Trimethylamine N-Oxide Promotes Vascular Inflammation Through Signaling of Mitogen-Activated Protein Kinase and Nuclear Factor-κB

Yi-Shen-Hua-Shi regulates intestinal microbiota dysbiosis and protects against proteinuria in patients with chronic kidney disease: a randomized controlled study

CONTEXT

Yi-Shen-Hua-Shi (YSHS) is a traditional Chinese medicine that treats chronic kidney disease (CKD). However, its efficacy in reducing proteinuria and underlying mechanisms is unknown.

OBJECTIVE

This single-center randomized controlled trial explored whether YSHS could improve proteinuria and modulate the gut microbiota.

MATERIALS AND METHODS

120 CKD patients were enrolled and randomized to receive the renin-angiotensin-aldosterone system (RAAS) inhibitor plus YSHS (n = 56) or RAAS inhibitor (n = 47) alone for 4 months, and 103 patients completed the study. We collected baseline and follow-up fecal samples and clinical outcomes from participants. Total bacterial DNA was extracted, and the fecal microbiome was analyzed using bioinformatics.

RESULTS

Patients in the intervention group had a significantly higher decrease in 24-h proteinuria. After 4 months of the YSHS intervention, the relative abundance of bacteria that have beneficial effects on the body, such as Faecalibacterium, Lachnospiraceae, Lachnoclostridium, and Sutterella increased significantly, while pathogenic bacteria such as the Eggerthella and Clostridium innocuum group decreased. However, we could not find these changes in the control group. Redundancy analysis showed that the decline in 24-h proteinuria during follow-up was significantly correlated with various taxa of gut bacteria, such as Lachnospiraceae and the Lachnoclostridium genus in the YSHS group. KEGG analysis also showed the potential role of YSHS in regulating glycan, lipid, and vitamin metabolism.

DISCUSSION AND CONCLUSION

The YSHS granule reduced proteinuria associated with mitigating intestinal microbiota dysbiosis in CKD patients. The definite mechanisms of YSHS to improve proteinuria need to be further explored.

TRIAL REGISTRATION

ChiCTR2300076136, retrospectively registered.

TMAO induces pyroptosis of vascular endothelial cells and atherosclerosis in ApoE-/- mice via MBOAT2-mediated endoplasmic reticulum stress

Trimethylamine N-oxide (TMAO), a metabolite produced by intestinal flora, is recognized as an independent risk factor for atherosclerosis and atherosclerotic cardiovascular diseases. However, the underlying mechanism remains poorly understood. Here, we showed that dietary TMAO supplementation accelerates atherosclerosis in ApoE-/- mice. Pyroptosis and the expression of phospholipid-modifying enzyme MBOAT2 were increased in endothelial cells within atherosclerotic lesions. Genetic upregulation of MBOAT2 via adeno-associated virus with endothelium-specific promoter results in increased atherosclerotic lesions in ApoE-/- mice. Mechanistically, the overexpression of MBOAT2 disrupted glycerophospholipid metabolism and induced endothelial cell pyroptosis in an Endoplasmic reticulum stress-dependent manner. These data reveal that TMAO promotes endothelial cell pyroptosis and the progression of atherosclerotic lesions through the upregulation of MBOAT2, indicating that MBOAT2 is a promising therapeutic target for atherosclerosis.

Gastrointestinal germinal center B cell depletion and reduction in IgA+ plasma cells in HIV-1 infection

Gastrointestinal (GI) B cells and plasma cells (PCs) are critical to mucosal homeostasis and the host response to HIV-1 infection. Here, high-resolution mapping of human B cells and PCs sampled from the colon and ileum during both viremic and suppressed HIV-1 infection identified a reduction in germinal center (GC) B cells and follicular dendritic cells (FDCs) during HIV-1 viremia. Immunoglobulin A-positive (IgA+) PCs are the major cellular output of intestinal GCs and were significantly reduced during viremic HIV-1 infection. PC-associated transcriptional perturbations, including type I interferon signaling, persisted in antiretroviral therapy (ART)-treated individuals, suggesting ongoing disruption of the intestinal immune milieu during ART. GI humoral immune perturbations were associated with changes in the intestinal microbiome composition and systemic inflammation. These findings highlight a key immune defect in the GI mucosa due to HIV-1 viremia.

Gastrointestinal germinal center B cell depletion and reduction in IgA + plasma cells in HIV-1 infection

Gastrointestinal (GI) B cells and plasma cells (PCs) are critical to mucosal homeostasis and the host response to HIV-1 infection. Here, high resolution mapping of human B cells and PCs sampled from the colon and ileum during both viremic and suppressed HIV-1 infection identified a reduction in germinal center (GC) B cells and follicular dendritic cells (FDCs) during HIV-1 viremia. IgA + PCs are the major cellular output of intestinal GCs and were significantly reduced during viremic HIV-1 infection. PC-associated transcriptional perturbations, including type I interferon signaling, persisted in antiretroviral therapy (ART)-treated individuals, suggesting ongoing disruption of the intestinal immune milieu during ART. GI humoral immune perturbations were associated with changes in the intestinal microbiome composition and systemic inflammation. These findings highlight a key immune defect in the GI mucosa due to HIV-1 viremia.

One Sentence Summary

Intestinal germinal center B cell reduction in HIV-1 infection linked to reduced IgA + plasma cells and systemic inflammation.

Decreasing of Trimethylamine N-Oxide by Cecal Microbiota and Choline-Trimethylamine Lyase are Associated with Sishen Pill on Diarrhea with Kidney-Yang Deficiency Syndrome

Background

Sishen Pill (SSP) is a traditional Chinese medicine prescription commonly used to treat diarrhea with kidney-yang deficiency syndrome. The aim was to investigate the underlying mechanisms of SSP's therapeutic effects, providing experimental evidence for its mechanism of action.

Methods

A mouse model of diarrhea with kidney-yang deficiency syndrome was induced using adenine combined with Folium sennae. After successful model replication, SSP decoction was administered. CutC activity, TMAO, IL-6, TNF-α levels, and cecal content microbiota were measured.

Results

SSP significantly improved the general behavioral characteristics of diarrhea mice, and reduced CutC activity, TMAO and IL-6 levels. Sequencing results indicated significant changes at the phylum and genus levels. Correlation analysis revealed a positive correlation between CutC activity and Faecalibaculum (p<0.05) and Chryseobacterium (p<0.05), and a significant negative correlation with Prevotellaceae UCG-001, Rikenella (p<0.05), Acinetobacter (p<0.05), Parasutterella (p<0.05), and Lacticaseibacillus (p<0.05). TNF-α levels showed a significant negative correlation with Lacticaseibacillus (p<0.05), Prevotellaceae UCG-001 (p<0.01), Parasutterella (p<0.05), and Candidatus Saccharimonas (p<0.05). IL-6 levels exhibited a significant negative correlation with Rikenella (p<0.05), Acinetobacter (p<0.05), Prevotellaceae UCG-001 (p<0.05), Lacticaseibacillus (p<0.01), and Parasutterella (p<0.05), and a significant positive correlation with Faecalibaculum (p<0.05), Chryseobacterium (p<0.01), and A2. Serum TMAO levels showed a significant positive correlation with Faecalibaculum (p<0.05) and Chryseobacterium (p<0.01), and hepatic TMAO levels exhibited a significant positive correlation with Chryseobacterium (p<0.05).

Conclusion

SSP significantly alleviated the symptoms of diarrhea with kidney-yang deficiency syndrome by modulating the cecal microbiota, downregulating CutC activity, and reducing TMAO and inflammatory factor levels. The cecal microbiota-CutC-TMAO-inflammatory cytokine axis may be a key mechanism underlying the therapeutic effects of SSP.

Aucubin ameliorates atherosclerosis by modulating tryptophan metabolism and inhibiting endothelial-mesenchymal transitions via gut microbiota regulation

BACKGROUND

The gut microbiota is believed to influence atherosclerosis (AS), and Aucubin (Au), a natural compound found in the traditional Chinese medicine Eucommia ulmoides Oliver, is being explored as a potential treatment for cardiovascular disease. Yet, the specific impact of Au on AS through the gut microbiota remains unclear.

PURPOSE

This study aimed to highlight the potential of Au in improving AS by influencing gut microbiota and investigating its potential mechanisms by which it and its metabolites of gut microbiota regulate lipid metabolism, inflammation and endothelial dysfunction.

METHODS

The impact of Au on AS in ApoE-/- mice was examined, followed by a fecal microbiota transplantation experiment to confirm the influence of Au on AS through gut microbiota. Subsequent analysis of fecal and serum samples using 16S rRNA gene sequencing and metabolomics revealed distinct features of gut microbiota and metabolites. Identified metabolites were then utilized in vivo experiments to investigate underlying mechanisms.

RESULTS

Au treatment effectively reduced dietary-induced dyslipidemia and endothelial dysfunction in a dose-dependent manner in atherosclerotic mice. It also improved vascular plaque accumulation and inflammation, increased aortic valve fibrous cap thickness, and decreased necrotic core and collagen fiber area. Subsequently, we observed a substantial increase in indole-3-acrylic acid (IAA), a microbe-derived metabolite, in cecal contents and serum, along with a significant rise in Lactobacillus abundance responsible for IAA production. Our findings demonstrated that IAA played a crucial role in alleviating AS. Furthermore, we discovered that IAA activated the Aryl hydrocarbon receptor (AhR) and suppressed the TGF-β/Smad pathway, potentially ameliorating endothelial-mesenchymal transitions in atherosclerotic mice.

CONCLUSION

These findings suggested that Au's anti-atherosclerotic effects were primarily due to elevated Lactobacillus-derived IAA, thereby potentially contributing to alleviating AS.

The Association between the Gut Microbiota and Erectile Dysfunction

PURPOSE

Explore the causal relationship between the gut microbiota and erectile dysfunction (ED) at phylum, class, order, family, and genus levels, and identify specific pathogenic bacteria that may be associated with the onset and progression of ED.

MATERIALS AND METHODS

The genetic variation data of 196 human gut microbiota incorporated in our study came from the human gut microbiome Genome Wide Association Studies (GWAS) dataset released by the MiBioGen Consortium. The GWAS statistics for ED were extracted from one study by Bovijn et al., which included 223,805 participants of European ancestry, of whom 6,175 were diagnosed with ED. Subsequently, Mendelian randomization (MR) analysis was carried out to explore whether a causal relationship exists between the gut microbiota and ED. Additionally, bidirectional MR analysis was performed to examine the directionality of the causal relationship.

RESULTS

Through MR analysis, we found that family Lachnospiraceae (odds ratio [OR]: 1.27, 95% confidence interval [CI]: 1.05-1.52, p=0.01) and its subclass genus LachnospiraceaeNC2004 group (OR: 1.17, 95% CI: 1.01-1.37, p=0.04) are associated with a higher risk of ED. In addition, genus Oscillibacter (OR: 1.17, 95% CI: 1.02-1.35, p=0.03), genus Senegalimassilia (OR: 1.32, 95% CI: 1.06-1.64, p=0.01) and genus Tyzzerella3 (OR: 1.14, 95% CI: 1.02-1.27, p=0.02) also increase the risk of ED. In contrast, the inverse variance weighted estimate of genus RuminococcaceaeUCG013 (OR: 0.77, 95% CI: 0.61-0.96, p=0.02) suggests that it has a protective effect against the occurrence of ED.

CONCLUSIONS

This study preliminarily identified 6 bacterial taxa that may have a causal relationship with ED, including family Lachnospiraceae, genus Lachnospiraceae NC2004 group, Oscillibacter, Senegalimassilia, Tyzzerella 3 and Ruminococcaceae UCG013. These identified important bacterial taxa may serve as candidates for microbiome intervention in future ED clinical trials.

Polysaccharides to postbiotics: Nurturing bone health via modulating "gut-immune axis"

The increasing prevalence of individuals affected by bone pathologies globally has sparked catastrophic concerns. Ankylosing spondylitis, osteoporosis, rheumatoid arthritis, osteoarthritis, and fractures alone impact an estimated 1.71 billion people worldwide. The gut microbiota plays a crucial role in interacting with the host through the synthesis of a diverse range of metabolites called gut-associated metabolites (GAMs), which originate from external dietary substrates or endogenous host compounds. Many metabolic disorders have been linked to alterations in the gut microbiota's activity and composition. The development of metabolic illnesses has been linked to certain microbiota-derived metabolites, such as branched-chain amino acids, bile acids, short-chain fatty acids, tryptophan, trimethylamine N-oxide, and indole derivatives. Moreover, the modulation of gut microbiota through biotics (prebiotics, probiotics and postbiotics) presents a promising avenue for therapeutic intervention. Biotics selectively promote the growth of beneficial gut bacteria, thereby enhancing the production of GAMs with potential beneficial effects on bone metabolism. Understanding the intricate interplay between GAMs, and bone-associated genes through molecular informatics holds significant promise for early diagnosis, prognosis, and novel treatment strategies for various bone disorders.

The association between the gut microbiota metabolite trimethylamine N-oxide and heart failure

This systematic review explores the relationship between the gut microbiota metabolite trimethylamine N-oxide (TMAO) and heart failure (HF), given the significant impact of TMAO on cardiovascular health. A systematic search and meta-analysis of peer-reviewed studies published from 2013 to 2024 were conducted, focusing on adult patients with heart failure and healthy controls. The review found that elevated levels of TMAO are associated with atherosclerosis, endothelial dysfunction, and increased cardiovascular disease risk, all of which can exacerbate heart failure. The analysis also highlights that high TMAO levels are linked to reduced left ventricular ejection fraction (LVEF) and glomerular filtration rate (GFR), further supporting TMAO's role as a biomarker in heart failure assessment. The findings suggest that interventions targeting gut microbiota to reduce TMAO could potentially benefit patients with heart failure, although further research is needed to evaluate the effectiveness of such approaches.

Advances in the study of the relationship between gut microbiota and erectile dysfunction

INTRODUCTION

In recent years, in-depth research has revealed that gut microbiota has an inseparable relationship with erectile dysfunction (ED) in men.

OBJECTIVES

(1) To review the correlation between gut microbiota and ED from the perspective of its impact on men's mental health, metabolism, immunity, and endocrine regulation and (2) to provide reference to further explore the pathogenesis of ED and the improvement of clinical treatment plans.

METHODS

PubMed was used for the literature search to identify publications related to ED and gut microbiota.

RESULTS

Gut microbiota may induce depression and anxiety through the microbiota-gut-brain axis, leading to the occurrence of psychological ED. It may also cause vascular endothelial dysfunction and androgen metabolism disorder by interfering with lipid metabolism, immunity, and endocrine regulation, leading to the occurrence of organic ED.

CONCLUSION

Gut microbiota and its metabolites play an important role in the occurrence and development of ED. As a new influencing factor of ED, gut microbiota disorder is expected to become a target for treatment.

Gut Microbiota Mediates Neuroinflammation in Alzheimer's Disease: Unraveling Key Factors and Mechanistic Insights

The gut microbiota, the complex community of microorganisms that inhabit the gastrointestinal tract, has emerged as a key player in the pathogenesis of neurodegenerative disorders, including Alzheimer's disease (AD). AD is characterized by progressive cognitive decline and neuronal loss, associated with the accumulation of amyloid-β plaques, neurofibrillary tangles, and neuroinflammation in the brain. Increasing evidence suggests that alterations in the composition and function of the gut microbiota, known as dysbiosis, may contribute to the development and progression of AD by modulating neuroinflammation, a chronic and maladaptive immune response in the central nervous system. This review aims to comprehensively analyze the current role of the gut microbiota in regulating neuroinflammation and glial cell function in AD. Its objective is to deepen our understanding of the pathogenesis of AD and to discuss the potential advantages and challenges of using gut microbiota modulation as a novel approach for the diagnosis, treatment, and prevention of AD.

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.

Gut microbiota and myocardial infarction: A bibliometric analysis from 2004 to 2023

Background

In recent years, numerous studies have suggested that the gut microbiota and its metabolites are closely related to myocardial infarction. Utilizing insights from these research findings may be advantageous in the prevention, treatment, and prognosis of myocardial infarction. We have employed bibliometric methodology to summarize the progress made in this research area over the past 20 years, identify the hotspots, and highlight the developmental tendencies, providing a reference for future research in this field.

Methods

We searched the content related to this field in the Web of Science Core Collection database, with a time range from 2001 to 2023. We used VOSviewer, CiteSpace, and Scimago Graphica software to visualize the search results.

Results

We included 889 reports in this study. The country with the most publications was China, while the country with the greatest influence was the United States. An analysis of institutions showed that the Chinese Academy of Medical Sciences had the largest volume of publications, whereas the Cleveland Clinic had the most influential ones. An author analysis showed Stanley L Hazen to have published the most and to also have been the most influential researcher. An analysis of all the journals publishing articles related to the search terms showed that PLoS One journal had the highest number of publications (18 articles), while Atherosclerosis journal had the most influential articles. The results of our reference analysis showed a strong association between Trimethylamine N-oxide and myocardial infarction. We found that increased intestinal permeability may be related to the progression of cardiovascular diseases, a high-fiber diet may help in the prevention of diseases such as myocardial infarction, and populations with a high intake of red meat may have an increased risk of myocardial infarction. Keyword analysis suggested that 'cardiac fibrosis' and 'major bleeding' were promising research directions in the future, and supplementing food intake with short-chain fatty acids was looked upon as a promising approach to treating coronary heart disease.

Conclusion

The gut microbiota are closely related to myocardial infarction, and investigating this relationship is crucial for the prevention and treatment of myocardial infarction, where interdisciplinary research and international cooperation are indispensable.

Targeting Gut Microbiota with Probiotics and Phenolic Compounds in the Treatment of Atherosclerosis: A Comprehensive Review

Atherosclerosis (AS) is a chronic inflammatory vascular disease. Dysregulated lipid metabolism, oxidative stress, and inflammation are the major mechanisms implicated in the development of AS. In addition, evidence suggests that gut dysbiosis plays an important role in atherogenesis, and modulation of the gut microbiota with probiotics and phenolic compounds has emerged as a promising strategy for preventing and treating AS. It has been shown that probiotics and phenolic compounds can improve atherosclerosis-related parameters by improving lipid profile, oxidative stress, and inflammation. In addition, these compounds may modulate the diversity and composition of the gut microbiota and improve atherosclerosis. The studies evaluated in the present review showed that probiotics and phenolic compounds, when consumed individually, improved atherosclerosis by modulating the gut microbiota in various ways, such as decreasing gut permeability, decreasing TMAO and LPS levels, altering alpha and beta diversity, and increasing fecal bile acid loss. However, no study was found that evaluated the combined use of probiotics and phenolic compounds to improve atherosclerosis. The available literature highlights the synergistic potential between phenolic compounds and probiotics to improve their health-promoting properties and functionalities. This review aims to summarize the available evidence on the individual effects of probiotics and phenolic compounds on AS, while providing insights into the potential benefits of nutraceutical approaches using probiotic strains, quercetin, and resveratrol as potential adjuvant therapies for AS treatment through modulation of the gut microbiota.

The Role of the Gut Microbiota in Complications among Hemodialysis Patients

The composition of the gut microbiota varies among end-stage renal disease (ESRD) patients on the basis of their mode of renal replacement therapy (RRT), with notably more pronounced dysbiosis occurring in those undergoing hemodialysis (HD). Interventions such as dialysis catheters, unstable hemodynamics, strict dietary restrictions, and pharmacotherapy significantly alter the intestinal microenvironment, thus disrupting the gut microbiota composition in HD patients. The gut microbiota may influence HD-related complications, including cardiovascular disease (CVD), infections, anemia, and malnutrition, through mechanisms such as bacterial translocation, immune regulation, and the production of gut microbial metabolites, thereby affecting both the quality of life and the prognosis of patients. This review focuses on alterations in the gut microbiota and its metabolites in HD patients. Additionally, understanding the impact of the gut microbiota on the complications of HD could provide insights into the development of novel treatment strategies to prevent or alleviate complications in HD patients.

Mechanisms of hepatic and renal injury in lipid metabolism disorders in metabolic syndrome

Metabolic syndrome (MetS) is a group of metabolic abnormalities that identifies people at risk for diabetes and cardiovascular disease. MetS is characterized by lipid disorders, and non-alcoholic fatty liver disease (NAFLD) and diabetic kidney disease (DKD) are thought to be the common hepatic and renal manifestations of MetS following abnormal lipid metabolism. This paper reviews the molecular mechanisms of lipid deposition in NAFLD and DKD, highlighting the commonalities and differences in lipid metabolic pathways in NAFLD and DKD. Hepatic and renal steatosis is the result of lipid acquisition exceeding lipid processing, i.e., fatty acid uptake and lipid regeneration exceed fatty acid oxidation and export. This process is directly regulated by the interactions of nuclear receptors, transporter proteins and transcription factors, whereas pathways such as oxidative stress, autophagy, cellular pyroptosis and gut flora are also key regulatory hubs for lipid metabolic homeostasis but act slightly differently in the liver and kidney. Such insights based on liver-kidney similarities and differences offer potential options for improved treatment.

Semi-supervised meta-learning elucidates understudied molecular interactions

Many biological problems are understudied due to experimental limitations and human biases. Although deep learning is promising in accelerating scientific discovery, its power compromises when applied to problems with scarcely labeled data and data distribution shifts. We develop a deep learning framework-Meta Model Agnostic Pseudo Label Learning (MMAPLE)-to address these challenges by effectively exploring out-of-distribution (OOD) unlabeled data when conventional transfer learning fails. The uniqueness of MMAPLE is to integrate the concept of meta-learning, transfer learning and semi-supervised learning into a unified framework. The power of MMAPLE is demonstrated in three applications in an OOD setting where chemicals or proteins in unseen data are dramatically different from those in training data: predicting drug-target interactions, hidden human metabolite-enzyme interactions, and understudied interspecies microbiome metabolite-human receptor interactions. MMAPLE achieves 11% to 242% improvement in the prediction-recall on multiple OOD benchmarks over various base models. Using MMAPLE, we reveal novel interspecies metabolite-protein interactions that are validated by activity assays and fill in missing links in microbiome-human interactions. MMAPLE is a general framework to explore previously unrecognized biological domains beyond the reach of present experimental and computational techniques.

Developing and evaluating the construct validity of a dietary pattern predictive of plasma TMAO and choline

BACKGROUND AND AIMS

The metabolism of choline (highly present in animal products) can produce trimethylamine N-oxide (TMAO), a metabolite with atherosclerotic effects; however, dietary fiber may suppress this metabolic pathway. This study aimed to develop a dietary pattern predictive of plasma TMAO and choline concentrations using reduced rank regression (RRR) and to evaluate its construct validity.

METHODS AND RESULTS

Diet and plasma concentrations of choline (μmol/L) and TMAO (μmol/L) were assessed in 1724 post-menopausal women who participated in an ancillary study within the Women's Health Initiative Observational Study (1993-1998). The TMAO dietary pattern was developed using RRR in half of the sample (Training Sample) and applied to the other half of the sample (Validation Sample) to evaluate its construct validity. Energy-adjusted food groups were the predictor variables and plasma choline and TMAO, the response variables. ANCOVA and linear regression models were used to assess associations between each biomarker and the dietary pattern score. Discretionary fat, potatoes, red meat, and eggs were positively associated with the dietary pattern, while yogurt, fruits, added sugar, and starchy vegetables were inversely associated. Mean TMAO and choline concentrations significantly increased across increasing quartiles of the dietary pattern in the Training and Validation samples. Positive associations between the biomarkers and the TMAO dietary pattern were also observed in linear regression models (Validation Sample: TMAO, adjusted beta-coefficient = 0.037 (p-value = 0.0088); Choline, adjusted beta-coefficient = 0.011 (p-value = 0.0224).

CONCLUSION

We established the TMAO dietary pattern, a dietary pattern reflecting the potential of the diet to contribute to plasma concentrations of TMAO and choline.

Effects of resveratrol on changes in trimethylamine-N-oxide and circulating cardiovascular factors following exercise training among older adults

PURPOSE

Trimethylamine-N-oxide (TMAO) is a gut-derived metabolite associated with cardiovascular disease (CVD). In preclinical and observational studies, resveratrol and exercise training have been suggested as potential strategies to reduce the systemic levels of TMAO. However, evidence from experimental studies in humans remains unknown. This project examined the dose-dependent effects of a combined resveratrol intervention with exercise training on circulating TMAO and other related metabolite signatures in older adults with high CVD risk.

METHODS

Forty-one older adults [mean (±SD) age of 72.1 (6.8) years] participated in a 12-week supervised center-based, multi-component exercise training intervention [2×/week; 80 min/session] and were randomized to one of two resveratrol dosages [Low: 500 vs. High:1000 mg/day] or a cellulose-based placebo. Serum/plasma were collected at baseline and post-intervention and evaluated for TMAO and associated analytes.

RESULTS

After the 12-week intervention, TMAO concentration increased over time, regardless of treatment [mean (±SD) Placebo: 11262 (±3970); Low:13252 (±1193); High: 12661(±3359) AUC; p = 0.04]. Each resveratrol dose produced different changes in metabolite signatures. Low dose resveratrol upregulated metabolites associated with bile acids biosynthesis (i.e., glycochenodeoxycholic acid, glycoursodeoxycholic acid, and glycocholic acid). High dose resveratrol modulated metabolites enriched for glycolysis, and pyruvate, propanoate, β-alanine, and tryptophan metabolism. Different communities tightly correlated to TMAO and resveratrol metabolites were associated with the lipid and vascular inflammatory clinical markers [|r| > 0.4, p < 0.05].

CONCLUSION

These findings suggest a distinct dose-dependent adaptation response to resveratrol supplementation on circulating metabolite signatures but not on TMAO among high-risk CVD older adults when combined with an exercise training intervention.

Microbiome miracles and their pioneering advances and future frontiers in cardiovascular disease

Cardiovascular diseases (CVDs) represent a significant global health challenge, underscoring the need for innovative approaches to prevention and treatment. Recent years have seen a surge in interest in unraveling the complex relationship between the gut microbiome and cardiovascular health. This article delves into current research on the composition, diversity, and impact of the gut microbiome on CVD development. Recent advancements have elucidated the profound influence of the gut microbiome on disease progression, particularly through key mediators like Trimethylamine-N-oxide (TMAO) and other microbial metabolites. Understanding these mechanisms reveals promising therapeutic targets, including interventions aimed at modulating the gut microbiome's interaction with the immune system and its contribution to endothelial dysfunction. Harnessing this understanding, personalized medicine strategies tailored to individuals' gut microbiome profiles offer innovative avenues for reducing cardiovascular risk. As research in this field continues to evolve, there is vast potential for transformative advancements in cardiovascular medicine, paving the way for precision prevention and treatment strategies to address this global health challenge.

Anthocyanins as natural bioactives with anti-hypertensive and atherosclerotic potential: Health benefits and recent advances

BACKGROUND

Hypertension is a highly prevalent chronic metabolic illness affecting individuals of all age groups. Furthermore, it is a significant risk factor for the development of atherosclerosis (AS), as a correlation between hypertension and AS has been observed. However, the effective treatments for either of these disorders appear to be uncommon.

METHODS

A systematic search of articles published in PubMed, Web of Science, ScienceDirect, Scopus, and Google Scholar databases over the last decade was performed using the following keywords: hypertension, AS, anthocyanins, antioxidants, gut microbes, health benefits, and bioactivity.

RESULTS

The available research indicates that anthocyanin consumption can achieve antioxidant effects by inducing the activation of intracellular nuclear factor erythroid 2-related factor (Nrf2) and the expression of antioxidant genes. Moreover, previous reports showed that anthocyanins can enhance the human body's ability to fight against inflammation and cancer through the inhibition of inflammatory factors and the regulation of related signaling pathways. They can also protect the blood vessels and nervous system by regulating the production and function of endothelial nitric oxide synthase (eNOS). Gut microorganisms play an important role in various chronic diseases. Our research has also investigated the role of anthocyanins in the metabolism of the gut microbiota, leading to significant breakthroughs. This study not only presents a unique strategy for reducing the risk of cardiovascular diseases (CVDs) without the need for medicine but also provides insights into the development and utilization of intestinal probiotic dietary supplements.

CONCLUSION

In this review, different in vitro and in vivo studies have shown that anthocyanins slow down the onset and progression of hypertension and AS through different mechanisms. In addition, gut microbial metabolites also play a crucial role in diseases through the gut-liver axis.

Deficiency of flavin-containing monooxygenase 3 protects kidney function after ischemia-reperfusion in mice

The kidney is vulnerable to ischemia and reperfusion (I/R) injury that can be fatal after major surgery. Currently, there are no effective treatments for I/R-induced kidney injury. Trimethylamine N-oxide (TMAO) is a gut-derived metabolite linked to many diseases, but its role in I/R-induced kidney injury remains unclear. Here, our clinical data reveals an association between preoperative systemic TMAO levels and postoperative kidney injury in patients after post-cardiopulmonary bypass surgery. By genetic deletion of TMAO-producing enzyme flavin-containing monooxygenase 3 (FMO3) and dietary supplementation of choline to modulate TMAO levels, we found that TMAO aggravated acute kidney injury through the triggering of endoplasmic reticulum (ER) stress and worsened subsequent renal fibrosis through TGFβ/Smad signaling activation. Together, our study underscores the negative role of TMAO in I/R-induced kidney injury and highlights the therapeutic potential through the modulation of TMAO levels by targeting FMO3, thereby mitigating acute kidney injury and preventing subsequent renal fibrosis.

MCC950 as a promising candidate for blocking NLRP3 inflammasome activation: A review of preclinical research and future directions

The NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome is a key component of the innate immune system that triggers inflammation and pyroptosis and contributes to the development of several diseases. Therefore, blocking the activation of the NLRP3 inflammasome has therapeutic potential for the treatment of these diseases. MCC950, a selective small molecule inhibitor, has emerged as a promising candidate for blocking NLRP3 inflammasome activation. Ongoing research is focused on elucidating the specific targets of MCC950 as well as assessfing its metabolism and safety profile. This review discusses the diseases that have been studied in relation to MCC950, with a focus on stroke, Alzheimer's disease, liver injury, atherosclerosis, diabetes mellitus, and sepsis, using bibliometric analysis. It then summarizes the potential pharmacological targets of MCC950 and discusses its toxicity. Furthermore, it traces the progression from preclinical to clinical research for the treatment of these diseases. Overall, this review provides a solid foundation for the clinical therapeutic potential of MCC950 and offers insights for future research and therapeutic approaches.

The Complement System Is Essential for Arteriogenesis by Enhancing Sterile Inflammation as a Relevant Step in Collateral Artery Growth

Arteriogenesis is an inflammatory driven mechanism, describing the growth of a natural bypass from pre-existing collateral arteries to compensate for an occluded artery. The complement system component C3 is a potent natural inflammatory activator. Here, we investigated its impact on the process of collateral artery growth using C3-deficient (C3 -/-) and wildtype control mice in a murine hindlimb model of arteriogenesis. Induction of arteriogenesis by unilateral femoral artery ligation resulted in decreased perfusion recovery in C3 -/- mice on day 7 as shown by Laser Doppler imaging. Immunofluorescence staining revealed a reduced vascular cell proliferation in C3 -/- mice. Gene expression analysis displayed a significant reduction in monocyte chemoattractant protein-1 (MCP-1) expression in C3 -/- mice. Interestingly, 3 days after induction of arteriogenesis, the number of macrophages (CD68+) recruited to growing collaterals was not affected by C3 deficiency. However, a significant reduction in inflammatory M1-like polarized macrophages (CD68+/MRC1-) was noted. Forced mast cell activation by Compound 48/80 as well as exogenous MCP-1 application rescued the number of M1-like polarized macrophages along with perfusion recovery in C3 -/- mice. In summary, this study demonstrates that complement C3 influences arteriogenesis by mediating MCP-1 expression, which is essential for the induction and enhancement of sterile inflammation.

Short-chain fatty acid butyrate against TMAO activating endoplasmic-reticulum stress and PERK/IRE1-axis with reducing atrial arrhythmia

INTRODUCTION

The accumulation of microbiota-derived trimethylamine N-oxide (TMAO) in the atrium is linked to the development and progression of atrial arrhythmia. Butyrate, a major short-chain fatty acid, plays a crucial role in sustaining intestinal homeostasis and alleviating systemic inflammation, which may reduce atrial arrhythmogenesis.

OBJECTIVES

This study explored the roles of butyrate in regulating TMAO-mediated atrial remodeling and arrhythmia.

METHODS

Whole-cell patch clamp experiments, Western blotting, and immunocytochemistry were used to analyze electrical activity and signaling, respectively, in TMAO-treated HL-1 atrial myocytes with or without sodium butyrate (SB) administration. Telemetry electrocardiographic recording and echocardiography and Masson's trichrome staining and immunohistochemistry were employed to examine atrial function and histopathology, respectively, in mice treated with TMAO with and without SB administration.

RESULTS

Compared with control cells, TMAO-treated HL-1 myocytes exhibited reduced action potential duration (APD), elevated sarcoplasmic reticulum (SR) calcium content, larger L-type calcium current (ICa-L), increased Na+/Ca2+ exchanger (NCX) current, and increased potassium current. However, the combination of SB and TMAO resulted in similar APD, SR calcium content, ICa-L, transient outward potassium current (Ito), and ultrarapid delayed rectifier potassium current (IKur) compared with controls. Additionally, TMAO-treated HL-1 myocytes exhibited increased activation of endoplasmic reticulum (ER) stress signaling, along with increased PKR-like ER stress kinase (PERK)/IRE1α axis activation and expression of phospho-IP3R, NCX, and Kv1.5, compared with controls or HL-1 cells treated with the combination of TMAO and SB. TMAO-treated mice exhibited atrial ectopic beats, impaired atrial function, increased atrial fibrosis, and greater activation of ER stress signaling with PERK/IRE1α axis activation compared with controls and mice treated with TMAO combined with SB.

CONCLUSION

TMAO administration led to PERK/IRE1α axis activation, which may increase atrial remodeling and arrhythmogenesis. SB treatment mitigated TMAO-elicited ER stress. This finding suggests that SB administration is a valuable strategy for treating TMAO-induced atrial arrhythmia.

Association between monosodium glutamate consumption with changes in gut microbiota and related metabolic dysbiosis-A systematic review

Monosodium glutamate (MSG) is used as a common food additive in some foods. However, based on our search and knowledge, no comprehensive study discussed the effect of MSG on the human gut microbiome. In this study, the effects of MSG on the gut microbiome, liver, and kidney were performed. Data were collected from databases including PubMed, Scopus, Web of Science, and ScienceDirect using the search strategy and keywords. Finally, 14 eligible studies were selected for systematic review. This study provides a new perspective on the effects of MSG on the gut flora, shedding light on the potential relationship between MSG intake and human health.

The gut microbiota derived metabolite trimethylamine N-oxide: Its important role in cancer and other diseases

An expanding body of research indicates a correlation between the gut microbiota and various diseases. Metabolites produced by the gut microbiota act as mediators between the gut microbiota and the host, interacting with multiple systems in the human body to regulate physiological or pathological functions. However, further investigation is still required to elucidate the underlying mechanisms. One such metabolite involved in choline metabolism by gut microbes is trimethylamine (TMA), which can traverse the intestinal epithelial barrier and enter the bloodstream, ultimately reaching the liver where it undergoes oxidation catalyzed by flavin-containing monooxygenase 3 (FMO3) to form trimethylamine N-oxide (TMAO). While some TMAO is eliminated through renal excretion, remaining amounts circulate in the bloodstream, leading to systemic inflammation, endoplasmic reticulum (ER) stress, mitochondrial stress, and disruption of normal physiological functions in humans. As a representative microbial metabolite originating from the gut, TMAO has significant potential both as a biomarker for monitoring disease occurrence and progression and for tailoring personalized treatment strategies for patients. This review provides an extensive overview of TMAO sources and its metabolism in human blood, as well as its impact on several major human diseases. Additionally, we explore the latest research areas related to TMAO along with future directions.

Role of Gut Microbial Metabolites in the Pathogenesis of Primary Liver Cancers

Hepatobiliary malignancies, which include hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), are the sixth most common cancers and the third leading cause of cancer-related death worldwide. Hepatic carcinogenesis is highly stimulated by chronic inflammation, defined as fibrosis deposition, and an aberrant imbalance between liver necrosis and nodular regeneration. In this context, the gut-liver axis and gut microbiota have demonstrated a critical role in the pathogenesis of HCC, as dysbiosis and altered intestinal permeability promote bacterial translocation, leading to chronic liver inflammation and tumorigenesis through several pathways. A few data exist on the role of the gut microbiota or bacteria resident in the biliary tract in the pathogenesis of CCA, and some microbial metabolites, such as choline and bile acids, seem to show an association. In this review, we analyze the impact of the gut microbiota and its metabolites on HCC and CCA development and the role of gut dysbiosis as a biomarker of hepatobiliary cancer risk and of response during anti-tumor therapy. We also discuss the future application of gut microbiota in hepatobiliary cancer management.

Trimethylamine N-oxide predicts cardiovascular events in coronary artery disease patients with diabetes mellitus: a prospective cohort study

Background

Gut microbiota has significant impact on the cardio-metabolism and inflammation, and is implicated in the pathogenesis and progression of atherosclerosis. However, the long-term prospective association between trimethylamine N-oxide (TMAO) level and major adverse clinical events (MACEs) in patients with coronary artery disease (CAD) with or without diabetes mellitus (DM) habitus remains to be investigated.

Methods

This prospective, single-center cohort study enrolled 2090 hospitalized CAD patients confirmed by angiography at Beijing Hospital from 2017-2020. TMAO levels were performed using liquid chromatography-tandem mass spectrometry. The composite outcome of MACEs was identified by clinic visits or interviews annually. Multivariate Cox regression analysis, Kaplan-Meier analysis, and restricted cubic splines were mainly used to explore the relationship between TMAO levels and MACEs based on diabetes mellitus (DM) habitus.

Results

During the median follow-up period of 54 (41, 68) months, 266 (12.7%) developed MACEs. Higher TMAO levels, using the tertile cut-off value of 318.28 ng/mL, were significantly found to be positive dose-independent for developing MACEs, especially in patients with DM (HR 1.744, 95%CI 1.084-2.808, p = 0.022).

Conclusions

Higher levels of TMAO are significantly associated with long-term MACEs among CAD patients with DM. The combination of TMAO in patients with CAD and DM is beneficial for risk stratification and prognosis.

Trimethylamine N-Oxide in Aquatic Foods

Trimethylamine N-oxide (TMAO), a characteristic nonprotein nitrogen compound, is widely present in seafood, which exhibits osmoregulatory effects for marine organisms in vivo and plays an important role in aquaculture and aquatic product preservation. However, much attention has been focused on the negative effect of TMAO since it has recently emerged as a putative promoter of chronic diseases. To get full knowledge and maximize our ability to balance the positive and negative aspects of TMAO, in this review, we comprehensively discuss the TMAO in aquatic products from the aspects of physiological functions for marine organisms, flavor, quality, the conversion of precursors, the influences on human health, and the seafood ingredients interaction consideration. Though the circulating TMAO level is inevitably enhanced after seafood consumption, dietary seafood still exhibits beneficial health effects and may provide nutraceuticals to balance the possible adverse effects of TMAO.

Alteration of the gut microbiome in patients with heart failure: A systematic review and meta-analysis

Recent research has revealed that alterations of the gut microbiome (GM) play a comprehensive role in the pathophysiology of HF. However, findings in this field remain controversial. In this study, we focus on differences in GM diversity and abundance between HF patients and non-HF people, based on previous 16 S ribosomal RNA (16rRNA) gene sequencing. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive search of PubMed, Web of Science, Embase, Cochrane Library, and Ovid databases using the keyword "Heart failure" and "Gastrointestinal Microbiome". A significant decrease in alpha diversity was observed in the HF patients (Chao1, I2 = 87.5 %, p < 0.001; Shannon index, I2 = 62.8 %, p = 0.021). At the phylum level, the HF group exhibited higher abundances of Proteobacteria (I2 = 92.0 %, p = 0.004) and Actinobacteria (I2 = 82.5 %, p = 0.010), while Bacteroidetes (I2 = 45.1 %, p = 0.017) and F/B ratio (I2 = 0.0 %, p＜0.001) were lower. The Firmicutes showed a decreasing trend but did not reach statistical significance (I2 = 82.3 %, p = 0.127). At the genus level, the relative abundances of Streptococcus, Bacteroides, Alistipes, Bifidobacterium, Escherichia-Shigella, Enterococcus and Klebsiella were increased in the HF group, whereas Ruminococcus, Faecalibacterium, Dorea and Megamona exhibited decreased relative abundances. Dialister, Blautia and Prevotella showed decreasing trends but without statistical significance. This observational meta-analysis suggests that GM changes are associated with HF, manifesting as alterations in GM abundance, disruptions in the production of short-chain fatty acids (SCFAs) bacteria, and an increase in trimethylamine N-oxide (TMAO) producing bacteria.

Type 3 resistant starch from Canna edulis reduce lipid levels in patients with mild hyperlipidemia through altering gut microbiome: A double- blind randomized controlled trial

Type 3 resistant starch from Canna edulis (Ce-RS3) is an insoluble dietary fiber which could improve blood lipids in animals, but clinically robust evidence is still lacking. We performed a double-blind randomized controlled trial to assess the effects of Ce-RS3 on lipids in mild hyperlipidemia. One hundred and fifteen patients were included followed the recruitment criteria, and were randomly allocated to receive Ce-RS3 or placebo (native starch from Canna edulis) for 12 weeks (20 g/day). In addition to serum lipids, complete blood counts, serum inflammatory factors, antioxidant indexes, and dietary survey, 16 S rRNA sequencing technique was utilized to analyze the gut microbiota alterations. Targeted quantitative metabolomics (TQM) was used to detect metabolite changes. Compared with the placebo, Ce- RS3 significantly decreased levels of total cholesterol, lowdensity lipoprotein cholesterol, and non-high-density lipoprotein cholesterol, and increased the glutathione peroxidase. Based on the 16 S rRNA sequencing, TQM, the correlation analysis, as well as the Kyoto Encyclopedia of Genes (KEGG) and Genomes and Human Metabolome Database (HMDB) analysis, we found that Ce-RS3 could increase the abundances of genera Faecalibacterium and Agathobacter, while reduce the abundances of genera norank_f_Ruminococcaceae and Christensenellaceae_R-7_ group to regulate phenylalanine metabolism, which could reduce the fatty acid biosynthesis and fatty acid elongation in the mitochondria to lower blood lipids. Conclusively, we firstly confirmed the feasibility of Ce-RS3 for clinical application, which presents a novel, effective therapy for the mild hyperlipidemia. (Chictr. org. cn. Clinical study on anti-mild hyperlipidemia of Canna edulis RS3 resistant starch, ID Number: ChiCTR2200062871).

Role of Trimethylamine N-Oxide in Heart Failure

Heart failure (HF) is a clinical syndrome characterizing by typical physical signs and symptomatology resulting from reduced cardiac output and/or intracardiac pressure at rest or under stress due to structural and/or functional abnormalities of the heart. HF is often the final stage of all cardiovascular diseases and a significant risk factor for sudden cardiac arrest, death, and liver or kidney failure. Current pharmacological treatments can only slow the progression and recurrence of HF. With advancing research into the gut microbiome and its metabolites, one such trimethylamine N-oxide (TMAO)-has been implicated in the advancement of HF and is correlated with poor prognosis in patients with HF. However, the precise role of TMAO in HF has not yet been clarified. This review highlights and concludes the available evidence and potential mechanisms associated with HF, with the hope of contributing new insights into the diagnosis and prevention of HF.

Therapeutic manipulation of the microbiome in liver disease

Myriad associations between the microbiome and various facets of liver physiology and pathology have been described in the literature. Building on descriptive and correlative sequencing studies, metagenomic studies are expanding our collective understanding of the functional and mechanistic role of the microbiome as mediators of the gut-liver axis. Based on these mechanisms, the functional activity of the microbiome represents an attractive, tractable, and precision medicine therapeutic target in several liver diseases. Indeed, several therapeutics have been used in liver disease even before their description as a microbiome-dependent approach. To bring successful microbiome-targeted and microbiome-inspired therapies to the clinic, a comprehensive appreciation of the different approaches to influence, collaborate with, or engineer the gut microbiome to coopt a disease-relevant function of interest in the right patient is key. Herein, we describe the various levels at which the microbiome can be targeted-from prebiotics, probiotics, synbiotics, and antibiotics to microbiome reconstitution and precision microbiome engineering. Assimilating data from preclinical animal models, human studies as well as clinical trials, we describe the potential for and rationale behind studying such therapies across several liver diseases, including metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, cirrhosis, HE as well as liver cancer. Lastly, we discuss lessons learned from previous attempts at developing such therapies, the regulatory framework that needs to be navigated, and the challenges that remain.

Shizukaol C alleviates trimethylamine oxide-induced inflammation through activating Keap1-Nrf2-GSTpi pathway in vascular smooth muscle cell

BACKGROUND

Cardiovascular disease is one of the main causes of global mortality, and there is an urgent need for effective treatment strategies. Gut microbiota-dependent metabolite trimethylamine-N-oxide (TMAO) promotes the development of cardiovascular diseases, and shizukaol C, a natural sesquiterpene isolated from Chloranthus multistachys with various biological activities, might exhibit beneficial role in preventing TMAO-induced vascular inflammation.

PURPOSE

The purpose of this study was to investigate the anti-inflammatory effects and the underlying mechanisms of shizukaol C on TMAO-induced vascular inflammation.

METHODS

The effect and underlying mechanism of shizukaol C on TMAO-induced adhesion molecules expression, bone marrow-derived macrophages (BMDM) adhesion to VSMC were evaluated by western blot, cell adhesion assay, co-immunoprecipitation, immunofluorescence assay, and quantitative Real-Time PCR, respectively. To verify the role of shizukaol C in vivo, TMAO-induced vascular inflammation model were established using guidewire-induced injury on mice carotid artery. Changes in the intima area and the expression of GSTpi, VCAM-1, CD68 were examined using haematoxylin-eosin staining, and immunofluorescence assay.

RESULTS

Our data demonstrated that shizukaol C significantly suppressed TMAO-induced adhesion molecule expression and the bone marrow-derived macrophages (BMDM) adhesion in vascular smooth muscle cells (VSMC). Mechanically, shizukaol C inhibited TMAO-induced c-Jun N-terminal kinase (JNK)-nuclear factor-kappa B (NF-κB)/p65 activation, and the JNK inhibition was dependent on the shizukaol C-mediated glutathione-S-transferase pi (GSTpi) expression. By further molecular docking and protein-binding analysis, we demonstrated that shizukaol C directly binds to Keap1 to induce Nrf2 nuclear translocation and upregulated GSTpi expression. Consistently, our in vivo experiment showed that shizukaol C elevated the expression level of GSTpi in carotid arteries and alleviates TMAO-induced vascular inflammation.

CONCLUSION

Shizukaol C exerts anti-inflammatory effects in TMAO-treated VSMC by targeting Keap1 and activating Nrf2-GSTpi signaling and resultantly inhibits the downstream JNK-NF-κB/p65 activation and VSMC adhesion, and alleviates TMAO-induced vascular inflammation in vivo, suggesting that shizukaol C may be a potential drug for treating TMAO-induced vascular diseases.

Applied physiology: gut microbiota and antimicrobial therapy

The gut microbiota plays an important role in maintaining human health and in the pathogenesis of several diseases. Antibiotics are among the most commonly prescribed drugs and have a significant impact on the structure and function of the gut microbiota. The understanding that a healthy gut microbiota prevents the development of many diseases has also led to its consideration as a potential therapeutic target. At the same time, any factor that alters the gut microbiota becomes important in this approach. Exercise and antibacterial therapy have a direct effect on the microbiota. The review reflects the current state of publications on the mechanisms of intestinal bacterial involvement in the pathogenesis of cardiovascular, metabolic, and neurodegenerative diseases. The physiological mechanisms of the influence of physical activity on the composition of the gut microbiota are considered. The mechanisms of the common interface between exercise and antibacterial therapy will be considered using the example of several socially important diseases. The aim of the study is to show the physiological relationship between the effects of exercise and antibiotics on the gut microbiota.

Polyphenols from hickory nut reduce the occurrence of atherosclerosis in mice by improving intestinal microbiota and inhibiting trimethylamine N-oxide production

BACKGROUND

Trimethylamine N-oxide (TMAO), a metabolite produced by intestinal microbiota through metabolizing phosphatidylcholine, choline, l-carnitine and betaine in the diet, has been implicated in the pathogenesis of atherosclerosis (AS). Concurrently, dietary polyphenols have garnered attention for their potential to ameliorate obesity, diabetes and atherosclerosis primarily by modulating the intestinal microbial structure. Hickory (Carya cathayensis) nut, a polyphenol-rich food product favored for its palatability, emerges as a candidate for exploration.

HYPOTHESIS/PURPOSE

The relationship between polyphenol of hickory nut and atherosclerosis prevention will be firstly clarified, providing theoretical basis for the discovery of natural products counteracting TMAO-induced AS process in hickory nut.

STUDY DESIGN AND METHODS

Employing Enzyme-linked Immunosorbent Assay (ELISA) and histological examination of aortic samples, the effects of total polyphenol extract on obesity index, inflammatory index and pathological changes of atherosclerosis in C57BL/6 J mice fed with high-fat and high choline diet were evaluated. Further, the composition, abundance, and function of mouse gut microbiota were analyzed through 16srDNA sequencing. Concurrently, the levels of TMAO and the expression of key enzymes (CutC and FMO3) involved in its synthesis are quantified using ELISA, Western Blot and Real-Time Quantitative PCR (RT-qPCR). Additionally, targeted metabolomic profiling of the hickory nut polyphenol extract was conducted, accompanied by molecular docking simulations to predict interactions between candidate polyphenols and the CutC/FMO3 using Autodock Vina. Finally, the docking prediction were verified by microscale thermophoresis (MST) .

RESULTS

Polyphenol extracts of hickory nut improved the index of obesity and inflammation, and alleviated the pathological changes of atherosclerosis in C57BL/6 J mice fed with high-fat and high-choline diet. Meanwhile, these polyphenol extracts also changed the composition and function of intestinal microbiota, and increased the abundance of microorganisms in mice. Notably, the abundance of intestinal microbiota endowed with CutC gene was significantly reduced, coherent with expression of CutC catalyzing TMA production. Moreover, polyphenol extracts also decreased the expression of FMO3 in the liver, contributing to the reduction of TMAO levels in serum. Furthermore, metabonomic profile analysis of these polyphenol extracts identified 647 kinds of polyphenols. Molecular docking predication further demonstrated that Casuariin and Cinnamtannin B2 had the most potential inhibition on the enzymatic activities of CutC or FMO3, respectively. Notably, MST analysis corroborated the potential for direct interaction between CutC enzyme and available polyphenols such as Corilagin, (-)-Gallocatechin gallate and Epigallocatechin gallate.

CONCLUSION

Hickory polyphenol extract can mitigate HFD-induced AS by regulating intestinal microflora in murine models. In addition, TMA-FMO3-TMAO pathway may play a key role in this process. This research unveils, for the inaugural time, the complex interaction between hickory nut-derived polyphenols and gut microbial, providing novel insights into the role of dietary polyphenols in AS prevention.

Gut microbiota metabolites and risk of major adverse cardiovascular events and death: A systematic review and meta-analysis

BACKGROUND

Gut microbial metabolites such as trimethylamine N-oxide (TMAO) and its precursors, namely betaine, L-carnitine, and choline, have been implicated as risk factors for cardiovascular events and mortality development. Therefore, we aim to perform a systematic review and meta-analysis to assess the validity of these associations.

METHODS

MEDLINE and Scopus were queried from their inception to August 2023 to identify studies that quantified estimates of the associations of TMAO with the development of major adverse cardiovascular events (MACE) or death. A random-effects meta-analysis was conducted to pool unadjusted or multivariable-adjusted hazard ratios (HR) and their 95% confidence intervals. The primary endpoint was the risk of MACE and all-cause death.

RESULTS

30 prospective observational studies (n = 48 968) were included in the analysis. Elevated TMAO levels were associated with a significantly greater risk of MACE and all-cause death compared to low TMAO levels (HR: 1.41, 95% CI 1.2-1.54, P < .00001, I2 = 43%) and (HR: 1.55, 95% CI 1.37-1.75, P < .00001, I2 = 46%), respectively. Furthermore, high levels of either L-carnitine or choline were found to significantly increase the risk of MACE. However, no significant difference was seen in MACE in either high or low levels of betaine.

CONCLUSION

Elevated concentrations of TMAO were associated with increased risks of MACE and all-cause mortality. High levels of L-carnitine/choline were also significantly associated with an increased risk of MACE. However, no significant difference was found between high or low levels of betaine for the outcome of MACE.

Therapeutic potential of lipid-lowering probiotics on the atherosclerosis development

Hypercholesterolemia is a critical risk factor for atherosclerosis, mostly attributed to lifestyle behavior such as diet. Recent advances have emphasized the critical effects of gastrointestinal bacteria in the pathology of hypercholesterolemia and atherosclerosis, suggesting that the gastrointestinal microbiome can therefore provide efficient therapeutic targets for preventing and treating atherosclerosis. Thus, interventions, such as probiotic therapy, aimed at altering the bacterial composition introduce a promising therapeutic procedure. In the current review, we will provide an overview of anti-atherogenic probiotics contributing to lipid-lowering, inhibiting atherosclerotic inflammation, and suppressing bacterial atherogenic metabolites.

Network and Experimental Pharmacology on Mechanism of Yixintai Regulates the TMAO/PKC/NF-κB Signaling Pathway in Treating Heart Failure

Objective

This study aims to explore the mechanism of action of Yixintai in treating chronic ischemic heart failure by combining bioinformatics and experimental validation.

Materials and Methods

Five potential drugs for treating heart failure were obtained from Yixintai (YXT) through early mass spectrometry detection. The targets of YXT for treating heart failure were obtained by a search of online databases. Gene ontology (GO) functional enrichment analysis and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analyses were conducted on the common targets using the DAVID database. A rat heart failure model was established by ligating the anterior descending branch of the left coronary artery. A small animal color Doppler ultrasound imaging system detected cardiac function indicators. Hematoxylin-eosin (HE), Masson's, and electron microscopy were used to observe the pathological morphology of the myocardium in rats with heart failure. The network pharmacology analysis results were validated by ELISA, qPCR, and Western blotting.

Results

A total of 107 effective targets were obtained by combining compound targets and eliminating duplicate values. PPI analysis showed that inflammation-related proteins (TNF and IL1B) were key targets for treating heart failure, and KEGG enrichment suggested that NF-κB signaling pathway was a key pathway for YXT treatment of heart failure. Animal model validation results indicated the following: YXT can significantly reduce the content of intestinal microbiota metabolites such as trimethylamine oxide (TMAO) and improve heart failure by improving the EF and FS values of heart ultrasound in rats and reducing the levels of serum NT-proBNP, ANP, and BNP to improve heart failure. Together, YXT can inhibit cardiac muscle hypertrophy and fibrosis in rats and improve myocardial ultrastructure and serum IL-1β, IL-6, and TNF-α levels. These effects are achieved by inhibiting the expressions of NF-κB and PKC.

Conclusion

YXT regulates the TMAO/PKC/NF-κB signaling pathway in heart failure.

The Role of Gut Microbiota in the Etiopathogenesis of Multiple Chronic Diseases

Chronic diseases (CD) may result from a combination of genetic factors, lifestyle and social behaviours, healthcare system influences, community factors, and environmental determinants of health. These risk factors frequently coexist and interact with one another. Ongoing research and a focus on personalized interventions are pivotal strategies for preventing and managing chronic disease outcomes. A wealth of literature suggests the potential involvement of gut microbiota in influencing host metabolism, thereby impacting various risk factors associated with chronic diseases. Dysbiosis, the perturbation of the composition and activity of the gut microbiota, is crucial in the etiopathogenesis of multiple CD. Recent studies indicate that specific microorganism-derived metabolites, including trimethylamine N-oxide, lipopolysaccharide and uremic toxins, contribute to subclinical inflammatory processes implicated in CD. Various factors, including diet, lifestyle, and medications, can alter the taxonomic species or abundance of gut microbiota. Researchers are currently dedicating efforts to understanding how the natural progression of microbiome development in humans affects health outcomes. Simultaneously, there is a focus on enhancing the understanding of microbiome-host molecular interactions. These endeavours ultimately aim to devise practical approaches for rehabilitating dysregulated human microbial ecosystems, intending to restore health and prevent diseases. This review investigates how the gut microbiome contributes to CD and explains ways to modulate it for managing or preventing chronic conditions.

TMAO enhances TNF-α mediated fibrosis and release of inflammatory mediators from renal fibroblasts

Trimethylamine-N-oxide (TMAO) is a gut microbiota-derived metabolite and TNF-α is proinflammatory cytokine, both known to be associated with renal inflammation, fibrosis and chronic kidney disease. However, today there are no data showing the combined effect of TMAO and TNF-α on renal fibrosis-and inflammation. The aim of this study was to investigate whether TMAO can enhance the inflammatory and fibrotic effects of TNF-α on renal fibroblasts. We found that the combination of TNF-α and TMAO synergistically increased fibronectin release and total collagen production from renal fibroblasts. The combination of TMAO and TNF-α also promoted increased cell proliferation. Both renal proliferation and collagen production were mediated through Akt/mTOR/ERK signaling. We also found that TMAO enhanced TNF-α mediated renal inflammation by inducing the release of several cytokines (IL-6, LAP TGF-beta-1), chemokines (CXCL-6, MCP-3), inflammatory-and growth mediators (VEGFA, CD40, HGF) from renal fibroblasts. In conclusion, we showed that TMAO can enhance TNF-α mediated renal fibrosis and release of inflammatory mediators from renal fibroblasts in vitro. Our results can promote further research evaluating the combined effect of TMAO and inflammatory mediators on the development of kidney disease.

Gut Microbiome and Its Role in Valvular Heart Disease: Not a "Gutted" Relationship

The role of the gut microbiome (GM) and oral microbiome (OM) in cardiovascular disease (CVD) has been increasingly being understood in recent years. It is well known that GM is a risk factor for various CVD phenotypes, including hypertension, dyslipidemia, heart failure and atrial fibrillation. However, its role in valvular heart disease (VHD) is less well understood. Research shows that, direct, microbe-mediated and indirect, metabolite-mediated damage as a result of gut dysbiosis and environmental factors results in a subclinical, chronic, systemic inflammatory state, which promotes inflammatory cell infiltration in heart valves and subsequently, via pro-inflammatory molecules, initiates a cascade of reaction, resulting in valve calcification, fibrosis and dysfunction. This relationship between GM and VHD adds a pathophysiological link to the pathogenesis of VHD, which can be aimed therapeutically, in order to prevent or regress any risk for valvular pathologies. Therapeutic interventions include dietary modifications and lifestyle interventions, in order to influence environmental factors that can promote gut dysbiosis. Furthermore, the combination of probiotics and prebiotics, as well as fecal m transplantation and targeted treatment with inducers or inhibitors of microbial enzymes have showed promising results in animal and/or clinical studies, with the potential to reduce the inflammatory state and restore the normal gut flora in patients. This review, thus, is going to discuss the pathophysiological links behind the relationship of GM, CVD and VHD, as well as explore the recent data regarding the effect of GM-altering treatment in CVD, cardiac function and systemic inflammation.

Quinic acid regulated TMA/TMAO-related lipid metabolism and vascular endothelial function through gut microbiota to inhibit atherosclerotic

BACKGROUND

Quinic acid (QA) and its derivatives have good lipid-lowering and hepatoprotective functions, but their role in atherosclerosis remains unknown. This study attempted to investigate the mechanism of QA on atherogenesis in Apoe-/- mice induced by HFD.

METHODS

HE staining and oil red O staining were used to observe the pathology. The PCSK9, Mac-3 and SM22a expressions were detected by IHC. Cholesterol, HMGB1, TIMP-1 and CXCL13 levels were measured by biochemical and ELISA. Lipid metabolism and the HMGB1-SREBP2-SR-BI pathway were detected by PCR and WB. 16 S and metabolomics were used to detect gut microbiota and serum metabolites.

RESULTS

QA or low-frequency ABX inhibited weight gain and aortic tissue atherogenesis in HFD-induced Apoe-/- mice. QA inhibited the increase of cholesterol, TMA, TMAO, CXCL13, TIMP-1 and HMGB1 levels in peripheral blood of Apoe-/- mice induced by HFD. Meanwhile, QA or low-frequency ABX treatment inhibited the expression of CAV-1, ABCA1, Mac-3 and SM22α, and promoted the expression of SREBP-1 and LXR in the vascular tissues of HFD-induced Apoe-/- mice. QA reduced Streptococcus_danieliae abundance, and promoted Lactobacillus_intestinalis and Ileibacterium_valens abundance in HFD-induced Apoe-/- mice. QA altered serum galactose metabolism, promoted SREBP-2 and LDLR, inhibited IDOL, FMO3 and PCSK9 expression in liver of HFD-induced Apoe-/- mice. The combined treatment of QA and low-frequency ABX regulated microbe-related Glycoursodeoxycholic acid and GLYCOCHENODEOXYCHOLATE metabolism in HFD-induced Apoe-/- mice. QA inhibited TMAO or LDL-induced HCAECs damage and HMGB1/SREBP2 axis dysfunction, which was reversed by HMGB1 overexpression.

CONCLUSIONS

QA regulated the gut-liver lipid metabolism and chronic vascular inflammation of TMA/TMAO through gut microbiota to inhibit the atherogenesis in Apoe-/- mice, and the mechanism may be related to the HMGB1/SREBP2 pathway.

Probiotics, gut microbiome, and cardiovascular diseases: An update

Cardiovascular diseases (CVD) are one of the most challenging diseases and many factors have been demonstrated to affect their pathogenesis. One of the major factors that affect CVDs, especially atherosclerosis, is the gut microbiota (GM). Genetics play a key role in linking CVDs with GM, in addition to some environmental factors which can be either beneficial or harmful. The interplay between GM and CVDs is complex due to the numerous mechanisms through which microbial components and their metabolites can influence CVDs. Within this interplay, the immune system plays a major role, mainly based on the immunomodulatory effects of microbial dysbiosis and its resulting metabolites. The resulting modulation of chronic inflammatory processes was found to reduce the severity of CVDs and to maintain cardiovascular health. To better understand the specific roles of GM-related metabolites in this interplay, this review presents an updated perspective on gut metabolites related effects on the cardiovascular system, highlighting the possible benefits of probiotics in therapeutic strategies.

The gut microbiome as a modulator of arterial function and age-related arterial dysfunction

The arterial system is integral to the proper function of all other organs and tissues. Arterial function is impaired with aging, and arterial dysfunction contributes to the development of numerous age-related diseases, including cardiovascular diseases. The gut microbiome has emerged as an important regulator of both normal host physiological function and impairments in function with aging. The purpose of this review is to summarize more recently published literature demonstrating the role of the gut microbiome in supporting normal arterial development and function and in modulating arterial dysfunction with aging in the absence of overt disease. The gut microbiome can be altered due to a variety of exposures, including physiological aging processes. We explore mechanisms by which the gut microbiome may contribute to age-related arterial dysfunction, with a focus on changes in various gut microbiome-related compounds in circulation. In addition, we discuss how modulating circulating levels of these compounds may be a viable therapeutic approach for improving artery function with aging. Finally, we identify and discuss various experimental considerations and research gaps/areas of future research.

Gut microbial metabolite trimethylamine N-oxide induces aortic dissection

Aortic dissection (AD) is the most catastrophic vascular disease with a high mortality rate. Trimethylamine N-oxide (TMAO), a gut microbial metabolite, has been implicated in the pathogenesis of cardiovascular diseases. However, the role of TMAO in AD and the underlying mechanisms remain unclear. This study aimed to explore the effects of TMAO on AD. Plasma and fecal samples from patients with AD and healthy individuals were collected to analyze TMAO levels and gut microbial species, respectively. The plasma levels of TMAO were significantly higher in 253 AD patients compared with those in 98 healthy subjects (3.47, interquartile range (IQR): 2.33 to 5.18 μM vs. 1.85, IQR: 1.40 to 3.35 μM; p < 0.001). High plasma TMAO levels were positively associated with AD severity. An increase in the relative abundance of TMA-producing genera in patients with AD was revealed using 16S rRNA sequencing. In the angiotensin II or β-aminopropionitrile-induced rodent model of AD, mice fed a TMAO-supplemented diet were more likely to develop AD compared to mice fed a normal diet. Conversely, TMAO depletion mitigated AD formation in the BAPN model. RNA sequencing of aortic endothelial cells isolated from mice administered TMAO revealed significant upregulation of genes involved in inflammatory pathways. The in vitro experiments verified that TMAO promotes endothelial dysfunction and activates nuclear factor (NF)-κB signaling. The in vivo BAPN-induced AD model confirmed that TMAO increased aortic inflammation. Our study demonstrates that the gut microbial metabolite TMAO aggravates the development of AD at least in part by inducing endothelial dysfunction and inflammation. This study provides new insights into the etiology of AD and ideas for its management.

High-throughput metabolomics identifies new biomarkers for cervical cancer

BACKGROUND

Cervical cancer (CC) is a danger to women's health, especially in many developing countries. Metabolomics can make the connection between genotypes and phenotypes. It provides a wide spectrum profile of biological processes under pathological or physiological conditions.

METHOD

In this study, we conducted plasma metabolomics of healthy volunteers and CC patients and integratively analyzed them with public CC tissue transcriptomics from Gene Expression Omnibus (GEO).

RESULT

Here, we screened out a panel of 5 metabolites to precisely distinguish CC patients from healthy volunteers. Furthermore, we utilized multi-omics approaches to explore patients with stage I-IIA1 and IIA2-IV4 CC and comprehensively analyzed the dysregulation of genes and metabolites in CC progression. We identified that plasma levels of trimethylamine N-oxide (TMAO) were associated with tumor size and regarded as a risk factor for CC. Moreover, we demonstrated that TMAO could promote HeLa cell proliferation in vitro. In this study, we delineated metabolic profiling in healthy volunteers and CC patients and revealed that TMAO was a potential biomarker to discriminate between I-IIA1 and IIA2-IV patients to indicate CC deterioration.

CONCLUSION

Our study identified a diagnostic model consisting of five metabolites in plasma that can effectively distinguish CC from healthy volunteers. Furthermore, we proposed that TMAO was associated with CC progression and might serve as a potential non-invasive biomarker to predict CC substage.

IMPACT

These findings provided evidence of the important role of metabolic molecules in the progression of cervical cancer disease, as well as their ability as potential biomarkers.

Research progress in the relationship between gut microbiota metabolite trimethylamine N-oxide and ischemic stroke

Ischemic stroke (IS) is a severe cerebrovascular disease that seriously endangers human health. Gut microbiota plays a key role as an intermediate mediator in bidirectional regulation between the brain and the intestine. In recent years, trimethylamine N-oxide (TMAO) as a gut microbiota metabolite has received widespread attention in cardiovascular diseases. Elevated levels of TMAO may increase the risk of IS by affecting IS risk factors such as atherosclerosis, atrial fibrillation, hypertension, and type 2 diabetes. TMAO exacerbates neurological damage in IS patients, increases the risk of IS recurrence, and is an independent predictor of post-stroke cognitive impairment (PSCI) in patients. Current research suggests that the mechanisms of TMAO action include endothelial dysfunction, promoting of foam cell formation, influence on cholesterol metabolism, and enhancement of platelet reactivity. Lowering plasma TMAO levels through the rational use of traditional Chinese medicine, dietary management, vitamins, and probiotics can prevent and treat IS.

Inflammation and Organic Cation Transporters Novel (OCTNs)

Inflammation is a physiological condition characterized by a complex interplay between different cells handled by metabolites and specific inflammatory-related molecules. In some pathological situations, inflammation persists underlying and worsening the pathological state. Over the years, two membrane transporters namely OCTN1 (SLC22A4) and OCTN2 (SLC22A5) have been shown to play specific roles in inflammation. These transporters form the OCTN subfamily within the larger SLC22 family. The link between these proteins and inflammation has been proposed based on their link to some chronic inflammatory diseases such as asthma, Crohn's disease (CD), and rheumatoid arthritis (RA). Moreover, the two transporters show the ability to mediate the transport of several compounds including carnitine, carnitine derivatives, acetylcholine, ergothioneine, and gut microbiota by-products, which have been specifically associated with inflammation for their anti- or proinflammatory action. Therefore, the absorption and distribution of these molecules rely on the presence of OCTN1 and OCTN2, whose expression is modulated by inflammatory cytokines and transcription factors typically activated by inflammation. In the present review, we wish to provide a state of the art on OCTN1 and OCTN2 transport function and regulation in relationships with inflammation and inflammatory diseases focusing on the metabolic signature collected in different body districts and gene polymorphisms related to inflammatory diseases.