Gut microbiota dysbiosis in stable coronary artery disease combined with type 2 diabetes mellitus influences cardiovascular prognosis

Molecular Mechanisms and Emerging Precision Therapeutics in the Gut Microbiota-Cardiovascular Axis

A microbiome in the gut plays a significant role in cardiovascular health and disease. Dysbiosis is an imbalance in the gut microbiome, leading to multiple cardiovascular diseases (CVD) such as atherosclerosis, hypertension, and heart failure. Gut microbe-derived metabolites such as trimethylamine-N-oxide (TMAO) and short-chain fatty acids (SCFAs) are important mediators of the gut-heart axis. Evaluation of the relationship between the gut microbiome and host biomarkers with CVD requires the integration of metagenomics and metabolomics with meta-omics approaches. The literature review found that microbes and metabolic signatures are associated with the risk and progression of CVD. The development of precision therapeutic approaches for targeting gut microbiota includes preventing adverse microbial effects using probiotics, prebiotics, and the drug-as-bug approach to inhibit harmful metabolites of microbiomes, and fecal microbiota transplantation (FMT). However, the implication and practice of these findings in clinical settings face challenges due to the heterogeneity of study designs, difficulty in the determination of causality, and the impact of confounding factors such as diet, medication, and potential inter-individual gut microbiome variability. Future researchers are recommended to conduct longitudinal studies to further establish both gut microbiome associations with CVD and develop successful precision therapeutics approaches based on the microbiome for the treatment of CVD.

Intestinal microbiome as a diagnostic marker of coronary artery disease: a systematic review and meta-analysis

BACKGROUND

The intestinal microbiome has been recently linked to several metabolic and chronic disorders, one of which is coronary artery disease (CAD). Our study aimed to analyze the intestinal microbiome of CAD patients and assess the eligibility of dysbiosis as a diagnostic marker of CAD.

METHODS

PubMed, Scopus, Embase, and Web of Science were searched using terms, such as 'CAD' and 'microbiome'. Only observational controlled studies were included. R version 4.2.2 was used for the analysis.

RESULTS

A significant association was found between the CAD group and increased Simpson and Shannon Indices compared with the control group (MD=0.04, 95% CI=0.03-0.05, and MD=0.11, 95% CI=0.01-0.22, respectively). Our analysis yielded a statistically significant association between the CAD group and increased Prevotella genus (MD=13.27, 95% CI=4.12-22.42, P-value=0.004), Catenibacterium genus (MD=0.09, 95% CI=0.09-0.10), Pseudomonas genus (MD=0.54, 95% CI=0.29-0.78, P-value), and Subdoligranulum (MD=-0.06, 95% CI=-0.06 to -0.06) compared with the control group. Another significant association was detected between the CAD group and decreased Bacteroides vulgatus and Bacteroides dorei (MD=-10.31, 95% CI=-14.78 to -5.84, P-value <0.00001).

CONCLUSION

Dysbiosis is an acceptable diagnostic marker of CAD. Decreased B. dorei and B. vulgatus among CAD patients suggests a protective role of these bacteria. Future clinical trials are necessary to investigate the potential benefit of supplementation of these bacteria in treating or preventing CAD.

Metformin's dual impact on Gut microbiota and cardiovascular health: A comprehensive analysis

Cardiovascular diseases (CVD) cause significant global morbidity, mortality and public health burden annually. CVD alters richness, diversity, and composition of Gut microbiota along with RAS and histopathological differences. Present study explores Metformin role in mitigating doxorubicin induced cardiovascular toxicity/remodeling. Animals were divided into 4 groups with n=6: Group I (N. Control) free access to diet and water; Group II (MET. Control) on oral Metformin (250 mg/kg) daily; Group III (DOX. Control) alternate day intraperitoneal Doxorubicin (3 mg/kg) totaling 18 mg/kg; Group IV (DOX. MET. Control) received both daily oral Metformin (250 mg/kg) and alternate day Doxorubicin (3 mg/kg). Gut microbial analysis was made from stool before animals were sacrificed for biochemical and histopathological analysis. Significant alterations were observed in ɑ and β-diversity with new genus from Firmicutes, specifically Clostridia_UCG-014, Eubacterium ruminantium, and Tunicibacter, were prevalent in both the DOX. Control and DOX.MET groups. Proteobacteria, represented by Succinivibrio, were absent in all groups. Additionally, Parabacteroides from the Bacteroidia phylum was absent in all groups except the N. control. In the DOX.MET Control group, levels of Angiotensin II ( 7.75± 0.49 nmol/min, p<0.01) and Renin (2.60±0.26 ng/ml/hr) were significantly reduced. Conversely, levels of CK-MB, Fibrinogen, Troponin, CRP ( p < 0.0001), and TNFɑ (p < 0.05) were elevated. Histopathological examination revealed substantial cardiac changes, including Fibrinogen and fat deposition and eosinophilic infiltration, as well as liver damage characterized by binucleated cells and damaged hepatocytes, along with altered renal tissues in the DOX.MET.Control group. The findings suggest that MET. significantly modifies gut microbiota, particularly impacting the Firmicutes and Proteobacteria phyla. The reduction in Angiotensin II levels, alongside increased inflammatory markers and myocardial damage, highlights the complex interactions and potential adverse effects associated with MET therapy on cardiovascular health.

Unravelling the Gut Microbiome Role in Cardiovascular Disease: A Systematic Review and a Meta-Analysis

A notable shift in understanding the human microbiome's influence on cardiovascular disease (CVD) is underway, although the causal association remains elusive. A systematic review and meta-analysis were conducted to synthesise current knowledge on microbial taxonomy and metabolite variations between healthy controls (HCs) and those with CVD. An extensive search encompassing three databases identified 67 relevant studies (2012-2023) covering CVD pathologies from 4707 reports. Metagenomic and metabolomic data, both qualitative and quantitative, were obtained. Analysis revealed substantial variability in microbial alpha and beta diversities. Moreover, specific changes in bacterial populations were shown, including increased Streptococcus and Proteobacteria and decreased Faecalibacterium in patients with CVD compared with HC. Additionally, elevated trimethylamine N-oxide levels were reported in CVD cases. Biochemical parameter analysis indicated increased fasting glucose and triglycerides and decreased total cholesterol and low- and high-density lipoprotein cholesterol levels in diseased individuals. This study revealed a significant relationship between certain bacterial species and CVD. Additionally, it has become clear that there are substantial inconsistencies in the methodologies employed and the reporting standards adhered to in various studies. Undoubtedly, standardising research methodologies and developing extensive guidelines for microbiome studies are crucial for advancing the field.

Unveiling the microbiota-metabolite-myocardium axis: a novel perspective on cardiovascular health

Introduction

Cardiovascular diseases, including myocardial infarction, remain a leading cause of death globally. Emerging evidence suggests the gut microbiota plays a crucial role in cardiovascular health. This study aims to explore the impact of gut microbiota on myocardial infarction using a mouse model.

Methods

The research utilizes a multi-omics approach, including 16S rDNA sequencing and LC-MS-based metabolomics to analyze fecal and serum samples from mice modeled to mimic myocardial infarction. This methodology allows for a comprehensive analysis of microbial populations and their metabolic output.

Results

The findings reveal a significant reduction in gut microbiota α-diversity in mice with induced myocardial infarction compared to healthy controls. Notably, there is an increase in populations of Fusobacteria and Clostridia. Metabolomic analysis indicates disruptions in amino acid and energy metabolism, suggesting a metabolic dysregulation linked to myocardial health.

Discussion

The study proposes a novel microbiota-metabolite-myocardium axis, where specific microbial metabolites may directly affect heart health. This connection points to the gut microbiota as a potential player in the pathogenesis of myocardial infarction and may open new therapeutic avenues targeting the gut microbiome to combat cardiovascular diseases.

Human gut microbiome: Therapeutic opportunities for metabolic syndrome-Hype or hope?

Shifts in gut microbiome composition and metabolic disorders are associated with one another. Clinical studies and experimental data suggest a causal relationship, making the gut microbiome an attractive therapeutic goal. Diet, intake of probiotics or prebiotics and faecal microbiome transplantation (FMT) are methods to alter a person's microbiome composition. Although FMT may allow establishing a proof of concept to use microbiome modulation to treat metabolic disorders, studies show mixed results regarding the effects on metabolic parameters as well as on the composition of the microbiome. This review summarizes the current knowledge on diet, probiotics, prebiotics and FMT to treat metabolic diseases, focusing on studies that also report alterations in microbiome composition. Furthermore, clinical trial results on the effects of common drugs used to treat metabolic diseases are synopsized to highlight the bidirectional relationship between the microbiome and metabolic diseases. In conclusion, there is clear evidence that microbiome modulation has the potential to influence metabolic diseases; however, it is not possible to distinguish which intervention is the most successful. In addition, a clear commitment from all stakeholders is necessary to move forward in the direction of developing targeted interventions for microbiome modulation.

Integrated Gut Microbiota and Urine Metabolite Analyses of T2DM with NAFLD Rat Model

Globally 80% type 2 diabetes mellitus (T2DM) patients suffer nonalcoholic fatty liver disease (NAFLD). The interplay of gut microbiota and endogenous metabolic networks has not yet been reported in the setting of T2DM with NAFLD. As such, this study utilized 16S rRNA gene sequencing to assess the changes in intestinal flora and nuclear magnetic resonance spectroscopy (1H NMR) to identify potential metabolites in a T2DM with NAFLD rat model. Spearman correlation analysis was performed to explore the relationship between gut microbiota and metabolites. Results revealed that among T2DM with NAFLD rats, diversity indexes of intestinal microbiota were distinctly decreased while levels of 18 bacterial genera within the intestinal tract were significantly altered. In addition, levels of eight metabolites mainly involved in the synthesis and degradation of ketone bodies, the TCA cycle, and butanoate metabolism were altered. Correlation analysis revealed that gut bacteria such as Blautia, Ruminococcus torques group, Allobaculum, and Lachnoclostridium strongly associate with 3-hydroxybutyrate, acetone, acetoacetate, 2-oxoglutarate, citrate, creatinine, hippurate, and allantoin. Our findings can provide a basis for future development of targeted treatments.

Pharmacological and Nutritional Modulation of Metabolome and Metagenome in Cardiometabolic Disorders

Cardiometabolic disorders are major causes of morbidity and mortality worldwide. A growing body of research indicates that the gut microbiota, whether it interacts favorably or not, plays an important role in host metabolism. Elucidating metabolic pathways may be crucial in preventing and treating cardiometabolic diseases, and omics methods are key to studying the interaction between the fecal microbiota and host metabolism. This review summarizes available studies that combine metabolomic and metagenomic approaches to describe the effects of drugs, diet, nutrients, and specific foods on cardiometabolic health and to identify potential targets for future research.

Low glycemic index potato biscuits alleviate physio-histological damage and gut dysbiosis in rats with type-2 diabetes mellitus induced by high-sugar and high-fat diet and streptozotocin

Type 2 diabetes mellitus (T2DM) is the most common type of diabetes globally and poses a major concern for human health. This study aimed to investigate the effects on T2DM of low-glycemic index (GI) potato biscuits with oat bran and inulin as functional additives. T2DM was induced in rats by streptozotocin (STZ) and a high-sugar and high-fat diet. The alleviation of T2DM by low-GI potato biscuits at different doses was evaluated based on the analysis of glycolipid levels, histological observations, inflammatory markers and gut microbiota structure. Compared to wheat biscuits, low-GI potato biscuits resulted in lower postprandial blood glucose levels. After eight weeks of intervention, fasting blood sugar levels were 16.9% lower in T2DM rats fed high-dose low-GI potato biscuits than in untreated T2DM rats. Moreover, the intervention with low-GI potato biscuits significantly alleviated T2DM-induced pathological damage, glucose and lipid metabolic disorders, and inflammation by reversing the levels of total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, transforming growth factor-β, interleukin-1β, interleukin-6 and tumor necrosis factor-α. Moreover, the levels of short-chain fatty acids and gut microbiota structure in T2DM rats were significantly reversed. The abundance of beneficial bacteria (e.g., Bifidobacterium, Lachnoclostridium, Roseburia) in the gut of T2DM rats was significantly increased whereas the abundance of Escherichia-Shigella and Desulfovibrio decreased. The present study revealed that low-GI potato biscuits alleviated damages caused by high-sugar and high-fat diet- and STZ-induced T2DM in rats, as well as reversed disturbances in the gut microbiota. Thus, low-GI potato biscuits are potentially beneficial to T2DM patients.

Alterations in gut microbiota and urine metabolomics in infants with yin-deficiency constitution aged 0–2 years

Background

Based on the constitution theroy, infants are classified into balanced constitution (BC) and unbalanced constitution. Yin-deficiency constitution (YINDC) is a common type of unbalanced constitutions in Chinese infants. An infant's gut microbiota directly affects the child's health and has long-term effects on the maturation of the immune and endocrine systems throughout life. However, the gut microbiota of infants with YINDC remains unknown. Herein, we aimed to evaluate the intestinal flora profiles and urinary metabolites in infant with YINDC, find biomarkers to identify YINDC, and promote our understanding of infant constitution classification.

Methods

Constitutional Medicine Questionnaires were used to assess the infants' constitution types. 47 infants with 21 cases of YINDC and 26 cases of BC were included, and a cross-sectional sampling of stool and urine was conducted. Fecal microbiota was characterized using 16S rRNA sequencing, and urinary metabolomics was profiled using UPLC-Q-TOF/MS method. YINDC markers with high accuracy were identified using receiver operating characteristic (ROC) analysis.

Results

The diversity and composition of intestinal flora and urinary metabolites differed significantly between the YINDC and BC groups. A total of 13 obviously different genera and 55 altered metabolites were identified. Stool microbiome shifts were associated with urine metabolite changes. A combined marker comprising two genera may have a high potential to identify YINDC with an AUC of 0.845.

Conclusions

Infants with YINDC had a unique gut microbiota and metabolomic profile resulting in a constitutional microclassification. The altered gut microbiome in YINDC may account for the higher risk of cardiovascular diseases. Metabolomic analysis of urine showed that metabolic pathways, including histidine metabolism, proximal tubule bicarbonate reclamation, arginine biosynthesis, and steroid hormone biosynthesis, were altered in infants with YINDC. Additionally, the combined bacterial biomarker had the ability to identify YINDC. Identifying YINDC in infancy and intervening at an early stage is crucial for preventing cardiovascular diseases.

The gut microbiota pathway mechanisms of diabetes

The contribution of dysbiotic gut microbiota configuration is essential when making reference to the metabolic disorders by increasing energy. It is important to understand that the gut microbiota induced metabolic disease mechanisms and inflammations. Thus it is imperative to have an insight into the state of all chronic subclinical inflammations influencing disease outcomes. However, from the emerging studies, there still exist inconsistencies in the findings of such studies. While making the best out of the reasons for inconsistencies of the findings, this review is designed to make a clear spell out as to the inconsistence of gut microbiota with respect to diabetes. It considered gut-virome alterations and diabetes and gut-bacteriome-gut-virome-alterations and diabetes as confounding factors. The review further explained some study design strategies that will spontaneously eliminate any potential confounding factors to lead to a more evidence based diabetic-gut microbiota medicine. Lipopolysaccharide (LPS) pro-inflammatory, metabolic endotoxemia and diet/gut microbiota insulin-resistance and low-grade systemic inflammation induced by gut microbiota can trigger pro-inflammatory cytokines in insulin-resistance, consequently, leading to the diabetic condition. While diet influences the gut microbiota, the consequences are mainly the constant high levels of pro-inflammatory cytokines in the circulatory system. Of recent, dietary natural products have been shown to be anti-diabetic. The effects of resveratrol on the gut showed an improved lipid profile, anti-inflammatory properties and ameliorated the endotoxemia, tight junction and glucose intolerance.

Gut microbiota and bile acids partially mediate the improvement of fibroblast growth factor 21 on methionine-choline-deficient diet-induced non-alcoholic fatty liver disease mice

Non-alcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis, inflammation, and fibrosis, as well as gut dysbiosis. Fibroblast growth factor 21 (FGF21), which regulates glucose and lipid metabolism, has been proven to have a good effect on NAFLD. However, the modulating process between FGF21 and gut microbiota remains unclear in treating NAFLD. Here, the fecal microbiota composition of 30 patients with NAFLD who had undergone liver biopsy and 29 matched healthy participants were studied, together with the fecal bile acid (BA) profile. Treatment with FGF21 was given in methionine-choline-deficient (MCD) diet-induced NAFLD model C57BL/6 mice. An antibiotic cocktail and fecal microbiota transplantation were used to further confirm the benefits of FGF21 that were partially attributable to the change in gut microbiota. Patients with NAFLD had higher serum FGF21 levels and dysregulated fecal microbiota compositions and fecal BA profiles. In NAFLD mice, FGF21 significantly reduced steatohepatitis and collagen deposition in vivo and restored intestinal structure. FGF21 treatment also changed gut microbiota composition and regulated dysbiosis in BA metabolism. After treatment with an antibiotic cocktail, FGF21 partially alleviated hepatic and intestinal damage in NAFLD mice. Furthermore, fecal microbiota transplantation from FGF21-treated mice showed benefits similar to FGF21 therapy. The improvement using FGF21 in MCD diet-induced NAFLD mice is partially mediated via gut microbiota and BA. Gut microbiota-regulated BA metabolism may be a potential target of FGF21 in improving NAFLD.

Plasma Gut Microbe-Derived Metabolites Associated with Peripheral Artery Disease and Major Adverse Cardiac Events

Cardiovascular diseases are associated with gut dysbiosis, but the role of microbe-derived metabolites as biomarkers or modulators of cardiovascular disease are not well understood. This is a targeted metabolomics study to investigate the association of nine microbe-derived metabolites with lower extremity peripheral artery disease (PAD), a form of atherosclerosis, and major adverse cardiac events (MACE). The study cohort consists of individuals with intermittent claudication and ankle-brachial index (ABI) < 0.9 (N = 119) and controls without clinically-apparent atherosclerosis (N = 37). The primary endpoint was MACE, a composite endpoint of myocardial infarction, coronary revascularization, stroke, transient ischemic attack, or cardiac-related death. Plasma metabolite concentrations differed significantly between the PAD and control groups. After adjustment for traditional atherosclerosis risk factors, kynurenine, hippuric acid, indole-3-propionic acid (IPA), and indole-3-aldehyde (I3A) concentrations were negatively associated with PAD, whereas indoxyl sulfate and 3-hydroxyanthranilic acid were positively associated. Hippuric acid, IPA, and I3A correlated with ABI, a surrogate for atherosclerotic disease burden. Those in the highest I3A concentration quartile had significantly improved freedom from MACE during follow-up compared to those in the lowest quartile. This study identifies specific indole- and phenyl-derived species impacted by gut microbial metabolic pathways that could represent novel microbiome-related biomarkers of PAD.

The role of the gut microbiota in health and cardiovascular diseases

The gut microbiota is critical to human health, such as digesting nutrients, forming the intestinal epithelial barrier, regulating immune function, producing vitamins and hormones, and producing metabolites to interact with the host. Meanwhile, increasing evidence indicates that the gut microbiota has a strong correlation with the occurrence, progression and treatment of cardiovascular diseases (CVDs). In patients with CVDs and corresponding risk factors, the composition and ratio of gut microbiota have significant differences compared with their healthy counterparts. Therefore, gut microbiota dysbiosis, gut microbiota-generated metabolites, and the related signaling pathway may serve as explanations for some of the mechanisms about the occurrence and development of CVDs. Several studies have also demonstrated that many traditional and latest therapeutic treatments of CVDs are associated with the gut microbiota and its generated metabolites and related signaling pathways. Given that information, we summarized the latest advances in the current research regarding the effect of gut microbiota on health, the main cardiovascular risk factors, and CVDs, highlighted the roles and mechanisms of several metabolites, and introduced corresponding promising treatments for CVDs regarding the gut microbiota. Therefore, this review mainly focuses on exploring the role of gut microbiota related metabolites and their therapeutic potential in CVDs, which may eventually provide better solutions in the development of therapeutic treatment as well as the prevention of CVDs.

Gut Microbiota: An Important Player in Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is one of the common metabolic diseases in the world. Due to the rise in morbidity and mortality, it has become a global health problem. To date, T2DM still cannot be cured, and its intervention measures mainly focus on glucose control as well as the prevention and treatment of related complications. Interestingly, the gut microbiota plays an important role in the development of metabolic diseases, especially T2DM. In this review, we introduce the characteristics of the gut microbiota in T2DM population, T2DM animal models, and diabetic complications. In addition, we describe the molecular mechanisms linking host and the gut microbiota in T2DM, including the host molecules that induce gut microbiota dysbiosis, immune and inflammatory responses, and gut microbial metabolites involved in pathogenesis. These findings suggest that we can treat T2DM and its complications by remodeling the gut microbiota through interventions such as drugs, probiotics, prebiotics, fecal microbiota transplantation (FMT) and diets.

Circulating Nucleic Acid-Based Biomarkers of Type 2 Diabetes

Type 2 diabetes (T2D) is a deficiency in how the body regulates glucose. Uncontrolled T2D will result in chronic high blood sugar levels, eventually resulting in T2D complications. These complications, such as kidney, eye, and nerve damage, are even harder to treat. Identifying individuals at high risk of developing T2D and its complications is essential for early prevention and treatment. Numerous studies have been done to identify biomarkers for T2D diagnosis and prognosis. This review focuses on recent T2D biomarker studies based on circulating nucleic acids using different omics technologies: genomics, transcriptomics, and epigenomics. Omics studies have profiled biomarker candidates from blood, urine, and other non-invasive samples. Despite methodological differences, several candidate biomarkers were reported for the risk and diagnosis of T2D, the prognosis of T2D complications, and pharmacodynamics of T2D treatments. Future studies should be done to validate the findings in larger samples and blood-based biomarkers in non-invasive samples to support the realization of precision medicine for T2D.

Gut Microbiome in Chronic Coronary Syndrome Patients

Despite knowledge of classical coronary artery disease (CAD) risk factors, the morbidity and mortality associated with this disease remain high. Therefore, new factors that may affect the development of CAD, such as the gut microbiome, are extensively investigated. This study aimed to evaluate gut microbiome composition in CAD patients in relation to the control group. We examined 169 CAD patients and 166 people in the control group, without CAD, matched in terms of age and sex to the study group. Both populations underwent a detailed health assessment. The microbiome analysis was based on the V3-V4 region of the 16S rRNA gene (NGS method). Among 4074 identified taxonomic units in the whole population, 1070 differed between study groups. The most common bacterial types were Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria. Furthermore, a higher Firmicutes/Bacteroidetes ratio in the CAD group compared with the control was demonstrated. Firmicutes/Bacteroidetes ratio, independent of age, sex, CAD status, LDL cholesterol concentration, and statins treatment, was related to altered phosphatidylcholine concentrations obtained in targeted metabolomics. Altered alpha-biodiversity (Kruskal-Wallis test, p = 0.001) and beta-biodiversity (Bray-Curtis metric, p < 0.001) in the CAD group were observed. Moreover, a predicted functional analysis revealed some taxonomic units, metabolic pathways, and proteins that might be characteristic of the CAD patients' microbiome, such as increased expressions of 6-phospho-β-glucosidase and protein-N(pi)-phosphohistidine-sugar phosphotransferase and decreased expressions of DNA topoisomerase, oxaloacetate decarboxylase, and 6-beta-glucosidase. In summary, CAD is associated with altered gut microbiome composition and function.