The association between trimethylamine N-oxide levels and coronary microvascular dysfunction and prognosis in patients with ST-elevation myocardial infarction.

BACKGROUND AND AIMS: Coronary microvascular dysfunction (CMD) is common after ST-elevation myocardial infarction (STEMI), leading to adverse clinical outcomes. However, its diagnosis remains difficult, and mechanisms elusive. This study explores the role of Trimethylamine N-oxide (TMAO), a gut microbiota metabolite, as a potential biomarker for diagnosing CMD in STEMI patients. METHODS: This prospective, observational study enrolled 210 STEMI patients with multivessel coronary artery disease who underwent primary percutaneous coronary intervention (PCI). TMAO levels were measured at baseline, 3 months, and 12 months post-PCI, whilst coronary physiology was assessed at 3 months. The primary endpoint was the incidence of CMD at 3 months, with the secondary endpoint being major adverse cardiovascular and cerebrovascular events (MACCE) at 12 months. An additional 59 consecutive patients were enrolled for validation. RESULTS: TMAO levels varied from baseline to 3 months, then stabilised. The areas under the ROC curve for baseline TMAO and TMAO at 3-month were 0.55 (95 % CI 0.46-0.64; p = 0.426), and 0.80 (95 % CI 0.73-0.87; p < 0.001), respectively. The optimal cut-off for TMAO at 3-month to diagnose CMD was 3.91, with similar sensitivity and specificity in the derivation and validation cohort. The incidence of MACCE was higher in patients with TMAO≥3.91 (41.4 % vs 10.7 %; p < 0.001). The addition of 3-month TMAO improved the diagnostic performance of traditional risk factors. CONCLUSION: TMAO is a robust biomarker for CMD and is significantly associated with the incidence of MACCE. TMAO has the potential in guiding clinical decision-making and suggests an interplay between gut microbiota and CMD.

Mo(IV) Ion-Modulated BSA-Protected Gold Nanocluster Probe for Fluorescence Turn-On Detection of Trimethylamine N-Oxide (TMAO).

Trimethylamine N-oxide (TMAO), a molecule produced by the microbiota, has been associated with human health and illness. Its early discovery in body fluids may affect our understanding of the pathophysiology and treatment of many illnesses. Therefore, our knowledge of the pathophysiology and diagnostics of disorders associated with TMAO might be enhanced by the creation of dependable and fast methods for TMAO detection. Therefore, we developed a fluorescent probe for detecting TMAO utilizing an on-off-on strategy. Bovine serum albumin (BSA)@AuNCs luminescence is effectively quenched by Mo4+ because BSA@AuNCs and Mo4+ have a strong binding relationship. Mo4+ ions can substantially decrease the emission intensity of gold nanoclusters by establishing a BSA@AuNCs-Mo system. Then, the luminescence of BSA@AuNCs was restored due to the interaction between Mo4+ and TMAO. A significant linear relationship was seen between the emission intensity and TMAO concentration within the 0-201 µM range, with a detection limit of 1.532 µM. Additionally, the method can measure TMAO in blood and urine samples.

Circulating trimethylamine N-oxide is correlated with high coronary artery atherosclerotic burden in individuals with newly diagnosed coronary heart disease.

BACKGROUND: Trimethylamine N-oxide (TMAO) is a metabolite derived from the gut microbiota and has been reported to be correlated with cardiovascular diseases. Although TMAO is associated with the severity of coronary artery disease in subjects with coronary heart disease (CHD) history. However, the correlation between TMAO and the atherosclerotic burden in newly diagnosed cases of CHD is unknown. METHODS: In this hospital-based study, we enrolled 429 individuals newly diagnosed with CHD undergoing coronary angiography. Plasma TMAO was assessed before coronary angiography. SYNTAX score was computed during coronary angiography to estimate the coronary artery atherosclerotic burden. Both linear and logistic regression analyses were conducted to explore the correlation between plasma TMAO levels and SYNTAX score in newly diagnosed CHD population. RESULTS: The TMAO in patients with SYNTAX ≥ 33 and subjects with SYNTAX < 23 were 6.10 (interquartile range [IQR]: 3.53 to 9.15) µmol/L and 4.90 [IQR: 3.25 to 7.68] µmol/L, respectively. Linear regression adjusting for traditional risk factors showed TMAO level was positively correlated with SYNTAX score (ß = 0.179; p = 0.006) in CHD population. When TMAO was added to models with traditional risk factors, the predictive value improved significantly, with the receiver operating characteristic curve (AUC) increased from 0.7312 to 0.7502 (p = 0.003). Stratified analysis showed that the correlations did not hold true for subjects who were non-smoker or with histories of diabetes. None of the stratifying factors significantly altered the correlation (all p for interaction < 0.05). CONCLUSIONS: We found a positive linear correlation between plasma TMAO and SYNTAX score among newly diagnosed CHD individuals in Chinese population.

The Role of Gut Microbiota and Its Metabolites in Patients with Heart Failure.

Heart failure (HF) is a significant health concern; early detection and prevention are crucial. Recent studies suggest that the gut microbiota and its metabolites may influence HF development and risk factors. We explored this relationship by examining changes in gut microbiota composition and metabolite levels in HF patients. HF patients often exhibit decreased alpha and beta diversity compared to controls, suggesting lower bacterial richness and community variation. Changes in specific bacterial phyla were observed, with decreases in Firmicutes (e.g., Ruminococcus) and Bacteroidetes (e.g., Prevotella) and increases in Proteobacteria (e.g., Escherichia, Shigella, and Klebsiella) and Actinobacteria. Gut-microbiota-related metabolites have been identified, potentially affecting various body systems, including the cardiovascular system. Among these are short-chain fatty acids (SCFAs), betaine, trimethylamine N-oxide (TMAO), phenylalanine, tryptophan-kynurenine, and phenylacetylgutamine (PAGIn). Although SCFAs positively affect our organisms, patients with HF have been observed to experience a decline in bacteria responsible for producing these chemical compounds. There have been indications of possible links between betaine, TMAO, phenylalanine, tryptophan-kynurenine, PAGIn, and heart failure. TMAO and phenylalanine, in particular, show promise as potential prognostic factors. However, their clinical significance has not yet been thoroughly evaluated and requires further investigation.

Metabolomic and genomic insights into TMA degradation by a novel halotolerant strain - Paracoccus sp. PS1.

Trimethylamine N-oxide (TMAO) is a gut metabolite that acts as a biomarker for chronic diseases, and is generated by the oxidation of trimethylamine (TMA) produced by gut microflora. Since, microbial degradation of TMA is predicted to be used to restrict the production of TMAO, we aimed to isolate bacterial strains that could effectively degrade TMA before being oxidized to TMAO. As marine fish is considered to have a rich content of TMAO, we have isolated TMA degrading isolates from fish skin. Out of the fourteen isolates, depending on their rapid TMA utilization capability in mineral salt medium supplemented with TMA as a sole carbon and nitrogen source, isolate PS1 was selected as our desired isolate. Its TMA degrading capacity was further confirmed through spectrophotometric, Electrospray Ionization Time-of-Flight Mass Spectrometry (ESI TOF-MS) and High performance liquid chromatography (HPLC) analysis and in silico analysis of whole genome (WG) gave further insights of protein into its TMA degradation pathways. PS1 was taxonomically identified as Paracoccus sp. based on its 16S rRNA and whole genome sequence analysis. As PS1 possesses the enzymes required for degradation of TMA, clinical use of this isolate has the potential to reduce TMAO generation in the human gut.

Distinguishing benign and malignant thyroid nodules using plasma trimethylamine N-oxide, carnitine, choline and betaine.

PURPOSE: Trimethylamine N-oxide (TMAO), a gut microbiome-derived metabolite, and its precursors (carnitine, choline, betaine) have not been fully examined in relation to thyroid cancer (TC) risk. The aim of this study was to assess the value of TMAO and its precursors in diagnosis of benign and malignant thyroid nodules. METHODS: In this study, high-performance liquid chromatography-tandem mass spectrometry was utilized to measure the levels of plasma TMAO and its precursors (choline, carnitine, and betaine) in 215 TC patients, 63 benign thyroid nodules (BTN) patients and 148 healthy controls (HC). The distribution of levels of TMAO and its precursors among the three groups were compared by the Kruskal-Wallis test. Receiver operating characteristic curve (ROC) analysis was performed to evaluate the sensitivity, specificity, and the predictive accuracy of single and combined biomarkers. RESULTS: In comparison to HC, TC showed higher levels of TMAO and lower levels of its precursors (carnitine, choline, and betaine) (all P < 0.001). Plasma choline (P < 0.01) and betaine (P < 0.05) were declined in BTN than HC. The levels of carnitine (P < 0.001) and choline (P < 0.05) were significantly higher in BTN than that in TC group. Plasma TMAO showed lower levels in TC with lymph node metastasis (101.5 (73.1-144.5) ng/ml) than those without lymph node metastasis (131 (84.8-201) ng/ml, P < 0.05). Combinations of these four metabolites achieved good performance in the differential diagnosis, with the area under the ROC curve of 0.703, 0.741, 0.793 when discriminating between TC and BTN, BTN and HC, TC and HC, respectively. CONCLUSION: Plasma TMAO, along with its precursors could serve as new biomarkers for the diagnosis of benign and malignant thyroid nodules.

Gut Microbiota Metabolite TMA May Mediate the Effects of TMAO on Glucose and Lipid Metabolism in C57BL/6J Mice.

SCOPE: Gut microbiota can convert a variety of alkaloids and TMAO into TMA, which is then transported by the blood to the liver, and converted into TMAO. In recent years, TMAO has attracted wide attention as a metabolic risk factor in cardiovascular disease, diabetes, and other diseases. However, it is still unclear about the role of gut microbial metabolite TMA in the adverse health impacts of TMAO. METHODS AND RESULTS: Male C57BL/6J is treated with intraperitoneal (i.p.) or oral TMAO for 8 weeks, the area under the OGTT curve of oral group is significantly increased by about 15% compared to the control and injection groups. Serum triglyceride levels in the oral group are significantly higher by 28.2% and 24.6% than those in the control and injection groups, respectively. Meanwhile, cholesterol content in serum is significantly elevated by 27.6% and 30.7%. Similarly, proinflammatory factors gene expressions are significantly increased with oral but not i.p. TMAO intervention. Furthermore, transformation in HepG2 cells shows that TMAO could not be converted into TMA by hepatocytes. CONCLUSION: The adverse effects of TMAO on glucose and lipid metabolism in C57BL/6J mice may act through gut microbiota metabolite TMA.

Microbiome interactions with different risk factors in development of myocardial infarction.

Among all non-communicable diseases, Cardiovascular Diseases (CVDs) stand as the leading global cause of mortality. Within this spectrum, Myocardial Infarction (MI) strikingly accounts for over 15 % of all deaths. The intricate web of risk factors for MI, comprising family history, tobacco use, oral health, hypertension, nutritional pattern, and microbial infections, is firmly influenced by the human gut and oral microbiota, their diversity, richness, and dysbiosis, along with their respective metabolites. Host genetic factors, especially allelic variations in signaling and inflammatory markers, greatly affect the progression or severity of the disease. Despite the established significance of the human microbiome-nutrient-metabolite interplay in associations with CVDs, the unexplored terrain of the gut-heart-oral axis has risen as a critical knowledge gap. Moreover, the pivotal role of the microbiome and the complex interplay with host genetics, compounded by age-related changes, emerges as an area of vital importance in the development of MI. In addition, a distinctive disease susceptibility and severity influenced by gender-based or ancestral differences, adds a crucial insights to the association with increased mortality. Here, we aimed to provide an overview on interactions of microbiome (oral and gut) with major risk factors (tobacco use, alcohol consumption, diet, hypertension host genetics, gender, and aging) in the development of MI and therapeutic regulation.

Effects of Lizhong Tongmai acupuncture on TMAO, CD36 expression, and cholesterol deposition in atherosclerotic mice. / "理中通脉"æ³•é’ˆåˆºå¯¹åŠ¨è„‰ç²¥æ ·ç¡¬åŒ–å°é¼ TMAO、CD36表达及胆固醇沉积的影响.

OBJECTIVES: To observe the effects of Lizhong Tongmai acupuncture (acupuncture for regulating middle jiao and promoting meridians) on trimethylamine-N-oxide (TMAO), CD36 expression, and cholesterol deposition in atherosclerotic (AS) mice, exploring potential mechanism of electroacupuncture (EA) in treating AS. METHODS: A total of 31 male SPF-grade C57BL/6J ApoE-/- mice were fed with high-fat diet for 8 weeks to establish AS model. After successful modeling, the remaining 30 mice were randomly divided into a model group, a medication group, and an EA group, with 10 mice in each group. An additional 10 normal mice of the same strain were selected as a blank group. The mice in the blank group and the model group received no intervention. The mice in the medication group were treated with intragastric administration of atorvastatin calcium. The mice in the EA group were treated with EA at "Neiguan" (PC 6), "Tianshu" (ST 25) and "Zusanli" (ST 36). The same-side "Neiguan" (PC 6) and "Zusanli" (ST 36), "Tianshu" (ST 25) and the tail of the mice were connected to the EA apparatus, with disperse-dense wave, a frequency of 2 Hz/15 Hz, and a current intensity of 0.3 mA for 10 min per session. Acupuncture was performed unilaterally per session, alternating between the left and right sides, with a frequency of once every other day. After intervention, HE staining was used to observe the pathological morphology of the aorta. Microplate assays were conducted to measure triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels in serum. Ultra high performance liquid chromatography-mass spectrometry technique (UPLC-MS) was employed to detect TMAO level in plasma. Western blot was performed to assess CD36 protein expression level in the aorta. Microanalysis was used to measure cholesterol ester (CE) level in the aorta and the CE/TC ratio was calculated. RESULTS: Compared with the blank group, the mice in the model group exhibited significant pathological changes of atherosclerosis, serum TG, TC, LDL-C levels were increased (P<0.01), and HDL-C level was decreased (P<0.01); the plasma TMAO level, aortic CE level, and the CE/TC ratio were increased (P<0.01), along with elevated CD36 protein expression level in the aorta (P<0.01). Compared with the model group, the mice in the medication group and the EA group showed improvements in aortic pathology, serum TG, TC, LDL-C levels were reduced, HDL-C levels were increased (P<0.05); plasma TMAO levels, aortic CE levels, and the CE/TC ratio were decreased (P<0.01), and CD36 protein expression levels were lowered (P<0.05). The serum TG and TC levels in the EA group were higher than those in the medication group (P<0.05). CONCLUSIONS: The Lizhong Tongmai acupuncture can ameliorate aortic pathological changes, regulate blood lipid levels, reduce plasma TMAO level, inhibit CD36 protein expression in the aorta, and decrease cholesterol deposition. These effects may contribute to the therapeutic mechanism of EA in treating AS.

Evaluation of the Feasibility of In Vitro Metabolic Interruption of Trimethylamine with Resveratrol Butyrate Esters and Its Purified Monomers.

Resveratrol (RSV), obtained from dietary sources, has been shown to reduce trimethylamine oxide (TMAO) levels in humans, and much research indicates that TMAO is recognized as a risk factor for cardiovascular disease. Therefore, this study investigated the effects of RSV and RSV-butyrate esters (RBE) on the proliferation of co-cultured bacteria and HepG2 cell lines, respectively, and also investigated the changes in trimethylamine (TMA) and TMOA content in the medium and flavin-containing monooxygenase-3 (FMO3) gene expression. This study revealed that 50 µg/mL of RBE could increase the population percentage of Bifidobacterium longum at a rate of 53%, while the rate was 48% for Clostridium asparagiforme. In contrast, co-cultivation of the two bacterial strains effectively reduced TMA levels from 561 ppm to 449 ppm. In addition, regarding TMA-induced HepG2 cell lines, treatment with 50 µM each of RBE, 3,4'-di-O-butanoylresveratrol (ED2), and 3-O-butanoylresveratrol (ED4) significantly reduced FMO3 gene expression from 2.13 to 0.40-1.40, which would also contribute to the reduction of TMAO content. This study demonstrated the potential of RBE, ED2, and ED4 for regulating TMA metabolism in microbial co-cultures and cell line cultures, which also suggests that the resveratrol derivative might be a daily dietary supplement that will be beneficial for health promotion in the future.

Exploratory Transcriptomic Profiling Reveals the Role of Gut Microbiota in Vascular Dementia.

Stroke is the second most common cause of cognitive impairment and dementia. Vascular dementia (VaD), a cognitive impairment following a stroke, is common and significantly impacts the quality of life. We recently demonstrated via gut microbe transplant studies that the gut microbe-dependent trimethylamine-N-oxide (TMAO) pathway impacts stroke severity, both infarct size and long-term cognitive outcomes. However, the molecular mechanisms that underly the role of the microbiome in VaD have not been explored in depth. To address this issue, we performed a comprehensive RNA-sequencing analysis to identify differentially expressed (DE) genes in the ischemic cerebral cortex of mouse brains at pre-stroke and post-stroke day 1 and day 3. A total of 4016, 3752 and 7861 DE genes were identified at pre-stroke and post-stroke day 1 and day 3, respectively. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated pathways of neurodegeneration in multiple diseases, chemokine signaling, calcium signaling, and IL-17 signaling as the key enriched pathways. Inflammatory response genes interleukin-1 beta (Il-1ß), chemokines (C-X-C motif chemokine ligand 10 (Cxcl10), chemokine ligand 2 (Ccl2)), and immune system genes (S100 calcium binding protein 8 (S100a8), lipocalin-2 (Lcn2)) were among the most significantly upregulated genes. Hypocretin neuropeptide precursor (Hcrt), a neuropeptide, and transcription factors such as neuronal PAS domain protein 4 (Npas4), GATA binding protein 3 (Gata3), and paired box 7 (Pax7) were among the most significantly downregulated genes. In conclusion, our results indicate that higher plasma TMAO levels induce differential mRNA expression profiles in the ischemic brain tissue in our pre-clinical stroke model, and the predicted pathways provide the molecular basis for regulating the TMAO-enhanced neuroinflammatory response in the brain.

Microbiota Effect on Trimethylamine N-Oxide Production: From Cancer to Fitness-A Practical Preventing Recommendation and Therapies.

Trimethylamine N-oxide (TMAO) is a microbial metabolite derived from nutrients, such as choline, L-carnitine, ergothioneine and betaine. Recently, it has come under the spotlight for its close interactions with gut microbiota and implications for gastrointestinal cancers, cardiovascular disease, and systemic inflammation. The culprits in the origin of these pathologies may be food sources, in particular, high fat meat, offal, egg yolk, whole dairy products, and fatty fish, but intercalated between these food sources and the production of pro-inflammatory TMAO, the composition of gut microbiota plays an important role in modulating this process. The aim of this review is to explain how the gut microbiota interacts with the conversion of specific compounds into TMA and its oxidation to TMAO. We will first cover the correlation between TMAO and various pathologies such as dysbiosis, then focus on cardiovascular disease, with a particular emphasis on pro-atherogenic factors, and then on systemic inflammation and gastrointestinal cancers. Finally, we will discuss primary prevention and therapies that are or may become possible. Possible treatments include modulation of the gut microbiota species with diets, physical activity and supplements, and administration of drugs, such as metformin and aspirin.

Neither Trimethylamine-N-Oxide nor Trimethyllysine Is Associated with Atherosclerosis: A Cross-Sectional Study in Older Japanese Adults.

Recent evidence suggests that trimethylamine-N-oxide (TMAO), a metabolite of L-carnitine and choline, is linked to atherosclerosis and cardiovascular diseases. As TMAO content is very high in fish, we raised the following question: why do Japanese people, who consume lots of fish, show a low risk of atherosclerosis? To address this question, we investigated the effects of TMAO and other L-carnitine-related metabolites on carotid intima-media thickness (IMT). Participants were recruited from a small island and a mountainous region. Plasma L-carnitine, γ-butyrobetaine (γBB), TMAO, trimethyllysine (TML), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) levels were measured using liquid or gas chromatography-mass spectrometry. Plasma L-carnitine concentration was higher in men than in women. TMAO and TML were significantly higher in the residents of the island than in the mountainous people. In multiple linear regression analyses in all participants, TML showed a significant inverse association with max-IMT and plaque score (PS), whereas TMAO did not show any associations. In women, L-carnitine was positively associated with max-IMT and PS. TMAO was correlated with both EPA and DHA levels, implying that fish is a major dietary source of TMAO in Japanese people. Our study found that plasma TMAO was not an apparent risk factor for atherosclerosis in elderly Japanese people, whereas a low level of TML might be a potential risk. L-carnitine may be a marker for atherosclerosis in women.

Trimethylamine N-oxide: role in cell senescence and age-related diseases.

INTRODUCTION: Hayflick and Moorhead first demonstrated cell senescence as the irreversible growth arrest of cells after prolonged cultivation. Telomere shortening and oxidative stress are the fundamental mechanisms that drive cell senescence. Increasing studies have shown that TMAO is closely associated with cellular aging and age-related diseases. An emerging body of evidence from animal models, especially mice, has identified that TMAO contributes to senescence from multiple pathways and appears to accelerate many neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. However, the specific mechanism of how TMAO speeds aging is still not completely clear. MATERIAL AND METHODS: In this review, we summarize some key findings in TMAO, cell senescence, and age-related diseases. We focused particular attention on the potential mechanisms for clinical transformation to find ways to interfere with the aging process. CONCLUSION: TMAO can accelerate cell senescence by causing mitochondrial damage, superoxide formation, and promoting the generation of pro-inflammatory factors.

Trimethylamine N-Oxide as a Potential Risk Factor for Non-communicable Diseases: A Systematic Review.

BACKGROUND: Trimethylamine N-Oxide (TMAO), as a gut microbiota-derived metabolite, has been associated with a number of chronic diseases like cardiovascular diseases. OBJECTIVE: Considering the increasing prevalence of non-communicable diseases (NCDs), we conducted a systematic review to discuss the TMAO association with NCDs. METHODS: A comprehensive search has been conducted on PubMed, Web of Science, and Scopus databases up to December, 2020. The inclusion criteria were all related observational studies that surveyed the association between TMAO levels and non-communicable diseases. Interventional studies, animal experiments, reviews, case reports, letters, congress abstracts, and studies that were not published in English were excluded. Moreover, related review studies were separately discussed. RESULTS: Within 2191 recorded studies, 99 cross-sectional, case-control and cohort studies met the inclusion criteria. The most common diseases associated with TMAO levels are cardiovascular diseases, diabetes, kidney disease, stroke, inflammatory diseases, neurological disorders, and cancer. Elevated TMAO levels as a consequence of alteration in gut microbiota composition and dietary intake can lead to the incidence of NCDs. The high levels of TMAO can disrupt the homeostasis of glucose and lipids and induce inflammation that leads to serious NCDs. CONCLUSION: There is a dose-response relationship between TMAO levels and NCDs progression. Therefore, it can be studied as a therapeutic target or prognostic biomarker for dealing with NCDs.

Microbial regulation of offspring diseases mediated by maternal-associated microbial metabolites.

The microbiota plays a crucial role in individuals' early and long-term health. Previous studies indicated that the microbial regulation of health may start before birth. As the in utero environment is (nearly) sterile, the regulation is probably be originated from maternal microbiota and mediated by their metabolites transferred across the placenta. After the birth, various metabolites are continuously delivered to offspring through human milk feeding. Meanwhile, some components, for example, human milk oligosaccharides, in human milk can only be fermented by microbes, which brings beneficial effects on offspring health. Hence, we speculated that human milk-derived metabolites may also play roles in microbial regulation. However, reports between maternal-associated microbial metabolites and offspring diseases are still lacking and sparsely distributed in several fields. Also, the definition of the maternal-associated microbial metabolite is still unclear. Thus, it would be beneficial to comb through the current knowledge of these metabolites related to diseases for assisting our goals of early prediction, early diagnosis, early prevention, or early treatment through actions only on mothers. Therefore, this review aims to present studies showing how researchers came to the path of investigating these metabolites and then to present studies linking them to the development of offspring asthma, type 1 diabetes mellitus, food allergy, neonatal necrotizing enterocolitis, or autism spectrum disorder. Potential English articles were collected from PubMed by searching terms of disease(s), maternal, and a list of microbial metabolites. Articles published within 5 years were preferred.

A red wine intervention does not modify plasma trimethylamine N-oxide but is associated with broad shifts in the plasma metabolome and gut microbiota composition.

BACKGROUND: Gut microbiota profiles are closely related to cardiovascular diseases through mechanisms that include the reported deleterious effects of metabolites, such as trimethylamine N-oxide (TMAO), which have been studied as diagnostic and therapeutic targets. Moderate red wine (RW) consumption is reportedly cardioprotective, possibly by affecting the gut microbiota. OBJECTIVES: To investigate the effects of RW consumption on the gut microbiota, plasma TMAO, and the plasma metabolome in men with documented coronary artery disease (CAD) using a multiomics assessment in a crossover trial. METHODS: We conducted a randomized, crossover, controlled trial involving 42 men (average age, 60 y) with documented CAD comparing 3-wk RW consumption (250 mL/d, 5 d/wk) with an equal period of alcohol abstention, both preceded by a 2-wk washout period. The gut microbiota was analyzed via 16S rRNA high-throughput sequencing. Plasma TMAO was evaluated by LC-MS/MS. The plasma metabolome of 20 randomly selected participants was evaluated by ultra-high-performance LC-MS/MS. The effect of RW consumption was assessed by individual comparisons using paired tests during the abstention and RW periods. RESULTS: Plasma TMAO did not differ between RW intervention and alcohol abstention, and TMAO concentrations showed low intraindividual concordance over time, with an intraclass correlation coefficient of 0.049 during the control period. After RW consumption, there was significant remodeling of the gut microbiota, with a difference in ß diversity and predominance of Parasutterella, Ruminococcaceae, several Bacteroides species, and Prevotella. Plasma metabolomic analysis revealed significant changes in metabolites after RW consumption, consistent with improved redox homeostasis. CONCLUSIONS: Modulation of the gut microbiota may contribute to the putative cardiovascular benefits of moderate RW consumption. The low intraindividual concordance of TMAO presents challenges regarding its role as a cardiovascular risk biomarker at the individual level. This study was registered at clinical trials.gov as NCT03232099.

The transformation of atrial fibroblasts into myofibroblasts is promoted by trimethylamine N-oxide via the Wnt3a/ß-catenin signaling pathway.

Background: Atrial fibrosis is an important pathophysiological mechanism in the development and maintenance of atrial fibrillation. Trimethylamine N-oxide (TMAO) is one of the most widely studied microbial metabolites involved in the promotion of cardiac fibrosis. TMAO promotes phenotypic transformation, proliferation, and migration and increases collagen secretion in cardiac fibroblasts. The Wnt/ß-catenin pathway also plays a key role in the promotion of cardiac fibroblasts into myofibroblasts. Methods: The expression of Alpha-smooth muscle actin (α-SMA) was determined to identify the formation of myofibroblasts. The effects of TMAO on the proliferation and migration of atrial fibroblasts were detected by cell counting kit 8, and transwell assays, respectively. Western blot and immunofluorescence were used to detect the activation of the ß-catenin pathway by TMAO and the phenotypic transformation and collagen secretion of the atrial fibroblasts. Western blot and immunofluorescence assays were performed to detect the effects of exogenous Wnt3a and TMAO on the activation of ß-catenin pathway and the phenotypic transformation of atrial fibroblasts. Results: TMAO promoted the proliferation and migration of atrial fibroblasts. TMAO also promoted the phenotypic transformation, migration, and collagen secretion of the atrial fibroblasts by activating the ß-catenin pathway. Exogenous Wnt3a and TMAO synergistically promoted the activation and phenotypic transformation of the ß-catenin pathway in atrial fibroblasts. Conclusions: TMAO promotes the transformation of atrial fibroblasts into myofibroblasts by activating Wnt3a/ß-catenin signaling pathway.

Association of Uremic Solutes With Cardiovascular Death in Diabetic Kidney Disease.

RATIONALE & OBJECTIVE: Cardiovascular disease (CVD) is a major cause of mortality among people with diabetic kidney disease (DKD). The pathophysiology is inadequately explained by traditional CVD risk factors. The uremic solutes trimethylamine-N-oxide (TMAO) and asymmetric and symmetric dimethylarginine (ADMA, SDMA) have been linked to CVD in kidney failure with replacement therapy (KFRT), but data are limited in populations with diabetes and less severe kidney disease. STUDY DESIGN: Observational cohort. SETTINGS & PARTICIPANTS: Random subcohort of 555 REGARDS (Reasons for Geographic and Racial Differences in Stroke) study participants with diabetes and estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 at study entry. EXPOSURE: ADMA, SDMA, and TMAO assayed by liquid chromatography-mass spectrometry in plasma and urine. OUTCOME: Cardiovascular mortality (primary outcome); all-cause mortality and incident KFRT (secondary outcomes). ANALYTICAL APPROACH: Plasma concentrations and ratios of urine to plasma concentrations of ADMA, SDMA, and TMAO were tested for association with outcomes. Adjusted Cox regression models were fitted and hazard ratios of outcomes calculated per standard deviation and per doubling, and as interquartile comparisons. RESULTS: The mean baseline eGFR was 44 mL/min/1.73 m2. Cardiovascular death, overall mortality, and KFRT occurred in 120, 285, and 89 participants, respectively, during a mean 6.2 years of follow-up. Higher plasma ADMA and SDMA (HRs of 1.20 and 1.28 per 1-SD greater concentration), and lower ratios of urine to plasma concentrations of ADMA, SDMA, and TMAO (HRs per halving of 1.53, 1.69, and 1.38) were associated with cardiovascular mortality. Higher plasma concentrations of ADMA, SDMA, and TMAO (HRs of 1.31, 1.42, and 1.13 per 1-SD greater concentration) and lower urine to plasma ratios of ADMA, SDMA, and TMAO (HRs per halving of 1.34, 1.37, and 1.26) were associated with all-cause mortality. Higher plasma ADMA and SDMA were associated with incident KFRT by categorical comparisons (HRs of 2.75 and 2.96, comparing quartile 4 to quartile 1), but not in continuous analyses. LIMITATIONS: Single cohort, restricted to patients with diabetes and eGFR < 60 mL/min/1.73 m2, potential residual confounding by GFR, no dietary information. CONCLUSIONS: Higher plasma concentrations and lower ratios of urine to plasma concentrations of uremic solutes were independently associated with cardiovascular and all-cause mortality in DKD. Associations of ratios of urine to plasma concentrations with mortality suggest a connection between renal uremic solute clearance and CVD pathogenesis.

Gut microbiota-dependent metabolite trimethylamine N-oxide (TMAO) and cardiovascular risk in patients with suspected functionally relevant coronary artery disease (fCAD).

BACKGROUND: Trimethylamine N-oxide (TMAO) has been associated with cardiovascular outcomes. However, the diagnostic value of TMAO and its precursors have not been assessed for functionally relevant coronary artery disease (fCAD) and its prognostic potential in this setting needs to be evaluated. METHODS: Among 1726 patients with suspected fCAD serum TMAO, and its precursors betaine, choline and carnitine, were quantified using liquid chromatography tandem mass spectrometry. Diagnosis of fCAD was performed by myocardial perfusion single photon emission tomography (MPI-SPECT) and coronary angiography blinded to marker concentrations. Incident all-cause death, cardiovascular death (CVD) and myocardial infarction (MI) were assessed during 5-years follow-up. RESULTS: Concentrations of TMAO, betaine, choline and carnitine were significantly higher in patients with fCAD versus those without (TMAO 5.33 µM vs 4.66 µM, p < 0.001); however, diagnostic accuracy was low (TMAO area under the receiver operating curve [AUC]: 0.56, 95% CI [0.53-0.59], p < 0.001). In prognostic analyses, TMAO, choline and carnitine above the median were associated with significantly (p < 0.001 for all) higher cumulative events for death and CVD during 5-years follow-up. TMAO remained a significant predictor for death and CVD even in full models adjusted for renal function (HR = 1.58 (1.16, 2.14), p = 0.003; HR = 1.66 [1.07, 2.59], p = 0.025). Prognostic discriminative accuracy for TMAO was good and robust for death and CVD (2-years AUC for CVD 0.73, 95% CI [0.65-0.80]). CONCLUSION: TMAO and its precursors, betaine, choline and carnitine were significantly associated with fCAD, but with limited diagnostic value. TMAO was a strong predictor for incident death and CVD in patients with suspected fCAD. CLINICAL TRIAL REGISTRATION: NCT01838148.