Trimethylamine-N-Oxide Induces Vascular Inflammation by Activating the NLRP3 Inflammasome Through the SIRT3-SOD2-mtROS Signaling Pathway

The mitochondria-gut microbiota crosstalk - A novel frontier in cardiovascular diseases

Cardiovascular diseases (CVDs), including hypertension, atherosclerosis, and cardiomyopathy among others, remain the leading cause of global morbidity and mortality. Despite advances in treatment, the complex pathophysiology of CVDs necessitates innovative approaches to improve patient outcomes. Recent research has uncovered a dynamic interplay between mitochondria and gut microbiota, fundamentally altering our understanding of cardiovascular health. However, while existing studies have primarily focused on individual components of this axis, this review examines the bidirectional communication between these biological systems and their collective impact on cardiovascular health. Mitochondria, serving as cellular powerhouses, are crucial for maintaining cardiovascular homeostasis through oxidative phosphorylation (OXPHOS), calcium regulation, and redox balance. Simultaneously, the gut microbiota influences cardiovascular function through metabolite production, barrier integrity maintenance, and immune system modulation. The mitochondria-gut microbiota axis operates through various molecular mechanisms, including microbial metabolites such as trimethylamine N-oxide (TMAO), short-chain fatty acids (SCFA), and secondary bile acids, which directly influence mitochondrial function. Conversely, mitochondrial stress signals and damage-associated molecular patterns (DAMPs) affect gut microbial communities and barrier function. Key signalling pathways, including AMP-activated protein kinase (AMPK), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and the silent information regulator 1-peroxisome proliferator-activated receptor gamma coactivator 1-alpha (SIRT1-PGC-1α) axis, integrate these interactions, highlighting their role in CVD pathogenesis. Understanding these interactions has revealed promising therapeutic targets, suggesting new therapies aimed at both mitochondrial function and gut microbiota composition. Thus, this review provides a comprehensive framework for leveraging the mitochondria-gut microbiota axis in providing newer therapeutics for CVDs by targeting the AMPK/SIRT-1/PGC-1α/NF-κB signalling.

Honokiol ameliorates pyroptosis in intestinal ischemia‑reperfusion injury by regulating the SIRT3‑mediated NLRP3 inflammasome

Intestinal ischemia‑reperfusion (IIR) injury is caused by the restoration of blood supply after a period of ischemia. It occurs in numerous clinical pathologies, such as intestinal obstruction, incarcerated hernia and septic shock, with mortality rates of 50‑80%. Honokiol (HKL), isolated from the herb Magnolia officinalis, is a biphenolic natural product with antioxidative, antibacterial, antitumor and anti‑inflammatory properties. Additionally, HKL has protective effects in ischemia‑reperfusion injuries, but its role and specific mechanisms in IIR injury are yet to be elucidated. In the present study, the superior mesenteric artery was ligated in rats to establish an IIR model. Hematoxylin and eosin staining and ELISA revealed that HKL administration ameliorated IIR‑induced injury in rats, which was demonstrated by a reduced destruction to the intestinal mucosa, as well as a reduced serum intestinal fatty acid‑binding protein concentration and Chiu's score in 10 mg/kg HKL treated IIR‑induced rats compared with those without HKL treatment. Additionally, immunohistochemical (IHC) staining and western blotting revealed that the occludin and tight junction protein 1 protein levels were increased in the 10 mg/kg HKL treated IIR‑induced rats compared with those without HKL treatment. Furthermore, an in vitro hypoxia/reoxygenation (H/R) cell model was established using IEC‑6 cells. Cell Counting Kit‑8 and lactate dehydrogenase (LDH) assays indicated that HKL mitigated the H/R‑inhibited cell viability and decreased the LDH levels in cell supernatants. Mechanistically, immunofluorescent (IF) staining and western blotting revealed that HKL inhibited H/R‑triggered pyroptosis. Furthermore, Mito‑Tracker, mitochondrial membrane potential and MitoSOX staining as well as western blotting revealed that reducing mitochondrial reactive oxygen species (ROS) inhibited the H/R‑induced pyroptosis by mitigating mitochondrial dysfunction. In the present H/R cell model, HKL improved the mitochondrial function by increasing the expression of sirtuin 3 (SIRT3), while IF staining and western blotting indicated that silencing SIRT3 notably reduced the beneficial effect of HKL on pyroptosis. In addition, IHC staining and western blotting revealed that HKL treatment mitigated the IIR‑induced pyroptosis in rats. Therefore, HKL treatment may mitigate IIR‑induced mitochondrial dysfunction and reduce mitochondrial ROS production by increasing the expression of SIRT3 protein, potentially resulting in an inhibition of pyroptosis during IIR.

Gut-Heart Axis: The Role of Gut Microbiota and Metabolites in Heart Failure

Heart failure is a global health issue with significant mortality and morbidity. There is increasing evidence that alterations in the gastrointestinal microbiome, gut epithelial permeability, and gastrointestinal disorders contribute to heart failure progression through various pathways, including systemic inflammation, metabolic dysregulation, and modulation of cardiac function. Moreover, several medications used to treat heart failure directly impact the microbiome. The relationship between the gastrointestinal tract and the heart is bidirectional, termed the gut-heart axis. It is increasingly understood that diet-derived microbial metabolites are key mechanistic drivers of the gut-heart axis. This includes, for example, trimethylamine N-oxide and short-chain fatty acids. This review discusses current insights into the interplay between heart failure, its associated risk factors, and the gut microbiome, focusing on key metabolic pathways, the role of dietary interventions, and the potential for gut-targeted therapies. Understanding these complex interactions could pave the way for novel strategies to mitigate heart failure progression and improve patient outcomes.

Elevated Trimethylamine-N-oxide (TMAO) Is Associated with Vascular Access Dysfunction in Maintenance Hemodialysis Patients

INTRODUCTION

Elevated levels of trimethylamine-N-oxide (TMAO), a metabolite produced by gut microbiota, have been associated with cardiovascular diseases and complications in various populations. However, its role in vascular access dysfunction in hemodialysis patients remains underexplored. This study investigates the potential relationship between TMAO levels and vascular access dysfunction in maintenance hemodialysis patients.

METHODS

This study included 80 hemodialysis patients. The baseline serum TMAO levels were measured, and clinical characteristics and dialysis-related data were collected. They were followed up on vascular access dysfunction events over a period of 1 year. The association between serum TMAO levels and vascular access dysfunction events were investigated.

FINDINGS

In our cohort, we observed a wide distribution of serum concentrations, with a median concentration of 15.2 μmol/L and a maximum concentration of 245.3 μmol/L. Patients were stratified into a low-TMAO group and a high-TMAO group according to the median value of TMAO concentrations. Those in the high-TMAO group had a significantly higher incidence of vascular access dysfunction events (p = 0.023). TMAO was independently associated with vascular access dysfunction events after adjusting for some potential vascular access dysfunction risk factors.

DISCUSSION

This study suggests that elevated serum TMAO levels may serve as an independent risk factor for vascular access dysfunction in hemodialysis patients. Reducing TMAO levels may potentially decrease the incidence of vascular access dysfunction, warranting further investigation into this therapeutic approach.

Trimethylamine N-oxide induces cardiac diastolic dysfunction by down-regulating Piezo1 in mice with heart failure with preserved ejection fraction

AIMS

The present study aimed to investigate the direct link between trimethylamine N-oxide (TMAO) and diastolic dysfunction in heart failure with preserved ejection fraction (HFpEF).

MATERIALS AND METHODS

Diastolic dysfunction is the main manifestation of HFpEF, so the "two-hit" mouse HFpEF model are used. After treated with high-fat diet (HFD) and N[w]-nitro-l-arginine methyl ester (L-NAME) for 8 weeks, the cardiac function, myocardial fibrosis, oxidative stress levels, and molecular alterations were assessed.

KEY FINDINGS

The HFpEF mice displayed a declined diastolic function, characterized by an increase in the E/E' ratio, accompanied by a significant increase in plasma brain natriuretic peptide levels and cardiac fibrosis and down-regulation of SERCA2 expression, while, DMB treatment improved diastolic function. Subsequently, TMAO was injected intraperitoneally into the mice for 1 month and found that TMAO induced diastolic dysfunction. In addition, we found that either the HFD and L-NAME or TMAO treatment down-regulated Piezo1 expression, and the cardiomyocyte-specific Piezo1 knockout mice (Piezo1ΔCM) also had diastolic dysfunction. Moreover, the NOX4 expression was up-regulated and the reactive oxygen species levels were increased in the heart tissues of Piezo1ΔCM or TMAO-treated mice, which was reversed by a Piezo1 activator (Yoda1) in the TMAO-treated mice. Yoda1 also reversed diastolic dysfunction in the HFpEF mice.

SIGNIFICANCE

In conclusion, our data revealed that TMAO-induced oxidative stress injury by down-regulating Piezo1 to be involve in cardiac diastolic dysfunction of HFpEF. It should be noted that this preclinical study did not evaluate HFpEF-related symptoms such as exercise intolerance or pulmonary congestion, which warrant further validation.

Gut Microbiota Metabolite TMAO and Adolescent Cardiometabolic Health: A Cross-sectional Analysis

Background

Trimethylamine N-oxide (TMAO) is a metabolite derived from gut microbiota that has been associated with cardiovascular and metabolic disease risk in adults. However, its role in assessing cardiometabolic risk in adolescents is unclear.

Objective

This study investigates the association between serum TMAO levels and cardiometabolic health indicators in Brazilian adolescents.

Materials and Methods

This is a multicenter, cross-sectional analysis involving 4446 participants aged 12 to 17 years from four Brazilian cities. Serum TMAO levels were quantified using liquid chromatography-tandem mass spectrometry, and associations with clinical, metabolic, and inflammatory variables were evaluated through multivariate linear regression analyses.

Results

After adjusting for potential confounders, being in the highest tertile of serum TMAO was positively associated with waist circumference [β 1.45; 95% confidence interval (CI) 0.77, 2.14; P < .001], body mass index Z-score (β .19; 95% CI 0.10, 0.27; P < .001), and C-reactive protein (β .24; 95% CI 0.13, 0.34; P < .001). A negative association between the highest tertile of TMAO and fasting plasma glucose was also observed (β -1.22; 95% CI -1.77, -0.66; P < .001).

Conclusion

TMAO may serve as an emerging biomarker for cardiometabolic risk assessment in adolescents.

Systemic lupus erythematosus and atherosclerosis: immune pathways and the uncharted territory of gut microbiota and metabolism

Patients with Systemic Lupus Erythematosus (SLE) are significantly more susceptible to atherosclerosis, which may elevate their mortality risk. The review explores recent understandings of the origins and remedies for atherosclerosis associated with SLE. Our focus is particularly on the consequences of immune system disparities, interruptions in intestinal bacteria, and metabolic complications. The influence of SLE on atherosclerosis extends past usual risk elements, including processes specific to the disease. The list encompasses excessive immune cell activity, production of autoantibodies, inflammatory responses. A variety of therapies for atherosclerosis linked to SLE encompass cholesterol-lowering medications, anti-inflammatory drugs, immune suppressors, antimalarials, interferon treatments, NET inhibitors, and methods aimed at T and B-cells. However, existing research has its shortcomings, necessitating additional clinical trials to ascertain the efficacy and security of these therapies. The direct interactions among SLE, gut microbiota, metabolism, and atherosclerosis is underexplored, presenting innovation opportunities. Research into specific gut microbial strains and metabolites' effects on immune responses and atherosclerosis progression in SLE patients is needed. Such research could uncover novel therapeutic targets and biomarkers, advancing prevention and treatment strategies for SLE cardiovascular complications.

Metabolomic analysis reveals trimethylamine N-oxide as a biomarker for poor outcome of severe spontaneous intracerebral hemorrhage patients receiving surgical treatment

Background and objectives

Patients suffering from severe spontaneous intracerebral hemorrhage (SSICH) are at high risk of cardiocerebrovascular diseases postoperatively, which hugely affect patients' long-term outcomes. Metabolic features could reflect the pathological change of the cardiocerebrovascular system and might serve as biomarkers for evaluating the risk of poor outcomes in SSICH patients. The current study aimed to find the early-warning biomarkers for poor outcomes in SSICH patients after surgery.

Methods

Severe spontaneous intracerebral hemorrhage patients receiving surgical treatment from a referring hospital were prospectively included and formed the primary cohort after propensity score matching. The primary outcome is poor 180 days after hemorrhage (modified Rankin scale ≥4). Metabolomics analysis on 3-, 7-, and 30-day serum and cerebrospinal fluid samples after surgery revealed the dysregulated metabolites of SSICH patients within the primary cohort. Within the validation cohort of SSICH patients receiving surgical treatment from a multicenter, prospective cohort, dysregulated metabolites were validated and evaluated to see whether they could serve as biomarkers for 180-day poor outcomes by area under the curve (AUC).

Results

The primary cohort included 20 SSICH patients with good 180-day outcome and 20 with poor outcome. Untargeted metabolomics analysis found 25 co-dysregulated metabolites, including trimethylamine N-oxide (TMAO), among 3-day, 7-day, and 30-day metabolism features between SSICH patients with poor outcome and good outcome after surgery. A good correlation was found in TMAO between serum and cerebrospinal fluid on 3rd day after surgery. Based on the validation cohort of 794 SSICH patients (147 patients had 180-day poor outcome), the targeted metabolomics analysis revealed increasing TMAO on 3rd day after surgery as a risk factor of poor outcomes (odds ratio, 4.7; 95%CI, 3.6-6.2; p < 0.001), with a good predictive value (AUC, 0.81).

Conclusion

This study demonstrated increasing serum TMAO level as an early-warning biomarker for 180-day poor outcomes of SSICH patients receiving surgical treatment.

Clinical trial registration

Chinese Clinical Trial Registry, ChiCTR1900024406, https://www.chictr.org.cn/showproj.html?proj=40640.

Fecal Calprotectin as a Prognostic Biomarker for Mortality and Renal Outcomes in Chronic Kidney Disease

BACKGROUND/OBJECTIVES

Fecal calprotectin (FC) is a biomarker of intestinal inflammation widely used in the assessment of gastrointestinal disorders. However, its role in chronic kidney disease (CKD) remains unclear. Given the growing recognition of the gut-kidney axis in CKD pathophysiology, this study aimed to investigate the association between FC levels, systemic inflammation, renal outcomes, and mortality in CKD patients.

METHODS

We enrolled a total of 515 CKD patients who underwent fecal calprotectin measurement between 2016 and 2023. After applying the exclusion criteria (inflammatory bowel disease, ongoing renal replacement therapy, or incomplete laboratory data), 260 patients were included in the final analysis and stratified into low-FC (<102 μg/g, n = 130) and high-FC (≥102 μg/g, n = 130) groups based on the median FC value. Factors associated with kidney disease progression and patient survival were analyzed.

RESULTS

Patients in the high-FC group (≥102 μg/g) were significantly older (72.8 ± 14.63 vs. 64.02 ± 18.15 years, p < 0.0001) and had a higher prevalence of diabetes mellitus (55.38% vs. 42.31%, p = 0.0349), heart failure (21.54% vs. 7.69%, p = 0.0016), and history of acute kidney injury (33.85% vs. 18.46%, p = 0.0048). Elevated FC was independently associated with increased mortality risk (hazards ratio [HR] 1.658, 95% confidence interval [CI] 1.034-2.658, p = 0.0357) with higher mortality rates (48.36 vs. 18.46 per 100,000 person-years). Subgroup analyses revealed stronger associations between FC and mortality in males (HR 2.160, 95% CI 1.046-4.463, p = 0.0375), elderly patients (≥75 years) (HR 2.122, 95% CI 1.209-3.725, p = 0.0088), and non-diabetic patients (HR 2.487, 95% CI 1.141-5.421, p = 0.0219). While FC was not significantly associated with end-stage kidney disease (ESKD) progression (odds ratio [OR] 1.289, 95% CI 0.455-3.650, p = 0.6323), higher FC levels paradoxically predicted slower estimated glomerular filtration rate (eGFR) decline (OR 2.763, 95% CI 1.139-6.699, p = 0.0245). Combined analysis revealed patients with both elevated FC and high-sensitivity C-reactive protein (hs-CRP) had the highest mortality risk (HR 3.504, 95% CI 1.163-10.554, p < 0.0001) compared to those with low levels of both markers.

CONCLUSIONS

FC is a potential prognostic biomarker for mortality in CKD patients, independently of traditional inflammatory markers. Further research is warranted to elucidate the mechanisms underlying its paradoxical relationship with renal outcomes and its potential role in risk stratification and therapeutic targeting in CKD.

Gut microbiota-derived metabolites: Potential targets for cardiorenal syndrome

The characteristic of cardiorenal syndrome (CRS) is simultaneous damage to both the heart and kidneys. CRS has caused a heavy burden of mortality and incidence rates worldwide. The regulation of host microbiota metabolism that triggers heart and kidney damage is an emerging research field that promotes a new perspective on cardiovascular risk. We summarize current studies from bench to bedside of gut microbiota-derived metabolites to better understand CRS in the context of gut microbiota-derived metabolites. We focused on the involvement of gut microbiota-derived metabolites in the pathophysiology of CRS, including lipid and cholesterol metabolism disorders, coagulation abnormalities and platelet aggregation, oxidative stress, endothelial dysfunction, inflammation, mitochondrial damage and energy metabolism disorders, vascular calcification and renal fibrosis, as well as emerging therapeutic approaches targeting CRS metabolism in gut microbiota-derived metabolites which provides an innovative treatment approach for CRS to improve patient prognosis and overall quality of life.

High-fat diet induces sarcopenic obesity in natural aging rats through the gut-trimethylamine N-oxide-muscle axis

INTRODUCTION

The lack of suitable animal models for sarcopenic obesity (SO) limits in-depth research into the disease. Emerging studies have demonstrated that gut dysbiosis is involved in the development of SO. As the importance of microbial metabolites is starting to unveil, it is necessary to comprehend the specific metabolites associated with gut microbiota and SO.

OBJECTIVES

We aimed to investigate whether high-fat diet (HFD) causes SO in natural aging animal models and specific microbial metabolites that are involved in linking HFD and SO.

METHODS

Young rats received HFD or control diet for 80 weeks, and obesity-related metabolic disorders and sarcopenia were measured. 16S rRNA sequencing and non-targeted and targeted metabolomics methods were used to detect fecal gut microbiota and serum metabolites. Gut barrier function was evaluated by intestinal barrier integrity and intestinal permeability. Trimethylamine N-oxide (TMAO) treatment was further conducted for verification.

RESULTS

HFD resulted in body weight gain, dyslipidemia, impaired glucose tolerance, insulin resistance, and systemic inflammation in natural aging rats. HFD also caused decreases in muscle mass, strength, function, and fiber cross-sectional area and increase in muscle fatty infiltration in natural aging rats. 16S rRNA sequencing and nontargeted and targeted metabolomics analysis indicated that HFD contributed to gut dysbiosis, mainly characterized by increases in deleterious bacteria and TMAO. HFD destroyed intestinal barrier integrity and increased intestinal permeability, as evaluated by reducing levels of colonic mucin-2, tight junction proteins, goblet cells and elevating serum level of fluorescein isothiocyanate-dextran 4. Correlation analysis showed a positive association between TMAO and SO. In addition, TMAO treatment aggravated the development of SO in HFD-fed aged rats through regulating the ROS-AKT/mTOR signaling pathway.

CONCLUSION

HFD leads to SO in natural aging rats, partially through the gut-microbiota-TMAO-muscle axis.

Trimethylamine-N-Oxide (TMAO) as a Rising-Star Metabolite: Implications for Human Health

The intestinal microbiota, hosting trillions of microorganisms that inhabit the gastrointestinal tract, functions as a symbiotic organism that plays a crucial role in regulating health by producing biologically active molecules that can enter systemic circulation. Among them, trimethylamine-N-oxide (TMAO), an organic compound derived from dietary sources and microbial metabolism, has emerged as a critical biomarker linking diet, the gut microbiota, and the host metabolism to various pathological conditions. This comprehensive review highlights TMAO's biosynthesis, physiological functions, and clinical significance, focusing on its mechanistic contributions to cardiovascular and neurodegenerative diseases. Notably, TMAO-mediated pathways include endothelial dysfunction, inflammation via NLRP3 inflammasome activation, and cholesterol metabolism disruption, which collectively accelerate atherosclerosis and disease progression. Nonetheless, this work underscores the innovative potential of targeting TMAO through dietary, nutraceutical, and microbiota-modulating strategies to mitigate its pathological effects, marking a transformative approach in the prevention and management of TMAO-related disorders.

Antibiotic-induced gut dysbiosis: unraveling the gut-heart axis and its impact on cardiovascular health

Cardiovascular diseases (CVDs) remain the major cause of morbidity and mortality amongst people of all ages across the world. Research suggests that the initiation and progression of CVDs are associated with antibiotic-induced gut dysbiosis. Antibiotics are primarily intended to be used to treat bacterial infections, which can alter gut microbiota (GM) composition, by lowering the abundance of beneficial bacteria, like Firmicutes, Bacteroidetes, and increasing the profusion of Enterobacteriaceae, leading to harm on gut health. Additionally, it reduces short-chain fatty acids (SCFAs) and bile acid metabolism, increases trimethylamine N-oxide (TMAO) production, intestinal permeability allowing lipopolysaccharide (LPS) and TMAO into systemic circulation. SCFAs play a key role in lipid metabolism, inflammation, and strengthening of the intestinal barrier, and participate in CVDs through FFAR2 and FFAR3 receptors, whereas dysbiosis reduces SCFAs levels and worsens these effects. TMAO enhances oxidative stress, inflammation, endothelial dysfunction, and cholesterol dysregulation, thus worsening CVDs. Furthermore, LPS develops systemic inflammation, insulin resistance, and endothelial dysfunction by activating the NF-κB pathway. Dysbiosis also affects bile acid synthesis, disrupting lipid and glucose metabolism, further participating in the progression of CVDs. This article aims to explore the role of gut dysbiosis in various CVDs, including congenital heart disease, hypertension, valvular heart disease, coronary heart disease, and heart failure. Furthermore, this article aims to bridge the knowledge gap regarding the gut-heart axis by exploring how antibiotics alter the gut microbiota homeostasis, further contributing to the development of CVDs and therapeutic interventions that reduce cardiovascular risks and restore the gut microbiota homeostasis.

The microbial metabolite trimethylamine N-oxide and the kidney diseases

Trimethylamine N-oxide (TMAO), a metabolite, is a co-metabolite produced by both gut microbiota and livers, originating from foods rich in choline or carnitine. Emerging evidence suggests that TMAO may play a role in the pathogenesis of various kidney diseases, including acute kidney injury and chronic kidney disease. Research has demonstrated that heightened levels of TMAO are correlated with a heightened likelihood of kidney disease advancement and cardiovascular incidents among individuals with chronic kidney disease. Furthermore, TMAO has been observed to stimulate inflammation, oxidative stress, and fibrosis in animal models of kidney disease. Mechanistically, TMAO may contribute to kidney disease pathogenesis by inhibiting autophagy, activating the NLRP3 inflammasome, and inducing mitochondrial dysfunction. Therefore, targeting TMAO may represent a promising therapeutic strategy for the treatment of kidney diseases. Future studies are needed to further investigate the role of TMAO in kidney disease pathogenesis and to develop TMAO-targeted therapies for the prevention and treatment of kidney diseases.

Dihydromyricetin Suppresses Lipopolysaccharide-Induced Intestinal Injury Through Reducing Reactive Oxygen Species Generation and NOD-Like Receptor Pyrin Domain Containing 3 Inflammasome Activation

As an integral component of the gram-negative bacterial cellular envelope, excess production of lipopolysaccharide (LPS) regularly precipitates causing intestinal damage and barrier dysfunction in avian species. Dihydromyricetin (DHM), a naturally occurring constituent in rattan tea, exhibits protective characteristics against various tissue injuries. However, the intervention mechanism of DHM on intestinal injury induced by LPS in chickens has not been determined. Consequently, this study aimed to elucidate the mechanisms through which DHM mitigates LPS-induced intestinal damage in chickens through the reactive oxygen species (ROS)-NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome. Primary intestinal epithelial cells (IECs) were isolated and cultured from 14-day-old specific pathogen free (SPF) chicken embryos, and DHM ranging from 20 to 320 μmol/L increased cell survival rates. Additionally, DHM at 20 and 40 μmol/L demonstrated reduction in oxidative stress and ROS accumulation, mirroring the impact of ROS inhibitor (2.5 mmol/L NAC). DHM efficiently regulated ROS production, thereby augmenting ZO-1, occludin and claudin-1 expression to enhance barrier function; upregulating bcl-2 expression and downregulating bax and caspase-3 expression to regulate apoptosis and suppressing inflammation in IECs. Suppression of ROS subsequently attenuates NLRP3 inflammasome activation, leading to a remarkable downregulation of IL-1β, IL-18 and lactate dehydrogenase (LDH) secretion, consistent with direct inactivation of NLRP3 inflammasome (10 μmol/L MCC950). Notably, DHM diminished IL-1β and IL-18 levels and LDH activity via suppression of ROS-regulated NLRP3 and caspase-1 expression and activation. In summary, DHM prevents LPS-induced intestinal impairment by modulating ROS generation and NLRP3 inflammasome activation.

Trimethylamine N-oxide as a potential prognostic biomarker for mortality in patients with COVID-19 disease

PURPOSE

Trimethylamine N-oxide (TMAO) is suggested as a biomarker for inflammatory and cardiovascular diseases which are identified as risk factors for severe cases of coronavirus disease 2019 (COVID-19). Our primary aim was to assess prognostic potential of serum TMAO levels in predicting COVID-19-related mortality. The secondary aim was to examine the potential of various biochemical parameters, particularly those associated with inflammation or thrombosis, as predictors of mortality.

PATIENTS AND METHODS

In this prospective and single-centre study, COVID-19 patients were categorized as death (group 1) or discharged (group 2) based on their in-hospital mortality status. The characteristics of participants were documented, and clinical data, including TMAO, angiotensin-converting enzyme-2 (ACE2), and neutrophil to lymphocyte ratio (NLR), were determined. The association of these independent variables with the COVID-19-related mortality, was assessed by calculation of crude odds ratios (OR) in bivariate and logistic regression analysis. Receiver operation characteristic (ROC) analysis was used for cut-off values.

RESULTS

The serum levels of TMAO, ACE2 and NLR were markedly higher in group 1 on the days of hospital admission (p ​< ​0.05, p ​< ​0.05, and p ​< ​0.01, respectively). Serum TMAO levels (OR 1.422; 95 ​% CI [1.067-1.894]; p ​= ​0.016) and NLR (OR 1.166; 95 ​% CI [1.012-1.343]; p ​= ​0.033) were determined as independent predictors for COVID-19-related mortality with after multivariate logistic regression analysis. The optimal cut-off values were detected as 7.9 ​ng/ml for TMAO (71 ​% sensitivity, 68 ​% specificity, AUC ​= ​0.701).

CONCLUSIONS

The findings of this initial study indicate that serum TMAO levels and NLR may be useful in predicting mortality in the early stages of COVID-19.

Gut microbial metabolites: The bridge connecting diet and atherosclerosis, and next-generation targets for dietary interventions

Mounting evidence indicates that gut microbial metabolites are central hubs linking the gut microbiota to atherosclerosis (AS). Gut microbiota enriched with pathobiont bacteria responsible for producing metabolites like trimethylamine N-oxide and phenylacetylglutamine are related to an increased risk of cardiovascular events. Furthermore, gut microbiota enriched with bacteria responsible for producing short-chain fatty acids, indole, and its derivatives, such as indole-3-propionic acid, have demonstrated AS-protective effects. This study described AS-related gut microbial composition and how microbial metabolites affect AS. Summary findings revealed gut microbiota and their metabolites-targeted diets could benefit AS treatment. In conclusion, dietary interventions centered on the gut microbiota represent a promising strategy for AS treatment, and understanding diet-microbiota interactions could potentially be devoted to developing novel anti-AS therapies.

Independent Predictors of Circulating Trimethylamine N-Oxide (TMAO) and Resistin Levels in Subjects with Obesity: Associations with Carotid Intima-Media Thickness and Metabolic Parameters

Background: Obesity contributes to cardiometabolic risk, including subclinical atherosclerosis and insulin resistance. This study examines the predictive roles of trimethylamine N-oxide (TMAO) and resistin in relation to carotid intima-media thickness and metabolic parameters; Methods: Sixty adults (18-71 years) with varying body weights were assessed for body composition, subclinical atherosclerosis, and blood biomarkers, including TMAO and resistin; Results: TMAO correlated strongly with CIMT (r = 0.674, p < 0.001), indicating its role in subclinical atherosclerosis. Logistic regression identified TMAO (threshold 380; AUC = 0.880, accuracy = 91.7%) as a predictor of cardiometabolic risk. Resistin was associated with CIMT, WHR, and total cholesterol, inversely linked to LDL cholesterol (p = 0.003). Less active participants exhibited higher TMAO (p = 0.001) and resistin (p = 0.02). Family histories of obesity and diabetes correlated with elevated TMAO, while resistin linked to shorter sleep duration and diabetes history, highlighting their importance in obesity-related cardiometabolic risks; Conclusions: TMAO is strongly linked to abdominal fat, insulin resistance, and subclinical atherosclerosis, while resistin is associated with lipid metabolism and aging. Their combined assessment enhances the prediction of obesity-related cardiometabolic risk, supporting their role in risk stratification and targeted interventions.

Endothelial Dysfunction: Redox Imbalance, NLRP3 Inflammasome, and Inflammatory Responses in Cardiovascular Diseases

Endothelial dysfunction (ED) is characterized by an imbalance between vasodilatory and vasoconstrictive factors, leading to impaired vascular tone, thrombosis, and inflammation. These processes are critical in the development of cardiovascular diseases (CVDs) such as atherosclerosis, hypertension and ischemia/reperfusion injury (IRI). Reduced nitric oxide (NO) production and increased oxidative stress are key contributors to ED. Aging further exacerbates ED through mitochondrial dysfunction and increased oxidative/nitrosative stress, heightening CVD risk. Antioxidant systems like superoxide-dismutase (SOD), glutathione-peroxidase (GPx), and thioredoxin/thioredoxin-reductase (Trx/TXNRD) pathways protect against oxidative stress. However, their reduced activity promotes ED, atherosclerosis, and vulnerability to IRI. Metabolic syndrome, comprising insulin resistance, obesity, and hypertension, is often accompanied by ED. Specifically, hyperglycemia worsens endothelial damage by promoting oxidative stress and inflammation. Obesity leads to chronic inflammation and changes in perivascular adipose tissue, while hypertension is associated with an increase in oxidative stress. The NLRP3 inflammasome plays a significant role in ED, being triggered by factors such as reactive oxygen and nitrogen species, ischemia, and high glucose, which contribute to inflammation, endothelial injury, and exacerbation of IRI. Treatments, such as N-acetyl-L-cysteine, SGLT2 or NLRP3 inhibitors, show promise in improving endothelial function. Yet the complexity of ED suggests that multi-targeted therapies addressing oxidative stress, inflammation, and metabolic disturbances are essential for managing CVDs associated with metabolic syndrome.

Circulating trimethylamine N-oxide and cardiovascular, cerebral, and renal diseases including mortality: Umbrella review of published systematic reviews and meta-analyses

AIMS

Several systematic reviews/meta-analyses of observational studies have demonstrated associations between circulating trimethylamine-N-oxide (TMAO) and cardiovascular, cerebral, and renal diseases, including mortality. However, causal roles for TMAO in these diseases are controversial. Interventions are lacking to show whether lowering TMAO in clinical trials could reduce the risks of these diseases. TMAO could still serve as a prognostic marker for the mentioned outcomes, but investigating this potential role requires robust methodologies. We conducted a systematic search and critical evaluation of published systematic reviews/meta-analyses in the field.

DATA SYNTHESIS

We identified 27 systematic reviews/meta-analyses on the association between TMAO and stroke (n = 7), cardiovascular disease including cause-specific and/or all-cause mortality (n = 14), and other related outcomes (n = 6). The majority of the systematic reviews/meta-analyses found higher blood TMAO concentrations in patients who were positive for the outcomes. Primary studies included populations with multiple risk factors for the given outcomes and did not sufficiently account for potential confounders. Prospective studies examining associations between baseline TMAO and subsequent disease outcomes in healthy populations were entirely absent. Furthermore, we identified serious flaws in methods, conduct and reporting in the majority of the published systematic reviews/meta-analyses, thus leading to critically low confidence in the results.

CONCLUSIONS

High quality systematic reviews/meta-analyses examining the associations between TMAO and cardiovascular or cerebral disease are needed to examine potential causal and/or predictive roles of TMAO in these diseases. This study is registered at the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42024534940).

The Role of Gut Microbiota-Derived Trimethylamine N-Oxide in the Pathogenesis and Treatment of Mild Cognitive Impairment

Mild cognitive impairment (MCI) represents a transitional stage between normal aging and dementia, often considered critical for dementia prevention. Despite its significance, no effective clinical treatment for MCI has yet been established. Emerging evidence has demonstrated a strong association between trimethylamine-N-oxide (TMAO), a prominent metabolite derived from the gut microbiota, and MCI, highlighting its potential as a biomarker and therapeutic target. TMAO has been implicated in increasing MCI risk through its influence on factors such as hypertension, cardiovascular disease, depression, diabetes, and stroke. Moreover, it contributes to MCI by promoting oxidative stress, disrupting the blood-brain barrier, impairing synaptic plasticity, inducing inflammation, causing mitochondrial metabolic disturbances, and facilitating abnormal protein aggregation. This review further explores therapeutic strategies targeting TMAO to mitigate MCI progression.

Gut-X axis

Recent advances in understanding the modulatory functions of gut and gut microbiota on human diseases facilitated our focused attention on the contribution of the gut to the pathophysiological alterations of many extraintestinal organs, including the liver, heart, brain, lungs, kidneys, bone, skin, reproductive, and endocrine systems. In this review, we applied the "gut-X axis" concept to describe the linkages between the gut and other organs and discussed the latest findings related to the "gut-X axis," including the underlying modulatory mechanisms and potential clinical intervention strategies.

NLRP3 inflammasome and gut microbiota-brain axis: a new perspective on white matter injury after intracerebral hemorrhage

ABSTRACT

Intracerebral hemorrhage is the most dangerous subtype of stroke, characterized by high mortality and morbidity rates, and frequently leads to significant secondary white matter injury. In recent decades, studies have revealed that gut microbiota can communicate bidirectionally with the brain through the gut microbiota-brain axis. This axis indicates that gut microbiota is closely related to the development and prognosis of intracerebral hemorrhage and its associated secondary white matter injury. The NACHT, LRR, and pyrin domain-containing protein 3 (NLRP3) inflammasome plays a crucial role in this context. This review summarizes the dysbiosis of gut microbiota following intracerebral hemorrhage and explores the mechanisms by which this imbalance may promote the activation of the NLRP3 inflammasome. These mechanisms include metabolic pathways (involving short-chain fatty acids, lipopolysaccharides, lactic acid, bile acids, trimethylamine-N-oxide, and tryptophan), neural pathways (such as the vagus nerve and sympathetic nerve), and immune pathways (involving microglia and T cells). We then discuss the relationship between the activated NLRP3 inflammasome and secondary white matter injury after intracerebral hemorrhage. The activation of the NLRP3 inflammasome can exacerbate secondary white matter injury by disrupting the blood-brain barrier, inducing neuroinflammation, and interfering with nerve regeneration. Finally, we outline potential treatment strategies for intracerebral hemorrhage and its secondary white matter injury. Our review highlights the critical role of the gut microbiota-brain axis and the NLRP3 inflammasome in white matter injury following intracerebral hemorrhage, paving the way for exploring potential therapeutic approaches.

Metabolomics with gut microbiota analysis of podophyllotoxin-mediated cardiotoxicity in mice based on the toxicological evidence chain (TEC) concept

Podophyllotoxin (PPT) is a lignan isolated from the traditional Chinese medicine Dysosma Versipellis, with significant anti-tumor activity. However, its cardiotoxicity restricts its clinical application. This study aims to investigate the cardiotoxicity of PPT in mice and its underlying mechanisms based on the concept of toxicological evidence chain (TEC). In this study, alterations in body weight, behavior, and the levels of myocardial enzymes and histopathology in mice were observed. Additionally, microbiome and metabolome were integrated to identify potential microorganisms, metabolic markers and major pathways with correlation analysis. The results indicated that PPT induced pathological changes in mice, including weight loss, diarrhea, alopecia and dehydration accompanied by increased levels of serum myocardial enzymes. The results of microbiome showed that PPT altered the gut microbiota composition, changing the abundance of microbial community. The results of metabolome studies indicated total of 55 differential metabolites were involved in glycine, serine, and threonine metabolism, alanine, glutamate, and aspartate metabolism, purine, pyrimidine metabolism, and steroid hormone metabolism. Integrating the results of microbiome and metabolome, it was concluded that PPT remodeled the gut microbiota composition, which in turn modified the gut microbiota metabolism, affecting amino acid metabolisms, nucleotide metabolism, and steroid hormone metabolism in the heart, potentially leading to energy metabolism disorders, apoptosis, and oxidative stress, ultimately inducing cardiotoxicity.

Active ingredients of traditional Chinese medicine inhibit NOD-like receptor protein 3 inflammasome: a novel strategy for preventing and treating heart failure

Heart failure (HF) has emerged as a significant global public health challenge owing to its high rates of morbidity and mortality. Activation of the NOD-like receptor protein 3 (NLRP3) inflammasome is regarded as a pivotal factor in the onset and progression of HF. Therefore, inhibiting the activation of the NLRP3 inflammasome may represent a promising therapeutic approach for preventing and treating HF. The active ingredients serve as the foundation for the therapeutic effects of traditional Chinese medicine (TCM). Recent research has revealed significant advantages of TCM active ingredients in inhibiting the activation of the NLRP3 inflammasome and enhancing cardiac structure and function in HF. The study aimed to explore the impact of NLRP3 inflammasome activation on the onset and progression of HF, and to review the current advancements in utilizing TCM active ingredients to inhibit the NLRP3 inflammasome for preventing and treating HF. This provides a novel perspective for the future development of precise intervention strategies targeting the NLRP3 inflammasome to prevent and treat HF.

Gut microbiota derived metabolite trimethylamine N-oxide influences prostate cancer progression via the p38/HMOX1 pathway

BACKGROUND

Prostate cancer was the fourth most diagnosed cancer worldwide in 2022. Radical treatments and androgen deprivation therapy benefit newly diagnosed patients but impact quality of life, often leading to castration-resistant prostate cancer. Short-term dietary changes significantly affect the gut microbiota, which differs markedly between prostate cancer patients and healthy individuals, impacting both cancer progression and treatment response. A high-choline diet increases the risk of fatal prostate cancer, potentially mediated by the conversion of choline to the trimethylamine N-oxide (TMAO) by the gut microbiota.

METHODS

The CCK8 assay was employed to investigate whether TMAO affects the proliferation ability of prostate cancer cells and to determine the appropriate drug concentration. Subsequently, CCK8 time gradients, colony formation assays, and EdU assays measured TMAO's influence on cell proliferation. Wound healing and transwell migration assays evaluated TMAO's effect on cell migration. RNA-seq analysis was performed to explore the mechanisms by which TMAO influences the proliferation and migration of prostate cancer cells. qPCR and Western blotting were utilized to validate the expression of related mRNA or proteins. Finally, we performed in vivo experiments to evaluate the effect of a high choline diet on the growth of subcutaneous tumors and lung metastases in mice.

RESULTS

Our study found that TMAO enhances the proliferation and migration of prostate cancer cells by upregulating HMOX1 via activation of the MAPK signaling pathway, specifically p38 MAPK. In mouse subcutaneous tumor and lung metastatic tumor experiments, the high-choline diet increased prostate cancer cell proliferation and migration, resulting in significantly greater tumor volume and number of metastases than controls.

CONCLUSION

This study is the first to demonstrate the role of the gut microbiota-derived metabolite TMAO in prostate cancer. TMAO promotes the proliferation and migration of prostate cancer cells by activating the p38 pathway and increasing HMOX1 expression. Reducing choline intake through dietary intervention may delay the onset and progression of prostate cancer, presenting significant clinical application value.

Impacts of intestinal microbiota metabolite trimethylamine N-oxide on cardiovascular disease: a bibliometric analysis

Background

Trimethylamine N-oxide (TMAO), a metabolite dependent on intestinal microbiota, is closely related to the emergence, progression, and prognosis of cardiovascular disease (CVD), and has received increasing attention in recent years.

Objective

The current research hotspots and future development trends in TMAO and CVD field are found through bibliometrics analysis, which provides reference for further study.

Methods

The bibliometrics tools VOSviewer and CiteSpace were used to analyze the publications from the Web of Science Core Collection (WOSCC) database. The articles published from 2004 to 2024 about the relationship between TMAO and CVD were retrieved. Bibliometric analysis includes annual publications, countries/regions, institutions, authors and co-cited authors, journals and cited-journals, references and keywords.

Results

After searching and screening, 1,466 publications were included for subsequent bibliometric analysis. Since 2014, the number of publications exposing the relationship between TMAO and CVD has increased rapidly, as has the frequency of citations. China, USA and Italy are the countries that publish the most relevant research. Cleveland Clinic is the leading institution in this field. Stanley L Hazen, Zeneng Wang and W H Wilson Tang are the most prolific authors in this field, and the latter two have the closest academic cooperation. American Journal of Clinical Nutrition and Journal of the American Heart Association are influential journals that publish research in this field. "Gut Microbial Metabolite TMAO Enhances Platelet Hyperreactivity and Thrombosis Risk" is the most frequently cited article. Keyword analysis shows that gut microbiota, metabolism, phosphatidylcholine and atherosclerosis (AS) are the hotspots in this field.

Conclusion

This study summarizes the research situation of TMAO and CVD in the past 20 years, focusing on the effect of TMAO on pathogenesis of AS, predictive value of TMAO on CVD risk, and dietary and drug intervention for TMAO. Probiotics and natural products may be the research focus of preventing and treating CVD by intervening TMAO in the future.

Gut microbiota: a novel target for exercise-mediated regulation of NLRP3 inflammasome activation

The NOD-like receptor family pyrin domain-containing 3 (NLRP3) is a key pattern recognition receptor in the innate immune system. Its overactivation leads to the production of pro-inflammatory cytokines, such as IL-1β and IL-18, which contribute to the development and progression of various diseases. In recent years, evidence has shown that gut microbiota plays an important role in regulating the activation of NLRP3 inflammasome. Variations in the function and composition of gut microbiota can directly or indirectly influence NLRP3 inflammasome activation by influencing bacterial components and gut microbiota metabolites. Additionally, exercise has been shown to effectively reduce NLRP3 inflammasome overactivation while promoting beneficial changes in gut microbiota. This suggests that gut microbiota may play a key role in mediating the effects of exercise on NLRP3 inflammasome regulation. This review explores the impact of exercise on gut microbiota and NLRP3 inflammasome activation, and examines the mechanisms through which gut microbiota mediates the anti-inflammatory effects of exercise, providing new avenues for research.

Salvianolic acid B alleviated myocardial ischemia-reperfusion injury via modulating SIRT3-mediated crosstalk between mitochondrial ROS and NLRP3

BACKGROUND

Mitochondrial ROS (mtROS) accumulation and NLRP3 inflammasome activation are critical in the pathogenesis of myocardial ischemia-reperfusion injury (MIRI). However, their upstream regulatory mechanisms and interaction remain inadequately understood.

PURPOSE

The study aims to investigate the therapeutic effect of Salvianolic acid B (Sal B) on MIRI and elucidate its potential molecular mechanism, mainly focusing on the role of SIRT3.

METHODS

SIRT3 was knocked down (SIRT3KD) and overexpressed (SIRT3OE) using small interfering RNA and plasmid, respectively. The role of SIRT3 in the cardioprotective effect of Sal B was explored using MIRI rat models and H9c2 cell hypoxia/reoxygenation (H/R) models. SIRT3, NLRP3 inflammasome proteins, and MnSOD expression were analyzed by Western blot and immunofluorescence staining. MtROS levels were assessed with mitochondrial superoxide indicators (MitoSOX™ Red). ELISA was utilized to measure the levels of LDH, CK-MB, cTnT, and markers of inflammation and oxidative stress. The interaction between SIRT3 and Sal B was studied through biolayer interferometry, cellular thermal shift assay and molecular docking.

RESULTS

Our findings revealed significantly decreased SIRT3 level, enhanced MnSOD acetylation, and activated NLRP3 inflammasome in myocardium after MIRI and H9c2 cardiomyocytes exposed to H/R conditions. SIRT3KD promoted MnSOD acetylation and NLRP3 expression, aggravating mtROS accumulation and inflammation. Conversely, SIRT3OE significantly inhibited MnSOD acetylation and NLRP3 inflammasome activation. In vitro studies confirmed the crosstalk between mtROS and NLRP3, demonstrating that mtROS scavenger inhibited NLRP3 inflammasome activation induced by H/R and SIRT3KD, and the NLRP3 inhibitor suppressed MnSOD acetylation in H/R and SIRT3KD cardiomyocytes. Interestingly, Sal B was found to bind and upregulate SIRT3, reduce the expression of Acy-MnSOD, NLRP3, ASC, Caspase-1, and GSDMD, inhibit oxidative stress and inflammatory response, decrease myocardial infarct size and ST-segment elevation, and restore myocardial morphology. However, the protective effect of Sal B against MIRI was nullified by a specific SIRT3 inhibitor.

CONCLUSION

This study unveils that the SIRT3-mediated interplay between mtROS and the NLRP3 inflammasome is pivotal in the pathogenesis of MIRI. Furthermore, it highlights Sal B as a novel therapeutic agent that alleviates MIRI by targeting SIRT3, offering new insights into MIRI treatment.

Reactive oxygen species in hypertension

Hypertension is a leading risk factor for stroke, heart disease and chronic kidney disease. Multiple interacting factors and organ systems increase blood pressure and cause target-organ damage. Among the many molecular elements involved in the development of hypertension are reactive oxygen species (ROS), which influence cellular processes in systems that contribute to blood pressure elevation (such as the cardiovascular, renal, immune and central nervous systems, or the renin-angiotensin-aldosterone system). Dysregulated ROS production (oxidative stress) is a hallmark of hypertension in humans and experimental models. Of the many ROS-generating enzymes, NADPH oxidases are the most important in the development of hypertension. At the cellular level, ROS influence signalling pathways that define cell fate and function. Oxidative stress promotes aberrant redox signalling and cell injury, causing endothelial dysfunction, vascular damage, cardiovascular remodelling, inflammation and renal injury, which are all important in both the causes and consequences of hypertension. ROS scavengers reduce blood pressure in almost all experimental models of hypertension; however, clinical trials of antioxidants have yielded mixed results. In this Review, we highlight the latest advances in the understanding of the role and the clinical implications of ROS in hypertension. We focus on cellular sources of ROS, molecular mechanisms of oxidative stress and alterations in redox signalling in organ systems, and their contributions to hypertension.

Red Meat Consumption and its Relationship With Cardiovascular Health: A Review of Pathophysiology and Literature

Red meat is the muscle meat of mammals like beef, lamb, and pork that is red due to the abundance of myoglobin pigment and becomes even darker when cooked. The global average per capita consumption of meat and the total amount of meat consumed is rising, and there has been a particularly marked increase in the global consumption of chicken and pork. The consumption of red meat has always been a contentious issue, with data suggesting benefits in terms of nutritional value and at the same time linking its consumption to major health disorders such as endocrine abnormalities, gastrointestinal issues, cancers, and cardiovascular diseases (CVDs). Despite being normalized by major food franchises, red meat consumption may lead to adverse cardiovascular outcomes such as atherosclerosis, ischemic heart disease, stroke, and cardiac failure. Given the evidence that indicates the consumption of red and processed meat as a risk factor for cardiovascular diseases and all-cause mortality, it is important to review the effects of red meat on the risk of cardiovascular diseases.

Nogo-A exacerbates sepsis-associated encephalopathy by modulating microglial SHP-2/NLRP3 balance and inducing ROS and M1 polarization

Sepsis, a systemic inflammatory response caused by infection, can lead to sepsis-associated encephalopathy (SAE), characterized by brain dysfunction without direct central nervous system infection. The pathogenesis of SAE involves blood-brain barrier disruption, neuroinflammation and neuronal death, with neuroinflammation being the core process. Nogo-A, a neurite growth-inhibitory protein in the central nervous system, is not well understood in sepsis. This study explores Nogo-A's mechanisms in sepsis, focusing on SAE. Using in vivo and in vitro methods, healthy SPF C57BL/6J male mice were divided into Sham, Nogo-A-NC-Model, and Nogo-A-KD-Model groups, with sepsis induced by abdominal ligation and puncture. Morris water maze tests assessed learning and memory, and brain tissues underwent hematoxylin-eosin (HE) staining, Nissl staining, and Western blot analysis. In vitro, Nogo-A gene knockdown models were constructed using BV-2 microglia cells to study inflammation and oxidative stress. Results showed Nogo-A expression affected learning and memory in septic mice, with knockdown reducing neuronal damage. Bioinformatics analysis suggested Nogo-A may activate reactive oxygen species (ROS) to inhibit p-SHP2, activating mitochondrial autophagy and promoting neuronal apoptosis. Western blot results confirmed that Nogo-A affects mitochondrial autophagy and neuronal survival by inhibiting SHP2 and activating ROS. Nogo-A's role in neuroinflammation and neuroprotection was emphasized, revealing its impact on endoplasmic reticulum (ER) stress, mitochondrial autophagy, and NLRP3 inflammasome activation. This study provides a theoretical basis for SAE treatment, suggesting further multi-gene and multi-pathway analyses and validation in clinical samples. Developing gene therapy and drug interventions targeting Nogo-A pathways will offer more effective treatment strategies.

Association between trimethylamine N-oxide and prognosis of patients with myocardial infarction: a meta-analysis

Background

Trimethylamine N-oxide (TMAO) has been widely explored and considered as a biomarker for adverse cardiovascular events. However, the relationships between TMAO adverse cardiovascular events are inconsistent in patients. Therefore, this meta-analysis aimed to estimate association between TMAO levels and the prognosis of patients with myocardial infarction (MI).

Methods

We searched PubMed, EMBASE, the Cochrane Library, and Web of Science from inception to July 2, 2023, to retrieve all relevant clinical trials. Associations between TMAO levels, major adverse cardiovascular events (MACE), all-cause mortality, recurrent MI, stroke, etc., were systematically addressed. Outcomes included MACE, all-cause mortality, recurrent MI, rehospitalization caused by heart failure, stroke, revascularization, SYNTAX score, and multivessel disease. A fixed/random-effects model should be adopted to calculate the pooled estimates. Besides, funnel plot, Begg's test and Egger' test were used to test publication bias.

Results

A total of nine studies were included in our meta-analysis. Our results indicated that higher TMAO levels were associated with greater risk of MACE (RR = 1.94; 95% CI = 1.39 to 2.73), all-cause mortality (RR = 1.56; 95% CI = 1.00 to 2.44), and MI (RR = 1.21; 95% CI = 1.01 to 1.45). No significant association was found in stroke, SYNTAX, and multivessel disease. Besides, our results reported that the association between TMAO levels and MACE after MI was not affected by the geographic localization.

Conclusion

This study was the first meta-analysis that showed a significant positive association of TMAO levels with MACE, all-cause mortality, and recurrent MI in patients with MI.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=460400, PROSPERO (CRD42023460400).

Trimethylamine N-oxide promotes PERK-mediated endothelial-mesenchymal transition and apoptosis thereby aggravates atherosclerosis

The endothelial-mesenchymal transition (EndMT) is involved in the development of atherosclerosis (AS) and is a key process in vascular endothelial injury. Oxidative stress, inflammation, and apoptosis are common causes of EndMT, and EndMT progression can further accelerate the development of AS. The metabolite trimethylamine N-oxide (TMAO) is produced by the gut microbiome and is implicated in the development of several diseases, including diabetes and chronic kidney disease. However, the impact of TMAO on transforming growth factor β1(TGF-β1)-induced EndMT remains unclear. We hypothesize that TMAO exacerbates plaque formation and cardiac function impairment by promoting EndMT. Herein, we showed that high serum TMAO levels caused plaque formation, cardiac function damage and haemodynamic changes in ApoE-/- mice. In vitro, TMAO upregulated mesenchymal markers and downregulated endothelial markers in HAECs. Furthermore, TMAO increased the migratory capacity of EndMT cells. Mechanistically, we found that PERK downregulation could alleviate TMAO-induced oxidative stress, EndMT, plaque formation and cardiac function damage. Further study showed that activated transcription factor 3 (ATF3), the downstream molecule of protein kinase RNA-like endoplasmic reticulum kinase (PERK), could bind with TGF-β1/2 and affect EndMT. Overall, TMAO promotes EndMT, possibly through the PERK-eIF2α-ATF4-CHOP or the PERk-eIF2α-ATF3-TGF-β signalling pathways.

Unveiling novel molecules and therapeutic targets in hypertension - A narrative review

Hypertension is a prevalent non-communicable disease with serious cardiovascular complications, including heart failure, myocardial infarction, and stroke, often resulting from uncontrolled hypertension. While current treatments primarily target the renin-angiotensin-aldosterone pathway, the therapeutic response remains modest in many patients, with some developing resistant hypertension. Newer therapeutic approaches aim to address hypertension from various aspects beyond conventional drugs, including targeting central nervous system pathways, inflammatory pathways, vascular smooth muscle function, and baroreceptors. Despite these advancements, each therapy faces unique clinical and mechanistic challenges that influence its clinical translatability and long-term viability. This review explores the mechanisms of novel molecules in preclinical and clinical development, highlights potential therapeutic targets, and discusses the challenges and ethical considerations related to hypertension therapeutics and their development.

TMAO Impairs Mouse Aortic Vasodilation by Inhibiting TRPV4 Channels in Endothelial Cells

Trimethylamine oxide (TMAO) is an intestinal flora metabolite associated with risk of cardiovascular diseases. Transient receptor potential vanilloid 4 (TRPV4) is a Ca2+-permeable ion channel that is essential for vasodilation and endothelial function. Currently, there are few studies on the effect of TMAO on TRPV4 channels. In the present study, Ca2+ imaging of vascular tissue showed that TMAO inhibited TRPV4-mediated Ca2+ influx into aortic endothelial cells in a dose-dependent manner. Furthermore, a whole-cell patch clamp assay showed that TMAO blocked TRPV4-mediated cation currents. Notably, results of aortic vascular tension measurement showed that TMAO impaired endothelium-dependent vasodilation in mouse aortic vessels through the TRPV4-NO pathway. Our results indicated that TMAO inhibited Ca2+ entry in endothelial cells and impaired vasodilation through the TRPV4-NO pathway in mice. These results provide scientific evidence for novel pathogenic mechanisms underlying the role of TMAO in cardiovascular disease.

Gut Microbiota as Predictive Biomarker for Chronic Heart Failure in Patients with Different Nutritional Risk

To examine the relationship between gut microbiota and disease development in chronic heart failure patients with different nutritional risk. The study analyzed stool samples from 62 CHF patients and 21 healthy peoples using 16S rRNA gene sequencing. CHF patients were separated into risk (n = 30) and non-risk group (n = 32) based on NRS2002 scores. Analysis methods used were LEfSe, random forest regression model, ROC curves, BugBase, PICRUSt2, metagenomeSeq. Risk group includes 11 cases of HFrEF, 6 cases of HFpEF, and 13 cases of HFmrEF. LefSe analysis confirmed that the risk group had higher levels of Enterobacter and Escherichia-Shigella. Correlation analysis revealed a negative correlation between prealbumin and Escherichia-Shigella. The presence of Enterobacter and Escherichia-Shigella worsens intestinal inflammation in CHF patients, impacting lysine metabolism by influencing its degradation metabolic function. This interference further disrupts albumin and prealbumin synthesis, leading to malnutrition in CHF patients and ultimately worsening the disease.

Increase of PCSK9 expression in diabetes promotes VEGFR2 ubiquitination to inhibit endothelial function and skin wound healing

Diabetic foot ulcers (DFUs) are a serious vascular disease. Currently, no effective methods are available for treating DFUs. Pro-protein convertase subtilisin/kexin type 9 (PCSK9) regulates lipid levels to promote atherosclerosis. However, the role of PCSK9 in DFUs remains unclear. In this study, we found that the expression of PCSK9 in endothelial cells (ECs) increased significantly under high glucose (HG) stimulation and in diabetic plasma and vessels. Specifically, PCSK9 promotes the E3 ubiquitin-protein ligase NEDD4 binding to vascular endothelial growth factor receptor 2 (VEGFR2), which led to the ubiquitination of VEGFR2, resulting in its degradation and downregulation in ECs. Furthermore, PCSK9 suppresses the expression and activation of AKT, endothelial nitric oxide synthase (eNOS), and ERK1/2, leading to decreased nitric oxide (NO) production and increased superoxide anion (O2._) generation, which impairs vascular endothelial function and angiogenesis. Importantly, using evolocumab to limit the increase in PCSK9 expression blocked the HG-induced inhibition of NO production and the increase in O2._ production, as well as inhibited the phosphorylation and expression of AKT, eNOS, and ERK1/2. Moreover, evolocumab improved vascular endothelial function and angiogenesis, and promoted wound healing in diabetes. Our findings suggest that targeting PCSK9 is a novel therapeutic approach for treating DFUs.

The role of the gut microbiota in the onset and progression of heart failure: insights into epigenetic mechanisms and aging

BACKGROUND

The gut microbiota (GM) plays a critical role in regulating human physiology, with dysbiosis linked to various diseases, including heart failure (HF). HF is a complex syndrome with a significant global health impact, as its incidence doubles with each decade of life, and its prevalence peaks in individuals over 80 years. A bidirectional interaction exists between GM and HF, where alterations in gut health can worsen the disease's progression.

MAIN BODY

The "gut hypothesis of HF" suggests that HF-induced changes, such as reduced intestinal perfusion and altered gut motility, negatively impact GM composition, leading to increased intestinal permeability, the release of GM-derived metabolites into the bloodstream, and systemic inflammation. This process creates a vicious cycle that further deteriorates heart function. GM-derived metabolites, including trimethylamine N-oxide (TMAO), short-chain fatty acids (SCFAs), and secondary bile acids (BAs), can influence gene expression through epigenetic mechanisms, such as DNA methylation and histone modifications. These epigenetic changes may play a crucial role in mediating the effects of dysbiotic gut microbial metabolites, linking them to altered cardiac health and contributing to the progression of HF. This process is particularly relevant in older individuals, as the aging process itself has been associated with both dysbiosis and cumulative epigenetic alterations, intensifying the interplay between GM, epigenetic changes, and HF, and further increasing the risk of HF in the elderly.

CONCLUSION

Despite the growing body of evidence, the complex interplay between GM, epigenetic modifications, and HF remains poorly understood. The dynamic nature of epigenetics and GM, shaped by various factors such as age, diet, and lifestyle, presents significant challenges in elucidating the precise mechanisms underlying this complex relationship. Future research should prioritize innovative approaches to overcome these limitations. By identifying specific metabolite-induced epigenetic modifications and modulating the composition and function of GM, novel and personalized therapeutic strategies for the prevention and/or treatment of HF can be developed. Moreover, targeted research focusing specifically on older individuals is crucial for understanding the intricate connections between GM, epigenetics, and HF during aging.

Microbiome-Derived Trimethylamine N-Oxide (TMAO) as a Multifaceted Biomarker in Cardiovascular Disease: Challenges and Opportunities

Biomarkers play a crucial role in various stages of disease management, including screening, diagnosis, prediction, prognosis, treatment, and safety monitoring. Although they are powerful tools in disease diagnosis, management, and drug development, identifying and validating reliable biomarkers remains a significant challenge. Among potential microbiome-derived biomarkers, trimethylamine N-oxide (TMAO) has gained notable attention for its link to atherosclerosis and cardiovascular risk. However, despite the growing body of research on TMAO, its practical application in clinical settings for disease management and patient outcome enhancement is still not a reality. This paper presents recent data on the utility of TMAO as a cardiovascular biomarker, categorized by its various roles: diagnostic, prognostic, susceptibility/risk, monitoring, pharmacodynamic/response, predictive, and safety. It also briefly discusses research on TMAO's potential role in cardiovascular disease development. While TMAO shows promise, particularly in prognostic applications, its reliability as a biomarker has been inconsistent across studies. These variances may result from several confounding factors that affect TMAO plasma levels, including diet, kidney function, and demographic variables. The review aims to elucidate the specific contexts in which TMAO can be valuable, potentially leading to more personalized and effective management of cardiovascular disease.

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.

Dysbiosis and fecal microbiota transplant: Contemplating progress in health, neurodegeneration and longevity

The gut-brain axis plays an important role in mental health. The intestinal epithelial surface is colonized by billions of commensal and transitory bacteria, known as the Gut Microbiota (GM). However, potential pathogens continuously stimulate intestinal immunity when they find the place. The last two decades have witnessed several studies revealing intestinal bacteria as a key factor in the health-disease balance of the gut, as well as disease-emergent in other parts of the body. Various neurological processes, such as cognition, learning, and memory, could be affected by dysbiosis in GM. Additionally, the aging process and longevity are related to systemic inflammation caused by dysbiosis. Commensal GM affects brain development, behavior, and healthy aging suggesting that building changes in GM might be a potential therapeutic method. The innovation in GM dysbiosis is intervention by Fecal Microbiota Transplantation (FMT), which has been confirmed as a therapy for recurrent Clostridium difficile infections and is promising for other clinical disorders, such as Parkinson's disease, Multiple Sclerosis (MS), Alzheimer's disease, and depression. Additionally, FMT may be possible to promote healthy aging, and extend longevity. This review aims to connect dysbiosis, neurological disorders, and aging and the potential of FMT as a therapeutic strategy to treat these disorders, and to enhance the quality of life in the elderly.

Cardiovascular Disease May Be Triggered by Gut Microbiota, Microbial Metabolites, Gut Wall Reactions, and Inflammation

Cardiovascular disease (CVD) may be inherited, as recently shown with the identification of single nucleotide polymorphisms (SNPs or "snips") on a 250 kb DNA fragment that encodes 92 proteins associated with CVD. CVD is also triggered by microbial dysbiosis, microbial metabolites, metabolic disorders, and inflammatory intestinal epithelial cells (IECs). The epithelial cellular adhesion molecule (Ep-CAM) and trefoil factor 3 (TFF3) peptide keeps the gut wall intact and healthy. Variations in Ep-CAM levels are directly linked to changes in the gut microbiome. Leptin, plasminogen activator inhibitor 1 (PAI1), and alpha-1 acid glycoprotein 1 (AGP1) are associated with obesity and may be used as biomarkers. Although contactin 1 (CNTN1) is also associated with obesity and adiposity, it regulates the bacterial metabolism of tryptophan (Trp) and thus appetite. A decrease in CNTN1 may serve as an early warning of CVD. Short-chain fatty acids (SCFAs) produced by gut microbiota inhibit pro-inflammatory cytokines and damage vascular integrity. Trimethylamine N-oxide (TMAO), produced by gut microbiota, activates inflammatory Nod-like receptors (NLRs) such as Nod-like receptor protein 3 (NLRP3), which increase platelet formation. Mutations in the elastin gene (ELN) cause supra valvular aortic stenosis (SVAS), defined as the thickening of the arterial wall. Many of the genes expressed by human cells are regulated by gut microbiota. The identification of new molecular markers is crucial for the prevention of CVD and the development of new therapeutic strategies. This review summarizes the causes of CVD and identifies possible CVD markers.

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.

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.

Metabolic mediators: microbial-derived metabolites as key regulators of anti-tumor immunity, immunotherapy, and chemotherapy

The human microbiome has recently emerged as a focal point in cancer research, specifically in anti-tumor immunity, immunotherapy, and chemotherapy. This review explores microbial-derived metabolites, emphasizing their crucial roles in shaping fundamental aspects of cancer treatment. Metabolites such as short-chain fatty acids (SCFAs), Trimethylamine N-Oxide (TMAO), and Tryptophan Metabolites take the spotlight, underscoring their diverse origins and functions and their profound impact on the host immune system. The focus is on SCFAs' remarkable ability to modulate immune responses, reduce inflammation, and enhance anti-tumor immunity within the intricate tumor microenvironment (TME). The review critically evaluates TMAO, intricately tied to dietary choices and gut microbiota composition, assessing its implications for cancer susceptibility, progression, and immunosuppression. Additionally, the involvement of tryptophan and other amino acid metabolites in shaping immune responses is discussed, highlighting their influence on immune checkpoints, immunosuppression, and immunotherapy effectiveness. The examination extends to their dynamic interaction with chemotherapy, emphasizing the potential of microbial-derived metabolites to alter treatment protocols and optimize outcomes for cancer patients. A comprehensive understanding of their role in cancer therapy is attained by exploring their impacts on drug metabolism, therapeutic responses, and resistance development. In conclusion, this review underscores the pivotal contributions of microbial-derived metabolites in regulating anti-tumor immunity, immunotherapy responses, and chemotherapy outcomes. By illuminating the intricate interactions between these metabolites and cancer therapy, the article enhances our understanding of cancer biology, paving the way for the development of more effective treatment options in the ongoing battle against cancer.

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.

Consumption of different types of meat and the risk of chronic limb-threatening ischemia: the Singapore Chinese Health Study

BACKGROUND

Although red meat consumption has been associated with risk of atherosclerotic coronary artery disease and stroke, no prospective study has examined this with the risk of chronic limb-threatening ischemia (CLTI).

METHODS

In a prospective study of 63,257 Chinese in Singapore, who were aged 45-74 years old at recruitment, diet was assessed via a validated semi-quantitative food frequency questionnaire. Incident CLTI cases were ascertained via linkage with nationwide hospital records for lower extremity amputation or angioplasty for peripheral arterial disease. Multivariable Cox models were used to examine associations between quartiles of meat intake and CLTI risk.

RESULTS

After a mean follow-up of 18.8 years, there were 1069 cases of CLTI. Higher intake of red meat intake was associated with increased risk of CLTI in a stepwise manner. Comparing extreme quartiles of red meat intake, the hazard ratio (HR) for the association with CLTI risk was 1.24 [95% confidence interval (CI) = 1.03-1.49; P-trend = 0.02]. In stratified analysis, red meat intake had a stronger association with CLTI risk among those without diabetes [HR (95% CI) comparing extreme quartiles = 1.41 (1.10-1.80); P-trend = 0.03] than among those with diabetes at baseline [HR (95% CI) comparing extreme quartiles = 1.04 (0.79-1.38); P-trend = 0.05] (P-interaction = 0.03). Otherwise, the associations were not different by sex, BMI, smoking status, hypertension, alcohol consumption, or history of cardiovascular diseases. Using a theoretical model in substitution analysis that substituted three servings per week of red meat with poultry or fish/shellfish, the relative risk of CLTI was reduced by 13-14%.

CONCLUSIONS

Consumption of red meat was associated with higher CLTI risk in this Asian cohort. Substituting red meat with poultry or fish/shellfish may reduce this risk.

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.