevity-related pathway regulation, and so on. The top 10 pathways were endocrine resistance, the NF-κB signaling pathway, the HIF-1 signaling pathway, apoptosis, cell senescence, the Ras signaling pathway, the MAPK signaling pathway, the FoxO signaling pathway, the P13K-Akt signaling pathway, and the p53 signaling pathway. The binding of active compounds to key proteins was verified based on the Swiss Dock database, and the molecular docking of 193 bioactive compounds was finally verified. Among them, SLC5A2, SLC5A1, LDHA, KLK1, KLF5, and GSTP1 had better binding to the protein molecules.

Conclusions

Empagliflozin may regulate the targets of SLC5A2, SLC5A1, LDHA, KLK1, KLF5, and GSTP1. There are numerous ways of treating T2DM with empagliflozin, including by regulating apoptosis, cell aging, as well as the NF-κB, HIF-1HIF-1, Ras, MAPK, FoxO, P13K-Akt, and p53 pathways.

Renal Health Improvement in Diabetes through Microbiome Modulation of the Gut-Kidney Axis with Biotics: A Systematic and Narrative Review of Randomized Controlled Trials

Diabetes mellitus is the most common endocrine disorder worldwide, with over 20% of patients ultimately developing diabetic kidney disease (DKD), a complex nephropathic complication that is a leading cause of end-stage renal disease. Various clinical trials have utilized probiotics, prebiotics, and synbiotics to attempt to positively modulate the gut microbiome via the gut-kidney axis, but consensus is limited. We conducted a multi-database systematic review to investigate the effect of probiotics, prebiotics, and synbiotics on various biomarkers of renal health in diabetes, based on studies published through 10 April 2022. Adhering to the Cochrane Collaboration and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, relevant articles were systematically screened and extracted by independent reviewers; subsequently, results were systematically compiled, analyzed, and expanded through a narrative discussion. A total of 16 publications encompassing 903 diabetic individuals met the inclusion criteria. Our findings show that some studies report statistically significant changes in common renal markers, such as serum creatinine, estimated glomerular filtration rate, blood urea nitrogen/urea, microalbuminuria, and uric acid, but not on serum albumin, sodium, potassium, phosphorous, or total urine protein. Interestingly, these nutraceuticals seem to increase serum uric acid concentrations, an inflammatory marker usually associated with decreased renal health. We found that probiotics from the Lactobacillus and Bifidobacterium families were the most investigated, followed by Streptococcus thermophilus. Prebiotics including inulin, galacto-oligosaccharide, and resistant dextrin were also examined. The single-species probiotic soymilk formulation of Lactobacillus plantarum A7 possessed effects on multiple renal biomarkers in DKD patients without adverse events. We further investigated the optimum nutraceutical formulation, discussed findings from prior studies, described the gut-kidney axis in diabetes and DKD, and finally commented on some possible mechanisms of action of these nutraceuticals on renal health in diabetics. Although probiotics, prebiotics, and synbiotics have shown some potential in ameliorating renal health degradation in diabetes via gut-kidney axis crosstalk, larger and more convincing trials with focused objectives and next-generation nutraceutical formulations are required to investigate their possible role as adjunct therapy in such patients.

Construction of in vitro fermentation model using gut microbiota relating to glucose and lipid metabolism: a supplementary method for initial screening of polysaccharides with hypoglycemic potentials

BACKGROUND

Besides in vitro fecal fermentation model, a few supplementary methods have been constructed for high-throughput screening of polysaccharides with hypoglycemic potentials. The purpose of this study was to establish a co-culture fermentation model constructed by gut microbiota relating to glucose and lipid metabolism as a supplementary method for comparatively evaluating the proliferative effects and hypoglycemic potentials of typical plant polysaccharides, e.g. konjac glucomannan, Lycium barbarum L. polysaccharide, oat glucan and alga-derived fucoidan.

RESULTS

The results showed that the mixing culture medium of butyrate-producing bacteria, Bacteroides, Bifidobacterium and Lactobacillus at a ratio of 50:40:9:1 was optimal. This testing model in line with quantitative polymerase chain reaction (qPCR) and metabolite analysis multi-dimensionally differentiated four polysaccharides possessing different behaviors on proliferation of total bacteria and specific genus or strain and accumulation of short chain fatty acids.

CONCLUSION

Our study provided crucial data for establishing an initial screening method for proliferative effect/specific structure-oriented extraction of polysaccharide with hypoglycemic potential. © 2022 Society of Chemical Industry.

Metformin with Versus without Concomitant Probiotic Therapy in Newly Diagnosed Patients with Type 2 Diabetes or Prediabetes: A Comparative Analysis in Relation to Glycemic Control, Gastrointestinal Side Effects, and Treatment Compliance

BACKGROUND

To evaluate the impact of concomitant use of probiotic BB-12 in metformin-treated patients with type 2 diabetes or prediabetes on glycemic control, metformin-related gastrointestinal side effects, and treatment compliance.

METHODS

A total of 156 patients (mean [standard deviation] age: 50.9 [9.9 years], 74.4% females) with newly diagnosed type 2 diabetes or prediabetes were randomly assigned to receive either metformin alone (n = 84, MET group) or metformin plus Bifidobacterium animalis subsp. lactis (BB-12) probiotic (n = 72, MET-PRO group). Data on body mass index (kg/m2), fasting blood glucose (mg/dL), blood lipids, and glycated hemoglobin (HbA1c) levels were recorded at baseline and at the third month of therapy. Data on gastrointestinal intolerance symptoms and treatment noncompliance were also recorded during post-treatment week 1 to week 4.

RESULTS

MET-PRO versus MET therapy was associated with a significantly higher rate of treatment compliance (91.7% vs 71.4%, P = .001), greater reduction from baseline HbA1c values (0.9 [0.4-1.6] vs 0.4 [0-1.6] %, P < .001) and lower likelihood of gastrointestinal intolerance symptoms, including abdominal pain (P = .031 to <.001), diarrhea (P = .005 to <.001) and bloating (P = .010 to <.001). Noncompliance developed later (at least 15 days after the therapy) in a significantly higher percentage of patients in the MET group (P = .001 for 15-21 days and P = .002 for 22-28 days).

CONCLUSION

In conclusion, the present study proposes the benefit of combining probiotics with metformin in the treatment of patients with T2D or prediabetes in terms of improved glycemic control and treatment adherence rather than correction of dyslipidemia or weight reduction.

Wholegrain fermentation affects gut microbiota composition, phenolic acid metabolism and pancreatic beta cell function in a rodent model of type 2 diabetes

The intestinal microbiota plays an important role in host metabolism via production of dietary metabolites. Microbiota imbalances are linked to type 2 diabetes (T2D), but dietary modification of the microbiota may promote glycemic control. Using a rodent model of T2D and an in vitro gut model system, this study investigated whether differences in gut microbiota between control mice and mice fed a high-fat, high-fructose (HFHFr) diet influenced the production of phenolic acid metabolites following fermentation of wholegrain (WW) and control wheat (CW). In addition, the study assessed whether changes in metabolite profiles affected pancreatic beta cell function. Fecal samples from control or HFHFr-fed mice were fermented in vitro with 0.1% (w/v) WW or CW for 0, 6, and 24 h. Microbiota composition was determined by bacterial 16S rRNA sequencing and phenolic acid (PA) profiles by UPLC-MS/MS. Cell viability, apoptosis and insulin release from pancreatic MIN6 beta cells and primary mouse islets were assessed in response to fermentation supernatants and selected PAs. HFHFr mice exhibited an overall dysbiotic microbiota with an increase in abundance of proteobacterial taxa (particularly Oxalobacteraceae) and Lachnospiraceae, and a decrease in Lactobacillus. A trend toward restoration of diversity and compositional reorganization was observed following WW fermentation at 6 h, although after 24 h, the HFHFr microbiota was monodominated by Cupriavidus. In parallel, the PA profile was significantly altered in the HFHFr group compared to controls with decreased levels of 3-OH-benzoic acid, 4-OH-benzoic acid, isoferulic acid and ferulic acid at 6 h of WW fermentation. In pancreatic beta cells, exposure to pre-fermentation supernatants led to inhibition of insulin release, which was reversed over fermentation time. We conclude that HFHFr mice as a model of T2D are characterized by a dysbiotic microbiota, which is modulated by the in vitro fermentation of WW. The differences in microbiota composition have implications for PA profile dynamics and for the secretory capacity of pancreatic beta cells.

Fufang Fanshiliu Decoction Revealed the Antidiabetic Effect through Modulating Inflammatory Response and Gut Microbiota Composition

Background

Diabetes mellitus brings serious threats and financial burdens to human beings worldwide. Fufang Fanshiliu decoction (FFSLD), a traditional Chinese medicine formula showing great antidiabetic effects, has been used in clinics for many years.

Objective

This study aims to explore the underlying therapeutic mechanisms of FFSLD in Type II diabetes mellitus (T2DM).

Methods

Sprague–Dawley rats induced by high-fat diet feeding combined with streptozotocin injection were used to establish the T2DM model. All rats were randomly divided into 6 groups: control, model, metformin, high dosage, middle dosage, and low dosage of FFSLD. After 4 weeks of treatment, serum, intestinal mucosa, and fecal samples were collected for further analysis. ELISA was used to detect the diabetic-related serum indicators and proinflammation cytokines. Gene or protein expressions of mitogen-activated protein kinase (MAPK), interleukin 1 beta (IL-1β), transforming growth factor-beta (TGF-β), and tumor necrosis factor-alpha (TNF-α) in intestinal mucosa were analyzed by quantitative real-time polymerase chain reaction (RT-PCR) or western blot. 16s rRNA gene sequencing was used to detect the changes of gut microbiome in these groups. Intestinal gut microbiota (GM) composition was further analyzed according to the sequencing libraries.

Results

FFSLD effectively recovered the diabetic-related biochemical indexes by reducing fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), insulin, and increasing high-density lipoprotein cholesterol (HDL-C). Furthermore, FFSLD significantly ameliorated the abnormal levels of proinflammation cytokines including IL-1β, IL-6, TNF-α, and TGF-β. In addition, the GM compositions of rats in control, model, and FFSLD treated groups were different. FFSLD significantly increased the relative abundance of Lactobacillus, Akkermansia, and Proteus, and reduced the relative abundance of Alistipes, Desulfovibrio, and Helicobacter. Moreover, these changed bacteria were closely related to the diabetic-related serum indicators and proinflammatory cytokines.

Conclusion

These results suggest that FFSLD alleviates diabetic symptoms in T2DM rats through regulating GM composition and inhibiting inflammatory response, which clarify the therapeutic mechanism of FFSLD on T2DM and provide a theoretical basis for its further clinical application.

The potential mechanism of Liu-Wei-Di-Huang Pills in treatment of type 2 diabetic mellitus: from gut microbiota to short-chain fatty acids metabolism

BACKGROUND

Type 2 diabetes mellitus (T2DM) has already become a global pandemic. Recently, reports showed its pathogenesis was closely related to a disorder of gut microbiota. In China, the Liu-Wei-Di-Huang Pills (LWDH) have treated T2DM for thousands of years. However, its therapeutic mechanism associated with gut microbiota is worthy of further study.

AIMS

This study aims to investigate the effects of LWDH on T2DM by regulating gut microbiota and short-chain fatty acids (SCFAs) in Goto-Kakizaki (GK) rats.

METHODS

T2DM models were successfully established based on GK rats and administrated with LWDH. The changes in fasting blood glucose (FBG), oral glucose tolerance test (OGTT), and serum insulin (INS) were determined, and the immunohistochemical (IHC) method was used to test INS expression in pancreas. The 16S-ribosomal DNA (16S rDNA) sequencing analysis assessed gut microbiota structural changes; a gas chromatography-mass spectrometer (GC-MS)-based metabolomics method was adopted to detect SCFA levels. The pathological morphology of jejunum was detected by hematoxylin-eosin (H&E) staining, and the expression of GPR43, GPR41, GLP-1, and GLP-1R was evaluated by qRT-PCR and ELISA, respectively.

RESULTS

We observed that GK rats treated with LWDH: (a) has altered the microbial structure and promoted the abundance of bacteria in Firmicutes, including Lactobacillus, Allobaculum, and Ruminococcus_2, (b) increased SCFAs levels involving acetic acid, propionic acid, and butyric acid and (c) alleviated T2DM and jejunum injuries potentially based on SCFAs-GPR43/41-GLP-1 pathway.

CONCLUSION

LWDH could improve T2DM by regulating gut microbiota and SCFAs, and the therapeutic mechanism might be related to the SCFAs-GPR43/41-GLP-1 pathway.

Peanut skin procyanidins ameliorate insulin resistance via modulation of gut microbiota and gut barrier in type 2 diabetic mice

BACKGROUND

Peanut skin procyanidins (PSP) have been shown to possess antidiabetic activities. However, the mechanism remains poorly understood due to its low bioavailability. This study aims to investigate the preventive effect of PSP on type 2 diabetes (T2D) in mice through regulating gut microbiota and gut barrier in mice with streptozotocin (STZ)-induced T2D. During the 30 consecutive days of the study, T2D mice were administered PSP intragastrically at 75, 150 and 300 mg kg^-1 body weight d^-1 .

RESULTS

PSP treatment obviously alleviated glucolipid metabolism disorders, decreased the levels of lipopolysaccharide (LPS), interleukin (IL)-6 and myeloperoxidase(MPO), and increased that of IL-10. PSP treatment enhanced the abundance of Lachnospiraceae_NK4A136_group, Alloprevotella, Akkermansia and Faecalibaculum, and reduced that of Muribaculaceae. Some of these were associated with the production of short-chain fatty acids and anti-inflammatory effect, suggesting their important roles in T2D mice. More importantly, PSP improved the gut barrier integrality by restoring gut morphology and enhancing tight junction protein expression including ZO1, claudin1 and occludin in colon. Subsequently, PSP ameliorated insulin resistance by decreasing the LPS/Toll-like receptor 4/c-Jun N-terminal kinase inflammatory response, and enhancing insulin receptor substrate 1/ phosphatidylinositol-3-kinase/protein kinase B insulin signaling pathways in the liver.

CONCLUSION

Peanut skin procyanidins may alleviate the symptoms of T2D by mitigating inflammatory response, modulating gut microbiota and improving intestinal integrity. © 2022 Society of Chemical Industry.

Potential role of Limosilactobacillus fermentum as a probiotic with anti-diabetic properties: A review

Oxidative stress, inflammation, and gut microbiota impairments have been implicated in the development and maintenance of diabetes mellitus. Strategies capable of recovering the community of commensal gut microbiota and controlling diabetes mellitus have increased in recent years. Some lactobacilli strains have an antioxidant and anti-inflammatory system capable of protecting against oxidative stress, inflammation, and diabetes mellitus. Experimental studies and some clinical trials have demonstrated that Limosilactobacillus fermentum strains can beneficially modulate the host antioxidant and anti-inflammatory system, resulting in the amelioration of glucose homeostasis in diabetic conditions. This review presents and discusses the currently available studies on the identification of Limosilactobacillus fermentum strains with anti-diabetic properties, their sources, range of dosage, and the intervention time in experiments with animals and clinical trials. This review strives to serve as a relevant and well-cataloged reference of Limosilactobacillus fermentum strains capable of inducing anti-diabetic effects and promoting health benefits.

Gut microbiota induces DNA methylation via SCFAs predisposing obesity-prone individuals to diabetes

Obesity-prone (OP) individuals have a significant predisposition to obesity and diabetes. Previously, we have found that OP individuals, despite being normal in weight and BMI, have already exhibited diabetes-related DNA methylation signatures. However, the underlying mechanisms remain obscure. Here we determined the effects of gut microbiota on DNA methylation and investigated the underlying mechanism from microbial-derived short-chain fatty acids (SCFAs). Diabetes-related DNA methylation loci were screened and validated in a new OP cohort. Moreover, the OP group was revealed to have distinct gut microbiota compositions, and fecal microbiota transplantation (FMT) demonstrated the role of gut microbiota in inducing diabetes-related DNA methylations and glucolipid disorders. UPLC-ESI-MS/MS analysis indicated a significantly lower level of total fecal SCFAs in the OP group. The gut microbiota from OP subjects yielded markedly decreased total SCFAs, while notably enriched propionate. Additionally, propionate was also identified by variable importance in projection (VIP) score as the most symbolic SCFAs of the OP group. Further cellular experiments verified that propionate could induce hypermethylation at locus cg26345888 and subsequently inhibit the expression of the target gene DAB1, which was crucially associated with clinical vitamin D deficiency and thus may affect the development and progression of diabetes. In conclusion, our study revealed that gut microbiota-derived propionate induces specific DNA methylation, thus predisposing OP individuals to diabetes. The findings partially illuminate the mechanisms of diabetes susceptibility in OP populations, implying gut microbiota and SCFAs may serve as promising targets both for clinical treatment and medication development of diabetes.

New Advances in Improving Bone Health Based on Specific Gut Microbiota

The gut microbiota has been shown to play an important role in the pathogenesis of various diseases, including metabolic diseases, cardiovascular diseases, and cancer. Recent studies suggest that the gut microbiota is also closely associated with bone metabolism. However, given the high diversity of the gut microbiota, the effects of different taxa and compositions on bone are poorly understood. Previous studies demonstrated that the mechanisms underlying the effects of the gut microbiota on bone mainly include its modulation of nutrient absorption, intestinal permeability, metabolites (such as short-chain amino acids), immune responses, and hormones or neurotransmitters (such as 5-hydroxytryptamine). Several studies found that external interventions, such as dietary changes, improved bone health and altered the composition of the gut microbiota. This review summarises the beneficial gut bacteria and explores how dietary, natural, and physical factors alter the diversity and composition of the gut microbiota to improve bone health, thereby providing potential new insight into the prevention of osteoporosis.

Association of gut microbiota with glycaemic traits and incident type 2 diabetes, and modulation by habitual diet: a population-based longitudinal cohort study in Chinese adults

AIMS/HYPOTHESIS

The gut microbiome is mainly shaped by diet, and varies across geographical regions. Little is known about the longitudinal association of gut microbiota with glycaemic control. We aimed to identify gut microbiota prospectively associated with glycaemic traits and type 2 diabetes in a geographically diverse population, and examined the cross-sectional association of dietary or lifestyle factors with the identified gut microbiota.

METHODS

The China Health and Nutrition Survey is a population-based longitudinal cohort covering 15 provinces/megacities across China. Of the participants in that study, 2772 diabetes-free participants with a gut microbiota profile based on 16S rRNA analysis were included in the present study (age 50.8 ± 12.7 years, mean ± SD). Using a multivariable-adjusted linear mixed-effects model, we examined the prospective association of gut microbiota with glycaemic traits (fasting glucose, fasting insulin, HbA1c and HOMA-IR). We constructed a healthy microbiome index (HMI), and used Poisson regression to examine the relationship between the HMI and incident type 2 diabetes. We evaluated the association of dietary or lifestyle factors with the glycaemic trait-related gut microbiota using a multivariable-adjusted linear regression model.

RESULTS

After follow-up for 3 years, 123 incident type 2 diabetes cases were identified. We identified 25 gut microbial genera positively or inversely associated with glycaemic traits. The newly created HMI (per SD unit) was inversely associated with incident type 2 diabetes (risk ratio 0.69, 95% CI 0.58, 0.84). Furthermore, we found that several microbial genera that were favourable for the glycaemic trait were consistently associated with healthy dietary habits (higher consumption of vegetable, fruit, fish and nuts).

CONCLUSIONS/INTERPRETATION

Our results revealed multiple gut microbiota prospectively associated with glycaemic traits and type 2 diabetes in a geographically diverse population, and highlighted the potential of gut microbiota-based diagnosis or therapy for type 2 diabetes.

DATA AVAILABILITY

The code for data analysis associated with the current study is available at https://github.com/wenutrition/Microbiota-T2D-CHNS.

Gut microbiota, bile acids, and nature compounds

Natural compounds (NPs) have historically made a major contribution to pharmacotherapy in various diseases and drug discovery. In the past decades, studies on gut microbiota have shown that the efficacy of NPs can be affected by the interactions between gut microbiota and NPs. On one hand, gut microbiota can metabolize NPs. On the other hand, NPs can influence the metabolism and composition of gut microbiota. Among gut microbiota metabolites, bile acids (BAs) have attracted widespread attention due to their effects on the body homeostasis and the development of diseases. Studies have also confirmed that NPs can regulate the metabolism of BAs and ultimately regulate the physiological function of the body and disease progresses. In this review, we comprehensively summarize the interactions among NPs, gut microbiota, and BAs. In addition, we also discuss the role of microbial BAs metabolism in understanding the toxicity and efficacy of NPs. Furthermore, we present personal insights into the future research directions of NPs and BAs.

The Promising Role of Microbiome Therapy on Biomarkers of Inflammation and Oxidative Stress in Type 2 Diabetes: A Systematic and Narrative Review

Background

One in 10 adults suffer from type 2 diabetes (T2D). The role of the gut microbiome, its homeostasis, and dysbiosis has been investigated with success in the pathogenesis as well as treatment of T2D. There is an increasing volume of literature reporting interventions of pro-, pre-, and synbiotics on T2D patients.

Methods

Studies investigating the effect of pro-, pre-, and synbiotics on biomarkers of inflammation and oxidative stress in T2D populations were extracted from databases such as PubMed, Scopus, Web of Science, Embase, and Cochrane from inception to January 2022.

Results

From an initial screening of 5,984 hits, 47 clinical studies were included. Both statistically significant and non-significant results have been compiled, analyzed, and discussed. We have found various promising pro-, pre-, and synbiotic formulations. Of these, multistrain/multispecies probiotics are found to be more effective than monostrain interventions. Additionally, our findings show resistant dextrin to be the most promising prebiotic, followed closely by inulin and oligosaccharides. Finally, we report that synbiotics have shown excellent effect on markers of oxidative stress and antioxidant enzymes. We further discuss the role of metabolites in the resulting effects in biomarkers and ultimately pathogenesis of T2D, bring attention toward the ability of such nutraceuticals to have significant role in COVID-19 therapy, and finally discuss few ongoing clinical trials and prospects.

Conclusion

Current literature of pro-, pre- and synbiotic administration for T2D therapy is promising and shows many significant results with respect to most markers of inflammation and oxidative stress.

The Microbiota-Gut-Brain Axis in Depression: The Potential Pathophysiological Mechanisms and Microbiota Combined Antidepression Effect

Depression is a kind of worldwide mental illness with the highest morbidity and disability rate, which is often accompanied by gastrointestinal symptoms. Experiments have demonstrated that the disorder of the intestinal microbial system structure plays a crucial role in depression. The gut–brain axis manifests a potential linkage between the digestion system and the central nervous system (CNS). Nowadays, it has become an emerging trend to treat diseases by targeting intestinal microorganisms (e.g., probiotics) and combining the gut–brain axis mechanism. Combined with the research, we found that the incidence of depression is closely linked to the gut microbiota. Moreover, the transformation of the gut microbiota system structure is considered to have both positive and negative regulatory effects on the development of depression. This article reviewed the mechanism of bidirectional interaction in the gut–brain axis and existing symptom-relieving measures and antidepression treatments related to the gut microbiome.

Effects of gut microbiota-derived extracellular vesicles on obesity and diabetes and their potential modulation through diet

Obesity and diabetes incidence rates are increasing dramatically, reaching pandemic proportions. Therefore, there is an urgent need to unravel the mechanisms underlying their pathophysiology. Of particular interest is the close interconnection between gut microbiota dysbiosis and obesity and diabetes progression. Hence, microbiota manipulation through diet has been postulated as a promising therapeutic target. In this regard, secretion of gut microbiota-derived extracellular vesicles is gaining special attention, standing out as key factors that could mediate gut microbiota-host communication. Extracellular vesicles (EVs) derived from gut microbiota and probiotic bacteria allow to encapsulate a wide range of bioactive molecules (such as/or including proteins and nucleic acids) that could travel short and long distances to modulate important biological functions with the overall impact on the host health. EV-derived from specific bacteria induce differential physiological responses. For example, a high-fat diet-induced increase of the proteobacterium Pseudomonas panacis-derived EV is closely associated with the progression of metabolic dysfunction in mice. In contrast, Akkermansia muciniphila EV are linked with the alleviation of high-fat diet-induced obesity and diabetes in mice. Here, we review the newest pieces of evidence concerning the potential role of gut microbiota and probiotic-derived EV on obesity and diabetes onset, progression, and management, through the modulation of inflammation, metabolism, and gut permeability. In addition, we discuss the role of certain dietary patterns on gut microbiota-derived EV profile and the clinical implication that dietary habits could have on metabolic diseases progression through the shaping of gut microbiota-derived EV.

NEAT1: A novel long non-coding RNA involved in mediating type 2 diabetes and its various complications

Background:

Nuclear‐enriched abundant transcript 1 (abbreviated as NEAT1) refers to a long-chain non-coding RNA involved within various physiological and pathological processes. This study aimed at clarifying the effect and molecule system of neat1 within nonalcoholic fatty liver disease (NAFLD) as well as type 2 diabetes (T2DM).

Method:

In this review, we summarize and analyze current studies concerning mechanisms of NEAT1 in the development of type 2 diabetes and its complications. Also, we search the papers of NEAT1 in applying to NAFLD. The related studies were obtained through a systematic search of Pubmed.

Results:

Neat1 displays a close correlation with how T2DM occurs and develops, and it was confirmed to be significantly up-regulated in T2DM and its various complications (e.g., diabetics nephropathy, diabetics cardiomyopathy, diabetics retinopathy as well as diabetic neuropathy). Besides, neat1 is capable of impacting the occurrence, development and prognosis of NAFLD and T2DM.

Conclusion:

LncRNA neat1 is likely to act as a novel therapeutic target for and T2DM and its complications. Moreover, nonalcoholic fatty liver disease is also correlated with NEAT1.

Prospective Study Reveals Host Microbial Determinants of Clinical Response to Fecal Microbiota Transplant Therapy in Type 2 Diabetes Patients

Background

Increasing evidence shows that alterations in gut microbiome (GM) contribute to the development of type 2 diabetes mellitus (T2DM), and fecal microbiota transplantation (FMT) successfully treats various human diseases. However, the benefits of FMT therapy to T2DM patients remain unknown.

Methods

We enrolled 17 patients with T2DM for nonblinded, one-armed intervention trial of FMT. A total of 20 healthy individuals were recruited as the baseline control. HbA1c% and metabolic parameter change were evaluated in 17 T2DM patients 12 weeks after they received FMT from healthy donors. The GM composition was characterized by 16S rRNA gene amplicon sequencing from fecal samples prior to and 12 weeks after FMT treatment.

Results

We found that the GM of T2DM patients was reconstituted by FMT. We observed a statistically significant decrease in HbA1c% (from 7.565 ± 0.148 to 7.190 ± 0.210, p<0.01), blood glucose (from 8.483 ± 0.497 to 7.286 ± 0.454 mmol/L, p<0.01), and uric acid (from 309.4 ± 21.5 to 259.1 ± 15.8 µmol/L, p<0.01) while a significant increase in postprandial C-peptide (from 4.503 ± 0.600 to 5.471 ± 0.728 ng/ml, p<0.01) at 12 weeks after FMT. Closely evaluating the changes in these assays, we found individual variability in response to FMT treatment. Out of 17 T2DM patients, 11 were found to significantly improve T2DM symptoms. The FMT responders have significantly higher levels of the family Rikenellaceae and the genus Anaerotruncus (family Ruminococcaceae) in their pretreated fecal in comparison to nonresponders, which could predict the clinical response with an area under the curve of 0.83.

Conclusion

Our findings suggest that certain T2DM patients can potentially benefit from FMT, and the pretreated abundance of Rikenellaceae and Anaerotruncus in the fecal of patients may serve as potential biomarkers for selecting T2DM patients to receive FMT.

Targeting Gut Microbiota With Natural Polysaccharides: Effective Interventions Against High-Fat Diet-Induced Metabolic Diseases

Unhealthy diet, in particular high-fat diet (HFD) intake, can cause the development of several metabolic disorders, including obesity, hyperlipidemia, type 2 diabetes mellitus (T2DM), non-alcoholic fatty liver disease (NAFLD), and metabolic syndrome (MetS). These popular metabolic diseases reduce the quality of life, and induce premature death worldwide. Evidence is accumulating that the gut microbiota is inextricably associated with HFD-induced metabolic disorders, and dietary intervention of gut microbiota is an effective therapeutic strategy for these metabolic dysfunctions. Polysaccharides are polymeric carbohydrate macromolecules and sources of fermentable dietary fiber that exhibit biological activities in the prevention and treatment of HFD-induced metabolic diseases. Of note, natural polysaccharides are among the most potent modulators of the gut microbiota composition. However, the prebiotics-like effects of polysaccharides in treating HFD-induced metabolic diseases remain elusive. In this review, we introduce the critical role of gut microbiota human health and HFD-induced metabolic disorders. Importantly, we review current knowledge about the role of natural polysaccharides in improving HFD-induced metabolic diseases by regulating gut microbiota.

The Herb Pair Radix Rehmanniae and Cornus Officinalis Attenuated Testicular Damage in Mice With Diabetes Mellitus Through Butyric Acid/Glucagon-Like Peptide-1/Glucagon-Like Peptide-1 Receptor Pathway Mediated by Gut Microbiota

Growing body of research indicates that Traditional Chinese Medicine (TCM) interact with gut microbiota (GM) after oral administration. Radix Rehmanniae and Cornus Officinalis (RR-CO), a well-known TCM pair, is often used to treat diabetes mellitus (DM) and its complications. The current study aimed to explore the protective effects of RR-CO on DM induced testicular damage by modulating GM. The RR-CO treatments significantly reduced hyperglycemia, ameliorated testicular ultrastructural damage and inflammation in DM model to varying degrees. Additionally, 16S-ribosomal DNA (rDNA) sequencing results showed that RR-CO treatment increased the amount of butyric acid-producing GM, such as Clostridiaceae_1 family, and decreased the abundance of Catabacter, Marvinbryantia, and Helicobacter genera. RR-CO fecal bacteria transplantation (RC-FMT) increased the abundance of Clostridiaceae_1 in the Model FMT (M-FMT) group and ameliorated testicular damage. Furthermore, treatment with RR-CO increased the fecal butyric acid level, serum Glucagon-like peptide-1 (GLP-1) level, and testicular GLP-1 receptor (GLP-1R) expression compared to those in DM mice. Finally, intraperitoneal administration of sodium butyrate (SB) significantly improved the pathological damage to the testis and reduced inflammation in the DM group. These data demonstrated a protective effect of RR-CO on DM-induced testicular damage by modulation of GM, which may be mediated by the butyric acid/GLP/GLP-1R pathway.