Human gut microbiota changes reveal the progression of glucose intolerance

Evidence of traditional Chinese medicine for treating type 2 diabetes mellitus: from molecular mechanisms to clinical efficacy

CONTEXT

The global prevalence of type 2 diabetes mellitus (T2DM) has increased significantly in recent decades. Despite numerous studies and systematic reviews, there is a gap in comprehensive and up-to-date evaluations in this rapidly evolving field.

OBJECTIVE

This review provides a comprehensive and current overview of the efficacy of Traditional Chinese Medicine (TCM) in treating T2DM.

METHODS

A systematic review was conducted using PubMed, Web of Science, Wanfang Data, CNKI, and Medline databases, with a search timeframe extending up to November 2023. The search strategy involved a combination of subject terms and free words in English, including 'Diabetes,' 'Traditional Chinese Medicine,' 'TCM,' 'Hypoglycemic Effect,' 'Clinical Trial,' and 'Randomized Controlled Trial.' The studies were rigorously screened by two investigators, with a third investigator reviewing and approving the final selection based on inclusion and exclusion criteria.

RESULTS

A total of 108 relevant papers were systematically reviewed. The findings suggest that TCMs not only demonstrate clinical efficacy comparable to existing Western medications in managing hypoglycemia but also offer fewer adverse effects and a multitarget therapeutic approach. Five main biological mechanisms through which TCM treats diabetes were identified: improving glucose transport and utilization, improving glycogen metabolism, promoting GLP-1 release, protecting pancreatic islets from damage, and improving intestinal flora.

CONCLUSIONS

TCM has demonstrated significant protective effects against diabetes and presents a viable option for the prevention and treatment of T2DM. These findings support the further exploration and integration of TCM into broader diabetes management strategies.

Gut microbiome: A revolution in type II diabetes mellitus

Type II diabetes mellitus (T2DM) has experienced a dramatic increase globally across countries of various income levels over the past three decades. The persistent prevalence of T2DM is attributed to a complex interplay of genetic and environmental factors. While numerous pharmaceutical therapies have been developed, there remains an urgent need for innovative treatment approaches that offer effectiveness without significant adverse effects. In this context, the exploration of the gut microbiome presents a promising avenue. Research has increasingly shown that the gut microbiome of individuals with T2DM exhibits distinct differences compared to healthy individuals, suggesting its potential role in the disease’s pathogenesis and progression. This emerging field offers diverse applications, particularly in modifying the gut environment through the administration of prebiotics, probiotics, and fecal microbiome transfer. These inter-ventions aim to restore a healthy microbiome balance, which could potentially alleviate or even reverse the metabolic dysfunctions associated with T2DM. Although current results from clinical trials have not yet shown dramatic effects on diabetes management, the groundwork has been laid for deeper investigation. Ongoing and future clinical trials are critical to advancing our understanding of the microbiome’s impact on diabetes. By further elucidating the mechanisms through which microbiome alterations influence insulin resistance and glucose metabolism, researchers can develop more targeted interventions. The potential to harness the gut microbiome in developing new therapeutic strategies offers a compelling prospect to transform the treatment landscape of T2DM, potentially reducing the disease’s burden significantly with approaches that are less reliant on traditional pharmaceuticals and more focused on holistic, systemic health improvements.

Gut microbiota mediates ambient PM2.5 exposure-induced abnormal glucose metabolism via short-chain fatty acids

PM2.5 exposure has been found to cause gut dysbiosis and impair glucose homeostasis in human and animals, yet their underlying biological connection remain unclear. In the present study, we aim to investigate the biological significance of gut microbiota in PM2.5-induced glucose metabolic abnormalities. Our results showed that microbiota depletion by antibiotics treatment significantly alleviated PM2.5-induced glucose intolerance and insulin resistance, as indicated by the intraperitoneal glucose tolerance test, glucose-induced insulin secretion, insulin tolerance test, insulin-induced phosphorylation levels of Akt and GSK-3β in insulin sensitive tissues. In addition, faecal microbiota transplantation (FMT) from PM2.5-exposed donor mice successfully remodeled the glucose metabolism abnormalities in recipient mice, while the transplantation of autoclaved faecal materials did not. Faecal microbiota analysis demonstrated that the composition and alpha diversity of the gut bacterial community were altered by PM2.5 exposure and in FMT recipient mice. Furthermore, short-chain fatty acids levels analysis showed that the circulating acetate was significantly decreased in PM2.5-exposed donor and FMT recipient mice, and supplementation of sodium acetate for 3 months successfully improved the glucose metabolism abnormalities induced by PM2.5 exposure. These results indicate that manipulating gut microbiota or its metabolites could be a potential strategy for preventing the adverse health effects of ambient PM2.5.

Identifying microbiome-based changes and biomarkers prior to disease development in mother and child, with a focus on gestational diabetes mellitus: protocol for the DANish Maternal and Offspring Microbiome (DANMOM) cohort study

INTRODUCTION

The human gut microbiota is associated with gestational diabetes mellitus (GDM), which imposes a risk of developing long-term health problems for mother and child. Most studies on GDM and microbiota have been cross-sectional, which makes it difficult to make any conclusions on causality. Furthermore, it is important to assess if a dysbiotic microbiota is passed from the mother to the child, and then being at risk of developing metabolic health problems later in life. The DANish Maternal and Offspring Microbiome study aims to identify gut microbiota-related factors involved in metabolic dysfunction in women with GDM and their offspring. Importantly, the study design allows for early detection of biological changes associated with later development of metabolic disease. This could provide us with unique tools to support early diagnosis or implement preventative measures.

METHODS AND ANALYSIS

Pregnant women are included in the study after the 11-14 weeks' prenatal ultrasound scan and followed throughout pregnancy with enrolment of the offspring at birth. 202 women and 112 children have been included from North Denmark Regional Hospital and Aalborg University Hospital in Denmark. Mother and child are followed until the children reach the age of 5 years. From the mother, we collect faeces, urine, blood, saliva, vaginal fluid and breast milk samples, in addition to faeces and a blood sample from the child. Microbiota composition in biological samples will be analysed using 16S rRNA gene sequencing and compared with demographic and clinical data from medical charts, registers and questionnaires. Sample and data collection will continue until July 2028.

ETHICS AND DISSEMINATION

The study protocol has been approved by the North Denmark Region Committee on Health Research Ethics (N20190007). Written informed consent is obtained from all participants prior to study participation. Study results will be published in international peer-reviewed journals and presented at international conferences. The results will also be presented to the funders of the study and study participants.

Study on the mechanism of modified Gegen Qinlian decoction in regulating the intestinal flora-bile acid-TGR5 axis for the treatment of type 2 diabetes mellitus based on macro genome sequencing and targeted metabonomics integration

BACKGROUND

Currently, there are many drugs available for the treatment of type 2 diabetes mellitus (T2DM), but most of them cause various side effects due to the need for long-term use. As a traditional Chinese medicine, Gegen Qinlian Decoction (GQD) has shown good efficacy and low side effects in the treatment of T2DM in both clinical and basic research. Based on relevant traditional Chinese medicine theories, dried ginger is innovatively added the formula of traditional GQD to create a modified GQD. This modification reduces the side effects of traditional GQD while exerting its therapeutic effect on T2DM. Previous studies have found that the modified GQD can regulate endoplasmic reticulum stress in the liver, inhibit hepatic gluconeogenesis, protect pancreatic islet β cells, and control blood sugar levels by inhibiting the FXR/neuronal ceramide signaling pathway. GQD can also regulate the intestinal microbiota to achieve therapeutic and protective effects in various gastrointestinal diseases. However, there is no research exploring whether the modified GQD achieves its therapeutic mechanism for T2DM by regulating the intestinal microbiota.

PURPOSE

To explore the mechanism of modified GQD in the treatment of T2DM based on multi-omics, focusing on its effect on the "intestinal flora bile acid TGR5'' axis.

METHODS

The T2DM model was established using db/db mice, which were randomly divided into a model group, metformin group, high-dose GQD group, medium-dose GQD group, low-dose GQD group, while m/m mice were used as blank control. The drug intervention lasted for 12 weeks, during which the general conditions, oral glucose tolerance (OGT), blood glucose, and lipid-related indexes were recorded. Additionally, the fasting insulin (FINS), c-peptide, GLP-1 in serum, and cAMP in the ileum were measured by ELISA assay. Furthermore, the composition, abundance, and function of the intestinal microbiota were determined by macro genome sequencing, while bile acid was detected by targeted metabonomics. For histological evaluation, HE staining was used to observe the pathological changes of the ileum and pancreas, and the ultrastructure of the ileum and pancreas was observed by transmission electron microscopy. Apoptosis in the ileum tissue was detected by Tunel staining. Moreover, the mRNA and protein expressions of TGR5, PKA, CREB, PC1/3, GLP-1, and their phosphorylation levels in the ileum were detected by qPCR, immunohistochemistry, and Western blot; The expression of INS in the pancreas was also evaluated using immunohistochemistry. Finally, double immunofluorescence staining was used to detect the co-localization expression of TGR5 and GLP-1, NeuroD1, and GLP-1 in the ileum.

RESULTS

The modified GQD was found to significantly reduce blood glucose, improve oral glucose tolerance, and blood lipid levels, as well as alleviate the injury of the ileum and pancreas in T2DM mice. Furthermore, modified GQD was found to effectively regulate intestinal flora, improve bile acid metabolism, activate the TRG5/cAMP/PKA/CREB signal pathway, and stimulate GLP-1 secretion.

CONCLUSION

GQD can regulate the "intestinal flora-bile acid-TGR5" axis and has a therapeutic effect on T2DM in mice.

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.

The potential role of Akkermansia muciniphila in liver health

Akkermansia muciniphila (A. muciniphila) is a 'star strain' that has attracted much attention in recent years. A. muciniphila can effectively regulate host metabolism, significantly affect host immune function, and play an important role in balancing host health and disease. As one of the organs most closely related to the gut (the two can communicate through the hepatic portal vein and bile duct system), liver is widely affected by intestinal microorganisms. A growing body of evidence suggests that A. muciniphila may alleviate liver-related diseases by improving the intestinal barrier, energy metabolism and regulating inflammation through its protein components and metabolites. This paper systematically reviews the key roles of A. muciniphila and its derivatives in maintaining liver health and improving liver disease.

Quantification and Correlation Analysis of Bacteroides Species with Diabetes-Related Amino Acids in Individuals with Prediabetes and Type 2 Diabetes Mellitus

Background: The relationship between gut microbiota and diabetes-related amino acids significantly impacts insulin resistance and obesity. We aimed to quantify two Bacteroidetes species and their correlation with branched-chain amino acids, aromatic amino acids, and glutamate in prediabetes (preDM) and type 2 diabetes mellitus (T2DM). Methods: Fecal samples were collected from 68 participants, including 21 with T2DM, 23 with preDM, and 24 with normal glycemic tolerance (NGT). The abundance of Bacteroides vulgatus and Bacteroides thetaiotaomicron was determined by quantitative real-time polymerase chain reaction. Plasma amino acid measurements were performed using liquid chromatography coupled with tandem mass spectrometry. Results: The quantities of B. vulgatus and B. thetaiotaomicron were reduced in preDM and T2DM than in NGT subjects, but it was not statistically significant. The concentrations of leucine, valine, and tyrosine were significantly higher in preDM and T2DM than in NGT subjects (P < 0.05). A negative correlation was observed between B. thetaiotaomicron abundance and two aromatic amino acids (tyrosine, r = -0.28, P = 0.04; phenylalanine, r = -0.26, P = 0.05). Conclusions: These findings imply that, since gut microbiota varies throughout ethnic groups, further research with many participants will be required to determine the abundance of B. vulgatus and B. thetaiotaomicron in preDM and T2DM and their association with diabetes-related amino acids.

Personalized Microbial Fingerprint Associated with Differential Glycemic Effects of a Whole Grain Rye Intervention on Chinese Adults

SCOPE

This study aims to identify the gut enterotypes that explain differential responses to intervention with whole grain rye by proposing an "enterotype - metabolic" model.

METHODS AND RESULTS

A 12-week randomized controlled trial is conducted in Chinese adults, with 79 subjects consuming whole grain products with fermented rye bran (FRB) and 77 consuming refined wheat products in this exploratory post-hoc analysis. Responders or non-responders are identified according to whether blood glucose decreased by more than 10% after rye intervention. Compared to non-responders, responders in FRB have higher baseline Bacteroides (p < 0.001), associated with reduced blood glucose (p < 0.001), increased Faecalibacterium (p = 0.020) and Erysipelotrichaceae_UCG.003 (p = 0.022), as well as deceased 7β-hydroxysteroid dehydrogenase (p = 0.033) after intervention. The differentiated gut microbiota and metabolites between responders and non-responders after intervention are enriched in aminoacyl-tRNA biosynthesis.

CONCLUSION

The work confirms the previously suggested importance of microbial enterotypes in differential responses to whole grain interventions and supports taking enterotypes into consideration for improved efficacy of whole grain intervention for preventing type 2 diabetes. Altered short-chain fatty acids and bile acid metabolism might be a potential mediator for the beneficial effects of whole grain rye on glucose metabolism.

The Antidiabetic Potential of Probiotics: A Review

Diabetes has become one of the most prevalent global epidemics, significantly impacting both the economy and the health of individuals. Diabetes is associated with numerous complications, such as obesity; hyperglycemia; hypercholesterolemia; dyslipidemia; metabolic endotoxemia; intestinal barrier damage; insulin-secretion defects; increased oxidative stress; and low-grade, systemic, and chronic inflammation. Diabetes cannot be completely cured; therefore, current research has focused on developing various methods to control diabetes. A promising strategy is the use of probiotics for diabetes intervention. Probiotics are a class of live, non-toxic microorganisms that can colonize the human intestine and help improve the balance of intestinal microbiota. In this review, we summarize the current clinical studies on using probiotics to control diabetes in humans, along with mechanistic studies conducted in animal models. The primary mechanism by which probiotics regulate diabetes is improved intestinal barrier integrity, alleviated oxidative stress, enhanced immune response, increased short-chain fatty acid production, etc. Therefore, probiotic supplementation holds great potential for the prevention and management of diabetes.

Antrodia camphorata Supplementation during Early Life Alters Gut Microbiota and Inhibits Young-Onset Intestinal Tumorigenesis in APC1638N Mice Later in Life

Young-onset colorectal cancer is an increasing concern worldwide due to the growing prevalence of Westernized lifestyles in childhood and adolescence. Environmental factors during early life, particularly early-life nutrition, significantly contribute to the increasing incidence. Recently, there have been reports of beneficial effects, including anti-inflammation and anti-cancer, of a unique fungus (Antrodia camphorate, AC) native to Taiwan. The objective of this study is to investigate the impact of AC supplementation in early life on the development of young-onset intestinal tumorigenesis. APC1638N mice were fed with a high-fat diet (HF) at 4-12 weeks of age, which is equivalent to human childhood/adolescence, before switching to a normal maintenance diet for an additional 12 weeks up to 24 weeks of age, which is equivalent to young to middle adulthood in humans. Our results showed that the body weight in the HF groups significantly increased after 8 weeks of feeding (p < 0.05). Following a switch to a normal maintenance diet, the change in body weight persisted. AC supplementation significantly suppressed tumor incidence and multiplicity in females (p < 0.05) and reduced IGF-1 and Wnt/β-catenin signaling (p < 0.05). Moreover, it altered the gut microbiota, suppressed inflammatory responses, and created a microenvironment towards suppressing tumorigenesis later in life.

Functional Properties, Rheological Characteristics, Simulated Digestion, and Fermentation by Human Fecal Microbiota of Polysaccharide from Morchella importuna

Morchella importuna polysaccharide (MIP) has been proven to have obvious hypoglycemic effects on mice with type 2 diabetes (T2DM). This study looked at the functional and rheological characteristics of MIP, and investigated the effects of MIP on the human fecal microbiota through in vitro fermentation experiments. The outcomes demonstrate the excellent oil-holding capacity, emulsifying, foaming, and rheological characteristics of MIP. After salivary gastrointestinal digestion, the Mw of MIP decreased from 398.2 kDa and 21.5 kDa to 21.9 kDa and 11.7 kDa. By 16S rRNA sequencing of bacteria fermented in vitro, it was found that MIP did not improve the richness and diversity of intestinal microorganisms, but it may exert an anti-T2DM function by significantly increasing the relative abundance of Firmicutes and promoting Ruminococcaceae_UCG_014, Bacteroides, and Blautia proliferation. Escherichia-Shigella could also be inhibited to improve the intestinal microenvironment. In addition, the fermentation of MIP increased the total short-chain fatty acid (SCFA) concentration from 3.23 mmol/L to 39.12 mmol/L, and the propionic acid content increased significantly. In summary, MIP has excellent processing performance and is expected to exert potential anti-T2DM activity through the human intestinal microbiota, which has broad market prospects.

Gut microbiota-based prediction for the transition from normal glucose tolerance (NGT) to impaired glucose tolerance (IGT) in a remote island cohort study

AIM

The present cohort study explored whether specific gut microbiota (GM) profile would predict the development of impaired glucose tolerance (IGT) in individuals with normal glucose tolerance (NGT).

METHODS

A total of 114 study subjects with NGT in Kumejima island, Japan participated in the present study and underwent 75 g oral glucose tolerance tests at baseline and one year later. We compared the profile of GM at baseline between individuals who consistently maintained NGT (NRN, n = 108) and those who transitioned from NGT to IGT (NTI, n = 6).

RESULTS

Within-individual bacterial richness and evenness as well as inter-individual bacterial composition showed no significant differences between NRN and NTI. Of note, however, partial least squares discriminant analyses revealed distinct compositions of GM between groups, with no overlap in their 95 % confidence interval ellipses. Multi-factor analyses at the genus level demonstrated that the proportions of CF231, Corynebacterium, Succinivibrio, and Geobacillus were significantly elevated in NTI compared to NRN (p < 0.005, FDR < 0.1, respectively) after adjusting for age, sex, HbA1c level, and BMI.

CONCLUSIONS

Our data suggest that increased proportion of specific GM is linked to the future deterioration of glucose tolerance, thereby serving as a promising predictive marker for type 2 diabetes mellitus.

Investigating the causal association between gut microbiota and type 2 diabetes: a meta-analysis and Mendelian randomization

Background

Studies have shown that gut dysbiosis contributes to the pathophysiology of type 2 diabetes mellitus (T2DM). Identifying specific gut microbiota dysbiosis may provide insight into the pathogenesis of T2DM.

Purpose

This study investigated the causal relationship between gut microbiota and T2DM using meta-analysis and Mendelian randomization (MR).

Methods

In the first part, we searched for literature on gut microbiota and T2DM, and conducted a meta-analysis. We observed differences in glycosylated hemoglobin and fasting blood glucose levels in both groups. Second, we obtained GWAS data from genome-wide association study database 19 (GWAS). We used two-sample MR analysis to verify the forward and reverse causal associations between gut microbiota and T2DM. Additionally, we selected the European GWAS data from the European Bioinformatics Institute (EBI) as a validation set for external validation of the MR analysis. In the third part, we aimed to clarify which gut microbiota contribute to the degree of causal association between group disorders and T2DM through multivariate MR analysis and Bayesian model averaging (MR-BMA).

Results

1. According to the meta-analysis results, the glycated hemoglobin concentration in the gut probiotic intervention group was significantly lower than in the control group. Following treatment, fasting blood glucose levels in the intervention group were significantly lower than those in the control group. 2. The results of two samples MR analysis revealed that there were causal relationships between six gut microbiota and T2DM. Genus Haemophilus and order Pasteurellaceae were negatively correlated with T2DM. Genus Actinomycetes, class Melanobacteria and genus Lactobacillus were positively correlated. Reverse MR analysis demonstrated that T2DM and gut microbiota did not have any reverse causal relationship. The external validation data set showed a causal relationship between gut microbiota and T2DM. 3. Multivariate MR analysis and MR-BMA results showed that the independent genus Haemophilus collection had the largest PP.

Conclusion

Our research results suggest that gut microbiota is closely related to T2DM pathogenesis. The results of further MR research and an analysis of the prediction model indicate that a variety of gut microbiota disorders, including genus Haemophilus, are causally related to the development of T2DM. The findings of this study may provide some insight into the diagnosis and treatment of T2DM.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO.

Effects of germinated brown rice and germinated black rice on people with type 2 diabetes mellitus combined with dyslipidaemia

Objective: This study aimed to observe the effects of germinated brown rice and germinated black rice on blood lipid levels, blood glucose levels and lipid metabolism-related enzymes in T2DM patients with dyslipidaemia and to study their effects on the gut microbiome and short-chain fatty acids. Methods: According to the inclusion and exclusion criteria, 68 subjects were randomly divided into a germinated brown rice group, a germinated black rice group and a white rice group. At the end of the intervention, relevant anthropometric indices, blood biochemistry, and levels of adipokines and lipid metabolism-related enzymes were measured. Faecal samples were collected for 16S rDNA high-throughput sequencing and for an analysis of short-chain fatty acids. Results: After 3 months of intervention with germinated brown rice, germinated black rice or white rice, 21 people in each group completed the intervention as required. At the end of the intervention, the levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in the germinated brown rice group and germinated black rice group were significantly lower than those in the white rice group. The levels of adiponectin (ADPN) and lecithin cholesterol acyltransferase (LCAT) in the germinated brown rice group were significantly higher than those in the white rice group (P < 0.05). At the genus level, interventions with germinated brown rice and germinated black rice significantly increased the relative abundance of Megamonas, Muribaculaceae and Alloprevotella and significantly decreased the relative abundance of Veillonella (P < 0.05). After 3 months of intervention, a significant decrease in waist circumference was observed within the germinated brown rice group compared to that at baseline (P < 0.05). Conclusions: Compared with the consumption of white rice, the consumption of germinated brown rice and germinated black rice can effectively regulate the glucose and lipid metabolism of this population. In addition, interventions involving the use of germinated brown rice and germinated black rice may further improve intestinal diversity and abundance, increase the relative abundance of Megamonas and decrease the relative abundance of Veillonella.

Purple sweet potato anthocyanins normalize the blood glucose concentration and restore the gut microbiota in mice with type 2 diabetes mellitus

Background

This study investigated the effects of purple sweet potato anthocyanins (PSPA) in a type 2 diabetes mellitus (T2DM) mouse model.

Methods

Sixty-five male mice were randomly divided into one control group and four experimental groups, which were fed with a high-fat diet and intraperitoneally injected with streptozotocin (STZ) to induce T2DM. The model mice were treated with 0 (M), 227.5 (LP), 455 (MP), or 910 (HP) mg/kg PSPA for ten days. ELISA, 16S rRNA sequencing, and hematoxylin and eosin staining were used to assess blood biochemical parameters, gut microbial composition, and liver tissue structure, respectively.

Results

The FBG concentration was significantly decreased in the LP (6.32 ± 1.05 mmol/L), MP (6.32 ± 1.05 mmol/L), and HP (5.65 ± 0.83 mmol/L) groups; the glycosylated hemoglobin levels were significantly decreased in the HP group (14.43 ± 7.12 pg/mL) compared with that in the M group (8.08 ± 1.04 mmol/L; 27.20 ± 7.72 pg/mL; P < 0.05). The PSPA treated groups also increased blood glutathione levels compared with M. PSPA significantly affected gut microbial diversity. The Firmicutes/Bacteroidetes ratio decreased by 38.9 %, 49.2 %, and 15.9 % in the LP, MP, and HP groups compared with that in the M group (0.62). The PSPAs treated groups showed an increased relative abundance of Lachnospiraceae_Clostridium, Butyricimonas, and Akkermansia and decreased abundance of nine bacterial genera, including Staphylococcus.

Conclusion

PSPA reduced blood glucose levels, increased serum antioxidant enzymes, and optimized the diversity and structure of the gut microbiota in mice with T2DM.

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.

Effect of oral tryptamines on the gut microbiome of rats-a preliminary study

Background

Psilocybin and related tryptamines have come into the spotlight in recent years as potential therapeutics for depression. Research on the mechanisms of these effects has historically focused on the direct effects of these drugs on neural processes. However, in addition to such neural effects, alterations in peripheral physiology may also contribute to their therapeutic effects. In particular, substantial support exists for a gut microbiome-mediated pathway for the antidepressant efficacy of other drug classes, but no prior studies have determined the effects of tryptamines on microbiota.

Methods

To address this gap, in this preliminary study, male Long Evans rats were treated with varying dosages of oral psilocybin (0.2 or 2 mg/kg), norbaeocystin (0.25 or 2.52 mg/kg), or vehicle and their fecal samples were collected 1 week and 3 weeks after exposure for microbiome analysis using integrated 16S ribosomal DNA sequencing to determine gut microbiome composition.

Results

We found that although treatment with neither psilocybin nor norbaeocystin significantly affected overall microbiome diversity, it did cause significant dose- and time-dependent changes in bacterial abundance at the phylum level, including increases in Verrucomicrobia and Actinobacteria, and decreases in Proteobacteria.

Conclusion and Implications

These preliminary findings support the idea that psilocybin and other tryptamines may act on the gut microbiome in a dose- and time-dependent manner, potentially identifying a novel peripheral mechanism for their antidepressant activity. The results from this preliminary study also suggest that norbaeocystin may warrant further investigation as a potential antidepressant, given the similarity of its effects to psilocybin.

Effects of modified-BHI medium on the growth and metabolites of Akkermansia muciniphila

Akkermansia muciniphila (Akk) has recently become popular due to its therapeutic effect on various diseases. However, Akk's high-density cultivation is difficult due to its anaerobic characteristics. Therefore, Akk was cultured with modified brain-heart infusion (M-BHI) to reach 1011 CFU/mL. 1H-NMR determined the metabolites of Akk and validated them by an amino acid analyzer. Compared to the BHI, Akk significantly up-regulated lactate, histidine, fumaric acid, cytidine, threonine, arginine, and hydroxyproline in the M-BHI and significantly down-regulated methionine, trimethylamine, and sarcosine. Regarding pathway enrichment analysis, histidine metabolism, arginine and proline metabolism, cysteine and methionine metabolism mainly regulate differential metabolites. In addition, M-BHI alters the metabolic profile by affecting Akk's involvement in amino acid metabolism remodeling. Changed metabolites showed that Akk fermentation in M-BHI may play a physiological role in regulating immune homeostasis and reducing risk factors related to diseases. Therefore, M-BHI provides a promising reference for Akk cultivation in future industrial preparation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01492-x.

Antidiabetic Potential of Tea and Its Active Compounds: From Molecular Mechanism to Clinical Evidence

Diabetes mellitus (DM) is a chronic endocrine disorder that poses a long-term risk to human health accompanied by serious complications. Common antidiabetic drugs are usually accompanied by side effects such as hepatotoxicity and nephrotoxicity. There is an urgent need for natural dietary alternatives for diabetic treatment. Tea (Camellia sinensis) consumption has been widely investigated to lower the risk of diabetes and its complications through restoring glucose metabolism homeostasis, safeguarding pancreatic β-cells, ameliorating insulin resistance, ameliorating oxidative stresses, inhibiting inflammatory response, and regulating intestinal microbiota. It is indispensable to develop effective strategies to improve the absorption of tea active compounds and exert combinational effects with other natural compounds to broaden its hypoglycemic potential. The advances in clinical trials and population-based investigations are also discussed. This review primarily delves into the antidiabetic potential and underlying mechanisms of tea active compounds, providing a theoretical basis for the practical application of tea and its active compounds against diabetes.

Causal effect between gut microbiota and metabolic syndrome in European population: a bidirectional mendelian randomization study

BACKGROUND

Observational studies have reported that gut microbiota composition is associated with metabolic syndrome. However, the causal effect of gut microbiota on metabolic syndrome has yet to be confirmed.

METHODS

We performed a bidirectional Mendelian randomization study to investigate the causal effect between gut microbiota and metabolic syndrome in European population. Summary statistics of gut microbiota were from the largest available genome-wide association study meta-analysis (n = 13,266) conducted by the MiBioGen consortium. The summary statistics of outcome were obtained from the most comprehensive genome-wide association studies of metabolic syndrome (n = 291,107). The inverse-variance weighted method was applied as the primary method, and the robustness of the results was assessed by a series of sensitivity analyses.

RESULTS

In the primary causal estimates, Actinobacteria (OR = 0.935, 95% CI = 0.878-0.996, P = 0.037), Bifidobacteriales (OR = 0.928, 95% CI = 0.868-0.992, P = 0.028), Bifidobacteriaceae (OR = 0.928, 95% CI = 0.868-0.992, P = 0.028), Desulfovibrio (OR = 0.920, 95% CI = 0.869-0.975, P = 0.005), and RuminococcaceaeUCG010 (OR = 0.882, 95% CI = 0.803-0.969, P = 0.009) may be associated with a lower risk of metabolic syndrome, while Lachnospiraceae (OR = 1.130, 95% CI = 1.016-1.257, P = 0.025), Veillonellaceae (OR = 1.055, 95% CI = 1.004-1.108, P = 0.034) and Olsenella (OR = 1.046, 95% CI = 1.009-1.085, P = 0.015) may be linked to a higher risk for metabolic syndrome. Reverse MR analysis demonstrated that abundance of RuminococcaceaeUCG010 (OR = 0.938, 95% CI = 0.886-0.994, P = 0.030) may be downregulated by metabolic syndrome. Sensitivity analyses indicated no heterogeneity or horizontal pleiotropy.

CONCLUSIONS

Our Mendelian randomization study provided causal relationship between specific gut microbiota and metabolic syndrome, which might provide new insights into the potential pathogenic mechanisms of gut microbiota in metabolic syndrome and the assignment of effective therapeutic strategies.

Effects of dietary phytosterols or phytosterol esters supplementation on growth performance, biochemical blood indices and intestinal flora of C57BL/6 mice

This study was conducted to evaluate the effects of phytosterols (PS) and phytosterol esters (PSE) on C57BL/6 mice. Three groups of 34 six-week-old C57BL/6 mice of specific pathogen free (SPF) grade, with an average initial body weight (IBW) of 17.7g, were fed for 24 days either natural-ingredient diets without supplements or diets supplemented with 89 mg/kg PS or diets supplemented with 400 mg/kg PSE. Growth performance, blood biochemistry, liver and colon morphology as well as intestinal flora status were evaluated. Both PS and PSE exhibited growth promotion and feed digestibility in mice. In blood biochemistry, the addition of both PS and PSE to the diet resulted in a significant decrease in Total Cholesterol (TC) and Triglyceride (TG) levels and an increase in Superoxide Dismutase (SOD) activity. No significant changes in liver and intestinal morphology were observed. Both increased the level of Akkermansia in the intestinal tract of mice. There was no significant difference between the effects of PS and PSE. It was concluded that dietary PS and PSE supplementation could improve growth performance, immune performance and gut microbiome structure in mice, providing insights into its application as a potential feed additive in animals production.

Characterization of the gut bacterial and viral microbiota in latent autoimmune diabetes in adults

Latent autoimmune diabetes in adults (LADA) is a heterogeneous disease characterized by autoantibodies against insulin producing pancreatic beta cells and initial lack of need for insulin treatment. The aim of the present study was to investigate if individuals with LADA have an altered gut microbiota relative to non-diabetic control subjects, individuals with type 1 diabetes (T1D), and individuals with type 2 diabetes (T2D). Bacterial community profiling was performed with primers targeting the variable region 4 of the 16S rRNA gene and sequenced. Amplicon sequence variants (ASVs) were generated with DADA2 and annotated to the SILVA database. The gut virome was sequenced, using a viral particle enrichment and metagenomics approach, assembled, and quantified to describe the composition of the viral community. Comparison of the bacterial alpha- and beta-diversity measures revealed that the gut bacteriome of individuals with LADA resembled that of individuals with T2D. Yet, specific genera were found to differ in abundance in individuals with LADA compared with T1D and T2D, indicating that LADA has unique taxonomical features. The virome composition reflected the stability of the most dominant order Caudovirales and the families Siphoviridae, Podoviridae, and Inoviridae, and the dominant family Microviridae. Further studies are needed to confirm these findings.

Multiomics analysis investigating the impact of a high-fat diet in female Sprague-Dawley rats: alterations in plasma, intestinal metabolism, and microbial composition

Introduction

With improvements in living conditions, modern individuals exhibit a pronounced inclination towards a high-fat diet, largely because of its distinctive gustatory appeal. However, the association between high-fat diets and metabolic complications has largely been ignored, and metabolic diseases such as obesity and non-alcoholic fatty liver disease now constitute a major public health concern. Because high-fat diets increase the risk of metabolic diseases, a thorough investigation into the impact of high-fat diets on gut microbiota and metabolism is required.

Methods

We utilize 16S rRNA sequencing and untargeted metabolomics analysis to demonstrate that SD rats fed a high-fat diet exhibited marked alterations in gut microbiota and plasma, intestinal metabolism.

Results

Changes in gut microbiota included a decreased abundance at phylum level for Verrucomicrobiota, and a decreased abundance at genus level for Akkermansia, Ralstonia, Bacteroides, and Faecalibacterium. Additionally, significant changes were observed in both intestinal and plasma metabolite levels, including an upregulation of bile acid metabolism, an upregulation of glucose-lipid metabolism, and increased levels of metabolites such as norlithocholic acid, cholic acid, D-fructose, D-mannose, fructose lactate, and glycerophosphocholine. We also investigated the correlations between microbial communities and metabolites, revealing a significant negative correlation between Akkermansia bacteria and cholic acid.

Discussion

Overall, our findings shed light on the relationship between symbiotic bacteria associated with high-fat diets and metabolic biomarkers, and they provide insights for identifying novel therapeutic approaches to mitigate disease risks associated with a high-fat diet.

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.

Unveiling the connection between gut microbiome and metabolic health in individuals with chronic spinal cord injury

Accumulating evidence has revealed that alterations in the gut microbiome following spinal cord injury (SCI) exhibit similarities to those observed in metabolic syndrome. Considering the causal role of gut dysbiosis in metabolic syndrome development, SCI-induced gut dysbiosis may be a previously unidentified contributor to the increased risk of cardiometabolic diseases, which has garnered attention. With a cross-sectional design, we evaluated the correlation between gut microbiome composition and functional potential with indicators of metabolic health among 46 individuals with chronic SCI. Gut microbiome communities were profiled using next-generation sequencing techniques. Indices of metabolic health, including fasting lipid profile, glucose tolerance, insulin resistance, and inflammatory markers, were assessed through fasting blood tests and an oral glucose tolerance test. We used multivariate statistical techniques (i.e., regularized canonical correlation analysis) to identify correlations between gut bacterial communities, functional pathways, and metabolic health indicators. Our findings spotlight bacterial species and functional pathways associated with complex carbohydrate degradation and maintenance of gut barrier integrity as potential contributors to improved metabolic health. Conversely, those correlated with detrimental microbial metabolites and gut inflammatory pathways demonstrated associations with poorer metabolic health outcomes. This cross-sectional investigation represents a pivotal initial step toward comprehending the intricate interplay between the gut microbiome and metabolic health in SCI. Furthermore, our results identified potential targets for future research endeavors to elucidate the role of the gut microbiome in metabolic syndrome in this population.NEW & NOTEWORTHY Spinal cord injury (SCI) is accompanied by gut dysbiosis and the impact of this on the development of metabolic syndrome in this population remains to be investigated. Our study used next-generation sequencing and multivariate statistical analyses to explore the correlations between gut microbiome composition, function, and metabolic health indices in individuals with chronic SCI. Our results point to potential gut microbial species and functional pathways that may be implicated in the development of metabolic syndrome.

The role of Akkermansia muciniphila in colorectal cancer: A double-edged sword of treatment or disease progression?

Colorectal cancer (CRC) is the second most cancer-related death worldwide. In recent years, probiotics have been used to reduce the potential risks of CRC and tumors with various mechanisms. Different bacteria have been suggested to play different roles in the progression, prevention, or treatment of CRC. Akkermansia muciniphila is considered a next-generation probiotic for preventing and treating some diseases. Therefore, in this review article, we aimed to describe and discuss different mechanisms of A. muciniphila as an intestinal microbiota or probiotic in CRC. Some studies suggested that the abundance of A. muciniphila was higher or increased in CRC patients compared to healthy individuals. However, the decreased abundance of A. muciniphila was associated with severe symptoms of CRC, indicating that A. muciniphila did not play a role in the development of CRC. In addition, A. muciniphila administration elevates gene expression of proliferation-associated molecules such as S100A9, Dbf4, and Snrpd1, or markers for cell proliferation. Some other studies suggested that inflammation and tumorigenesis in the intestine might promoted by A. muciniphila. Overall, the role of A. muciniphila in CRC development or inhibition is still unclear and controversial. Various methods of bacterial supplementation, such as viability, bacterial number, and abundance, could all influence the colonization effect of A. muciniphila administration and CRC progression. Overall, A. mucinipila has been revealed to modulate the therapeutic potential of immune checkpoint inhibitors. Preliminary human data propose that oral consumption of A. muciniphila is safe, but its efficacy needs to be confirmed in more human clinical studies.

Gut microbiota and therapy for obesity and type 2 diabetes

There has been a major increase in Type 2 diabetes and obesity in many countries, and this will lead to a global public health crisis, which not only impacts on the quality of life of individuals well but also places a substantial burden on healthcare systems and economies. Obesity is linked to not only to type 2 diabetes but also cardiovascular diseases, musculoskeletal disorders, and certain cancers, also resulting in increased medical costs and diminished quality of life. A number of studies have linked changes in gut in obesity development. Dysbiosis, a deleterious change in gut microbiota composition, leads to altered intestinal permeability, associated with obesity and Type 2 diabetes. Many factors affect the homeostasis of gut microbiota, including diet, genetics, circadian rhythms, medication, probiotics, and antibiotics. In addition, bariatric surgery induces changes in gut microbiota that contributes to the metabolic benefits observed post-surgery. Current obesity management strategies encompass dietary interventions, exercise, pharmacotherapy, and bariatric surgery, with emerging treatments including microbiota-altering approaches showing promising efficacy. While pharmacotherapy has demonstrated significant advancements in recent years, bariatric surgery remains one of the most effective treatments for sustainable weight loss. However, access to this is generally limited to those living with severe obesity. This underscores the need for non-surgical interventions, particularly for adolescents and mildly obese patients. In this comprehensive review, we assess longitudinal alterations in gut microbiota composition and functionality resulting from the two currently most effective anti-obesity treatments: pharmacotherapy and bariatric surgery. Additionally, we highlight the functions of gut microbiota, focusing on specific bacteria, their metabolites, and strategies for modulating gut microbiota to prevent and treat obesity. This review aims to provide insights into the evolving landscape of obesity management and the potential of microbiota-based approaches in addressing this pressing global health challenge.

Metformin and the Liver: Unlocking the Full Therapeutic Potential

Metformin is a highly effective medication for managing type 2 diabetes mellitus. Recent studies have shown that it has significant therapeutic benefits in various organ systems, particularly the liver. Although the effects of metformin on metabolic dysfunction-associated steatotic liver disease and metabolic dysfunction-associated steatohepatitis are still being debated, it has positive effects on cirrhosis and anti-tumoral properties, which can help prevent the development of hepatocellular carcinoma. Furthermore, it has been proven to improve insulin resistance and dyslipidaemia, commonly associated with liver diseases. While more studies are needed to fully determine the safety and effectiveness of metformin use in liver diseases, the results are highly promising. Indeed, metformin has a terrific potential for extending its full therapeutic properties beyond its traditional use in managing diabetes.

Akkermansia muciniphila: a potential candidate for ameliorating metabolic diseases

Metabolic diseases are comprehensive disease based on obesity. Numerous cumulative studies have shown a certain correlation between the fluctuating abundance of Akkermansia muciniphila and the occurrence of metabolic diseases. A. muciniphila, a potential probiotic candidate colonized in the human intestinal mucus layer, and its derivatives have various physiological functions, including treating metabolic disorders and maintaining human health. This review systematically explicates the abundance change rules of A. muciniphila in metabolic diseases. It also details the high efficacy and specific molecules mechanism of A. muciniphila and its derivatives in treating obesity, type 2 diabetes mellitus, cardiovascular disease, and non-alcoholic fatty liver disease.

Lead exposure exacerbates liver injury in high-fat diet-fed mice by disrupting the gut microbiota and related metabolites

Lead (Pb) is a widespread toxic endocrine disruptor that could cause liver damage and gut microbiota dysbiosis. However, the causal relationship and underlying mechanisms between the gut microbiota and Pb-induced liver injury are unclear. In this study, we investigated the metabolic toxicity caused by Pb exposure in normal chow (Chow) and high-fat diet (HFD) mice and confirmed the causal relationship by fecal microbial transplantation (FMT) and antibiotic cocktail experiments. The results showed that Pb exposure exacerbated HFD-induced hepatic lipid deposition, fibrosis, and inflammation, but it had no significant effect on Chow mice. Pb increased serum lipopolysaccharide (LPS) levels and induced intestinal inflammation and barrier damage by activating TLR4/NFκB/MLCK in HFD mice. Furthermore, Pb exposure disrupted the gut microbiota, reduced short-chain fatty acid (SCFA) concentrations and the colonic SCFA receptors, G protein-coupled receptor (GPR) 41/43/109A, in HFD mice. Additionally, Pb significantly inhibited the hepatic GPR109A-mediated adenosine 5'-monophosphate-activated protein kinase (AMPK) pathway, resulting in hepatic lipid accumulation. FMT from Pb-exposed HFD mice exacerbated liver damage, disturbed lipid metabolic pathways, impaired intestinal barriers, and altered the gut microbiota and metabolites in recipient mice. However, mice exposed to HFD + Pb and HFD mice had similar levels of these biomarkers in microbiota depleted by antibiotics. In conclusion, our study provides new insights into gut microbiota dysbiosis as a potential novel mechanism for human health related to liver function impairment caused by Pb exposure.

Assessing the causal relationship between gut microbiota and diabetic nephropathy: insights from two-sample Mendelian randomization

Background

The causal association between gut microbiota (GM) and the development of diabetic nephropathy (DN) remains uncertain. We sought to explore this potential association using two-sample Mendelian randomization (MR) analysis.

Methods

Genome-wide association study (GWAS) data for GM were obtained from the MiBioGen consortium. GWAS data for DN and related phenotypes were collected from the FinngenR9 and CKDGen databases. The inverse variance weighted (IVW) model was used as the primary analysis model, supplemented by various sensitivity analyses. Heterogeneity was assessed using Cochran's Q test, while horizontal pleiotropy was evaluated through MR-Egger regression and the MR-PRESSO global test. Reverse MR analysis was conducted to identify any reverse causal effects.

Results

Our analysis identified twenty-five bacterial taxa that have a causal association with DN and its related phenotypes (p < 0.05). Among them, only the g_Eubacterium_coprostanoligenes_group showed a significant causal association with type 1 DN (p < Bonferroni-adjusted p-value). Our findings remained consistent regardless of the analytical approach used, with all methods indicating the same direction of effect. No evidence of heterogeneity or horizontal pleiotropy was observed. Reverse MR analysis did not reveal any causal associations.

Conclusions

This study established a causal association between specific GM and DN. Our findings contribute to current understanding of the role of GM in the development of DN, offering potential insights for the prevention and treatment strategies for this condition.

Causal relationship between gut microbiota and diabetic nephropathy: a two-sample Mendelian randomization study

Objective

Emerging evidence has provided compelling evidence linking gut microbiota (GM) and diabetic nephropathy (DN) via the "gut-kidney" axis. But the causal relationship between them hasn't been clarified yet. We perform a Two-Sample Mendelian randomization (MR) analysis to reveal the causal connection with GM and the development of DN, type 1 diabetes nephropathy (T1DN), type 2 diabetes nephropathy (T2DN), type 1 diabetes mellitus (T1DM), and type 2 diabetes mellitus (T2DM).

Methods

We used summary data from MiBioGen on 211 GM taxa in 18340 participants. Generalized MR analysis methods were conducted to estimate their causality on risk of DN, T1DN, T2DN, T1DM and T2DM from FinnGen. To ensure the reliability of the findings, a comprehensive set of sensitivity analyses were conducted to confirm the resilience and consistency of the results.

Results

It was showed that Class Verrucomicrobiae [odds ratio (OR) =1.5651, 95%CI:1.1810-2.0742,PFDR=0.0018], Order Verrucomicrobiales (OR=1.5651, 95%CI: 1.1810-2.0742, PFDR=0.0018) and Family Verrucomicrobiaceae (OR=1.3956, 95%CI:1.0336-1.8844, PFDR=0.0296) had significant risk of DN. Our analysis found significant associations between GM and T2DN, including Class Verrucomimicrobiae (OR=1.8227, 95% CI: 1.2414-2.6763, PFDR=0.0139), Order Verrucomimicrobiae (OR=1.5651, 95% CI: 1.8227-2.6764, PFDR=0.0024), Rhodospirillales (OR=1.8226, 95% CI: 1.2412-2.6763, PFDR=0.0026), and Family Verrucomicroniaceae (OR=1.8226, 95% CI: 1.2412-2.6763, PFDR=0.0083). The Eubacteriumprotogenes (OR=0.4076, 95% CI: 0.2415-0.6882, PFDR=0.0021) exhibited a protection against T1DN. Sensitivity analyses confirmed that there was no significant heterogeneity and pleiotropy.

Conclusions

At the gene prediction level, we identified the specific GM that is causally linked to DN in both T1DM and T2DM patients. Moreover, we identified distinct microbial changes in T1DN that differed from those seen in T2DN, offering valuable insights into GM signatures associated with subtype of nephropathy.

High fat diet is associated with gut microbiota dysbiosis and decreased gut microbial derived metabolites related to metabolic health in young Göttingen Minipigs

The objectives were 1) to characterize a Göttingen Minipig model of metabolic syndrome regarding its colon microbiota and circulating microbial products, and 2) to assess whether ovariectomized female and castrated male minipigs show similar phenotypes. Twenty-four nine-week-old Göttingen Minipigs were allocated to four groups based on sex and diet: ovariectomized females and castrated males fed either chow or high-fat diet (HFD) for 12 weeks. At study end, body composition and plasma biomarkers were measured, and a mixed meal tolerance test (MMT) and an intravenous glucose tolerance test (IVGTT) were performed. The HFD groups had significantly higher weight gain, fat percentage, fasting plasma insulin and glucagon compared to the chow groups. Homeostatic model assessment of insulin resistance index (HOMA-IR) was increased and glucose effectiveness derived from the IVGTT and Matsuda´s insulin sensitivity index from the MMT were decreased in the HFD groups. The HFD groups displayed dyslipidemia, with significantly increased total-, LDL- and HDL-cholesterol, and decreased HDL/non-HDL cholesterol ratio. The colon microbiota of HFD minipigs clearly differed from the lean controls (GuniFrac distance matrix). The main bacteria families driving this separation were Clostridiaceae, Fibrobacteraceae, Flavobacteriaceae and Porphyromonadaceae. Moreover, the species richness was significantly decreased by HFD. In addition, HFD decreased the circulating level of short chain fatty acids and beneficial microbial metabolites hippuric acid, xanthine and trigonelline, while increasing the level of branched chain amino acids. Six and nine metabolically relevant genes were differentially expressed between chow-fed and HFD-fed animals in liver and omental adipose tissue, respectively. The HFD-fed pigs presented with metabolic syndrome, gut microbial dysbiosis and a marked decrease in healthy gut microbial products and thus displayed marked parallels to human obesity and insulin resistance. HFD-fed Göttingen Minipig therefore represents a relevant animal model for studying host-microbiota interactions. No significant differences between the castrated and ovariectomized minipigs were observed.

Effect of Blueberry Supplementation on a Diet-Induced Rat Model of Prediabetes-Focus on Hepatic Lipid Deposition, Endoplasmic Stress Response and Autophagy

Blueberries, red fruits enriched in polyphenols and fibers, are envisaged as a promising nutraceutical intervention in a plethora of metabolic diseases. Prediabetes, an intermediate state between normal glucose tolerance and type 2 diabetes, fuels the development of complications, including hepatic steatosis. In previous work, we have demonstrated that blueberry juice (BJ) supplementation benefits glycemic control and lipid profile, which was accompanied by an amelioration of hepatic mitochondrial bioenergetics. The purpose of this study is to clarify the impact of long-term BJ nutraceutical intervention on cellular mechanisms that govern hepatic lipid homeostasis, namely autophagy and endoplasmic reticulum (ER) stress, in a rat model of prediabetes. Two groups of male Wistar rats, 8-weeks old, were fed a prediabetes-inducing high-fat diet (HFD) and one group was fed a control diet (CD). From the timepoint where the prediabetic phenotype was achieved (week 16) until the end of the study (week 24), one of the HFD-fed groups was daily orally supplemented with 25 g/kg body weight (BW) of BJ (HFD + BJ). BW, caloric intake, glucose tolerance and insulin sensitivity were monitored throughout the study. The serum and hepatic lipid contents were quantified. Liver and interscapular brown and epidydimal white adipose tissue depots (iBAT and eWAT) were collected for histological analysis and to assess thermogenesis, ER stress and autophagy markers. The gut microbiota composition and the short-chain fatty acids (SCFAs) content were determined in colon fecal samples. BJ supplementation positively impacted glycemic control but was unable to prevent obesity and adiposity. BJ-treated animals presented a reduction in fecal SCFAs, increased markers of arrested iBAT thermogenesis and energy expenditure, together with an aggravation of HFD-induced lipotoxicity and hepatic steatosis, which were accompanied by the inhibition of autophagy and ER stress responses in the liver. In conclusion, despite the improvement of glucose tolerance, BJ supplementation promoted a major impact on lipid management mechanisms at liver and AT levels in prediabetic animals, which might affect disease course.

Gut microbiome signature of metabolically healthy obese individuals according to anthropometric, metabolic and inflammatory parameters

In this study, we investigated the characteristics of gut microbiome in the metabolically healthy obese (MHO) patients, and how they correlate with metabolic and inflammatory profiles. A total of 120 obese people without metabolic comorbidities were recruited, and their clinical phenotypes, metabolic and inflammatory parameters were analysed. The faecal microbial markers originating from bacterial cell and extracellular vesicle (EV) were profiled using 16S rDNA sequencing. The total study population could be classified into two distinct enterotypes (enterotype I: Prevotellaceae-predominant, enterotype II: Akkermansia/Bacteroides-predominant), based on their stool EV-derived microbiome profile. When comparing the metabolic and inflammatory profiles, subjects in enterotype I had higher levels of serum IL-1β [false discovery rate (FDR) q = 0.050] and had a lower level of microbial diversity than enterotype II (Wilcoxon rank-sum test p < 0.01). Subjects in enterotype I had relatively higher abundance of Bacteroidetes, Prevotellaceae and Prevotella-derived EVs, and lower abundance of Actinobacteria, Firmicutes, Proteobacteria, Akkermansia and Bacteroides-derived EVs (FDR q < 0.05). In conclusion, HMO patients can be categorised into two distinct enterotypes by the faecal EV-derived microbiome profile. The enterotyping may be associated with different metabolic and inflammatory profiles. Further studies are warranted to elucidate the long-term prognostic impact of EV-derived microbiome in the obese population.

Deciphering the Role of the Gut Microbiota in Exposure to Emerging Contaminants and Diabetes: A Review

Emerging pollutants, a category of compounds currently not regulated or inadequately regulated by law, have recently become a focal point of research due to their potential toxic effects on human health. The gut microbiota plays a pivotal role in human health; it is particularly susceptible to disruption and alteration upon exposure to a range of toxic environmental chemicals, including emerging contaminants. The disturbance of the gut microbiome caused by environmental pollutants may represent a mechanism through which environmental chemicals exert their toxic effects, a mechanism that is garnering increasing attention. However, the discussion on the toxic link between emerging pollutants and glucose metabolism remains insufficiently explored. This review aims to establish a connection between emerging pollutants and glucose metabolism through the gut microbiota, delving into the toxic impacts of these pollutants on glucose metabolism and the potential role played by the gut microbiota.

Polysaccharides (pectin, mucilage, and fructan inulin) and their fermented products: A critical analysis of their biochemical, gut interactions, and biological functions as antidiabetic agents

Diabetes mellitus is a globally metabolic endocrine syndrome marked by a deficiency of insulin secretion (type-1 DM) or glucose intolerance arising from insulin response impairment (type-2 DM) leading to abnormal glucose metabolism. With an increasing interest in natural dietary components for diabetes management, the identification of novel agents witnessed major discoveries. Plant-derived mucilage, pectin, and inulin are important non-starch polysaccharides that exhibit effective antidiabetic properties often termed soluble dietary fiber (SDF). SDF affects sugar metabolism through multiple mechanisms affecting glucose absorption and diffusion, modulation of carbohydrate metabolizing enzymes (α-amylase and α-glucosidase), ameliorating β-pancreatic cell dysfunction, and improving insulin release or sensitivity. Certain SDFs inhibit dipeptidyl peptidase-4 and influence the expression levels of genes related to glucose metabolism. This review is designed to discuss holistically and critically the antidiabetic effects of major SDF and their underlying mechanisms of action. This review should aid drug discovery approaches in developing novel natural antidiabetic drugs from SDF.

The effect of metformin combined with liraglutide on gut microbiota of Chinese patients with type 2 diabetes

BACKGROUND

Metformin (MET) is a first-line therapy for type-2 diabetes mellitus (T2DM). Liraglutide (LRG) is a glucagon-like peptide-1 receptor agonist used as a second-line therapy in combination with MET.

METHODS

We performed a longitudinal analysis comparing the gut microbiota of overweight and/or pre-diabetic participants (NCP group) with that of each following their progression to T2DM diagnosis (UNT group) using 16S ribosomal RNA gene sequencing of fecal bacteria samples. We also examined the effects of MET (MET group) and MET plus LRG (MET+LRG group) on the gut microbiota of these participants following 60 days of anti-diabetic drug therapy in two parallel treatment arms.

RESULTS

In the UNT group, the relative abundances of Paraprevotella (P = 0.002) and Megamonas (P = 0.029) were greater, and that of Lachnospira (P = 0.003) was lower, compared with the NCP group. In the MET group, the relative abundance of Bacteroides (P = 0.039) was greater, and those of Paraprevotella (P = 0.018), Blautia (P = 0.001), and Faecalibacterium (P = 0.005) were lower, compared with the UNT group. In the MET+LRG group, the relative abundances of Blautia (P = 0.005) and Dialister (P = 0.045) were significantly lower than in the UNT group. The relative abundance of Megasphaera in the MET group was significantly greater than in the MET+LRG group (P = 0.041).

CONCLUSIONS

Treatment with MET and MET+LRG results in significant alterations in gut microbiota, compared with the profiles of patients at the time of T2DM diagnosis. These alterations differed significantly between the MET and MET+LRG groups, which suggests that LRG exerted an additive effect on the composition of gut microbiota.

Oral Administration of the Antimicrobial Peptide Mastoparan X Alleviates Enterohemorrhagic Escherichia coli-Induced Intestinal Inflammation and Regulates the Gut Microbiota

The gut microbiota plays an important role in intestinal immune system development and in driving inflammation. Antibiotic administration for therapeutic purposes causes an imbalance in the gut microbiota. Antimicrobial peptides can regulate the gut microbiota and maintain intestinal homeostasis. The aim of this study was to investigate the anti-inflammatory effects and regulation of the gut microbiota by the orally administered antimicrobial peptide mastoparan X (MPX). In this study, Escherichia coli was used to induce intestinal inflammation, and the results showed that MPX+ E. coli alleviated weight loss and intestinal pathological changes in necropsy specimens of E. coli-infected mice. MPX+ E. coli reduced the serum levels of the inflammation-related proteins interleukin-2, interleukin-6, tumour necrosis factor-α, myeloperoxidase, and lactate dehydrogenase on days 7 and 28. Furthermore, MPX+ E. coli increased the length of villi and reduced the infiltration of inflammatory cells into the jejunum and colon post infection. Scanning electron microscopy and transmission electron microscopy results showed that MPX could improve the morphology of jejunum villi and microvilli and increase tight junction protein levels. 16S rRNA sequencing analysis of caecal content samples showed that the species diversity and richness were lower in the E. coli-infected group. At the genus level, MPX+ E. coli significantly reduced the abundance of Bacteroidales and Alistipes and enhanced the relative abundance of Muribaculaceae. Alpha-diversity analyses (Shannon index) showed that MPX significantly increased the microbial diversity of mice. Overall, this study is the first to investigate the effects of oral administration of MPX on intestinal inflammation and the gut microbiota, providing a new perspective regarding the prevention of enteritis and maintenance of intestinal homeostasis.

Global research trends in prediabetes over the past decade: Bibliometric and visualized analysis

OBJECT

This study aimed to investigate global research advances and hot trends in prediabetes in the last decade based on a bibliometric analysis of publications. Publications from 2013 to 2022 were retrieved from the Web of Science Core Collection database through a topic search. With the use of CiteSpace, VOS viewer, and Bibliometrix R software packages, the number of publications, production categories, countries/regions, institutions, authors, journals, references, and keywords were comprehensively analyzed to sort out the hot spots and directions of prediabetes and predict the future research directions. A total of 13,223 papers were recruited for this study by the end of March 3, 2023. A generally increasing trend was observed in the number of annual publications. PLOS ONE (journal), USA (national), and the University of Copenhagen (institutional) published the most papers in this research area. The top 3 contributor authors were Tuomilehto Jaakko, Rathmann Wolfgang, and Peters Annette. "Intestinal microbiota" (2020-2022) was the most populated keyword in terms of intensity, and "biomarkers," "gut microbiota," and "metabolomics" were the most populated keywords in the last 3 years. "Prediabetes: a high-risk state for diabetes development-2012" was the strongest burst reference. This study summarized the research hotspots and trends in prediabetes research in the last decade. Frontier research can be found in the journal Diabetes Care and Journal of Clinical Endocrinology Metabolism. Prediabetes research focuses on preventing risk factors to reduce the prevalence of prediabetes, and current research hotspots focus on gut microbes and metabolism-related biomarkers.

Microbiota Implications in Endocrine-Related Diseases: From Development to Novel Therapeutic Approaches

This comprehensive review article delves into the critical role of the human microbiota in the development and management of endocrine-related diseases. We explore the complex interactions between the microbiota and the endocrine system, emphasizing the implications of microbiota dysbiosis for the onset and progression of various endocrine disorders. The review aims to synthesize current knowledge, highlighting recent advancements and the potential of novel therapeutic approaches targeting microbiota-endocrine interactions. Key topics include the impact of microbiota on hormone regulation, its role in endocrine pathologies, and the promising avenues of microbiota modulation through diet, probiotics, prebiotics, and fecal microbiota transplantation. We underscore the importance of this research in advancing personalized medicine, offering insights for more tailored and effective treatments for endocrine-related diseases.

Effect of chronic noise exposure on glucose and lipid metabolism in mice via modulating gut microbiota and regulating CREB/CRTC2 and SREBP1/SCD pathway

Chronic noise exposure is correlated with gut microbiota dysbiosis and glucose and lipid metabolism disorders. However, evidence on the mechanisms underlying of gut microbiota alterations in chronic noise induced glucose and lipid metabolism disorders is limited, and the potential aftereffects of chronic noise exposure on metabolic disorders remain unclear. In present study, we established chronic daytime and nighttime noise exposure mice models to explore the effects and underlying mechanism of gut microbiota on chronic noise-induced glucose and lipid metabolism disorders. The results showed that exposure to chronic daytime or nighttime noise significantly increased the fasting blood glucose, serum and liver TG levels, impaired glucose tolerance, and decreased serum HDL-C levels and liver TC levels in mice. However, after 4 weeks of recovery, only serum TG of mice in nighttime noise recovery group remained elevated. Besides, exposure to chronic noise reduced the intestinal tight junction protein levels and increased intestinal permeability, while this effect did not completely dissipate even after the recovery period. Moreover, chronic noise exposure changed the gut microbiota and significantly regulated metabolites and metabolic pathways, and further activate hepatic gluconeogenesis CRTC2/CREB-PCK1 signaling pathway and lipid synthesis SREBP1/SCD signaling pathway through intestinal hepatic axis. Together, our findings demonstrated that chronic daytime and nighttime noise exposure could cause the glucose and lipid metabolism disorder by modulating the gut microbiota and serum metabolites, and activating hepatic gluconeogenic CREB/CRTC2-PCK1 signaling and lipid synthesis SREBP1/SCD signaling pathway. The potential aftereffects of noise exposure during wakefulness on metabolic disorders are more significant than that of noise exposure during sleep.

Gut microbiota as an efficacy marker of surgical treatment of obesity

OBJECTIVE

Aim: To study the impact of bariatric interventions on changes in the parameters of the intestinal microbiome.

PATIENTS AND METHODS

Materials and Methods: The research method is a prospective observational cohort monocentric study. 112 patients were included in the study. All patients had indications for surgical obesity treatment due to IFSO criteria. All patients were offered surgical treatment. 53 patients who consented to the operation formed the study group. 59 patients who refused surgical treatment formed the control group. The result of the study was evaluated one year after the start of treatment. The studied group of patients underwent bariatric interventions. The control group consisted of 59 obese patients who were treated conservatively.

RESULTS

Results: evaluating criteria was: %EWL (percentage of excess weight loss), comorbidity regression, life quality improvement. Overwhelming majority of surgically treated patients with gut microbiome composition improvement reached %EWL≥50. Patients who didn't have improvements in gut microbiota composition had insufficient efficacy of surgical treatment.

CONCLUSION

Conclusions: 1) Surgical treatment of obesity leads to the positive changes in the gut microbiota. 2) Operated patients, who had positive dynamics in changes of gut microbiota demonstrated sufficient efficacy of surgical treatment due to %EWL. 3) Firmicutes/Bacteriodetes ratio and Bacterioidetes/Faecalibacterium ratio can be one of the criteria of the efficacy of surgical treatment of obesity. 4) Patients of the control group, had positive dynamics of changes in gut microbiota much rarely than operated patients and the effectiveness of obesity treatment was insufficient.

Regulation of the innate immune response and gut microbiome by p53

p53 is a key tumor suppressor mutated in half of human cancers. In recent years, p53 was shown to regulate a wide variety of functions. From the transcriptome analysis of 24 tissues of irradiated mice, we identified 553 genes markedly induced by p53. Gene Ontology (GO) enrichment analysis found that the most associated biological process was innate immunity. 16S rRNA-seq analysis revealed that Akkermansia, which has anti-inflammatory properties and is involved in the regulation of intestinal barrier integrity, was decreased in p53-knockout (p53-/- ) mice after radiation. p53-/- mice were susceptible to radiation-induced GI toxicity and had a significantly shorter survival time than p53-wild-type (p53+/+ ) mice following radiation. However, administration of antibiotics resulted in a significant improvement in survival and protection against GI toxicity. Mbl2 and Lcn2, which have antimicrobial activity, were identified to be directly transactivated by p53 and secreted by liver into the circulatory system. We also found the expression of MBL2 and LCN2 was decreased in liver cancer tissues with p53 mutations compared with those without p53 mutations. These results indicate that p53 is involved in shaping the gut microbiome through its downstream targets related to the innate immune system, thus protecting the intestinal barrier.

Negative Lifestyle Factors Specific to Aging Persons Living with HIV and Multimorbidity

The primary goal of medical care during the pre-antiretroviral therapy (ART) era was to keep persons living with human immunodeficiency virus (HIV) alive, whereas since the advent of ART, the treatment objective has shifted to decreasing viral loads and infectiousness while increasing CD4+ T-cell counts and longevity. The health crisis, however, is in preventing and managing multimorbidity (ie, type 2 diabetes), which develops at a more accelerated or accentuated pace among aging persons living with HIV. Relative to the general population and age-matched uninfected adults, it may be more difficult for aging HIV-positive persons who also suffer from multimorbidity to improve negative lifestyle factors to the extent that their behaviors could support the prevention and management of diseases. With recommendations and a viable solution, this article explores the impact of negative lifestyle factors (ie, poor mental health, suboptimal nutrition, physical inactivity, alcohol use) on the health of aging individuals living with HIV.

Akkermansia muciniphila: a deworming partner independent of type 2 immunity

The gut microbiota has coevolved with the host for hundreds of millions of years, playing a beneficial role in host health. Human parasitic helminths are widespread and pose a pervasive global public health issue. Although Type 2 immunity provides partial resistance to helminth infections, the composition of the gut microbiota can change correspondingly. Therefore, it raises the question of what role the gut microbiota plays during helminth infection. Akkermansia muciniphila has emerged as a notable representative of beneficial microorganisms in the gut microbiota. Recent studies indicate that A. muciniphila is not merely associated with helminth infection but is also causally linked to infection. Here, we provide an overview of the crosstalk between A. muciniphila and enteric helminth infection. Our goal is to enhance our understanding of the interplay among A. muciniphila, helminths, and their hosts while also exploring the potential underlying mechanisms.

Examination of sex-specific interactions between gut microbiota and host metabolism after 12-week combined polyphenol supplementation in individuals with overweight or obesity

Polyphenols exert beneficial effects on host metabolism, which may be mediated by the gut microbiota. We investigated sex-specific differences in microbiota composition and interactions with cardiometabolic parameters after polyphenol supplementation in individuals with overweight/obesity. In a double-blind, randomized, placebo-controlled trial, 19 women and 18 men with normal glucose tolerance and body mass index >25 kg/m2 received epigallocatechin-3-gallate and resveratrol (EGCG+RES, 282 + 80 mg/d) or placebo supplements for 12 weeks. Fecal microbiota composition (16S rRNA gene amplicon sequencing, V3-V4 region), in vivo whole-body fat oxidation (indirect calorimetry), and mitochondrial respiration in permeabilized skeletal muscle fibers (SkM-Ox; ex vivo respirometry) were determined pre- and post-intervention. Overall, EGCG+RES supplementation did not affect gut microbiota composition. Akkermansia, Ruminococcaceae UCG-002, Subdoligranulum, and Lachnospiraceae UCG-004 were more abundant, while Veillonella, Tyzzerella 4, Clostridium innocuum group, Ruminococcus gnavus group, Escherichia-Shigella, and an uncultured Ruminococcaceae family genus were less abundant in women compared to men. In women, only baseline Eubacterium ventriosum group abundance correlated with EGCG+RES-induced changes in SkM-Ox. In men, low Dorea, Barnsiella, Anaerotruncus, Ruminococcus, Subdoligranulum, Coprococcus, Eubacterium ventriosum group, Ruminococcaceae UCG-003, and a Ruminococcaceae family genus abundance, and high Blautia abundance at baseline were associated with improvements in SkM-Ox. Changes in whole-body fat oxidation were not associated with gut microbiota features. We conclude that baseline microbiota composition predicts changes in SkM-Ox as a result of EGCG+RES supplementation in men but not in women. Men may be more prone to diet-induced, gut microbiota-related improvements in cardiometabolic health. These sex-differences should be further investigated in future precision-based intervention studies.

Comparative study of type 2 diabetes mellitus-associated gut microbiota between the Dai and Han populations

BACKGROUND

The global prevalence of type 2 diabetes mellitus (T2DM) is increasing. T2DM is associated with alterations of the gut microbiota, which can be affected by age, illness, and genetics. Previous studies revealed that there are discriminating microbiota compositions between the Dai and the Han populations. However, the specific gut microbiota differences between the two populations have not been elucidated.

AIM

To compare the gut microbiota differences in subjects with and without T2DM in the Dai and Han populations.

METHODS

A total of 35 subjects of the Han population (including 15 healthy children, 8 adult healthy controls, and 12 adult T2DM patients) and 32 subjects of the Dai population (including 10 healthy children, 10 adult healthy controls, and 12 adult T2DM patients) were enrolled in this study. Fasting venous blood samples were collected from all the subjects for biochemical analysis. Fecal samples were collected from all the subjects for DNA extraction and 16S rRNA sequencing, which was followed by analyses of the gut microbiota composition.

RESULTS

No significant difference in alpha diversity was observed between healthy children and adults. The diversity of gut microbiota was decreased in T2DM patients compared to the healthy adults in both the Dai and Han populations. There was a significant difference in gut microbiota between healthy children and healthy adults in the Han population with an increased abundance of Bacteroidetes and decreased Firmicutes in children. However, this difference was less in the Dai population. Significant increases in Bacteroidetes in the Han population and Proteobacteria in the Dai population and decreases in Firmicutes in both the Han and Dai population were observed in T2DM patients compared to healthy adults. Linear discriminant analysis Effect Size analysis also showed that the gut microbiota was different between the Han and Dai populations in heathy children, adults, and T2DM patients. Four bacteria were consistently increased and two consistently decreased in the Han population compared to the Dai population.

CONCLUSION

Differences in gut microbiota were found between the Han and Dai populations. A significant increase in Bacteroidetes was related to the occurrence of T2DM in the Han population, while a significant increase in Proteobacteria was related to the occurrence of T2DM in the Dai population.