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

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

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

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

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

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

PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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

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

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

Background

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

Methods

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

Results

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

Conclusion

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

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

Background

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

Objective

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

Methods

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

Results

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

Conclusion

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

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

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

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

BACKGROUND

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Reactive oxygen species in hypertension

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

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

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

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

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

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

Background

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

Methods

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

Results

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

Conclusion

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

Systematic Review Registration

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

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

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

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

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

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

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

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

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

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

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

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

BACKGROUND

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

MAIN BODY

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

CONCLUSION

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

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

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

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

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

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

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

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

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

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

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

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

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

Role of Gut Microbial Metabolites in Cardiovascular Diseases-Current Insights and the Road Ahead

Cardiovascular diseases (CVDs) are the leading cause of premature morbidity and mortality globally. The identification of novel risk factors contributing to CVD onset and progression has enabled an improved understanding of CVD pathophysiology. In addition to the conventional risk factors like high blood pressure, diabetes, obesity and smoking, the role of gut microbiome and intestinal microbe-derived metabolites in maintaining cardiovascular health has gained recent attention in the field of CVD pathophysiology. The human gastrointestinal tract caters to a highly diverse spectrum of microbes recognized as the gut microbiota, which are central to several physiologically significant cascades such as metabolism, nutrient absorption, and energy balance. The manipulation of the gut microbial subtleties potentially contributes to CVD, inflammation, neurodegeneration, obesity, and diabetic onset. The existing paradigm of studies suggests that the disruption of the gut microbial dynamics contributes towards CVD incidence. However, the exact mechanistic understanding of such a correlation from a signaling perspective remains elusive. This review has focused upon an in-depth characterization of gut microbial metabolites and their role in varied pathophysiological conditions, and highlights the potential molecular and signaling mechanisms governing the gut microbial metabolites in CVDs. In addition, it summarizes the existing courses of therapy in modulating the gut microbiome and its metabolites, limitations and scientific gaps in our current understanding, as well as future directions of studies involving the modulation of the gut microbiome and its metabolites, which can be undertaken to develop CVD-associated treatment options. Clarity in the understanding of the molecular interaction(s) and associations governing the gut microbiome and CVD shall potentially enable the development of novel druggable targets to ameliorate CVD in the years to come.

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

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

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

Background

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

Methods

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

Results

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

Conclusion

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

The mechanisms underlying acute myocardial infarction in chronic kidney disease patients undergoing hemodialysis

Cardiovascular disease (CVD) is a leading cause of death in chronic kidney disease (CKD). Hemodialysis is one of the main treatments for patients with end-stage kidney disease. Epidemiological data has shown that acute myocardial infarction (AMI) accounts for the main reason for death in patients with CKD under hemodialysis therapy. Immune dysfunction and changes in metabolism (including a high level of inflammatory cytokines, a disorder of lipid and mineral ion homeostasis, accumulation of uremic toxins et al.) during CKD can deteriorate stability of atherosclerotic plaque and promote vascular calcification, which are exactly the pathophysiological mechanisms underlying the occurrence of AMI. Meanwhile, the hemodialysis itself also has adverse effects on lipoprotein, the immune system and hemodynamics, which contribute to the high incidence of AMI in these patients. This review aims to summarize the mechanisms and further promising methods of prevention and treatment of AMI in CKD patients undergoing hemodialysis, which can provide an excellent paradigm for exploring the crosstalk between the kidney and cardiovascular system.

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

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

Oxidative Stress-Mediated Programmed Cell Death: a Potential Therapy Target for Atherosclerosis

Nowadays, as a type of orderly and active death determined by genes, programmed cell death (PCD), including apoptosis, pyroptosis, ferroptosis, and necroptosis, has attracted much attention owing to its participation in numerous chronic cardiovascular diseases, especially atherosclerosis (AS), a canonical chronic inflammatory disease featured by lipid metabolism disturbance. Abundant researches have reported that PCD under distinct internal conditions fulfills different roles of atherosclerotic pathological processes, including lipid core expansion, leukocyte adhesion, and infiltration. Noteworthy, emerging evidence recently has also suggested that oxidative stress (OS), an imbalance of antioxidants and oxygen free radicals, has the potential to mediate PCD occurrence via multiple ways, including oxidization and deubiquitination. Interestingly, more recently, several studies have proposed that the mediating mechanisms could effect on the atherosclerotic initiation and progression significantly from variable aspects, so it is of great clinical importance to clarify how OS-mediated PCD and AS interact. Herein, with the aim of summarizing potential and sufficient atherosclerotic therapy targets, we seek to provide extensive analysis of the specific regulatory mechanisms of PCD mediated by OS and their multifaceted effects on the entire pathological atherosclerotic progression.

Multi-metabolomics and intestine microbiome analysis: YZC extract ameliorates septic-ALI by modulating intestine microbiota to reduce TMAO/NLRP3 signaling

BACKGROUND

Sepsis causes inflammation in response to infection, often leading to acute lung injury (ALI). Yazhicao (Commelina communis L., YZC) is widely distributed in the global tropics and has good anti-respiratory inflammatory activity; however, the protection of YZC against septic-ALI has not been established.

PURPOSE

The role of YZC in septic-ALI will be investigated in this study.

METHODS AND RESULTS

In this study, YZC was shown to inhibit excessive inflammation and alleviate septic-ALI. Network pharmacology predicts that Quercetin, Acacetin and Diosmetin have the potential to serve as the pharmacological substance basis of YZC in alleviating septic-ALI. The metabolomics results indicated that YZC could improve the metabolic disorders caused by septic-ALI, which were mostly concerned with energy metabolism and amino acid metabolism, with Trimethylamine (TMA)/Trimethylamine N-oxide (TMAO) being potential small molecule metabolic markers for the clinical diagnosis and treatment of septic-ALI. YZC inhibits the initiation and progression of septic-ALI by controlling the TMA/TMAO metabolites. Our results also suggest that YZC protects the intestinal barrier from damage. Furthermore, our research indicated that YZC reduces TMAO synthesis by inhibiting TMA production through remodeling the intestine microbiota. We investigated the mechanism of YZC-mediated protection against septic-ALI and showed that YZC reduced the expression of proteins associated with NLRP3 inflammatory vesicles in the lung by inhibiting the expression of NF-κB.

CONCLUSION

These results show that YZC inhibits the NF-κB/NLRP3 signaling pathway by regulating metabolic and intestinal flora disorders in septic-ALI mice to reduce TMAO synthesis. This study presents a theoretical groundwork for the advancement of novel medications and clinical use of YZC to enhance septic-ALI and furnishes a theoretical rationale for regulating intestinal microbiota as a therapeutic instrument to treat sepsis and septic-ALI.

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

Background

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

Methods

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

Results

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

Conclusions

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

Trimethylamine N-Oxide in Aquatic Foods

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

B(a)P induces ovarian granulosa cell apoptosis via TRAF2-NFκB-Caspase1 axis during early pregnancy

Benzo(a)pyrene [B(a)P] is an environmental endocrine disruptor with reproductive toxicity. The corpus luteum (CL) of the ovary plays an important role in embryo implantation and pregnancy maintenance. Our previous studies have shown that B(a)P exposure affects embryo implantation and endometrial decidualization in mouse, but its effects and mechanisms on CL function remain unclear. In this study, we explore the mechanism of ovarian toxicity of B(a)P using a pregnant mouse model and an in vitro model of human ovarian granulosa cells (GCs) KGN. Pregnant mice were gavaged with corn oil or 0.2 mg/kg.bw B(a)P from pregnant day 1 (D1) to D7, while KGN cells were treated with DMSO, 1.0IU/mL hCG, or 1.0IU/mL hCG plus benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE), a B(a)P metabolite. Our findings revealed that B(a)P exposure damaged embryo implantation and reduced estrogen and progesterone levels in early pregnant mice. Additionally, in vitro, BPDE impaired luteinization in KGN cells. We observed that B(a)P/BPDE promoted oxidative stress (OS) and inflammation, leading to apoptosis rather than pyroptosis in ovaries and luteinized KGN cells. This apoptotic response was mediated by the activation of inflammatory Caspase1 through the cleavage of BID. Furthermore, B(a)P/BPDE inhibited TRAF2 expression and suppressed NFκB signaling pathway activation. The administration of VX-765 to inhibit the Caspase1 activation, over-expression of TRAF2 using TRAF2-pcDNA3.1 (+) plasmid, and BetA-induced activation of NFκB signaling pathway successfully alleviated BPDE-induced apoptosis and cellular dysfunction in luteinized KGN cells. These findings were further confirmed in the KGN cell treated with H2O2 and NAC. In conclusion, this study elucidated that B(a)P/BPDE induces apoptosis rather than pyroptosis in GCs via TRAF2-NFκB-Caspase1 during early pregnancy, and highlighting OS as the primary contributor to B(a)P/BPDE-induced ovarian toxicity. Our results unveil a novel role of TRAF2-NFκB-Caspase1 in B(a)P-induced apoptosis and broaden the understanding of mechanisms underlying unexplained luteal phase deficiency.

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

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

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.

Cannabidiol and Beta-Caryophyllene Combination Attenuates Diabetic Neuropathy by Inhibiting NLRP3 Inflammasome/NFκB through the AMPK/sirT3/Nrf2 Axis

BACKGROUND

In this study, we investigated in detail the role of cannabidiol (CBD), beta-caryophyllene (BC), or their combinations in diabetic peripheral neuropathy (DN). The key factors that contribute to DN include mitochondrial dysfunction, inflammation, and oxidative stress.

METHODS

Briefly, streptozotocin (STZ) (55 mg/kg) was injected intraperitoneally to induce DN in Sprague-Dawley rats, and we performed procedures involving Randall Sellito calipers, a Von Frey aesthesiometer, a hot plate, and cold plate methods to determine mechanical and thermal hyperalgesia in vivo. The blood flow to the nerves was assessed using a laser Doppler device. Schwann cells were exposed to high glucose (HG) at a dose of 30 mM to induce hyperglycemia and DCFDA, and JC1 and Mitosox staining were performed to determine mitochondrial membrane potential, reactive oxygen species, and mitochondrial superoxides in vitro. The rats were administered BC (30 mg/kg), CBD (15 mg/kg), or combination via i.p. injections, while Schwann cells were treated with 3.65 µM CBD, 75 µM BC, or combination to assess their role in DN amelioration.

RESULTS

Our results revealed that exposure to BC and CBD diminished HG-induced hyperglycemia in Schwann cells, in part by reducing mitochondrial membrane potential, reactive oxygen species, and mitochondrial superoxides. Furthermore, the BC and CBD combination treatment in vivo could prevent the deterioration of the mitochondrial quality control system by promoting autophagy and mitochondrial biogenesis while improving blood flow. CBD and BC treatments also reduced pain hypersensitivity to hyperalgesia and allodynia, with increased antioxidant and anti-inflammatory action in diabetic rats. These in vivo effects were attributed to significant upregulation of AMPK, sirT3, Nrf2, PINK1, PARKIN, LC3B, Beclin1, and TFAM functions, while downregulation of NLRP3 inflammasome, NFκB, COX2, and p62 activity was noted using Western blotting.

CONCLUSIONS

the present study demonstrated that STZ and HG-induced oxidative and nitrosative stress play a crucial role in the pathogenesis of diabetic neuropathy. We find, for the first time, that a CBD and BC combination ameliorates DN by modulating the mitochondrial quality control system.

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.

Shenfu injection improves isoproterenol-induced heart failure in rats by modulating co-metabolism and regulating the trimethylamine-N-oxide - inflammation axis

Heart failure (HF) is a chronic condition that progressively worsens and continues to be a major financial burden and public health concern. The "gut-heart" axis provides an innovative perspective and therapeutic strategy for preventing and treating heart failure. Shenfu injection (SFI) is a Traditional Chinese Medicine-based treatment demonstrating potential as a therapeutic strategy for heart failure. However, the precise therapeutic mechanisms of SFI in heart failure are not completely characterized. In this study, HF models were established utilizing subcutaneous multipoint injection of isoproterenol (ISO) at a dosage of 5 mg kg-1·d-1 for 7 days. Serum levels of inflammatory biomarkers were quantified using protein microarrays. Rat feces were analyzed using untargeted metabolomics research and 16S rRNA sequencing. The link between gut microbiota and metabolites was examined using a MetOrigin and Spearman correlation analysis. Our results show that Shenfu injection effectively enhances cardiac function in rats with ISO-induced heart failure by potentially modulating pro-/anti-inflammatory imbalance and reducing serum and urine Trimethylamine-N-oxide (TMAO) levels. Moreover, SFI significantly increases the abundance of Bacteroidota at the phylum level, thereby improving disrupted gut microbiota composition. Additionally, SFI supplementation enriches specific genera known for their capacity to produce short-chain fatty acids. SFI was found to be associated with three key metabolic pathways, as revealed by fecal metabonomics analysis, including the pentose phosphate pathway, pyrimidine metabolism, and purine metabolism. Metabolite tracing analysis revealed that Taurine and hypotaurine metabolism was found to be specific to the microbial community. The biosynthesis of Pyrimidine metabolism, Purine metabolism, beta-alanine metabolism, Naphthalene degradation, Pantothenate, and CoA biosynthesis were identified as co-metabolic pathways between microbes and host. The Spearman correlation analysis was also significantly correlated to differentially expressed metabolites regulated by SFI and the gut microbiota. These results suggest that SFI improves ISO-induced heart failure by modulating co-metabolism and regulating the TMAO-inflammation axis.

Loss of flavin-containing monooxygenase 3 modulates dioxin-like polychlorinated biphenyl 126-induced oxidative stress and hepatotoxicity

Dioxin-like pollutants (DLPs), such as polychlorinated biphenyl 126 (PCB 126), are synthetic chemicals classified as persistent organic pollutants. They accumulate in adipose tissue and have been linked to cardiometabolic disorders, including fatty liver disease. The toxicity of these compounds is associated with activation of the aryl hydrocarbon receptor (Ahr), leading to the induction of phase I metabolizing enzyme cytochrome P4501a1 (Cyp1a1) and the subsequent production of reactive oxygen species (ROS). Recent research has shown that DLPs can also induce the xenobiotic detoxification enzyme flavin-containing monooxygenase 3 (FMO3), which plays a role in metabolic homeostasis. We hypothesized whether genetic deletion of Fmo3 could protect mice, particularly in the liver, where Fmo3 is most inducible, against PCB 126 toxicity. To test this hypothesis, male C57BL/6 wild-type (WT) mice and Fmo3 knockout (Fmo3 KO) mice were exposed to PCB 126 or vehicle (safflower oil) during a 12-week study, at weeks 2 and 4. Various analyses were performed, including hepatic histology, RNA-sequencing, and quantitation of PCB 126 and F2-isoprostane concentrations. The results showed that PCB 126 exposure caused macro and microvesicular fat deposition in WT mice, but this macrovesicular fatty change was absent in Fmo3 KO mice. Moreover, at the pathway level, the hepatic oxidative stress response was significantly different between the two genotypes, with the induction of specific genes observed only in WT mice. Notably, the most abundant F2-isoprostane, 8-iso-15-keto PGE2, increased in WT mice in response to PCB 126 exposure. The study's findings also demonstrated that hepatic tissue concentrations of PCB 126 were higher in WT mice compared to Fmo3 KO mice. In summary, the absence of FMO3 in mice led to a distinctive response to dioxin-like pollutant exposure in the liver, likely due to alterations in lipid metabolism and storage, underscoring the complex interplay of genetic factors in the response to environmental toxins.

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

BACKGROUND

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Applied physiology: gut microbiota and antimicrobial therapy

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

Investigation of serum trimethylamine-N-oxide levels in missed abortion: A prospective study

OBJECTIVE

The aim of our study was to investigate the relationship between missed abortion and serum trimethylamine N-oxide (TMAO) levels.

METHODS

A total of 129 patients with 56 missed abortions and 73 healthy pregnancies were included in our study. Patients who had more than one pregnancy loss, had systemic disease (hypertension, diabetes, rheumatologic disease, hematologic disease, and so forth) and did not accept to participate in the study were excluded. Pregnant women who did not have a fetal heartbeat in the first 20th week of pregnancy were considered as missed abortion. Demographic characteristics of the patients were recorded. The serum TMAO levels of these patients were compared with the serum TMAO levels of healthy pregnant women with the same gestational week between the two groups.

RESULTS

The median (IQR) serum level of TMAO was significantly higher in woman with missed abortus compared to the healthy controls (201.5 [IQR, 129.75-345] vs 150 [IQR, 86.9-273], U = 1534, P = 0.015, rrb = 0.25 [95% CI: 0.05-0.43]). We observed a positive and significant relationship between serum TMAO levels and age of the patients (Spearman's rho = 0.272 [95% CI: 0.01-0.50], P = 0.043). However, no significant relationship was found between serum TMAO levels and BMI (Spearman's rho = 0.093 [95% CI: -0.18 to 0.35], P = 0.496).

CONCLUSION

In our study, we found that the serum TMAO level was higher in patients with missed abortion compared to healthy pregnancies. Serum TMAO levels measured at early gestational weeks can provide information about the course of pregnancy.

Causal relationship between gut microbiota and intracranial hemorrhage: A two-sample Mendelian randomization study

Patients with intracranial hemorrhage (ICH) usually have an imbalance in the gut microbiota (GM); however, whether this is a causal correlation remains unclear. This study used summary data from an open genome-wide association study to conduct double-sample Mendelian randomization (MR) to test the causal correlation between GM and ICH. First, we used a cutoff value of P < 10E-5 to select single nucleotide polymorphisms critical for each GM. Inverse variance weighted, weighted median, and MR-PRESSO methods were used to evaluate the strength of this causal association. Finally, functional maps and annotations from genome-wide association studies were used to determine the biological functions of the genes. MR analysis revealed that Rikenellaceae RC9 gut group was significantly positively correlated with ICH risk. For every unit increase in Rikenellaceae RC9 gut group, the relative risk of ICH increased by 34.4%(P = 4.62E-04). Rhodospirillales, Terrisporobacter, Veillonellaceae, Coprococcus 3, unknown genus, Alphaproteobacteria, and Allisonella groups were negatively correlated with the risk of ICH, while Anaerofilum, Eubacteriumbrachy group, Clostridia, Howardella, and Romboutsia were negatively correlated with the risk of ICH. Nonetheless, the specific role of single nucleotide polymorphisms gene enrichment requires further investigation. This study suggests the causal effect on ICH. The discovery of >10 GMs associated with ICH could be used to prevent and treat ICH.

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

INTRODUCTION

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Gut microbiota-host lipid crosstalk in Alzheimer's disease: implications for disease progression and therapeutics

Trillions of intestinal bacteria in the human body undergo dynamic transformations in response to physiological and pathological changes. Alterations in their composition and metabolites collectively contribute to the progression of Alzheimer's disease. The role of gut microbiota in Alzheimer's disease is diverse and complex, evidence suggests lipid metabolism may be one of the potential pathways. However, the mechanisms that gut microbiota mediate lipid metabolism in Alzheimer's disease pathology remain unclear, necessitating further investigation for clarification. This review highlights the current understanding of how gut microbiota disrupts lipid metabolism and discusses the implications of these discoveries in guiding strategies for the prevention or treatment of Alzheimer's disease based on existing data.