Gut microbiota-derived metabolite trimethylamine-N-oxide and multiple health outcomes: an umbrella review and updated meta-analysis

The association of plasma TMAO and body composition with the occurrence of PEW in maintenance hemodialysis patients

INTRODUCTION

This study aims to explore the relationship between trimethylamine N-oxide (TMAO), body composition, and protein-energy wasting (PEW) in patients undergoing maintenance hemodialysis (MHD).

METHODS

A total of 127 MHD patients participated in this study. Body composition was measured using the InBody770 multi-frequency body composition analyzer. Plasma TMAO concentrations were assessed by ELISA. Cross-sectional analysis was performed after collecting demographic data, dialysis-related data, laboratory parameters, and body composition data from MHD patients.

RESULTS

In MHD patients, the PEW group exhibited lower levels of hemoglobin (Hb), albumin (ALB), transferrin (TF), creatinine (Cr), triglycerides (TG), prealbumin (PALB), soft lean mass (SLM), body mass index (BMI), percent of body fat (PBF), arm muscle circumference (AMC), and phase angle (PHA) compared to the non-PEW group, while C-reactive protein (CRP) and trimethylamine-N-oxide (TMAO) levels, as well as Extracellular Water/Total Body Water (ECW/TBW) ratio, were higher in the PEW group than in the non-PEW group. After full adjustment, TMAO and ECW/TBW ratio were independent risk factors for PEW in MHD patients. Further, plasma TMAO levels correlated negatively with Cr, ALB, Hb, BMI, and PHA, and positively with ECW/TBW in MHD patients with PEW. The ROC curve analysis indicated that the area under the curve (AUC) for plasma TMAO in predicting PEW in MHD patients was 0.788.

CONCLUSIONS

Plasma TMAO levels and certain body composition are associated with the occurrence of PEW in MHD patients. Plasma TMAO levels appear to serve as a potential predictive marker for the onset of PEW.

Personalized Dietary Approaches to Optimizing Intestinal Microbial Health and Homeostasis

Diet has a profound impact in human health, which is partly driven by changes in the intestinal microbiota. Several associations between dietary intake and the intestinal microbiota composition and function have been described. Namely, the Mediterranean diet is associated with beneficial bacteria, while the intake of ultraprocessed foods is linked to dysbiosis. It is, therefore, very tempting to tailor dietary approaches to the individual needs of the microbiota; however, high-quality prospective data are lacking. Provisionally, a diet rich in fruits and vegetables and low in ultraprocessed foods is recommended to improve the intestinal microbiota composition and function.

The Effect of Red Meat Consumption on Circulating, Urinary and Fecal Trimethylamine-N-Oxide: A Systematic Review and Narrative Synthesis of Randomized Controlled Trials

BACKGROUND

Cardiovascular concerns exist about the effect of red meat on circulating concentrations of trimethylamine N-oxide (TMAO), an emerging cardiovascular risk factor.

OBJECTIVE

The aim was to conduct a systematic review of randomized controlled trials (RCTs) to evaluate the effect of higher red meat intake, compared to lower intake, on circulating, urinary and fecal TMAO concentrations in generally healthy adults and/or adults with stable chronic diseases.

METHODS

A systematic literature search was conducted using PubMed, the Cochrane Collaboration Library, and Web of Science. RCTs examining the effect of a ≥7-day dietary intervention featuring red meat on urinary, fecal and/or circulating (plasma or serum) concentration of TMAO in adults (≥18 years) were included. Eligible trials had a comparator group/condition that was exposed to a dietary intervention for ≥ 7 days lower in red meat and featuring white meat, fish, eggs, dairy, or plant-based protein sources.

RESULTS

In total, 375 publications were identified. Fifteen publications reporting the results of 13 RCTs (n=553; median duration 28 days), including 15 diet comparisons, were eligible. In six comparisons, higher circulating or urinary TMAO concentrations were observed following higher red meat intake (∼71-420 g/day) compared to comparator conditions lower in red meat. In seven comparisons, no differences in serum/plasma TMAO concentrations were observed with higher red meat-containing diets (∼60-156 g/day) compared to diets lower in red meat. Two comparisons showed that consuming higher red meat diets lowered TMAO concentrations after 28 days compared to lower red meat diets containing seafood.

CONCLUSION

In short-term studies (median duration of 28 days), higher red meat intake had inconsistent effects on circulating and urinary TMAO concentrations. Further high-quality research on red meat-related TMAO modulation, including effect magnitude and clinical relevance, is needed. REGISTRY AND REGISTRY NUMBER FOR SYSTEMATIC REVIEWS OR META-ANALYSES: Prospective Register of Systematic Reviews (PROSPERO) registration number: CRD42023396799 STATEMENT OF SIGNIFICANCE: This systematic review summarizes evidence on the effect of higher red meat intake, compared to lower intake of red meat, on circulating, urinary, and fecal concentrations of trimethylamine N-oxide (TMAO) in generally healthy adults and/or adults with stable chronic diseases. Higher red meat intake had inconsistent effects on TMAO concentrations, which may be partly related to differences in clinical trial methodology, inter-individual variability in diet-related TMAO modulation, and/or the overall healthfulness of the red meat-containing diet.

TMAO and diabetes: from the gut feeling to the heart of the problem

Elevated plasma levels of trimethylamine N-oxide (TMAO)-a compound derived from diet and the gut microbiome-have been widely studied for their association with diabetes risk and their potential role in disease pathophysiology and complications. However, clinical studies, both prospective and retrospective, have yielded conflicting results. For example, elevated levels of TMAO are frequently linked to an increased risk of cardiovascular and renal complications in individuals with diabetes. However, the robustness and independence of these associations differ across study populations and are influenced by the degree of adjustment for confounding risk factors. Considering insulin's regulatory effect on FMO3 activity in liver cells, TMAO may serve as a marker of hepatic insulin resistance, which could partially explain its association with diabetes risk. The role of TMAO in diabetes pathology remains controversial; while some studies emphasize its detrimental impact on insulin sensitivity and the progression of diabetes-related complications, others suggest potential protective effects. Investigating the largely unexplored role of TMAO's precursor, trimethylamine, may help elucidate these discrepancies. This review consolidates clinical and experimental findings to clarify TMAO's complex mechanistic contributions to diabetes pathology.

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.

Microbiota, mitochondria, and epigenetics in health and disease: converging pathways to solve the puzzle

Dysbiosis, which refers to an imbalance in the composition of the gut microbiome, has been associated with a range of metabolic disorders, including type 2 diabetes, obesity, and metabolic syndrome. Although the exact mechanisms connecting gut dysbiosis to these conditions are not fully understood, various lines of evidence strongly suggest a substantial role for the interaction between the gut microbiome, mitochondria, and epigenetics. Current studies suggest that the gut microbiome has the potential to affect mitochondrial function and biogenesis through the production of metabolites. A well-balanced microbiota plays a pivotal role in supporting normal mitochondrial and cellular functions by providing metabolites that are essential for mitochondrial bioenergetics and signaling pathways. Conversely, in the context of illnesses, an unbalanced microbiota can impact mitochondrial function, leading to increased aerobic glycolysis, reduced oxidative phosphorylation and fatty acid oxidation, alterations in mitochondrial membrane permeability, and heightened resistance to cellular apoptosis. Mitochondrial activity can also influence the composition and function of the gut microbiota. Because of the intricate interplay between nuclear and mitochondrial communication, the nuclear epigenome can regulate mitochondrial function, and conversely, mitochondria can produce metabolic signals that initiate epigenetic changes within the nucleus. Given the epigenetic modifications triggered by metabolic signals from mitochondria in response to stress or damage, targeting an imbalanced microbiota through interventions could offer a promising strategy to alleviate the epigenetic alterations arising from disrupted mitochondrial signaling.

Decoding TMAO in the Gut-Organ Axis: From Biomarkers and Cell Death Mechanisms to Therapeutic Horizons

The gut microbiota and its metabolites are bi-directionally associated with various human illnesses, which has received extensive attention. Trimethylamine N-oxide (TMAO) is a gut microbiota metabolite produced in the liver, which may serve the role of an "axis" connecting the gut and host organs. TMAO levels are significantly higher in the blood of individuals with cardiovascular, renal, neurological, and metabolic diseases. Endothelial cells are crucial for regulating microcirculation and maintaining tissue and organ barriers and are widely recognized as target cells for TMAO. TMAO not only induces endothelial dysfunction but also acts on various cell types, such as endothelial cells, epithelial cells, vascular smooth muscle cells, nerve cells, and pancreatic cells, triggering multiple cell death mechanisms, including necrosis and programmed cell death, thereby influencing host health. This paper thoroughly covers the origins, production, and metabolic pathways of TMAO, emphasizing its importance in the early detection and prognosis of human diseases in the "Gut-Organ" axis, as well as its mechanisms of influence on human diseases, particularly the cross-talk with cell death. Furthermore, we cover recent advances in treating human diseases by regulating gut microbiota structure and enzyme activity to influence TMAO metabolism and reduce TMAO levels, including the use of probiotics, prebiotics, antibiotics, anti-inflammatory drugs, antiplatelet drugs, hypoglycemic drugs, lipid-lowering drugs, and natural products.

"Gut Microbiota as a Therapeutic Target for Hypertension: Challenges and Insights for Future Clinical Applications" "Gut Microbiota and Hypertension Therapy"

PURPOSE OF REVIEW

Systemic hypertension is a major risk factor for cardiovascular disease and remains challenging to manage despite the widespread use of antihypertensive medications and lifestyle modifications. This review explores the role of gut microbiota in hypertension development and regulation, highlighting key mechanisms such as inflammation, gut-brain axis modulation, and bioactive metabolite production. We also assess the potential of microbiota-targeted therapies for hypertension management.

RECENT FINDINGS

Emerging evidence indicates that microbial dysbiosis, high-salt diets, and gut-derived metabolites such as short-chain fatty acids (SCFAs) and bile acids significantly influence blood pressure regulation. Preclinical and early clinical studies suggest that interventions targeting gut microbiota, including probiotics, prebiotics, synbiotics, fecal microbiota transplantation (FMT), and dietary modifications, may help modulate hypertension. However, variability in gut microbiota composition among individuals and limited human trial data pose challenges to translating these findings into clinical practice. While microbiota-based therapies show promise for hypertension management, further research is needed to establish their efficacy and long-term effects. Large-scale, standardized clinical trials are crucial for understanding the therapeutic potential and limitations of gut microbiota interventions. A deeper understanding of the gut-hypertension axis could lead to novel, personalized treatment strategies for hypertension.

Gut Microbiota in Heart Failure-The Role of Inflammation

Heart failure (HF) has become an immense health concern affecting almost 1-2% of the population globally. It is a complex syndrome characterized by activation of the sympathetic nervous system and the Renin-Angiotensin-Aldosterone (RAAS) axis as well as endothelial dysfunction, oxidative stress, and inflammation. The recent literature points towards the interaction between the intestinal flora and the heart, also called the gut-heart axis. The human gastrointestinal tract is naturally inhabited by various microbes, which are distinct for each patient, regulating the functions of many organs. Alterations of the gut microbiome, a process called dysbiosis, may result in systemic diseases and have been associated with heart failure through inflammatory and autoimmune mechanisms. The disorder of intestinal permeability favors the translocation of microbes and many metabolites capable of inducing inflammation, thus further contributing to the deterioration of normal cardiac function. Besides diet modifications and exercise training, many studies have revealed possible gut microbiota targeted treatments for managing heart failure. The aim of this review is to demonstrate the impact of the inflammatory environment induced by the gut microbiome and its metabolites on heart failure and the elucidation of these novel therapeutic approaches.

Probiotic Bifidobacterium reduces serum TMAO in unstable angina patients via the gut to liver to heart axis

Background and aims

Studies indicate that the gut microbiota and its metabolites are involved in the progression of cardiovascular diseases, and enterohepatic circulation plays an important role in this progression. This study aims to identify potential probiotics for the treatment of unstable angina (UA) and elucidate their mechanisms of action.

Methods

Initially, the gut microbiota from patients with UA and control was analyzed. To directly assess the effects of Bifidobacterium supplementation, 10 patients with UA were enrolled and administered Bifidobacterium (630 mg per intake twice a day for 1 month). The fecal metagenome, serum trimethylamine N-oxide (TMAO) levels, and other laboratory parameters were evaluated before and after Bifidobacterium supplementation.

Results

After supplementing with Bifidobacterium for 1 month, there were statistically significant differences (P < 0.05) in TMAO, aspartate aminotransferase, total cholesterol, and low-density lipoprotein compared to before. Additionally, the abundance of Bifidobacterium longum increased significantly, although the overall abundance of Bifidobacterium did not reach statistical significance. The gut microbiota, metabolites, and gut-liver axis are involved in the progression of UA, and potential mechanisms should be further studied.

Conclusions

Metagenomic analysis demonstrated a reduced abundance of Bifidobacterium in patients with UA. Supplementation with Bifidobacterium restored gut dysbiosis and decreased circulating TMAO levels in patients with UA. This study provides evidence that Bifidobacterium may exert cardiovascular-protective effects through the gut-liver-heart axis.

Clinical trial number

ChiCTR2400093946.

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).

Gut microbiome and bone health: update on mechanisms, clinical correlations, and possible treatment strategies

The intestinal microbiome is increasingly regarded as a relevant modulator of the pathophysiology of several age-related conditions, including frailty, sarcopenia, and cognitive decline. Aging is in fact associated with alteration of the equilibrium between symbiotic bacteria and opportunistic pathogens, leading to dysbiosis. The microbiome is able to regulate intestinal permeability and systemic inflammation, has a central role in intestinal amino acid metabolism, and produces a large number of metabolites and byproducts, with either beneficial or detrimental consequences for the host physiology. Recent evidence, from both preclinical animal models and clinical studies, suggests that these microbiome-centered pathways could contribute to bone homeostasis, regulating the balance between osteoblast and osteoclast function. In this systematic review, we provide an overview of the mechanisms involved in the gut-bone axis, with a particular focus on microbiome function and microbiome-derived mediators including short-chain fatty acids. We also review the current evidence linking gut microbiota dysbiosis with osteopenia and osteoporosis, and the results of the intervention studies on pre-, pro-, or post-biotics targeting bone mineral density loss in both animal models and human beings, indicating knowledge gaps and highlighting possible avenues for future research.

Efficacy and compatibility mechanism of bear bile powder in Shexiang Tongxin dropping pills for acute myocardial infarction treatment

BACKGROUND

Bear bile powder (BBP), a unique animal-derived medicine with anti-inflammatory and antioxidant effects, is used in Shexiang Tongxin dropping pills (STDP), which is applied to treat cardiovascular diseases, including acute myocardial infarction (AMI). The efficacy and compatibility mechanisms of action of BBP in STDP against cardiovascular diseases remain unclear. This study aimed to investigate the compatibility effects of BBP in STDP in rats with AMI.

METHODS

We investigated the compatibility effects of BBP in STDP in rats with AMI. Non-targeted metabonomics, 16S rRNA analysis, RNA sequencing, and network pharmacology were performed to explore the underlying mechanisms.

RESULTS

The combination of BBP and CF (STDP without BBP) significantly reduced AMI-induced infarction size, pathological alterations of cardiac tissues, and serum lactate dehydrogenase and creatine kinase levels in rats, compared with CF or BBP treatment alone. Gut microbiota and metabonomics results revealed that the combination treatment could upregulate the relative abundance of Lactobacillus and downregulate that of Helicobacter, Bilophila, and Butyricimonas, thereby rebalancing the gut microbiota dysbiosis induced by AMI. Consequently, the intestinal metabolite levels of oleoylcholine, glutamylalanine, isokobusone, and hemorphin-4 were altered. However, treatment with CF or BBP alone has a weaker effect on these bacteria. Additionally, the combination treatment induced a 62.34% gene reversion rate compared with 55.56% for BBP and 30.20% for CF treatment alone. Modulation of endothelin 1 and growth factor receptor-bound protein 2 was identified as a key synergistic mechanism underlying the anti-AMI effects of BBP in STDP.

CONCLUSION

This research provides a scientific explanation of the compatibility of BBP in STDP. Our findings suggested that combination treatment with CF and BBP synergistically attenuates AMI by altering gene expression, gut microbiota, and intestinal metabolite profiles.

Novel insights into the role of gut microbiota and its metabolites in diabetic chronic wounds

Wounds in patients with diabetes present significant physical and economic challenges due to impaired healing and prolonged inflammation, exacerbated by complex interactions between microbes. Especially, the development and healing of diabetic foot ulcers (DFUs) remain an urgent clinical problem. The human gut harbors a vast microbial ecosystem comprising intestinal flora and their metabolic products. Recent advancements in research have illuminated the concept of the "gut-skin axis," revealing intricate relationships between gut microbiota, microbiota-derived metabolites, and various skin diseases, including DFUs. This review aims to unravel the formation and healing process of DFUs in the context of the gut-skin axis. We reviewed the current research progress worldwide regarding to the gut-skin axis, compared and discussed significant changes in the microbiota colonizing the skin and gut in patients with DFUs. The roles of microbiota-derived metabolites such as lipopolysaccharides, short-chain fatty acids, and trimethylamine-N-oxide in the development of DFUs are highlighted. We also reviewed treatment strategies currently employed in clinical practice and identified potential therapeutic targets such as probiotics for treating DFUs. The need for more comprehensive experimental designs to elucidate the intricate relationship between gut microbiota and its metabolites in the context of DFUs are therefore highlighted.

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.

Association of probiotics, prebiotics, synbiotics or yogurt supplement with prevalence and all-cause mortality of depression: NHANES 2005-2016

BACKGROUND

A growing body of studies revealed that enteric dysbacteriosis could result in depression via the "gut-microbiota-brain axis" (GMBA). Whether probiotics, prebiotics, and synbiotics supplements could lessen the risk of depression is a topic attracting attention. This research was conducted to evaluate the relationship between probiotics, prebiotics, synbiotics, or yogurt supplements and depression with large cross-sectional data.

METHODS

All data in our research was sourced from the National Health and Nutrition Examination Survey (NHANES) (2005-2016). Probiotics, prebiotics, synbiotics, and yogurt supplements were identified using Food Frequency Questionnaire (FFQ) and Dietary Supplement Use 30-Day (DSQ). We employed the Patient Health Questionnaire (PHQ-9) for evaluating depression. Logistic regression and the Kaplan-Meier curve were performed to examine the correlation between the supplements and depression, as well as mortality.

RESULTS

A total of 17,745 adult participants were selected. The participants who supplemented probiotics, prebiotics, synbiotics, or yogurt products in the last 30 days showed a significantly lower depression rate compared with those who didn't. Specifically, the supplements could alleviate depressive symptoms including sad, anhedonia, sleep problems, fatigue, appetite changes, and psychomotor changes. This association was more prominent in specific populations such as the population aged 40-60 years, male, whites. The supplements also show more significant effects on increasing survival rates in patients with mild depression.

LIMITATION

Cross-sectional analysis reveals correlative but not causative association.

CONCLUSION

Based on the analysis of NHANES data, our research highlights the positive effect the supplements have on preventing depression, relieving depressive symptoms and increasing survival rates. This effect varied across populations.

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).

A Case-Control Study of Dietary Choline Intake and Risk of Colorectal Cancer Modified by Dietary B-Vitamin Intake

BACKGROUND/OBJECTIVES

The incidence of colorectal cancer (CRC) is rising, and Western diets high in red and processed meats may be contributing. It is important to identify dietary nutrients that increase CRC risk and perhaps interventions that may modulate such risk. The relationship between dietary choline intake and CRC is still unclear. We hypothesize that high dietary choline intake is associated with greater CRC risk, and B vitamin supplementation may modify this risk.

METHODS

In this case-control study, we collected demographic and dietary data using the validated National Cancer Institute CRC Risk Assessment Tool and Dietary Health Questionnaire III and analyzed colonoscopy outcomes. Logistic regression and stratified analyses were performed to calculate adjusted odds ratios and evaluate for effect modification.

RESULTS

Of 52 total patients, 21 had a normal colonoscopy result, and 31 were found to either have benign polyps or CRC. The average dietary choline intake was 207 mg/day in the normal group and 297 mg/day in the abnormal outcome group. A doubling in dietary choline intake was significantly associated with increased odds of polyps or CRC (OR 25.32, 95% CI 1.95-327.94). When stratified by vitamin B levels, the effect modification was difficult to confidently quantify due to the limited sample size.

CONCLUSIONS

Our findings suggest that higher dietary choline intake may be associated with an increased risk of CRC and its precursors, such as polyps. Although the potential modifying role of B vitamins was inconclusive, this study underscores the need for larger-scale research to further explore these associations and to assess the potential of dietary interventions in reducing CRC risk.

The Association Between Serum Trimethylamine N-Oxide and Arterial Stiffness in Chronic Peritoneal Dialysis Patients: A Cross-Sectional Study

Trimethylamine N-oxide (TMAO), a gut microbiome-derived metabolite, participates in the atherogenesis and vascular stiffening that is closely linked with cardiovascular (CV) complications and related deaths in individuals with kidney failure undergoing peritoneal dialysis (PD) therapy. In these patients, arterial stiffness (AS) is also an indicator of adverse CV outcomes. This study assessed the correlation between serum TMAO concentration quantified with high-performance liquid chromatography and mass spectrometry and central AS measured by carotid-femoral pulse wave velocity (cfPWV) in patients with chronic PD. Of the 160 participants included, 23.8% had a cfPWV of ≥10 m/s, which fulfilled the AS criteria. Multivariable logistic regression analysis revealed that TMAO, age, and waist circumference were positively associated with AS. Multivariable stepwise linear regression showed that underlying diabetes, advanced age, waist circumference, systolic blood pressure, and logarithmic-transformed TMAO were independently correlated with cfPWV. The area under the receiver operating characteristic curve for TMAO in differentiating AS from non-AS was 0.737. In conclusion, serum TMAO level was significantly independently correlated with central AS among participants undergoing PD for end-stage kidney failure.

Effects of probiotics supplementation on glycemic profile in adults with type 2 diabetes mellitus: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND

Disturbed glycemia and the resulting type 2 diabetes (T2D) are significant health concerns. Various approaches have been examined to improve glycemic control in patients with T2D. Modification of gut microbiome via administering probiotics has been extensively studied. The present study aims to sum up the existing literature which investigated the effect of probiotics on glycemic indices in individuals with T2D in the format of randomized controlled trials (RCTs).

METHODS

Online medical databases (PubMed, Scopus, and Web of Science) were searched from inception to January 2024. Eligible studies were included using pre-defined inclusion and exclusion criteria. Outcome variables included fasting blood sugar (FBS), insulin, hemoglobin A1c (HbA1c), and homeostatic model of insulin resistance (HOMA-IR). Weighted mean differences (WMDs) were estimated. Subgroup and dose-response analyses were conducted. P-values <0.05 were considered as statistically significant.

RESULTS

Out of 5636 records retrieved by the initial search, thirty-two RCTs were included in the final analyses. Supplementation with probiotics was observed to significantly improve indices of glycemic control; including FBS (WMD: -13.27 mg/dl; 95 % CI: -18.31, -8.22), HbA1c (WMD: -0.44 %; 95 % CI: -0.59, -0.28), insulin (WMD: -1.33 μIU/ml; 95 % CI: -2.57, -0.08), and HOMA-IR (WMD: -0.95; 95 % CI: -1.71, -0.18). Dose-response analysis revealed that increased duration of intervention results in a larger reduction only in FBS.

CONCLUSION

Supplementation with probiotics seems to improve indices of glycemic control. Nonetheless, taken into account the notable heterogeneity (with regard to dosage, duration, and the species/strains used) between the included studies and low quality of evidence, caution must be considered, especially when long-term clinical implications are intended.

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

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

A gender perspective on diet, microbiome, and sex hormone interplay in cardiovascular disease

A unique interplay between body and environment embeds and reflects host-microbiome interactions that contribute to sex-differential disease susceptibility, symptomatology, and treatment outcomes. These differences derive from individual biological factors, such as sex hormone action, sex-divergent immune processes, X-linked gene dosage effects, and epigenetics, as well as from their interaction across the lifespan. The gut microbiome is increasingly recognized as a moderator of several body systems that are thus impacted by its function and composition. In humans, biological sex components further interact with gender-specific exposures such as dietary preferences, stressors, and life experiences to form a complex whole, requiring innovative methodologies to disentangle. Here, we summarize current knowledge of the interactions among sex hormones, gut microbiota, immune system, and vascular health and their relevance for sex-differential epidemiology of cardiovascular diseases. We outline clinical implications, identify knowledge gaps, and place emphasis on required future studies to address these gaps. In addition, we provide an overview of the caveats associated with conducting cardiovascular research that require consideration of sex/gender differences. While previous work has inspected several of these components separately, here we call attention to further translational utility of a combined perspective from cardiovascular translational research, gender medicine, and microbiome systems biology.

Unveiling the causal effects of gut microbiome on trimethylamine N-oxide: evidence from Mendelian randomization

Objective

The relationship between gut microbiome and trimethylamine oxide (TMAO) has not been fully elucidated. We aimed to assess the causal effects of different gut microbes on TMAO using Mendelian randomization (MR).

Methods

Gut microbiome and TMAO datasets were acquired from genome-wide association studies and screened for single nucleotide polymorphisms according to the basic assumptions of MR. Inverse variance weighted was used as the main method in MR analysis to assess the causal relationship between the gut microbiome and TMAO. Finally, the MR-Egger intercept, Cochran's Q test, and leave-one-out sensitivity analysis were used to assess the horizontal pleiotropy, heterogeneity, and robustness of the results, respectively.

Results

MR analysis revealed that the species Bacteroides finegoldii (odds ratio [OR] 1.064, 95% confidence interval [CI] 1.003 to 1.128, p = 0.039), family Sutterellaceae (OR 1.188, 95% CI 1.003 to 1.407, p = 0.047), and phylum Pseudomonadota (OR 1.205, 95% CI 1.036 to 1.401, p = 0.016), as well as the species Bacteroides uniformis (OR 1.263, 95% CI 1.039 to 1.535, p = 0.019), were positively associated with increased genetic susceptibility to TMAO. In contrast, the species Bacteroides thetaiotaomicron (OR 0.813, 95% CI 0.696 to 0.950, p = 0.009) and Bilophila wadsworthia (OR 0.828, 95% CI 0.690 to 0.995, p = 0.044) were associated with reduced genetic susceptibility to TMAO. Additionally, the MR-Egger intercept indicated no horizontal pleiotropy (p ≥ 0.05), and Cochran's Q test and sensitivity analysis demonstrated that the results were not heterogeneous (p ≥ 0.05) and were robust.

Conclusion

Our findings revealed the role of the phylum Pseudomonadota, family Sutterellaceae, species Bacteroides finegoldii, and Bacteroides uniformis in increasing TMAO, as well as the species Bacteroides thetaiotaomicron and Bilophila wadsworthia in decreasing TMAO. This study provides new insights into the relationship between the gut microbiome and TMAO levels.

Low-Molecular-Weight Compounds Produced by the Intestinal Microbiota and Cardiovascular Disease

Cardiovascular disease is the main cause of mortality in industrialized countries, with over 500 million people affected worldwide. In this work, the roles of low-molecular-weight metabolites originating from the gut microbiome, such as short-chain fatty acids, hydrogen sulfide, trimethylamine, phenylacetic acid, secondary bile acids, indoles, different gases, neurotransmitters, vitamins, and complex lipids, are discussed in relation to their CVD-promoting or preventing activities. Molecules of mixed microbial and human hepatic origin, such as trimethylamine N-oxide and phenylacetylglutamine, are also presented. Finally, dietary agents with cardioprotective effects, such as probiotics, prebiotics, mono- and poly-unsaturated fatty acids, carotenoids, and polyphenols, are also discussed. A special emphasis is given to their gut microbiota-modulating properties.

Microbial metabolite trimethylamine-N-oxide induces intestinal carcinogenesis through inhibiting farnesoid X receptor signaling

PURPOSE

Microbial dysbiosis is considered as a hallmark of colorectal cancer (CRC). Trimethylamine-N-oxide (TMAO) as a gut microbiota-dependent metabolite has recently been implicated in CRC development. Nevertheless, evidence relating TMAO to intestinal carcinogenesis remains largely unexplored. Herein, we aimed to examine the crucial role of TMAO in CRC progression.

METHODS

Apcmin/+ mice were treated with TMAO or sterile PBS for 14 weeks. Intestinal tissues were isolated to evaluate the effects of TMAO on the malignant transformation of intestinal adenoma. The gut microbiota of mouse feces was detected by 16S rRNA sequencing analysis. HCT-116 cells were used to provide further evidence of TMAO on the progression of CRC.

RESULTS

TMAO administration increased tumor cell and stem cell proliferation, and decreased apoptosis, accompanied by DNA damage and gut barrier impairment. Gut microbiota analysis revealed that TMAO induced changes in the intestinal microbial community structure, manifested as reduced beneficial bacteria. Mechanistically, TMAO bound to farnesoid X receptor (FXR), thereby inhibiting the FXR-fibroblast growth factor 15 (FGF15) axis and activating the Wnt/β-catenin signaling pathway, whereas the FXR agonist GW4064 could blunt TMAO-induced Wnt/β-catenin pathway activation.

CONCLUSION

The microbial metabolite TMAO can enhance intestinal carcinogenesis by inhibiting the FXR-FGF15 pathway.

Association Between Trimethylamine N-oxide and Adverse Kidney Outcomes and Overall Mortality in Type 2 Diabetes Mellitus

CONTEXT

Type 2 diabetes (T2D) is the major contributor to chronic kidney disease and end-stage kidney disease (ESKD). The influence of trimethylamine N-oxide (TMAO) on kidney outcomes in T2D remains unclear.

OBJECTIVE

To examine the association between fasting serum TMAO levels and adverse kidney outcomes in patients with T2D.

METHODS

Between October 2016 and June 2020, patients with T2D were recruited and monitored every 3 months until December 2021. Serum TMAO levels were assessed using liquid chromatography-mass spectrometry. The primary kidney outcomes were doubling of serum creatinine levels or progression to ESKD necessitating dialysis; the secondary kidney outcome was a rapid 30% decline in estimated glomerular filtration rate within 2 years. All-cause mortality was also evaluated.

RESULTS

Among the 440 enrolled patients with T2D, those in the highest serum TMAO tertile (≥0.88 μM) were older, had a longer diabetes duration, elevated blood urea nitrogen, and lower estimated glomerular filtration rate. Over a median follow-up period of 4 years, 26 patients (5.9%) had a doubling of serum creatinine level or progression to ESKD. After propensity score weighting, the patients in the highest serum TMAO tertile had a 6.45-fold increase in the risk of doubling of serum creatinine levels or progression to ESKD and 5.86-fold elevated risk of rapid decline in kidney function compared with those in the lowest tertile. Additionally, the stepwise increase in serum TMAO was associated with all-cause mortality.

CONCLUSION

Patients with T2D with elevated circulating TMAO levels are at higher risk of doubling serum creatinine, progressing to ESKD, and mortality. TMAO is a potential biomarker for kidney function progression and mortality in patients with T2D.

Correlation between serum trimethylamine-N-oxide and body fat distribution in middle-aged and older adults: a prospective cohort study

BACKGROUND

Trimethylamine-N-oxide (TMAO) is linked with obesity, while limited evidence on its relationship with body fat distribution. Herein, we investigated the associations between serum TMAO and longitudinal change of fat distribution in this prospective cohort study.

METHODS

Data of 1964 participants (40-75y old) from Guangzhou Nutrition and Health Study (GNHS) during 2008-2014 was analyzed. Serum TMAO concentration was quantified by HPLC-MS/MS at baseline. The body composition was assessed by dual-energy X-ray absorptiometry at each 3-y follow-up. Fat distribution parameters were fat-to-lean mass ratio (FLR) and trunk-to-leg fat ratio (TLR). Fat distribution changes were derived from the coefficient of linear regression between their parameters and follow-up duration.

RESULTS

After an average of 6.2-y follow-up, analysis of covariance (ANCOVA) and linear regression displayed women with higher serum TMAO level had greater increments in trunk FLR (mean ± SD: 1.47 ± 4.39, P-trend = 0.006) and TLR (mean ± SD: 0.06 ± 0.24, P-trend = 0.011). Meanwhile, for women in the highest TMAO tertile, linear mixed-effects model (LMEM) analysis demonstrated the annual estimated increments (95% CI) were 0.03 (95% CI: 0.003 - 0.06, P = 0.032) in trunk FLR and 1.28 (95% CI: -0.17 - 2.73, P = 0.083) in TLR, respectively. In men, there were no similar significant observations. Sensitivity analysis yielded consistent results.

CONCLUSION

Serum TMAO displayed a more profound correlation with increment of FLR and TLR in middle-aged and older community-dwelling women in current study. More and further studies are still warranted in the future.

TRIAL REGISTRATION

NCT03179657.

Inflammatory Bowel Disease and Cardiovascular Disease: An Integrative Review With a Focus on the Gut Microbiome

Inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, is a chronic inflammatory condition of the gastrointestinal tract. Recent research indicates a significant link between IBD and cardiovascular disease (CVD), the leading cause of global morbidity and mortality. This review examines the association between IBD and CVD, emphasizing the role of the gut microbiome in this relationship. IBD patients have a higher risk of cardiovascular events, such as coronary artery disease, heart failure, and cerebrovascular incidents, primarily due to chronic systemic inflammation, genetic factors, and gut microbiota imbalance (dysbiosis). Dysbiosis in IBD increases intestinal permeability, allowing bacterial products to enter the bloodstream, which promotes inflammation and endothelial dysfunction, contributing to CVD. Understanding the gut microbiome's role in IBD and CVD suggests new therapeutic interventions. Modulating the microbiome through diet, probiotics, and fecal microbiota transplantation (FMT) are promising research avenues. These interventions aim to restore a healthy gut microbiota balance, potentially reducing inflammation and improving cardiovascular outcomes. Additionally, the review emphasizes the importance of regular cardiovascular risk assessments and personalized preventive measures in managing IBD patients. Such measures include routine monitoring of cardiovascular health, tailored lifestyle modifications, and early intervention strategies to mitigate cardiovascular risk. By integrating current knowledge, this review aims to improve understanding and management of the interconnected pathophysiology of IBD and CVD. This approach will ultimately enhance patient outcomes and provide a foundation for future research and clinical practice guidelines in this area.

Interactions between diet and gut microbiota in cancer

Dietary patterns and specific dietary components, in concert with the gut microbiota, can jointly shape susceptibility, resistance and therapeutic response to cancer. Which diet-microbial interactions contribute to or mitigate carcinogenesis and how they work are important questions in this growing field. Here we interpret studies of diet-microbial interactions to assess dietary determinants of intestinal colonization by opportunistic and oncogenic bacteria. We explore how diet-induced expansion of specific gut bacteria might drive colonic epithelial tumorigenesis or create immuno-permissive tumour milieus and introduce recent findings that provide insight into these processes. Additionally, we describe available preclinical models that are widely used to study diet, microbiome and cancer interactions. Given the rising clinical interest in dietary modulations in cancer treatment, we highlight promising clinical trials that describe the effects of different dietary alterations on the microbiome and cancer outcomes.

Role of Trimethylamine N-Oxide in Heart Failure

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

A single-blinded, randomized, parallel intervention to evaluate genetics and omics-based personalized nutrition in general population via an e-commerce tool: The PREVENTOMICS e-commerce study

BACKGROUND

Personalized nutrition (PN) has been proposed as a strategy to increase the effectiveness of dietary recommendations and ultimately improve health status.

OBJECTIVES

We aimed to assess whether including omics-based PN in an e-commerce tool improves dietary behavior and metabolic profile in general population.

METHODS

A 21-wk parallel, single-blinded, randomized intervention involved 193 adults assigned to a control group following Mediterranean diet recommendations (n = 57, completers = 36), PN (n = 70, completers = 45), or personalized plan (PP, n = 68, completers = 53) integrating a behavioral change program with PN recommendations. The intervention used metabolomics, proteomics, and genetic data to assist participants in creating personalized shopping lists in a simulated e-commerce retailer portal. The primary outcome was the Mediterranean diet adherence screener (MEDAS) score; secondary outcomes included biometric and metabolic markers and dietary habits.

RESULTS

Volunteers were categorized with a scoring system based on biomarkers of lipid, carbohydrate metabolism, inflammation, oxidative stress, and microbiota, and dietary recommendations delivered accordingly in the PN and PP groups. The intervention significantly increased MEDAS scores in all volunteers (control-3 points; 95% confidence interval [CI]: 2.2, 3.8; PN-2.7 points; 95% CI: 2.0, 3.3; and PP-2.8 points; 95% CI: 2.1, 3.4; q < 0.001). No significant differences were observed in dietary habits or health parameters between PN and control groups after adjustment for multiple comparisons. Nevertheless, personalized recommendations significantly (false discovery rate < 0.05) and selectively enhanced the scores calculated with biomarkers of carbohydrate metabolism (β: -0.37; 95% CI: -0.56, -0.18), oxidative stress (β: -0.37; 95% CI: -0.60, -0.15), microbiota (β: -0.38; 95% CI: -0.63, -0.15), and inflammation (β: -0.78; 95% CI: -1.24, -0.31) compared with control diet.

CONCLUSIONS

Integration of personalized strategies within an e-commerce-like tool did not enhance adherence to Mediterranean diet or improved health markers compared with general recommendations. The metabotyping approach showed promising results and more research is guaranteed to further promote its application in PN. This trial was registered at clinicaltrials.gov as NCT04641559 (https://clinicaltrials.gov/study/NCT04641559?cond=NCT04641559&rank=1).

Human Gut Microbiota in Cardiovascular Disease

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

Gut microbiota: a potential new regulator of hypertension

Hypertension is a significant risk factor for cardiovascular and cerebrovascular diseases and has become a global public health concern. Although hypertension results from a combination of factors, the specific mechanism is still unclear. However, increasing evidence suggests that gut microbiota is closely associated with the development of hypertension. We provide a summary of the composition and physiological role of gut microbiota. We then delve into the mechanism of gut microbiota and its metabolites involved in the occurrence and development of hypertension. Finally, we review various regimens for better-controlling hypertension from the diet, exercise, drugs, antibiotics, probiotics, and fecal transplantation perspectives.

Risk of incident cardiovascular disease among patients with gastrointestinal disorder: a prospective cohort study of 330 751 individuals

BACKGROUND AND AIMS

The associations between gastrointestinal diseases (GIs) and cardiovascular disease (CVD) were unclear. We conducted a prospective cohort study to explore their associations.

METHODS

This study included 330 751 individuals without baseline CVD from the UK Biobank cohort. Individuals with and without GIs were followed up until the ascertainment of incident CVDs, including coronary heart disease (CHD), cerebrovascular disease (CeVD), heart failure (HF), and peripheral artery disease (PAD). The diagnosis of diseases was confirmed with combination of the nationwide inpatient data, primary care data, and cancer registries. A multivariable Cox proportional hazard regression model was used to estimate the associations between GIs and the risk of incident CVD.

RESULTS

During a median follow-up of 11.8 years, 31 605 incident CVD cases were diagnosed. Individuals with GIs had an elevated risk of CVD (hazard ratio 1.37; 95% confidence interval 1.34-1.41, P < 0.001). Eleven out of 15 GIs were associated with an increased risk of CVD after Bonferroni-correction, including cirrhosis, non-alcoholic fatty liver disease, gastritis and duodenitis, irritable bowel syndrome, Barrett's esophagus, gastroesophageal reflux disease, peptic ulcer, celiac disease, diverticulum, appendicitis, and biliary disease. The associations were stronger among women, individuals aged ≤60 years, and those with body mass index ≥25 kg/m2.

CONCLUSIONS

This large-scale prospective cohort study revealed the associations of GIs with an increased risk of incident CVD, in particular CHD and PAD. These findings support the reinforced secondary CVD prevention among patients with gastrointestinal disorders.

Targeting the Gut-Kidney Axis in Diarrhea with Kidney-Yang Deficiency Syndrome: The Role of Sishen Pills in Regulating TMAO-Mediated Inflammatory Response

BACKGROUND Sishen Pills (SSPs) are commonly used to treat diarrhea with kidney-yang deficiency syndrome. Trimethylamine-N-oxide (TMAO) is produced through the metabolism of gut microbiota and can participate in diarrhea in kidney-yang deficiency syndrome by mediating the "gut-kidney axis" to transmit inflammatory factors. This study combined network pharmacology with animal experiments to explore whether SSPs can treat diarrhea with kidney-yang deficiency syndrome by affecting the interaction between TMAO and gut microbiota. MATERIAL AND METHODS A mouse model of diarrhea with kidney-yang deficiency syndrome was constructed by using adenine and Folium sennae decoction, and SSP decoction was used for treatment. This study utilized network pharmacology to predict the potential mechanisms of SSPs in treating diarrhea with kidney-yang deficiency syndrome. 16S rRNA high-throughput sequencing was used to analyze gut mucosal microbial characteristics. ELISA was used to measure TMAO, NOD-like receptor thermal protein domain associated protein 3 (NLRP3), interleukin-1ß (IL-1ß), and transforming growth factor-ß1 (TGF-ß1) levels. We performed Masson and immunohistochemical (Occludin, ZO-1) staining of kidney and small intestinal tissues. The fluorescein diacetate (FDA) hydrolysis spectrophotometric method was used to assess the microbial activity in contents of the small intestine. RESULTS Network pharmacology analysis revealed that SSPs can modulate 108 target points involved in the development of diarrhea, including IL-1ß and TNF. The experimental results demonstrated that SSP decoction significantly improved the general behavioral profiles of the mice, and also reduced TMAO, NLRP3, IL-1ß, and TGF-ß1 levels (P<0.05). Correlation analysis revealed significant positive correlations between TMAO concentrations and NLRP3, IL-1ß and TGF-ß1 levels (P<0.05). Pathological analysis revealed improvements in renal fibrosis and increased expression of the Occludin and ZO-1 proteins in intestinal tissue. In the SSP group, there was a significant increase in microbial activity (P<0.001). According to the sequencing results, the characteristic bacteria of the SSP and NR groups included Succinatimonas hippei, uncultured Solirubrobacter sp., and Clostridium tyrobutyricum. Furthermore, TMAO, NLRP3, IL-1ß, and TGF-ß1 were significantly positively correlated (P<0.05) with Succinatimonas hippei and Clostridium tyrobutyricum. By modulating Firmicutes, Succinatimonas hippei, and Clostridium tyrobutyricum, SSP decoction lowers TMAO levels to alleviate diarrhea with kidney-yang deficiency syndrome. CONCLUSIONS TMAO likely plays a significant role in the "gut-kidney axis" of diarrhea with kidney-yang deficiency syndrome. By adjusting gut microbiota to reduce the inflammatory response that is transmitted through the "gut-kidney axis" as a result of elevated TMAO levels, SSP decoction can alleviate diarrhea with kidney-yang deficiency syndrome.

Trimethylamine N-oxide, choline and its metabolites are associated with the risk of non-alcoholic fatty liver disease

It is inconclusive whether trimethylamine N-oxide (TMAO) and choline and related metabolites, namely trimethylamine (TMA), l-carnitine, betaine and dimethylglycine (DMG), are associated with non-alcoholic fatty liver disease (NAFLD). Our objective was to investigate these potential associations. Additionally, we sought to determine the mediating role of TMAO. In this 1:1 age- and sex-matched case-control study, a total of 150 pairs comprising NAFLD cases and healthy controls were identified. According to the fully adjusted model, after the highest tertile was compared with the lowest tertile, the plasma TMAO concentration (OR = 2·02 (95 % CI 1·04, 3·92); P trend = 0·003), l-carnitine concentration (OR = 1·79 (1·01, 3·17); P trend = 0·020) and DMG concentration (OR = 1·81 (1·00, 3·28); P trend = 0·014) were significantly positively associated with NAFLD incidence. However, a significantly negative association was found for plasma betaine (OR = 0. 50 (0·28, 0·88); P trend = 0·001). The restricted cubic splines model consistently indicated positive dose-response relationships between exposure to TMAO, l-carnitine, and DMG and NAFLD risk, with a negative association being observed for betaine. The corresponding AUC increased significantly from 0·685 (0·626, 0·745) in the traditional risk factor model to 0·769 (0·716, 0·822) when TMAO and its precursors were included (l-carnitine, betaine and choline) (P = 0·032). Mediation analyses revealed that 14·7 and 18·6 % of the excess NAFLD risk associated with l-carnitine and DMG, respectively, was mediated by TMAO (the P values for the mediating effects were 0·021 and 0·036, respectively). These results suggest that a higher concentration of TMAO is associated with increased NAFLD risk among Chinese adults and provide evidence of the possible mediating role of TMAO.

Ultra-processed foods and human health: An umbrella review and updated meta-analyses of observational evidence

BACKGROUND & AIMS

Ultra-processed food (UPF) intake has increased sharply over the last few decades and has been consistently asserted to be implicated in the development of non-communicable diseases. We aimed to evaluate and update the existing observational evidence for associations between ultra-processed food (UPF) consumption and human health.

METHODS

We searched Medline and Embase from inception to March 2023 to identify and update meta-analyses of observational studies examining the associations between UPF consumption, as defined by the NOVA classification, and a wide spectrum of health outcomes. For each health outcome, we estimated the summary effect size, 95% confidence interval (CI), between-study heterogeneity, evidence of small-study effects, and evidence of excess-significance bias. These metrics were used to evaluate evidence credibility of the identified associations.

RESULTS

This umbrella review identified 39 meta-analyses on the associations between UPF consumption and health outcomes. We updated all meta-analyses by including 122 individual articles on 49 unique health outcomes. The majority of the included studies divided UPF consumption into quartiles, with the lowest quartile being the reference group. We identified 25 health outcomes associated with UPF consumption. For observational studies, 2 health outcomes, including renal function decline (OR: 1.25; 95% CI: 1.18, 1.33) and wheezing in children and adolescents (OR: 1.42; 95% CI: 1.34, 1.49), showed convincing evidence (Class I); and five outcomes were reported with highly suggestive evidence (Class II), including diabetes mellitus, overweight, obesity, depression, and common mental disorders.

CONCLUSIONS

High UPF consumption is associated with an increased risk of a variety of chronic diseases and mental health disorders. At present, not a single study reported an association between UPF intake and a beneficial health outcome. These findings suggest that dietary patterns with low consumption of UPFs may render broad public health benefits.

Digestive dynamics: Unveiling interplay between the gut microbiota and the liver in macronutrient metabolism and hepatic metabolic health

Although the liver is the largest metabolic organ in the body, it is not alone in functionality and is assisted by "an organ inside an organ," the gut microbiota. This review attempts to shed light on the partnership between the liver and the gut microbiota in the metabolism of macronutrients (i.e., proteins, carbohydrates, and lipids). All nutrients absorbed by the small intestines are delivered to the liver for further metabolism. Undigested food that enters the colon is metabolized further by the gut microbiota that produces secondary metabolites, which are absorbed into portal circulation and reach the liver. These microbiota-derived metabolites and co-metabolites include ammonia, hydrogen sulfide, short-chain fatty acids, secondary bile acids, and trimethylamine N-oxide. Further, the liver produces several compounds, such as bile acids that can alter the gut microbial composition, which can in turn influence liver health. This review focuses on the metabolism of these microbiota metabolites and their influence on host physiology. Furthermore, the review briefly delineates the effect of the portosystemic shunt on the gut microbiota-liver axis, and current understanding of the treatments to target the gut microbiota-liver axis.

Antiaging Effects of Human Fecal Transplants with Different Combinations of Bifidobacterium bifidum LTBB21J1 and Lactobacillus casei LTL1361 in d-Galactose-Induced Mice

The feces of healthy middle-aged and old people were first transplanted into d-galactose-induced aging mice to construct humanized aging mice with gut microbiota (FMTC) to confirm the antiaging effect of probiotics produced from centenarians. The mouse model was then treated with centenarian-derived Bifidobacterium bifidum (FMTL), Lactobacillus casei (FMTB), and their mixtures (FMTM), and young mice were used as the control. Compared with the FMTC group, the results demonstrated that the probiotics and their combinations alleviated neuronal damage, increased antioxidant capacity, decreased inflammation, and enhanced cognitive and memory functions in aging mice. In the gut microbiota, the relative abundance of Lactobacillus, Ligilactobacillus, and Akkermansia increased and that of Desulfovibrio and Colidextribacter decreased in the FMTM group compared with that in the FMTC group. The three probiotic groups displayed significant changes in 15 metabolites compared with the FMTC group, with 4 metabolites showing increased expression and 11 metabolites showing decreased expression. The groups were graded as Control > FMTM > FMTB > FMTL > FMTC using a newly developed comprehensive quantitative scoring system that thoroughly analyzed the various indicators of this study. The beneficial antiaging effects of probiotics derived from centenarians were quantitatively described using a novel perspective in this study; it is confirmed that both probiotics and their combinations exert antiaging effects, with the probiotic complex group exhibiting a larger effect.

Interplay between metabolic dysfunction-associated fatty liver disease and renal function: An intriguing pediatric perspective

Over recent years, the nomenclature of non-alcoholic fatty liver disease has undergone significant changes. Indeed, in 2020, an expert consensus panel proposed the term "Metabolic (dysfunction) associated fatty liver disease" (MAFLD) to underscore the close association of fatty liver with metabolic abnormalities, thereby highlighting the cardiometabolic risks (such as metabolic syndrome, type 2 diabetes, insulin resistance, and cardiovascular disease) faced by these patients since childhood. More recently, this term has been further replaced with metabolic associated steatotic liver disease. It is worth noting that emerging evidence not only supports a close and independent association of MAFLD with chronic kidney disease in adults but also indicates its interplay with metabolic impairments. However, comparable pediatric data remain limited. Given the progressive and chronic nature of both diseases and their prognostic cardiometabolic implications, this editorial aims to provide a pediatric perspective on the intriguing relationship between MAFLD and renal function in childhood.

Integrative metagenomic and metabolomic analyses reveal the potential of gut microbiota to exacerbate acute pancreatitis

Early dysbiosis in the gut microbiota may contribute to the severity of acute pancreatitis (AP), however, a comprehensive understanding of the gut microbiome, potential pathobionts, and host metabolome in individuals with AP remains elusive. Hence, we employed fecal whole-metagenome shotgun sequencing in 82 AP patients and 115 matched healthy controls, complemented by untargeted serum metabolome and lipidome profiling in a subset of participants. Analyses of the gut microbiome in AP patients revealed reduced diversity, disrupted microbial functions, and altered abundance of 77 species, influenced by both etiology and severity. AP-enriched species, mostly potential pathobionts, correlated positively with host liver function and serum lipid indicators. Conversely, many AP-depleted species were short-chain fatty acid producers. Gut microflora changes were accompanied by shifts in the serum metabolome and lipidome. Specifically, certain gut species, like enriched Bilophila wadsworthia and depleted Bifidobacterium spp., appeared to contribute to elevated triglyceride levels in biliary or hyperlipidemic AP patients. Through culturing and whole-genome sequencing of bacterial isolates, we identified virulence factors and clinically relevant antibiotic resistance in patient-derived strains, suggesting a predisposition to opportunistic infections. Finally, our study demonstrated that gavage of specific pathobionts could exacerbate pancreatitis in a caerulein-treated mouse model. In conclusion, our comprehensive analysis sheds light on the gut microbiome and serum metabolome in AP, elucidating the role of pathobionts in disease progression. These insights offer valuable perspectives for etiologic diagnosis, prevention, and intervention in AP and related conditions.

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.

Assessment of the causal relationship between gut microbiota and cardiovascular diseases: a bidirectional Mendelian randomization analysis

BACKGROUND

Previous studies have shown an association between gut microbiota and cardiovascular diseases (CVDs). However, the underlying causal relationship remains unclear. This study aims to elucidate the causal relationship between gut microbiota and CVDs and to explore the pathogenic role of gut microbiota in CVDs.

METHODS

In this two-sample Mendelian randomization study, we used genetic instruments from publicly available genome-wide association studies, including single-nucleotide polymorphisms (SNPs) associated with gut microbiota (n = 14,306) and CVDs (n = 2,207,591). We employed multiple statistical analysis methods, including inverse variance weighting, MR Egger, weighted median, MR pleiotropic residuals and outliers, and the leave-one-out method, to estimate the causal relationship between gut microbiota and CVDs. Additionally, we conducted multiple analyses to assess horizontal pleiotropy and heterogeneity.

RESULTS

GWAS summary data were available from a pooled sample of 2,221,897 adult and adolescent participants. Our findings indicated that specific gut microbiota had either protective or detrimental effects on CVDs. Notably, Howardella (OR = 0.955, 95% CI: 0.913-0.999, P = .05), Intestinibacter (OR = 0.908, 95% CI:0.831-0.993, P = .03), Lachnospiraceae (NK4A136 group) (OR = 0.904, 95% CI:0.841-0.973, P = .007), Turicibacter (OR = 0.904, 95% CI: 0.838-0.976, P = .01), Holdemania (OR, 0.898; 95% CI: 0.810-0.995, P = .04) and Odoribacter (OR, 0.835; 95% CI: 0.710-0.993, P = .04) exhibited a protective causal effect on atrial fibrillation, while other microbiota had adverse causal effects. Similar effects were observed with respect to coronary artery disease, myocardial infarction, ischemic stroke, and hypertension. Furthermore, reversed Mendelian randomization analyses revealed that atrial fibrillation and ischemic stroke had causal effects on certain gut microbiotas.

CONCLUSION

Our study underscored the importance of gut microbiota in the context of CVDs and lent support to the hypothesis that increasing the abundance of probiotics or decreasing the abundance of harmful bacterial populations may offer protection against specific CVDs. Nevertheless, further research is essential to translate these findings into clinical practice.

From Liver to Brain: How MAFLD/MASLD Impacts Cognitive Function

Metabolic dysfunction-associated fatty liver disease or metabolic dysfunction-associated steatotic liver disease (MAFLD/MASLD), is a common chronic liver condition affecting a substantial global population. Beyond its primary impact on liver function, MAFLD/MASLD is associated with a myriad of extrahepatic manifestations, including cognitive impairment. The scope of cognitive impairment within the realm of MAFLD/MASLD is a matter of escalating concern. Positioned as an intermediate stage between the normal aging process and the onset of dementia, cognitive impairment manifests as a substantial challenge associated with this liver condition. Insights from studies underscore the presence of compromised executive function and a global decline in cognitive capabilities among individuals identified as being at risk of progressing to liver fibrosis. Importantly, this cognitive impairment transcends mere association with metabolic factors, delving deep into the intricate pathophysiology characterizing MAFLD/MASLD. The multifaceted nature of cognitive impairment in the context of MAFLD/MASLD is underlined by a spectrum of factors, prominently featuring insulin resistance, lipotoxicity, and systemic inflammation as pivotal contributors. These factors interplay within the intricate landscape of MAFLD/MASLD, fostering a nuanced understanding of the links between hepatic health and cognitive function. By synthesizing the available evidence, exploring potential mechanisms, and assessing clinical implications, the overarching aim of this review is to contribute to a more complete understanding of the impact of MAFLD/MASLD on cognitive function.

Therapeutic applications of gut microbes in cardiometabolic diseases: current state and perspectives

Cardiometabolic disease (CMD) encompasses a range of diseases such as hypertension, atherosclerosis, heart failure, obesity, and type 2 diabetes. Recent findings about CMD's interaction with gut microbiota have broadened our understanding of how diet and nutrition drive microbes to influence CMD. However, the translation of basic research into the clinic has not been smooth, and dietary nutrition and probiotic supplementation have yet to show significant evidence of the therapeutic benefits of CMD. In addition, the published reviews do not suggest the core microbiota or metabolite classes that influence CMD, and systematically elucidate the causal relationship between host disease phenotypes-microbiome. The aim of this review is to highlight the complex interaction of the gut microbiota and their metabolites with CMD progression and to further centralize and conceptualize the mechanisms of action between microbial and host disease phenotypes. We also discuss the potential of targeting modulations of gut microbes and metabolites as new targets for prevention and treatment of CMD, including the use of emerging technologies such as fecal microbiota transplantation and nanomedicine. KEY POINTS: • To highlight the complex interaction of the gut microbiota and their metabolites with CMD progression and to further centralize and conceptualize the mechanisms of action between microbial and host disease phenotypes. • We also discuss the potential of targeting modulations of gut microbes and metabolites as new targets for prevention and treatment of CMD, including the use of emerging technologies such as FMT and nanomedicine. • Our study provides insight into identification-specific microbiomes and metabolites involved in CMD, and microbial-host changes and physiological factors as disease phenotypes develop, which will help to map the microbiome individually and capture pathogenic mechanisms as a whole.

SAH and SAM/SAH ratio associate with acute kidney injury in critically ill patients: A case-control study

BACKGROUND

Acute kidney injury (AKI) is a serious clinical emergency with an acute onset, rapid progression and poor prognosis, which has high morbidity and mortality in hospitalized patients. DNA methylation plays an important role in the occurrence and progression of kidney disease, and aberrant methylation and certain altered methylation-related metabolites have been reported in AKI patients. However, the specific alterations of methylation-related metabolites in the AKI patients were not investigated clearly.

METHOD

In this study, 61 AKI and 61 matched non-AKI inpatients were recruited after propensity score matching the age and hypertension. And 11 methylation-related metabolites in the plasma and urine of the two groups were quantified by using UHPLC-MS/MS method.

RESULTS

Certain methylation-relate intermediates were up-regulated in the plasma (choline, trimethylamine N-oxide (TMAO), trimethyl lysine (TML), S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH)) and down-regulated in the urine of AKI inpatients (choline, betaine, TMAO, dimethylglycine (DMG), SAM and taurine). The correlation analysis revealed a relatively strong correlation between plasma SAH, SAM/SAH ratio and renal function index (serum creatinine (SCr) and estimated glomerular filtration rate (eGFR), r = 0.523-0.616), and the correlation of urinary intermediates with renal function index was weaker than that in the plasma. Furthermore, receiver operating characteristic (ROC) analysis showed that plasma SAH and urinary SAM/SAH ratio represented the best distinguishing efficiency with AUC 0.844 and 0.794, respectively. Moreover, the findings of binary regression analysis demonstrated plasma choline, TMAO, TML, SAM and SAH were the risk markers of AKI (up-regulation in plasma, OR > 1), urinary choline, betaine, TMAO, DMG and SAM were protective markers of AKI (down-regulation in urine, OR < 1), and SAM/SAH ratio was a protective marker in plasma and urine (down-regulation in both two biofluids, OR = 0.510, 0.383-0.678 in plasma, OR = 0.904, 0.854-0.968 in urine), indicating the increased risk of AKI when combined with the alteration of plasma and urinary levels.

CONCLUSION

The comprehensive analysis of plasma and urine samples from AKI inpatients offers a more extensive assessment of methylated metabolic alterations, suggesting a close relationship between AKI stress and altered methylation ability. The plasma level of SAH and SAM/SAH ratio and urinary SAM/SAH ratio both showed a strong correlation with renal function (SCr and eGFR) and good accuracy for distinguishing AKI in the two biomatrices, which exhibited promising prospects in predicting renal function decline and providing further information for the pathogenesis of AKI.

Untapped potential of gut microbiome for hypertension management

The gut microbiota has been shown to be associated with a range of illnesses and disorders, including hypertension, which is recognized as the primary factor contributing to the development of serious cardiovascular diseases. In this review, we conducted a comprehensive analysis of the progression of the research domain pertaining to gut microbiota and hypertension. Our primary emphasis was on the interplay between gut microbiota and blood pressure that are mediated by host and gut microbiota-derived metabolites. Additionally, we elaborate the reciprocal communication between gut microbiota and antihypertensive drugs, and its influence on the blood pressure of the host. The field of computer science has seen rapid progress with its great potential in the application in biomedical sciences, we prompt an exploration of the use of microbiome databases and artificial intelligence in the realm of high blood pressure prediction and prevention. We propose the use of gut microbiota as potential biomarkers in the context of hypertension prevention and therapy.

Ethanol-induced changes to the gut microbiome compromise the intestinal homeostasis: a review

The intestine is the largest organ in terms of surface area in the human body. It is responsible not only for absorbing nutrients but also for protection against the external world. The gut microbiota is essential in maintaining a properly functioning intestinal barrier, primarily through producing its metabolites: short-chain fatty acids, bile acids, and tryptophan derivatives. Ethanol overconsumption poses a significant threat to intestinal health. Not only does it damage the intestinal epithelium, but, maybe foremostly, it changes the gut microbiome. Those ethanol-driven changes shift its metabolome, depriving the host of the protective effect the physiological gut microbiota has. This literature review discusses the impact of ethanol consumption on the gut, the gut microbiota, and its metabolome, providing a comprehensive overview of the mechanisms through which ethanol disrupts intestinal homeostasis and discussing potential avenues for new therapeutic intervention.