Analyses of gut microbiota and plasma bile acids enable stratification of patients for antidiabetic treatment

Pharmacomicrobiomics: a new field contributing to optimizing drug therapy in Parkinson's disease

Gut microbiota, which act as a determinant of pharmacokinetics, have long been overlooked. In recent years, a growing body of evidence indicates that the gut microbiota influence drug metabolism and efficacy. Conversely, drugs also exert a substantial influence on the function and composition of the gut microbiota. Pharmacomicrobiomics, an emerging field focusing on the interplay of drugs and gut microbiota, provides a potential foundation for making certain advances in personalized medicine. Understanding the communication between gut microbiota and antiparkinsonian drugs is critical for precise treatment of Parkinson's disease. Here, we provide a historical overview of the interplay between gut microbiota and antiparkinsonian drugs. Moreover, we discuss potential mechanistic insights into the complex associations between gut microbiota and drug metabolism. In addition, we also draw attention to microbiota-based biomarkers for predicting antiparkinsonian drug efficacy and examine current state-of-the-art knowledge of microbiota-based strategies to optimize drug therapy in Parkinson's disease.

Anti-diabetic effect of dicaffeoylquinic acids is associated with the modulation of gut microbiota and bile acid metabolism

INTRODUCTION

The human gut microbiome plays a pivotal role in health and disease, notably through its interaction with bile acids (BAs). BAs, synthesized in the liver, undergo transformation by the gut microbiota upon excretion into the intestine, thus influencing host metabolism. However, the potential mechanisms of dicaffeoylquinic acids (DiCQAs) from Ilex kudingcha how to modulate lipid metabolism and inflammation via gut microbiota remain unclear.

OBJECTIVES AND METHODS

The objectives of the present study were to investigate the regulating effects of DiCQAs on diabetes and the potential mechanisms of action. Two mice models were utilized to investigate the anti-diabetic effects of DiCQAs. Additionally, analysis of gut microbiota structure and functions was conducted concurrently with the examination of DiCQAs' impact on gut microbiota carrying the bile salt hydrolase (BSH) gene, as well as on the enterohepatic circulation of BAs and related signaling pathways.

RESULTS

Our findings demonstrated that DiCQAs alleviated diabetic symptoms by modulating gut microbiota carrying the BSH gene. This modulation enhanced intestinal barrier integrity, increased enterohepatic circulation of conjugated BAs, and inhibited the farnesoid X receptor-fibroblast growth factor 15 (FGF15) signaling axis in the ileum. Consequently, the protein expression of hepatic FGFR4 fibroblast growth factor receptor 4 (FGFR4) decreased, accompanied by heightened BA synthesis, reduced hepatic BA stasis, and lowered levels of hepatic and plasma cholesterol. Furthermore, DiCQAs upregulated glucolipid metabolism-related proteins in the liver and muscle, including v-akt murine thymoma viral oncogene homolog (AKT)/glycogen synthase kinase 3-beta (GSK3β) and AMP-activated protein kinase (AMPK), thereby ameliorating hyperglycemia and mitigating inflammation through the down-regulation of the MAPK signaling pathway in the diabetic group.

CONCLUSION

Our study elucidated the anti-diabetic effects and mechanism of DiCQAs from I. kudingcha, highlighting the potential of targeting gut microbiota, particularly Acetatifactor sp011959105 and Acetatifactor muris carrying the BSH gene, as a therapeutic strategy to attenuate FXR-FGF15 signaling and ameliorate diabetes.

Enhancement of Acarbose Production in Actinoplanes sp. QQ-12 via Multiple Engineering Strategies

The α-glucosidase inhibitor acarbose is used in the treatment of type 2 diabetes mellitus. Metabolic engineering is crucial to overcome acarbose production bottlenecks. Herein, a genetic toolkit was developed to enable metabolic engineering in Actinoplanes sp.. The attachment/integration (Att/Int) systems of ΦBT1, pSAM2, R4, and TG1 showed conjugation frequencies of 0.98-24.4%. Furthermore, three mutants were constructed by deleting nontarget biosynthetic gene clusters (BGCs) and inserting one to three additional copies of the acarbose biosynthetic gene cluster (acb). These mutants, with 2, 3, and 4 copies of acb gene cluster, demonstrated titer increases of 69.4%, 99.3%, and 24.2%, respectively, with a sharply declined titer in the four-copy acb strain LGQ-17::3acb. To rescue the acarbose titer in LGQ-17::3acb, we overexpressed rate-limiting genes acbC, M, O, N, J, V, I, or S. The overexpression of acbJ and acbS resulted in acarbose titer increases of 1.04-fold and 98%, respectively. Furthermore, following fed-batch fermentation optimization in shake flasks, the titer of acarbose in LGQ-17::3acb::stnYp-acbJ increased by 1.1-fold to reach 8.12 g/L. This genetic engineering toolkit with multiple Att/Int systems and high conjugation frequencies paves the way for future genetic engineering in Actinoplanes sp., and the engineered strain shows excellent potential for industrial application.

Grape polyphenols reduce fasting glucose and increase hyocholic acid in healthy humans: a meta-omics study

Grape polyphenols (GPs) are rich in B-type proanthocyanidins, which promote metabolic resilience. Longitudinal metabolomic, metagenomic, and metaproteomic changes were measured in 27 healthy subjects supplemented with soy protein isolate (SPI, 40 g per day) for 5 days followed by GPs complexed to SPI (GP-SPI standardized to 5% GPs, 40 g per day) for 10 days. Fecal, urine, and/or fasting blood samples were collected before supplementation (day -5), after 5 days of SPI (day 0), and after 2, 4 and 10 days of GP-SPI. Most multi-omic changes observed after 2 and/or 4 days of GP-SPI intake were temporary, returning to pre-supplementation profiles by day 10. Shotgun metagenomics sequencing provided insights that could not be captured with 16S rRNA amplicon sequencing. Notably, 10 days of GP-SPI decreased fasting blood glucose and increased serum hyocholic acid (HCA), a glucoregulatory bile acid, which negatively correlated with one gut bacterial guild. In conclusion, GP-induced suppression of a bacterial guild may lead to higher HCA and lower fasting blood glucose.

Metabolic diseases in the East Asian populations

East Asian populations, which account for approximately 20% of the global population, have become central to the worldwide rise of metabolic diseases over the past few decades. The prevalence of metabolic disorders, including type 2 diabetes mellitus, hypertension and metabolic dysfunction-associated steatotic liver disease, has escalated sharply, contributing to a substantial burden of complications such as cardiovascular disease, chronic kidney disease, cancer and increased mortality. This concerning trend is primarily driven by a combination of genetic predisposition, unique fat distribution patterns and rapidly changing lifestyle factors, including urbanization and the adoption of Westernized dietary habits. Current advances in genomics, proteomics, metabolomics and microbiome research have provided new insights into the biological mechanisms that might contribute to the heightened susceptibility of East Asian populations to metabolic diseases. This Review synthesizes epidemiological data, risk factors and biomarkers to provide an overview of how metabolic diseases are reshaping public health in East Asia and offers insights into biological and societal drivers to guide effective, region-specific strategies.

Disentangling Organ-Specific Roles of Farnesoid X Receptor in Bile Acid and Glucolipid Metabolism

BACKGROUND AND AIMS

The farnesoid X receptor (FXR) is an attractive pharmaceutical target for metabolic dysfunction-associated steatotic liver disease (MASLD). However, its tissue-specific roles in energy metabolism remain controversial, hindering the development of effective therapies. To address this, new approaches are required.

METHODS

A novel mouse model was developed to facilitate the re-expression of endogenous FXR in specific tissues on a global FXR-null background. Liver-specific and gut-specific FXR re-expression models were generated. Mice were subjected to a high-fat diet (HFD) for 12 weeks, after which metabolic indices, bile acid (BA) profiles, and gut microbiota composition were analysed. Antibiotic treatment was used to mimic germ-free conditions.

RESULTS

The resistance of FXR-null mice to MASLD and most HFD-induced metabolic disorders, including increased body weight, adiposity, hepatic triglyceride (TG) accumulation, and hyperglycemia, was reversed by liver, but not gut, FXR re-expression. Gut FXR re-expression restored the increased intestinal TG absorption in FXR-null mice by limiting 12OH BA synthesis and inhibiting intestinal microsomal triglyceride transfer protein (MTTP). Moreover, gut FXR activity was essential for gut microbiota-driven promotion of diet-induced obesity (DIO) and MASLD.

CONCLUSIONS

Our study overcomes the limitations of traditional tissue-specific knockout models, providing a more comprehensive understanding of FXR's complex roles in metabolic homeostasis, encouraging the development of organ-specific FXR targeting strategy.

43 G > T polymorphism in the sucrase-isomaltase gene in the Chinese population prevents the glucose-lowering effect of acarbose

BACKGROUND

Acarbose is an α-glucosidase inhibitor widely used clinically for its significant hypoglycemic effect, albeit with inter-individual variations in response. The sucrase-isomaltase (SI) enzyme is the primary target of acarbose. This study aims to investigate the impact of genetic polymorphisms in the SI gene on the pharmacodynamics of acarbose.

METHODS

The Illumina sequencing platform and variation-related databases were employed to analyze probable gene polymorphism sites of SI. Based on the SI polymorphism sites, Chinese subjects (n = 66) were categorized into the wild-type homozygous group (Group A) and the heterozygous variant group (Group B, SI 43 G > T). The validated hexokinase method was utilized to determine glucose concentrations in participants' serum samples. The differences in blood glucose concentration reduction and pharmacodynamic parameters peak concentration (Cmax) and area under the curve (AUC0-2h) after administering the same dose of acarbose were analyzed between the two groups of subjects.

RESULTS

Our results showed that the mean changes in glucose Cmax, AUC0-2h, maximum increase, and maximum decrease in Group B were each lower by 67.66 %, 63.05 %, 53.17 %, and 50 % compared to Group A (all p < 0.05).

CONCLUSIONS

These data suggested that genetic polymorphism of the SI gene can significantly influence the hypoglycemic efficacy of acarbose, and the polymorphism of SI is associated with individual differences in clinical treatment outcomes.

Orlistat ameliorates lipid dysmetabolism in high-fat diet-induced mice via gut microbiota modulation

Orlistat reduces obesity by inhibiting gastrointestinal lipases, thereby blocking the absorption and accumulation of triglycerides in the intestine. It has been shown to improve lipid metabolism and alter intestinal microbial communities in animals and humans. However, the impact of Orlistat-induced changes in gut microbiota on obesity requires further investigation. In this study, we found that Orlistat significantly improved metabolic disorders, inhibited fat accumulation, and reshaped the structure of intestinal microbiota. Specifically, it reduced α diversity and increased the relative abundance of Verrucomicrobia and Akkermansia. Notably, antibiotic-induced gut microbiota depletion significantly weakened Orlistat's effect on improving metabolic disorders. Furthermore, microbiota transplanted from Orlistat-treated mice effectively alleviated lipid metabolic disorders caused by a high-fat diet. We also observed that Orlistat increased food intake in mice and inhibited the synthesis of appetite-regulating hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon (Gcg). However, antibiotic-depleted microbiota mitigated this inhibitory effect. Interestingly, although Orlistat altered the gut microbiota of mice, transplanting these microbiota did not inhibit the synthesis of appetite-regulating hormones. In summary, our results suggest that Orlistat can reshape the gut microbiota, and the altered gut microbiota works synergistically with Orlistat to improve metabolic disorders. This improvement is related to the increased abundance of Verrucomicrobia and Akkermansia.

Correlations Between Gut Microbiota Composition, Medical Nutrition Therapy, and Insulin Resistance in Pregnancy-A Narrative Review

Many physiological changes accompany pregnancy, most of them involving metabolic perturbations. Alterations in microbiota composition occur both before and during pregnancy and have recently been correlated with an important role in the development of metabolic complications, such as insulin resistance and gestational diabetes mellitus (GDM). These changes may be influenced by physiological adaptations to pregnancy itself, as well as by dietary modifications during gestation. Medical nutritional therapy (MNT) applied to pregnant women at risk stands out as one of the most important factors in increasing the microbiota's diversity at both the species and genus levels. In this review, we discuss the physiological changes during pregnancy and their impact on the composition of the intestinal microbiota, which may contribute to GDM. We also discuss findings from previous studies regarding the effectiveness of MNT in reducing insulin resistance. In the future, additional studies should aim to identify specific gut microbial profiles that serve as early indicators of insulin resistance during gestation. Early diagnosis, achievable through stool analysis or metabolite profiling, may facilitate the timely implementation of dietary or pharmaceutical modifications, thereby mitigating the development of insulin resistance and its associated sequelae.

Gut colonization of Bacteroides plebeius suppresses colitis-associated colon cancer development

Colon cancer development may be initiated by multiple factors, including chronic inflammation, genetic disposition, and gut dysbiosis. The loss of beneficial bacteria and increased abundance of detrimental microbes exacerbates disease progression. Bacteroides plebeius (B. plebeius) is a human gut microbe, and its colon colonization is enhanced by a seaweed-supplemented diet. We found that mice orally administered with B. plebeius and fed a diet containing 1% seaweed developed a unique gut microbial composition. By linear discriminant analysis effect size analysis, we found that B. plebeius colonization increased the abundance of Blautia coccoides and reduced the abundance of Akkermansia sp. and Dubosiella sp. We also showed that colonization of B. plebeius suppressed the colon tumor development induced by azoxymethane/dextran sulfate sodium in specific-pathogen-free mice, coinciding with a reduced abundance of Muribaculaceae sp., Closteridale sp., and Bilophila sp. Moreover, B. plebeius colonization in gnotobiotic mice resulted in enhanced production of selected metabolites, including propionic, taurocholic, cholic, alpha-, and beta-muricholic, as well as ursodeoxycholic acids. Importantly, some of these metabolites show anti-inflammatory and tumor-suppressive effects. We conclude that B. plebeius is able to restructure the gut microbial community and produce beneficial metabolites, leading to inhibition of colitis-associated colon cancer development.IMPORTANCEThis work delves into the pivotal role of gut microbiota in suppressing the progression of colitis-associated colon cancer. By investigating the impact of Bacteroides plebeius that can be colonized in mouse gut by feeding the animal with seaweed diet, we unveil a novel mechanism through which this beneficial bacterium reshapes the gut microbial community and produces metabolites with anti-inflammatory and tumor-suppressive properties. Such findings underscore the potential of harnessing specific microbes, like B. plebeius shown in this study, to modulate the gut ecosystem and mitigate the risk of colitis-associated colon cancer.

Zexie-Baizhu Decoction ameliorates non-alcoholic fatty liver disease through gut-adipose tissue crosstalk

ETHNOPHARMACOLOGICAL RELEVANCE

Zexie-Baizhu Decoction (AA), a Chinese Classical Formula composed of Alisma orientalis (Sam.) Juzep. and Aractylodes Macrocephala Koidz in the specific ratio of 5:2, has a long history of use in treating metabolic disorders. Recent studies have demonstrated AA's ameliorative effects on non-alcoholic fatty liver disease (NAFLD); however, the mechanism underlying its action on the gut and adipose tissue, key regulators of metabolism, have not been fully explored.

AIM OF THE STUDY

This study aimed to investigate the mechanisms by which AA regulates the homeostasis of gut and adipose tissue in NAFLD.

MATERIALS AND METHODS

AA (1500 mg/kg/day) or vehicle was administrated to the high-fat diet-induced and normal chow-fed mice (C57BL/6J). Plasma, the liver, gut microbiota, bile acids, and short-chain fatty acids in the gut, were systematically investigated. RNA sequencing analysis, reverse transcription quantitative real-time PCR, and Western Blotting were performed on the epididymal white adipose tissues (eWAT) to explore AA's influence on NAFLD. Lipidomics of the liver and eWAT were analyzed by liquid chromatography-mass spectrometry and desorption electrospray ionization mass spectrometry imaging.

RESULTS

Our study demonstrated that AA administration effectively alleviated liver injury induced by NAFLD, as evidenced by reduced hepatic fat accumulation and inflammation. Mechanistically, AA modulated the composition of the gut microbiota, promoting the growth of beneficial bacteria such as Akkermansia muciniphila and restoring the balance between Firmicutes and Bacteroidetes. Furthermore, AA regulated the levels of bile acids and short-chain fatty acids in the intestine, plasma, and liver. Correspondingly in the eWAT, AA administration activated bile acid receptor (Gpbar1) and short-chain fatty acid receptor (Ffar2), facilitating lipid breakdown and attenuating triglyceride accumulation. Transcriptome analysis revealed that AA influenced gene expression related to fatty acid metabolism, thermogenesis, insulin resistance, AMPK signaling, and the tricarboxylic acid (TCA) cycle, thereby improving NAFLD at the transcriptional level. Additionally, AA treatment significantly altered the lipid composition in the liver, reducing levels of diacylglycerols, triacylglycerols, phosphatidylserines, and cholesterol esters, while increasing levels of phosphatidic acids, phosphatidylethanolamines, and sphingomyelins.

CONCLUSION

Our study builds a connection between the gut and adipose tissue to understand the mechanism of AA on alleviating NAFLD, providing new insights into the development of targeted therapies for this condition.

The direct and indirect inhibition of proinflammatory adipose tissue macrophages by acarbose in diet-induced obesity

Inflammation is critical for obesity and obesity-induced insulin resistance (IR). In this study, we reveal the function and mechanism of acarbose on adipose tissue macrophage (ATM)-mediated inflammation in obesity and obesity-induced IR. First, acarbose enhances the abundance of propionic acid-producing Parasutterella, therefore indirectly inhibiting the survival and proinflammatory function of M1-like ATMs via GPR43. Most interestingly, acarbose can directly inhibit M1-like ATM-mediated inflammation through GPR120. Diet-induced obese mice exhibit nitrobenzoxadiazoles (NBD) fluorescence-labeled ATMs, but lean mice that also orally received NBD fluorescence-labeled acarbose do not exhibit NBD fluorescence-labeled ATMs. This direct inhibition of macrophages by acarbose is validated in mouse and human macrophages in vitro. In conclusion, our study reveals that acarbose directly and indirectly inhibits proinflammatory macrophage phenotype, which contributes to the improvement of obesity and obesity-induced IR. The understanding of the immune regulatory effects of acarbose may extend its potential for further therapeutic applications.

Diabetes and gut microbiome

Diabetes mellitus represents a significant global health problem. The number of people suffering from this metabolic disease is constantly rising and although the incidence is heterogeneous depending on region, country, economic situation, lifestyle, diet and level of medical care, it is increasing worldwide, especially among youths and children, mainly due to lifestyle and environmental changes. The pathogenesis of the two most common subtypes of diabetes mellitus, type 1 (T1DM) and type 2 (T2DM), is substantially different, so each form is characterized by a different causation, etiology, pathophysiology, presentation, and treatment. Research in recent decades increasingly indicates the potential role of the gut microbiome in the initiation, development, and progression of this disease. Intestinal microbes and their fermentation products have an important impact on host metabolism, immune system, nutrient digestion and absorption, gut barrier integrity and protection against pathogens. This review summarizes the current evidence on the changes in gut microbial populations in both types of diabetes mellitus. Attention is focused on changes in the abundance of specific bacterial groups at different taxonomic levels in humans, and microbiome shift is also assessed in relation to geographic location, age, diet and antidiabetic drug. The causal relationship between gut bacteria and diabetes is still unclear, and future studies applying new methodological approaches to a broader range of microorganisms inhabiting the digestive tract are urgently needed. This would not only provide a better understanding of the role of the gut microbiome in this metabolic disease, but also the use of beneficial bacterial species in the form of probiotics for the treatment of diabetes.

Alpha-Glucosidase Inhibitors in Aging and Aging-Related Diseases: Clinical Applications and Relevant Mechanisms

Aging is a complex and universal process marked by gradual functional declines at the cellular and tissue levels, often leading to a range of aging-related diseases such as diabetes, cardiovascular diseases, and cancer. Delaying the aging process can help prevent, slow down, and alleviate the severity of these various conditions, enhancing overall health and well-being. Alpha-glucosidase inhibitors (AGIs) are a class of widely used antidiabetic drugs that inhibit alpha-glucosidase in the small intestinal mucosa, delaying carbohydrate absorption and reducing postprandial hyperglycemia. Beyond their roles in diabetes treatment, AGIs have shown potential in extending lifespan and effectively treating aging-related diseases by modulating oxidative stress, gut microbiota, inflammatory responses, and nutrient-sensing pathways. This review summarizes recent advancements in the application of AGIs for preventing and treating aging and aging-related diseases, with a focus on their mechanisms and roles in these processes.

The gut-heart axis: a review of gut microbiota, dysbiosis, and cardiovascular disease development

Background

Cardiovascular diseases (CVDs) are a major cause of morbidity and mortality worldwide and there are strong links existing between gut health and cardiovascular health. Gut microbial diversity determines gut health. Dysbiosis, described as altered gut microbiota, causes bacterial translocations and abnormal gut byproducts resulting in systemic inflammation.

Objective

To review the current literature on the relationships between gut microbiota, dysbiosis, and CVD development, and explore therapeutic methods to prevent dysbiosis and support cardiovascular health.

Summary

Dysbiosis increases levels of pro-inflammatory substances while reducing those of anti-inflammatory substances. This accumulative inflammatory effect negatively modulates the immune system and promotes vascular dysfunction and atherosclerosis. High Firmicutes to Bacteroidetes ratios, high trimethylamine-n-oxide to short-chain fatty acid ratios, high indole sulfate levels, low cardiac output, and polypharmacy are all associated with worse cardiovascular outcomes. Supplementation with prebiotics and probiotics potentially alleviates some CVD risk. Blood and stool samples may be used in clinical practice to quantify and qualify gut bacterial ratios and byproducts, assess patients' risk for adverse cardiovascular outcomes, and track their gut health progress. Further research is required to set population-based cutoffs for normal and abnormal gut microbiota and byproduct ratios.

Acarbose impairs gut Bacteroides growth by targeting intracellular glucosidases

Acarbose is a type 2 diabetes medicine that prevents dietary starch breakdown into glucose by inhibiting host amylase and glucosidase enzymes. Numerous gut species in the Bacteroides genus enzymatically break down starch and change in relative abundance within the gut microbiome in acarbose-treated individuals. To mechanistically explain this observation, we used two model starch-degrading Bacteroides, Bacteroides ovatus (Bo), and Bacteroides thetaiotaomicron (Bt). Bt growth on starch polysaccharides is severely impaired by acarbose, whereas Bo growth is much less affected by the drug. The Bacteroides use a starch utilization system (Sus) to grow on starch. We hypothesized that Bo and Bt Sus enzymes are differentially inhibited by acarbose. Instead, we discovered that although acarbose primarily targets the Sus periplasmic GH97 enzymes in both organisms, the drug affects starch processing at multiple other points. Acarbose competes for transport through the TonB-dependent SusC proteins and binds to the Sus transcriptional regulators. Furthermore, Bo expresses a non-Sus GH97 (BoGH97D) when grown in starch with acarbose. The Bt homolog, BtGH97H, is not expressed in the same conditions, nor can overexpression of BoGH97D complement the Bt growth inhibition in the presence of acarbose. This work informs us about unexpected complexities of Sus function and regulation in Bacteroides, including variation between related species. Furthermore, this indicates that the gut microbiome may be a source of variable response to acarbose treatment for diabetes.

IMPORTANCE

Acarbose is a type 2 diabetes medication that works primarily by stopping starch breakdown into glucose in the small intestine. This is accomplished by the inhibition of host enzymes, leading to better blood sugar control via reduced ability to derive glucose from dietary starches. The drug and undigested starch travel to the large intestine where acarbose interferes with the ability of some bacteria to grow on starch. However, little is known about how gut bacteria interact with acarbose, including microbes that can use starch as a carbon source. Here, we show that two gut species, Bacteroides ovatus (Bo) and Bacteroides thetaiotaomicron (Bt), respond differently to acarbose: Bt growth is inhibited by acarbose, while Bo growth is less affected. We reveal a complex set of mechanisms involving differences in starch import and sensing behind the different Bo and Bt responses. This indicates the gut microbiome may be a source of variable response to acarbose treatment for diabetes via complex mechanisms in common gut microbes.

Bile acids as a key target: traditional Chinese medicine for precision management of insulin resistance in type 2 diabetes mellitus through the gut microbiota-bile acids axis

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease caused by insulin resistance (IR) and insufficient insulin secretion. Its characteristic pathophysiological processes involve the interaction of multiple mechanisms. In recent years, globally, the prevalence of T2DM has shown a sharp rise due to profound changes in socio-economic structure, the persistent influence of environmental factors, and the complex role of genetic background. It is worth noting that most T2DM patients show significant IR, which further exacerbates the difficulty of disease progression and prevention. In the process of extensively exploring the pathogenesis of T2DM, the dynamic equilibrium of gut microbes and its diverse metabolic activities have increasingly emphasized its central role in the pathophysiological process of T2DM. Bile acids (BAs) metabolism, as a crucial link between gut microbes and the development of T2DM, not only precisely regulates lipid absorption and metabolism but also profoundly influences glucose homeostasis and energy balance through intricate signaling pathways, thus playing a pivotal role in IR progression in T2DM. This review aims to delve into the specific mechanism through which BAs contribute to the development of IR in T2DM, especially emphasizing how gut microbes mediate the metabolic transformation of BAs based on current traditional Chinese medicine research. Ultimately, it seeks to offer new insights into the prevention and treatment of T2DM. Diet, genetics, and the environment intricately sculpt the gut microbiota and BAs metabolism, influencing T2DM-IR. The research has illuminated the significant impact of single herbal medicine, TCM formulae, and external therapeutic methods such as electroacupuncture on the BAs pool through perturbations in gut microbiota structure. This interaction affects glucose and lipid metabolism as well as insulin sensitivity. Additionally, multiple pathways including BA-FXR-SHP, BA-FXR-FGFR15/19, BA-FXR-NLRP3, BA-TGR5-GLP-1, BAs-TGR5/FXR signaling pathways have been identified through which the BAs pool significantly alter blood glucose levels and improve IR. These findings offer novel approaches for enhancing IR and managing metabolic disorders among patients with T2DM.

State-of-the-art review of theabrownins: from preparation, structural characterization to health-promoting benefits

As far as health benefit is concerned, dark tea is one of the best beverages in the world. Theabrownins are the major ingredient contributing to the health benefits of dark tea and known as "the soft gold in dark tea." A growing body of evidence indicated that theabrownins are macromolecular pigments with reddish-brown color and mellow taste, and mainly derived from the oxidative polymerization of tea polyphenols. Theabrownins are the main active ingredients in dark tea which brings multiple health-promoting effects in modulating lipid metabolism, reducing body weight gain, attenuating diabetes, mitigating NAFLD, scavenging ROS, and preventing tumors. More importantly, it's their substantial generation in microbial fermentation that endows dark tea with much stronger hypolipidemic effect compared with other types of tea. This review firstly summarizes the most recent findings on the preparation, structural characteristics, and health-promoting effects of theabrownins, emphasizing the underlying molecular mechanism, especially the different mechanisms behind the effect of theabrownins-mediated gut microbiota on the host's multiple health-promoting benefits. Furthermore, this review points out the main limitations of current research and potential future research directions, hoping to provide updated scientific evidence for their better theoretical research and industrial utilization.

Therapeutic Effects of Intermittent Fasting Combined with SLBZS and Prebiotics on STZ-HFD-Induced Type 2 Diabetic Mice

Purpose

This study aims to assess the therapeutic potential of combining Shen-Ling-Bai-Zhu-San (SLBZS) or prebiotics with intermittent fasting (IF) in type 2 diabetes mellitus (T2DM) mice and to investigate the synergistic effects and underlying mechanisms.

Methods

Type 2 diabetic mouse models were induced using high-fat diet (HFD) and streptozotocin (STZ), followed by IF treatment. Mice were then grouped for combined therapy with different doses of SLBZS and prebiotics. Fasting blood glucose (FBG) levels, body weight variations, and oral glucose tolerance tests were assessed to elucidate metabolic alterations. The hepatic and renal parameters were evaluated to determine systemic changes in T2DM mice, while the insulin levels were quantified by ELISA to assess glucose homeostasis. Gut microbiota alterations were examined via 16S rRNA sequencing. Alterations of the genes in relevant signaling pathways were analyzed using RT-qPCR.

Results

IF improved FBG, body weight, insulin levels, and other diabetes indicators. Combined IF with SLBZS or prebiotics yielded similar effects. Furthermore, it ameliorated dyslipidemia and mitigated hepatic and renal parameters in T2DM mice. Pancreatic tissue histopathology showed islet cell restoration post-intervention. IF therapy reduced the abnormally elevated GSK-3β gene expression and increased the abnormally reduced GLUT2 genes. Further analysis indicated that the combination of IF with prebiotics and high doses of SLBZS upregulated the expression of the INSR and IRS1 genes. Gut microbiota analysis revealed restored diversity and structure, with notable changes in specific bacterial families. At the family level, the contents of Akkermansiaceae and Bifidobacteriaceae were restored. Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt2) analysis suggested metabolic pathway alterations.

Conclusion

IF improved type 2 diabetic symptoms, with combined SLBZS and prebiotics showing similar effects. IF with high concentration of SLBZS and prebiotics doses upregulated the INSR and IRS1 genes and had superior effects on gut microbiota compared to IF alone.

A Dual Therapeutic Approach to Diabetes Mellitus via Bioactive Phytochemicals Found in a Poly Herbal Extract by Restoration of Favorable Gut Flora and Related Short-Chain Fatty Acids

Diabetes mellitus (DM), a metabolic and endocrine condition, poses a serious threat to human health and longevity. The emerging role of gut microbiome associated with bioactive compounds has recently created a new hope for DM treatment. UHPLC-HRMS methods were used to identify these compounds in a poly herbal ethanolic extract (PHE). The effects of PHE on body weight (BW), fasting blood glucose (FBG) level, gut microbiota, fecal short-chain fatty acids (SCFAs) production, and the correlation between DM-related indices and gut microbes, in rats were investigated. Chebulic acid (0.368%), gallic acid (0.469%), andrographolide (1.304%), berberine (6.442%), and numerous polysaccharides were the most representative constituents in PHE. A more significant BW gain and a reduction in FBG level towards normal of PHE 600 mg/kg treated rats group were resulted at the end of 28th days of the study. Moreover, the composition of the gut microbiota corroborated the study's hypothesis, as evidenced by an increased ratio of Bacteroidetes to Firmicutes and some beneficial microbial species, including Prevotella copri and Lactobacillus hamster. The relative abundance of Bifidobacterium pseudolongum, Ruminococcus bromii, and Blautia producta was found to decline in PHE treatment groups as compared to diabetic group. The abundance of beneficial bacteria in PHE 600 mg/kg treatment group was concurrently associated with increased SCFAs concentrations of acetate and propionate (7.26 nmol/g and 4.13 nmol/g). The findings of this study suggest a promising approach to prevent DM by demonstrating that these naturally occurring compounds decreased FBG levels by increasing SCFAs content and SCFAs producing gut microbiota.

Acarbose enhances the efficacy of immunotherapy against solid tumours by modulating the gut microbiota

The crucial role of gut microbiota in shaping immunotherapy outcomes has prompted investigations into potential modulators. Here we show that oral administration of acarbose significantly increases the anti-tumour response to anti-PD-1 therapy in female tumour-bearing mice. Acarbose modulates the gut microbiota composition and tryptophan metabolism, thereby contributing to changes in chemokine expression and increased T cell infiltration within tumours. We identify CD8+ T cells as pivotal components determining the efficacy of the combined therapy. Further experiments reveal that acarbose promotes CD8+ T cell recruitment through the CXCL10-CXCR3 pathway. Faecal microbiota transplantation and gut microbiota depletion assays indicate that the effects of acarbose are dependent on the gut microbiota. Specifically, acarbose enhances the efficacy of anti-PD-1 therapy via the tryptophan catabolite indoleacetate, which promotes CXCL10 expression and thus facilitates CD8+ T cell recruitment, sensitizing tumours to anti-PD-1 therapy. The bacterial species Bifidobacterium infantis, which is enriched by acarbose, also improves response to anti-PD-1 therapy. Together, our study endorses the potential combination of acarbose and anti-PD-1 for cancer immunotherapy.

Polysaccharide NAP-3 Synergistically Enhances the Efficiency of Metformin in Type 2 Diabetes via Bile Acid/GLP-1 Axis through Gut Microbiota Remodeling

The polysaccharides of edible mushrooms are excellent phytochemicals for adjuvant treatment of metabolic diseases, but the potential mechanisms of synergistic effects are unclear. In this work, we discovered that NAP-3 enhanced the efficiency of metformin in lipid and glucose metabolism in type 2 diabetic (T2D) mice in a gut microbiome-dependent way. NAP-3 remodeled the intestinal microbial, resulting in the decreased activity of bile salt hydrolases and upregulation of CYP27A1 and CYP7B1 functions in the alternative pathway of bile acid synthesis, which leads to accumulation of the conjugated bile acids in ileum, specifically TβMCA and TUDCA. The accumulated conjugated bile acids either blocked or stimulated the nuclear receptors Farnesoid-X-receptor and TGR5, inducing the release of GLP-1 and ultimately enhanced glucose metabolism in mice. Collectively, our research indicated that edible mushroom polysaccharide NAP-3 may serve as a promising adjunctive oral therapeutic agent for T2D.

Role of Gut Microbial Metabolites in Cardiovascular Diseases-Current Insights and the Road Ahead

Cardiovascular diseases (CVDs) are the leading cause of premature morbidity and mortality globally. The identification of novel risk factors contributing to CVD onset and progression has enabled an improved understanding of CVD pathophysiology. In addition to the conventional risk factors like high blood pressure, diabetes, obesity and smoking, the role of gut microbiome and intestinal microbe-derived metabolites in maintaining cardiovascular health has gained recent attention in the field of CVD pathophysiology. The human gastrointestinal tract caters to a highly diverse spectrum of microbes recognized as the gut microbiota, which are central to several physiologically significant cascades such as metabolism, nutrient absorption, and energy balance. The manipulation of the gut microbial subtleties potentially contributes to CVD, inflammation, neurodegeneration, obesity, and diabetic onset. The existing paradigm of studies suggests that the disruption of the gut microbial dynamics contributes towards CVD incidence. However, the exact mechanistic understanding of such a correlation from a signaling perspective remains elusive. This review has focused upon an in-depth characterization of gut microbial metabolites and their role in varied pathophysiological conditions, and highlights the potential molecular and signaling mechanisms governing the gut microbial metabolites in CVDs. In addition, it summarizes the existing courses of therapy in modulating the gut microbiome and its metabolites, limitations and scientific gaps in our current understanding, as well as future directions of studies involving the modulation of the gut microbiome and its metabolites, which can be undertaken to develop CVD-associated treatment options. Clarity in the understanding of the molecular interaction(s) and associations governing the gut microbiome and CVD shall potentially enable the development of novel druggable targets to ameliorate CVD in the years to come.

The complex link between the gut microbiome and obesity-associated metabolic disorders: Mechanisms and therapeutic opportunities

Microbial interactions are widespread and important processes that support the link between disease and microbial ecology. The gut microbiota is a major source of microbial stimuli that can have detrimental or beneficial effects on human health. It is also an endocrine organ that maintains energy homeostasis and host immunity. Obesity is a highly and increasingly prevalent metabolic disease and the leading cause of preventable death worldwide. An imbalance in the gut microbiome is associated with several diseases including obesity-related metabolic disorders. This review summarizes the complex association between the gut microbiome and obesity-associated metabolic diseases and validates the role and mechanisms of ecological dysregulation in the gut in obesity-associated metabolic disorders. Therapies that could potentially alleviate obesity-associated metabolic diseases by modulating the gut microbiota are discussed.

The Gut Microbiota and Diabetes: Research, Translation, and Clinical Applications-2023 Diabetes, Diabetes Care, and Diabetologia Expert Forum

This article summarizes the state of the science on the role of the gut microbiota (GM) in diabetes from a recent international expert forum organized by Diabetes, Diabetes Care, and Diabetologia, which was held at the European Association for the Study of Diabetes 2023 Annual Meeting in Hamburg, Germany. Forum participants included clinicians and basic scientists who are leading investigators in the field of the intestinal microbiome and metabolism. Their conclusions were as follows: 1) the GM may be involved in the pathophysiology of type 2 diabetes, as microbially produced metabolites associate both positively and negatively with the disease, and mechanistic links of GM functions (e.g., genes for butyrate production) with glucose metabolism have recently emerged through the use of Mendelian randomization in humans; 2) the highly individualized nature of the GM poses a major research obstacle, and large cohorts and a deep-sequencing metagenomic approach are required for robust assessments of associations and causation; 3) because single-time point sampling misses intraindividual GM dynamics, future studies with repeated measures within individuals are needed; and 4) much future research will be required to determine the applicability of this expanding knowledge to diabetes diagnosis and treatment, and novel technologies and improved computational tools will be important to achieve this goal.

SGLT-2 inhibitors and high-dose acarbose as potential high-risk combinations for ketosis and ketoacidosis in Asian patients with T2DM: A case series

Key Clinical Message

High-dose acarbose may increase the risk of diabetic ketosis/diabetic ketoacidosis in Asian patients on sodium-glucose cotransporter-2 inhibitors. Healthcare providers and patients should be cautious to avoid this combination.

Abstract

Low-calorie diets should be avoided in patients receiving sodium-glucose cotransporter-2 (SGLT-2) inhibitors to decrease the risk of diabetic ketoacidosis (DKA). High-dose acarbose can decelerate carbohydrate absorption. We detail three cases of diabetic ketosis (DK) following concurrent SGLT-2 inhibitor and high-dose acarbose therapy (acarbose 300 mg/day and dapagliflozin 10 mg/day). Patients, aged 38-63 years with 3-10 years of type 2 diabetes mellitus (T2DM), developed DK, indicated by moderate urinary ketones and high glucose (urine ketone 2+ to 3+ and glucose 3+ to 4+) without acidosis, within 4 days to 1 month post-therapy initiation. Serum glucose was 172.8-253.8 mg/dL; HbA1c was 9.97%-10.80%. The combination therapy was halted, and DK was managed with low-dose intravenous insulin and fluids, followed by intensive insulin therapy. High-dose acarbose with SGLT-2 inhibitors may increase the risk of DK/DKA in Asian patients.

2', 3', 5'-tri-O-acetyl-N6-(3-hydroxyphenyl) adenosine alleviates diet-induced hyperlipidemia by modulating intestinal gene expression profiles and metabolic pathway

There is a growing body of evidence suggesting that the composition of intestinal flora plays a significant role in regulating lipid metabolism. 2', 3', 5'-tri-O-acetyl-N6-(3-hydroxyphenyl) adenosine (IMMH007) is a new candidate compound for regulating blood cholesterol and other lipids. In this study, we conducted metagenomic and metabolomic analyses on samples from high-fat diet-fed (HFD) hamsters treated with IMMH007. Our findings revealed that IMM-H007 reversed the imbalance of gut microbiota caused by a high-fat diet. Additionally, it activated adiponectin receptor and pantothenate and CoA biosynthesis pathway-related genes, which are known to regulate lipid and glucose metabolism. Furthermore, IMM-H007 promotes cholesterol metabolism by reducing the abundance of genes and species associated with 7α-dehydroxylation and bile salt hydrolase (BSH). Metabolomics and pharmacological studies have shown that IMM-H007 effectively improved glucose and lipid metabolism disorders caused by HFD, reduced the aggregation of secondary bile acids (SBAs), significantly increased the content of hyodeoxycholic acid (HDCA), and also activated the expression of VDR in the small intestine. As a result, there was a reduction in the leakage of diamine oxidase (DAO) into the bloodstream in hamsters, accompanied by an upregulation of ZO-1 expression in the small intestine. The results suggested that IMM-H007 regulated glucose and lipid metabolism, promoted cholesterol metabolism through activating the expression of VDR, inhibiting inflammatory and improving the permeability of the intestinal barrier. Thus, our study provides new understanding of how IMM-H007 interacts with intestinal function, microbiota, and relevant targets, shedding light on its mechanism of action.

The gut microbiota and diabetes: research, translation, and clinical applications - 2023 Diabetes, Diabetes Care, and Diabetologia Expert Forum

This article summarises the state of the science on the role of the gut microbiota (GM) in diabetes from a recent international expert forum organised by Diabetes, Diabetes Care, and Diabetologia, which was held at the European Association for the Study of Diabetes 2023 Annual Meeting in Hamburg, Germany. Forum participants included clinicians and basic scientists who are leading investigators in the field of the intestinal microbiome and metabolism. Their conclusions were as follows: (1) the GM may be involved in the pathophysiology of type 2 diabetes, as microbially produced metabolites associate both positively and negatively with the disease, and mechanistic links of GM functions (e.g. genes for butyrate production) with glucose metabolism have recently emerged through the use of Mendelian randomisation in humans; (2) the highly individualised nature of the GM poses a major research obstacle, and large cohorts and a deep-sequencing metagenomic approach are required for robust assessments of associations and causation; (3) because single time point sampling misses intraindividual GM dynamics, future studies with repeated measures within individuals are needed; and (4) much future research will be required to determine the applicability of this expanding knowledge to diabetes diagnosis and treatment, and novel technologies and improved computational tools will be important to achieve this goal.

The Gut Microbiota and Diabetes: Research, Translation, and Clinical Applications-2023 Diabetes, Diabetes Care, and Diabetologia Expert Forum

This article summarizes the state of the science on the role of the gut microbiota (GM) in diabetes from a recent international expert forum organized by Diabetes, Diabetes Care, and Diabetologia, which was held at the European Association for the Study of Diabetes 2023 Annual Meeting in Hamburg, Germany. Forum participants included clinicians and basic scientists who are leading investigators in the field of the intestinal microbiome and metabolism. Their conclusions were as follows: 1) the GM may be involved in the pathophysiology of type 2 diabetes, as microbially produced metabolites associate both positively and negatively with the disease, and mechanistic links of GM functions (e.g., genes for butyrate production) with glucose metabolism have recently emerged through the use of Mendelian randomization in humans; 2) the highly individualized nature of the GM poses a major research obstacle, and large cohorts and a deep-sequencing metagenomic approach are required for robust assessments of associations and causation; 3) because single-time point sampling misses intraindividual GM dynamics, future studies with repeated measures within individuals are needed; and 4) much future research will be required to determine the applicability of this expanding knowledge to diabetes diagnosis and treatment, and novel technologies and improved computational tools will be important to achieve this goal.

Two weeks of acarbose treatment shows no effect on gut microbiome composition in patients with type 2 diabetes: a randomised, placebo-controlled, double-blind, crossover study

Aim

The alpha-glucosidase inhibitor acarbose is approved for the treatment of type 2 diabetes (T2D). It acts in the lumen of the gut by reducing intestinal hydrolysis and absorption of ingested carbohydrates. This reduces postprandial blood glucose concentration and increases the content of carbohydrates in the distal parts of the intestine potentially influencing gut microbiome (GM) composition and possibly impacting the gut microbiome (GM) dysbiosis associated with T2D. Here, we investigated the effect of acarbose on GM composition in patients with T2D.

Methods

Faecal samples were collected in a previously conducted randomised, placebo-controlled, double-blind, crossover study in which 15 individuals with metformin-treated T2D (age 57-85 years, HbA1c 40-74 mmol/mol, BMI 23.6-34.6 kg/m2) were subjected to two 14-day treatment periods with acarbose and placebo, respectively, separated by a 6-week wash-out period. Faecal samples were collected before and by the end of each treatment period. The GM profiles were evaluated by 16S rRNA gene amplicon sequencing.

Results

The GM profiles after the treatment periods with acarbose or placebo remained unaffected (P > 0.7) when compared with the GM profiles before treatment. This applied to the analysis of within-sample diversity (α-diversity) and between-sample bacterial composition diversity (β-diversity). Additionally, no dominant bacterial species differentiated the treatment groups, and only minor increases in the relative abundances of Klebsiella spp. and Escherichia coli (P < 0.05) were observed after acarbose treatment.

Conclusion

In patients with metformin-treated T2D, 14 days of treatment with acarbose showed only minor effects on GM as seen in increased relative abundances of Klebsiella spp. and Escherichia coli.

Human Gut Microbiota in Cardiovascular Disease

The gut ecosystem, termed microbiota, is composed of bacteria, archaea, viruses, protozoa, and fungi and is estimated to outnumber human cells. Microbiota can affect the host by multiple mechanisms, including the synthesis of metabolites and toxins, modulating inflammation and interaction with other organisms. Advances in understanding commensal organisms' effect on human conditions have also elucidated the importance of this community for cardiovascular disease (CVD). This effect is driven by both direct CV effects and conditions known to increase CV risk, such as obesity, diabetes mellitus (DM), hypertension, and renal and liver diseases. Cardioactive metabolites, such as trimethylamine N -oxide (TMAO), short-chain fatty acids (SCFA), lipopolysaccharides, bile acids, and uremic toxins, can affect atherosclerosis, platelet activation, and inflammation, resulting in increased CV incidence. Interestingly, this interaction is bidirectional with microbiota affected by multiple host conditions including diet, bile acid secretion, and multiple diseases affecting the gut barrier. This interdependence makes manipulating microbiota an attractive option to reduce CV risk. Indeed, evolving data suggest that the benefits observed from low red meat and Mediterranean diet consumption can be explained, at least partially, by the changes that these diets may have on the gut microbiota. In this article, we depict the current epidemiological and mechanistic understanding of the role of microbiota and CVD. Finally, we discuss the potential therapeutic approaches aimed at manipulating gut microbiota to improve CV outcomes. © 2024 American Physiological Society. Compr Physiol 14:5449-5490, 2024.

Bile acids and the gut microbiome are involved in the hyperthermia mediated by 3,4-methylenedioxymethamphetamine (MDMA)

Hyperthermia induced by phenethylamines, such as 3,4-methylenedioxymethamphetamine (MDMA), can lead to life-threatening complications and death. Activation of the sympathetic nervous system and subsequent release of norepinephrine and activation of uncoupling proteins have been demonstrated to be the key mediators of phenethylamine-induced hyperthermia (PIH). Recently, the gut microbiome was shown to also play a contributing role in PIH. Here, the hypothesis that bile acids (BAs) produced by the gut microbiome are essential to PIH was tested. Changes in the serum concentrations of unconjugated primary BAs cholic acid (CA) and chenodeoxycholic acid (CDCA) and secondary BA deoxycholic acid (DCA) were measured following MDMA (20 mg/kg, sc) treatment in antibiotic treated and control rats. MDMA-induced a significant hyperthermic response and reduced the serum concentrations of three BAs 60 min post-treatment. Pretreatment with antibiotics (vancomycin, bacitracin and neomycin) in the drinking water for five days resulted in the depletion of BAs and a hypothermic response to MDMA. Gut bacterial communities in the antibiotic-treated group were distinct from the MDMA or saline treatment groups, with decreased microbiome diversity and alteration in taxa. Metagenomic functions inferred using the bioinformatic tool PICRUSt2 on 16S rRNA gene sequences indicated that bacterial genes associated to BA metabolism are less abundant in the antibiotic-MDMA treated group. Overall, these findings suggest that gut bacterial produced BAs might play an important role in MDMA-induced hyperthermia.

Quercetin Alleviates Insulin Resistance and Repairs Intestinal Barrier in db/db Mice by Modulating Gut Microbiota

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease which seriously affects public health. Gut microbiota remains a dynamic balance state in healthy individuals, and its disorder may affect health status and even results in metabolic diseases. Quercetin, a natural flavonoid, has been shown to have biological activities that can be used in the prevention and treatment of metabolic diseases. This study aimed to explore the mechanism of quercetin in alleviating T2DM based on gut microbiota. db/db mice were adopted as the model for T2DM in this study. After 10 weeks of administration, quercetin could significantly decrease the levels of body weight, fasting blood glucose (FBG), serum insulin (INS), the homeostasis model assessment of insulin resistance (HOMA-IR), monocyte chemoattractant protein-1 (MCP-1), D-lactic acid (D-LA), and lipopolysaccharide (LPS) in db/db mice. 16S rRNA gene sequencing and untargeted metabolomics analysis were performed to compare the differences of gut microbiota and metabolites among the groups. The results demonstrated that quercetin decreased the abundance of Proteobacteria, Bacteroides, Escherichia-Shigella and Escherichia_coli. Moreover, metabolomics analysis showed that the levels of L-Dopa and S-Adenosyl-L-methionine (SAM) were significantly increased, but 3-Methoxytyramine (3-MET), L-Aspartic acid, L-Glutamic acid, and Androstenedione were significantly decreased under quercetin intervention. Taken together, quercetin could exert its hypoglycemic effect, alleviate insulin resistance, repair the intestinal barrier, remodel the intestinal microbiota, and alter the metabolites of db/db mice.

Acarbose glycosylation by AcbE for the production of acarstatins with enhanced α-amylase inhibitory activity

Acarbose is a potent glycosidase inhibitor widely used in the clinical treatment of type 2 diabetes mellitus (T2DM). Various acarbose analogs have been identified while exploring compounds with improved pharmacological properties. In this study, we found that AcbE from Actinoplanes sp. SE50/110 catalyzes the production of acarbose analogs that exhibit significantly improved inhibitory activity towards α-amylase than acarbose. Recombinant AcbE mainly catalyzed the formation of two new compounds, namely acarstatins A and B, using acarbose as substrate. Using high-resolution mass spectrometry, nuclear magnetic resonance, and glycosidase hydrolysis, we elucidated their chemical structures as O-α-d-maltosyl-(1 → 4)-acarbose and O-α-d-maltotriosyl-(1 → 4)-acarbose, respectively. Acarstatins A and B exhibited 1584- and 1478-fold greater inhibitory activity towards human salivary α-amylase than acarbose. Furthermore, both acarstatins A and B exhibited complete resistance to microbiome-derived acarbose kinase 1-mediated phosphorylation and partial resistance to acarbose-preferred glucosidase-mediated hydrolysis. Therefore, acarstatins A and B have great potential as candidate therapeutic agents for T2DM.

The alteration of fecal microbial and metabolic profile of gallstone patients in Taiwan: Single-center study

BACKGROUND

Gallstone disease is a common health problem worldwide. The role of the gut microbiota in gallstone pathogenesis remains obscure. Our aim was to evaluate the association and crosstalk between gut microbiota, gut metabolomic, and metabolic parameters in cholesterol gallstone patients, pigmented gallstone patients, and controls.

METHODS

We collected stool samples from healthy individuals and patients with gallstones in our hospital from March 2019 to February 2021. 16s rRNA sequencing was performed, followed by differential abundance analyses. Measurement of bile acids and short-chain fatty acids was conducted via targeted metabolomics.

RESULT

Thirty healthy individuals and 20 gallstone patients were recruited. The intergroup difference of microbial composition was significant between control and gallstone patients. The control group had more abundant Faecalibacterium , Prevotella 9 , and Bacteroides plebeius DSM 17135 . The cholesterol stones group had higher Desulfovibrionaceae and Bacteroides uniformis than the other two groups, while the pigment stone group had more abundant Escherichia-Shigella . In the analysis of metabolites, only n-butyric acid had a significantly higher concentration in the controls than in the gallstone group ( p < 0.01). The level of 3α-hydroxy-12 ketolithocholic acid, deoxycholic acid, and cholic acid showed no intergroup differences but was correlated to the serum cholesterol level and bacterial richness and evenness.

CONCLUSION

Our study revealed the key taxa that can discriminate between individuals with or without gallstones. We also identified metabolites that are possibly associated with metabolic parameter and bacterial diversity. However, the correlation of the metabolites to certain clusters of bacteria should be analyzed in a larger cohort.

Decoding the Gut Microbiota-Gestational Diabetes Link: Insights from the Last Seven Years

The human microbiome, a complex ecosystem of bacteria, viruses, and protozoans living in symbiosis with the host, plays a crucial role in human health, influencing everything from metabolism to immune function. Dysbiosis, or an imbalance in this ecosystem, has been linked to various health issues, including diabetes and gestational diabetes (GD). In diabetes, dysbiosis affects the function of adipose tissue, leading to the release of adipokines and cytokines, which increase inflammation and insulin resistance. During pregnancy, changes to the microbiome can exacerbate glucose intolerance, a common feature of GD. Over the past years, burgeoning insights into the gut microbiota have unveiled its pivotal role in human health. This article comprehensively reviews literature from the last seven years, highlighting the association between gut microbiota dysbiosis and GD, as well as the metabolism of antidiabetic drugs and the potential influences of diet and probiotics. The underlying pathophysiological mechanisms discussed include the impact of dysbiosis on systemic inflammation and the interplay with genetic and environmental factors. By focusing on recent studies, the importance of considering microbial health in the prevention and treatment of GD is emphasized, providing insights into future research directions and clinical applications to improve maternal-infant health outcomes.

Acarbose Impairs Gut Bacteroides Growth by Targeting Intracellular GH97 Enzymes

Acarbose is a type-2 diabetes medicine that inhibits dietary starch breakdown into glucose by inhibiting host amylase and glucosidase enzymes. Numerous gut species in the Bacteroides genus enzymatically break down starch and change in relative abundance within the gut microbiome in acarbose-treated individuals. To mechanistically explain this observation, we used two model starch-degrading Bacteroides, Bacteroides ovatus (Bo) and Bacteroides thetaiotaomicron (Bt). Bt growth is severely impaired by acarbose whereas Bo growth is not. The Bacteroides use a starch utilization system (Sus) to grow on starch. We hypothesized that Bo and Bt Sus enzymes are differentially inhibited by acarbose. Instead, we discovered that although acarbose primarily targets the Sus periplasmic GH97 enzymes in both organisms, the drug affects starch processing at multiple other points. Acarbose competes for transport through the Sus beta-barrel proteins and binds to the Sus transcriptional regulators. Further, Bo expresses a non-Sus GH97 (BoGH97D) when grown in starch with acarbose. The Bt homolog, BtGH97H, is not expressed in the same conditions, nor can overexpression of BoGH97D complement the Bt growth inhibition in the presence of acarbose. This work informs us about unexpected complexities of Sus function and regulation in Bacteroides, including variation between related species. Further, this indicates that the gut microbiome may be a source of variable response to acarbose treatment for diabetes.

Role of the microbiota-gut-heart axis between bile acids and cardiovascular disease

Bile acid (BA) receptors (e.g., farnesoid X-activated receptor, muscarinic receptor) are expressed in cardiomyocytes, endothelial cells, and vascular smooth muscle cells, indicating the relevance of BAs to cardiovascular disease (CVD). Hydrophobic BAs are cardiotoxic, while hydrophilic BAs are cardioprotective. For example, fetal cardiac insufficiency in maternal intrahepatic cholestasis during pregnancy, and the degree of fetal cardiac abnormality, is closely related to the level of hydrophobic BAs in maternal blood and infant blood. However, ursodeoxycholic acid (the most hydrophilic BA) can reverse/prevent these detrimental effects of increased levels of hydrophobic BAs on the heart. The gut microbiota (GM) and GM metabolites (especially secondary BAs) have crucial roles in hypertension, atherosclerosis, unstable angina, and heart failure. Herein, we describe the relationship between CVD and the GM at the BA level. We combine the concept of the "microbiota-gut-heart axis" (MGHA) and postulate the role and mechanism of BAs in CVD development. In addition, the strategies for treating CVD with BAs under the MGHA are proposed.

Deciphering unique and shared interactions between the human gut microbiota and oral antidiabetic drugs

The administration of oral antidiabetic drugs (OADs) to patients with type 2 diabetes elicits distinct and shared changes in the gut microbiota, with acarbose and berberine exhibiting greater impacts on the gut microbiota than metformin, vildagliptin, and glipizide. The baseline gut microbiota strongly associates with treatment responses of OADs.

Association between gut microbiota and diabetic nephropathy: a mendelian randomization study

Background

The correlation between diabetic nephropathy (DN) and gut microbiota (GM) has been suggested in numerous animal experiments and cross-sectional studies. However, a causal association between GM and DN has not been ascertained.

Methods

This research adopted MR analysis to evaluate the causal link between GM and DN derived from data acquired through publicly available genome-wide association studies (GWAS). The study utilized the inverse variance weighted (IVW) approach to assess causal association between GM and DN. Four additional methods including MR-Egger, weighted median, weighted mode, and simple mode were employed to ensure comprehensive analysis and robust results. The Cochran's Q test and the MR-Egger method were conducted to identify heterogeneity and horizontal pleiotropy, respectively. The leave-one-out approach was utilized to evaluate the stability of MR results. Finally, a reverse MR was performed to identify the reverse causal association between GM and DN.

Results

According to IVW analysis, Class Verrucomicrobiae (p = 0.003), Order Verrucomicrobiales (p = 0.003), Family Verrucomicrobiaceae (p = 0.003), Genus Akkermansia (p = 0.003), Genus Catenibacterium (p = 0.031), Genus Coprococcus 1 (p = 0.022), Genus Eubacterium hallii group (p = 0.018), and Genus Marvinbryantia (p = 0.023) were associated with a higher risk of DN. On the contrary, Class Actinobacteria (p = 0.037), Group Eubacterium ventriosum group (p = 0.030), Group Ruminococcus gauvreauii group (p = 0.048), Order Lactobacillales (p = 0.045), Phylum Proteobacteria (p = 0.017) were associated with a lower risk of DN. The sensitivity analysis did not identify any substantial pleiotropy or heterogeneity in the outcomes. We found causal effects of DN on 11 GM species in the reverse MR analysis. Notably, Phylum Proteobacteria and DN are mutually causalities.

Conclusion

This study identified the causal association between GM and DN with MR analysis, which may enhance the understanding of the intestinal-renal axis and provide novel potential targets for early non-invasive diagnosis and treatment of DN.

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.

Cluster-specific associations between the gut microbiota and behavioral outcomes in preschool-aged children

BACKGROUND

The gut microbiota is recognized as a regulator of brain development and behavioral outcomes during childhood. Nonetheless, associations between the gut microbiota and behavior are often inconsistent among studies in humans, perhaps because many host-microbe relationships vary widely between individuals. This study aims to stratify children based on their gut microbiota composition (i.e., clusters) and to identify novel gut microbiome cluster-specific associations between the stool metabolomic pathways and child behavioral outcomes.

METHODS

Stool samples were collected from a community sample of 248 typically developing children (3-5 years). The gut microbiota was analyzed using 16S sequencing while LC-MS/MS was used for untargeted metabolomics. Parent-reported behavioral outcomes (i.e., Adaptive Skills, Internalizing, Externalizing, Behavioral Symptoms, Developmental Social Disorders) were assessed using the Behavior Assessment System for Children (BASC-2). Children were grouped based on their gut microbiota composition using the Dirichlet multinomial method, after which differences in the metabolome and behavioral outcomes were investigated.

RESULTS

Four different gut microbiota clusters were identified, where the cluster enriched in both Bacteroides and Bifidobacterium (Ba2) had the most distinct stool metabolome. The cluster characterized by high Bifidobacterium abundance (Bif), as well as cluster Ba2, were associated with lower Adaptive Skill scores and its subcomponent Social Skills. Cluster Ba2 also had significantly lower stool histidine to urocanate turnover, which in turn was associated with lower Social Skill scores in a cluster-dependent manner. Finally, cluster Ba2 had increased levels of compounds involved in Galactose metabolism (i.e., stachyose, raffinose, alpha-D-glucose), where alpha-D-glucose was associated with the Adaptive Skill subcomponent Daily Living scores (i.e., ability to perform basic everyday tasks) in a cluster-dependent manner.

CONCLUSIONS

These data show novel associations between the gut microbiota, its metabolites, and behavioral outcomes in typically developing preschool-aged children. Our results support the concept that cluster-based groupings could be used to develop more personalized interventions to support child behavioral outcomes. Video Abstract.

Foodborne Carbon Dots Aggravate High-Fat-Diet-Induced Glucose Homeostasis Imbalance by Disrupting the Gut-Liver Axis

Foodborne carbon dots (CDs) are generally produced during cooking and exist in food items. Generally, CDs are regarded as nontoxic materials, but several studies have gradually confirmed the cytotoxicity of CDs, such as oxidative stress, reduced cellular activity, apoptosis, etc. However, studies focusing on the health effects of long-term intake of food-borne CDs are scarce, especially in populations susceptible to metabolic disease. In this study, we reported that CDs in self-brewing beer had no effect on glucose metabolism in CHOW-fed mice but exacerbated high-fat-diet (HFD)-induced glucose metabolism disorders via the gut-liver axis. Chronic exposure to foodborne CDs increased fasting glucose levels and exacerbated liver and intestinal barrier damage in HFD-fed mice. The 16s rRNA sequencing analysis revealed that CDs significantly altered the gut microbiota composition and promoted lipopolysaccharide (LPS) synthesis-related KEGG pathways (superpathway of (Kdo)2-lipid A, Kdo transfer to lipid IVA Ill (Chlamydia), lipid IVA biosynthesis, and so on) in HFD-fed mice. Mechanically, CD exposure increased the abundance of Gram-negative bacteria (Proteobacteria and Desulfovibrionaceae), thus producing excessive endotoxin-LPS, and then LPS was transferred by the blood circulation to the liver due to the damaged intestinal barrier. In the liver, LPS promoted TLR4/NF-κB/P38 MAPK signaling, thus enhancing systemic inflammation and exacerbating HFD-induced insulin resistance. However, pretreating mice with antibiotics eliminated these effects, indicating a key role for gut microbiota in CDs exacerbating glucose metabolism disorders in HFD-fed mice. The finding herein provides new insight into the potential health risk of foodborne nanoparticles in susceptible populations by disturbing the gut-liver axis.

Evaluation of Acarbose Bioequivalence in Healthy Chinese Populations Using Novel Pharmacodynamic End Points

Acarbose is a widely used α-glucosidase inhibitor for the management of postprandial hyperglycemia in patients with type 2 diabetes mellitus. Recent pilot studies on acarbose bioequivalence (BE) have successfully identified additional pharmacodynamic (PD) parameters as valid end points. Nevertheless, there was a scarcity of published pivotal studies using novel PD parameters. The purpose of the study is to investigate the acarbose BE using the new PD parameters. The study was conducted with an open, randomized, 2-period crossover design. A total of 64 healthy Chinese volunteers received either the reference (R) or test (T) acarbose at a dose of 2×50 mg orally, followed by a 1-week washout period. After sucrose treatment (baseline) and sucrose/acarbose co-administration, serum glucose, and insulin concentrations were assessed. The rectifying approach yielded geometric mean ratios of 102.9% for maximum serum glucose concentration with deduction of glucose concentration at 0 hour and 105.3% for the area under the serum glucose concentration-time curve profile 0-2 hours after coadministration of sucrose and acarbose with deduction of baseline (AUC0-2 h,r ). The 90% confidence intervals of maximum serum glucose concentration with deduction of glucose concentration at 0 hour and the area under the serum glucose concentration-time curve profile 0-2 hours after coadministration of sucrose and acarbose with deduction of baseline all fell within the acceptance limits. The incidence of adverse events after the T or R drug was comparable, and healthy subjects were well tolerated. The findings of our investigation clearly show that the PD parameters of the rectifying method exhibit enhanced suitability and sensitivity when assessing acarbose BE in healthy participants. The T and R drugs were bioequivalent using the novel PD parameters, and both drugs demonstrated good safety and tolerability.

Targeted LC-MS/MS profiling of bile acids reveals primary/secondary bile acid ratio as a novel biomarker for necrotizing enterocolitis

Bile acids (BAs) are involved in the development of necrotizing enterocolitis (NEC), which mainly occurs in preterm infants. We aim to identify the change of BAs in preterm infants and validate its potential value in the detection of NEC. Targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) was performed to measure the plasma BAs in healthy preterm infants and patients with NEC. By analyzing the level of BAs in healthy preterm infants, we found that the plasma concentrations of BAs were related to sex, gestational/postnatal age, birth weight, mode of birth, and feeding type after birth. The plasma levels of TCA, GCA, TCDCA, GCDCA, primary BAs, and total BAs and the primary/secondary BA ratio were decreased, while DCA, UDCA, and secondary BAs were increased in NEC. The primary/secondary BA ratio (cutoff point 62.9) can effectively differentiate NEC from healthy preterm infants, with an AUC of 0.9, a sensitivity of 94.5%, and a specificity of 78.1%. Combining the ratio with high-risk factors of NEC can better distinguish between NEC and control, with an AUC of 0.95. Importantly, significantly lower levels of primary/secondary BA ratio were found in infants with surgical NEC than in nonsurgical NEC cases. The cutoff point of 28.7 identified surgical NEC from nonsurgical NEC with sensitivity and specificity of 76.9% and 100%. Thus, our study identified that the primary/secondary BA ratio in the plasma can differentiate NEC from healthy preterm infants and effectively differentiate the surgical NEC from nonsurgical NEC. Therefore, LC-MS/MS was expected to be a novel measurement platform used to distinguish infants who are most in need of close monitoring or early surgical intervention.

Review on chronic metabolic diseases surrounding bile acids and gut microbiota: What we have explored so far

Bile acid, the final product of cholesterol breakdown, functions as a complex regulator and signaling factor in human metabolism. Chronic metabolic diseases pose significant medical challenges. Growing research underscores bile acids' capacity to enhance metabolism via diverse pathways, regulating disorders and offering treatment potential. Numerous bile-acid-triggered pathways have become treatment targets. This review outlines bile acid synthesis, its role as a signal in chronic metabolic diseases, and highlights its interaction with gut microbiota in different metabolic conditions. Exploring host-bacteria-bile acid links emerges as a valuable future research direction with clinical implications.

Bridging the Gap from Enterotypes to Personalized Dietary Recommendations: A Metabolomics Perspective on Microbiome Research

Advances in high-throughput DNA sequencing have propelled research into the human microbiome and its link to metabolic health. We explore microbiome analysis methods, specifically emphasizing metabolomics, how dietary choices impact the production of microbial metabolites, providing an overview of studies examining the connection between enterotypes and diet, and thus, improvement of personalized dietary recommendations. Acetate, propionate, and butyrate constitute more than 95% of the collective pool of short-chain fatty acids. Conflicting data on acetate's effects may result from its dynamic signaling, which can vary depending on physiological conditions and metabolic phenotypes. Human studies suggest that propionate has overall anti-obesity effects due to its well-documented chemistry, cellular signaling mechanisms, and various clinical benefits. Butyrate, similar to propionate, has the ability to reduce obesity by stimulating the release of appetite-suppressing hormones and promoting the synthesis of leptin. Tryptophan affects systemic hormone secretion, with indole stimulating the release of GLP-1, which impacts insulin secretion, appetite suppression, and gastric emptying. Bile acids, synthesized from cholesterol in the liver and subsequently modified by gut bacteria, play an essential role in the digestion and absorption of dietary fats and fat-soluble vitamins, but they also interact directly with intestinal microbiota and their metabolites. One study using statistical methods identified primarily two groupings of enterotypes Bacteroides and Ruminococcus. The Prevotella-dominated enterotype, P-type, in humans correlates with vegetarians, high-fiber and carbohydrate-rich diets, and traditional diets. Conversely, individuals who consume diets rich in animal fats and proteins, typical in Western-style diets, often exhibit the Bacteroides-dominated, B-type, enterotype. The P-type showcases efficient hydrolytic enzymes for plant fiber degradation but has limited lipid and protein fermentation capacity. Conversely, the B-type features specialized enzymes tailored for the degradation of animal-derived carbohydrates and proteins, showcasing an enhanced saccharolytic and proteolytic potential. Generally, models excel at predictions but often struggle to fully elucidate why certain substances yield varied responses. These studies provide valuable insights into the potential for personalized dietary recommendations based on enterotypes.

Effect of synbiotic supplementation on immune parameters and gut microbiota in healthy adults: a double-blind randomized controlled trial

Synbiotics are increasingly used by the general population to boost immunity. However, there is limited evidence concerning the immunomodulatory effects of synbiotics in healthy individuals. Therefore, we conducted a double-blind, randomized, placebo-controlled study in 106 healthy adults. Participants were randomly assigned to receive either synbiotics (containing Bifidobacterium lactis HN019 1.5 × 108 CFU/d, Lactobacillus rhamnosus HN001 7.5 × 107 CFU/d, and fructooligosaccharide 500 mg/d) or placebo for 8 weeks. Immune parameters and gut microbiota composition were measured at baseline, mid, and end of the study. Compared to the placebo group, participants receiving synbiotic supplementation exhibited greater reductions in plasma C-reactive protein (P = 0.088) and interferon-gamma (P = 0.008), along with larger increases in plasma interleukin (IL)-10 (P = 0.008) and stool secretory IgA (sIgA) (P = 0.014). Additionally, synbiotic supplementation led to an enrichment of beneficial bacteria (Clostridium_sensu_stricto_1, Lactobacillus, Bifidobacterium, and Collinsella) and several functional pathways related to amino acids and short-chain fatty acids biosynthesis, whereas reduced potential pro-inflammatory Parabacteroides compared to baseline. Importantly, alternations in anti-inflammatory markers (IL-10 and sIgA) were significantly correlated with microbial variations triggered by synbiotic supplementation. Stratification of participants into two enterotypes based on pre-treatment Prevotella-to-Bacteroides (P/B) ratio revealed a more favorable effect of synbiotic supplements in individuals with a higher P/B ratio. In conclusion, this study suggested the beneficial effects of synbiotic supplementation on immune parameters, which were correlated with synbiotics-induced microbial changes and modified by microbial enterotypes. These findings provided direct evidence supporting the personalized supplementation of synbiotics for immunomodulation.

Effect of Cichorium glandulosum on intestinal microbiota and bile acid metabolism in db/db mice

This study aims to investigate the effects of Chorum glandulosum Boiss. et Huet (CG) on the intestinal microbiota and serum bile acid (BA) in db/db mice. A total of 12 db/db mice were randomly divided into model (MOD), high-dose CG (CGH), and control (CON) groups. The CON and MOD groups received distilled water by gavage for 8 weeks. Whereas, the CGH group received an alcohol extract of CG at a dose of 200 mg/kg/day. Results showed that CG can reduce blood lipid levels. It change the composition of the intestinal microbiota, and increase the relative abundances of Muribaculaceae, Prevotellaceae, Bifidobacterium_pseudolongum, Bacteroidaceae in db/db mice as well. LC-MS metabolomics results showed that CG adjusted the serum BA levels. The results reduced the levels of primary BAs, such as cholic acid (CA) and chenodeoxycholic acid (CDCA). The results decreased the primary BA/secondary BA (PSA/SBA) ratio in db/db mice. Correlation analysis showed that the abundances of Bifidobacterium_pseudolongum and Bacteroidaceae were positively correlated with acetic acid level and negatively correlated with ursocholic acid (UCA), α-muricholic acid (αMCA), triglyceride (TG), and total cholesterol levels (TC), indicating an interaction between the intestinal microbiota and serum BAs. CG may play a positive role in the interaction between the intestinal microbiota and BAs in lipid metabolism.