High-Fiber Diet and Acetate Supplementation Change the Gut Microbiota and Prevent the Development of Hypertension and Heart Failure in Hypertensive Mice

Unripe apple polyphenols extract improves intestinal inflammation and restructures gut microbiota in spontaneously hypertensive rats

Natural polyphenolic extracts have been recognized to reduce the risk of hypertension. Coupled with evidence that gut dysbiosis is tightly linked to the development of hypertension, we hypothesized that modulating gut microbiota may be associated with the benefits of unripe apple polyphenols extract (UAPE). This study aimed to explore the effects of UAPE on hypertension and its complications, while elucidating the underlying mechanisms in spontaneously hypertensive rats (SHR). SHR received either vehicle (ddH2O), captopril (30 mg/kg body weight/day), or low-dose (10 mg/kg body weight/day), middle-dose (50 mg/kg body weight/day), or high-dose (250 mg/kg body weight/day) UAPE by oral gavage daily for 8 weeks. Concurrently, Wistar-Kyoto (WKY) rats received vehicle to serve as normotensive controls. We observed that UAPE offered protective effects against hypertension-induced blood pressure elevation (systolic blood pressure, diastolic blood pressure), glycolipid metabolic disorders (serum lipids, glucose), and renal damage (serum creatinine, renal histopathology) in SHR. Additionally, UAPE exerted gut health benefits via enhancing intestinal barrier integrity (colonic and ileal histopathology, colonic tight junction protein 1 and Occludin mRNA and protein) and mitigating intestinal inflammation (colonic TNFα and IL-6 mRNA) in SHR. Moreover, UAPE effectively alleviated the development of left ventricular hypertrophy (cardiac histopathology, echocardiography) and endothelial dysfunction (serum endothelial nitric oxide synthase, endothelin-1), both critical markers of hypertensive progression. Mechanistically, the anti-inflammatory effects of UAPE may be linked to the colonic inhibition of the HMGB1-TLR4-NF-κB signaling pathway (mRNA and protein for colonic HMGB1, TLR4, and P-P65) in SHR. Notably, UAPE elevated microbial richness and diversity, normalizing the Firmicutes/Bacteroidetes ratio. Besides, UAPE increased the beneficial bacteria linked to healthy states, including Intestinimonas_butyriciproducens, Lactobacillus_intestinalis, Ruminiclostridium, Oscillibacter_sp., and Bifidobacterium, reduced the harmful bacteria related to hypertension, upregulated health-promoting microbial function, and elevated the concentrations of gut microbiota-derived short chain fatty acids, including acetic acid and butyric acid, in SHR. Collectively, these observations support the antihypertensive effects of UAPE in the SHR model, highlighting the intimate link between UAPE, gut microbiota, and hypertension. Our findings provide novel insights into the UAPE-mediated improvements in hypertension and its complications, which may be intricately linked to the modulation of the microbiota-gut axis.

Beyond the gut: Unraveling the multifaceted influence of microbiome on cardiovascular health

Cardiovascular disease is one of the leading causes of death worldwide. Even while receiving adequate pharmacological treatment for their hypertension, people are nonetheless at greater risk for cardiovascular disease. There is growing evidence that the gut microbiota may have major positive and negative effects on blood pressure and illnesses related with it as more study into this topic is conducted. Trimethylamine n-oxide (TMAO) and short-chain fatty acids (SCFA) are two major by-products of the gut microbiota. TMAO is involved in the formation of other coronary artery diseases, including atherosclerosis and hypertension, while SCFAs play an important role in controlling blood pressure. Numerous investigations have confirmed the established link between dietary salt intake and hypertension. Reducing sodium in the diet is linked to lower rates of cardiovascular disease morbidity and mortality as well as lower rates of blood pressure and hypertension. In both human and animal research, high salt diets increase local and systemic tissue inflammation and compromise gut architecture. Given that the gut microbiota constantly interacts with the immune system and is required for the correct maturation of immune cells, it is scientifically conceivable that it mediates the inflammatory response. This review highlights the therapeutic possibilities for focusing on intestinal microbiomes as well as the potential functions of the gut microbiota and its metabolites in the development of hypertension.

Higenamine protects against doxorubicin-induced heart failure by attenuating ferroptosis via modulating the Nrf2/GPX4 signaling pathway

BACKGROUND

Higenamine (HG), a benzylisoquinoline alkaloid in Aconiti Lateralis Radix Praeparata (ALRP), has cardioprotective effects. Prior research indicated its potential anti-heart failure (HF) function, yet the molecular mechanism remained elusive.

PURPOSE

This study aimed to explore the underlying mechanism of HG against doxorubicin (DOX)-induced HF via an integrated approach involving gut microbiota, untargeted metabolomics, network pharmacology, and molecular biology.

METHODS

DOX was employed to induce HF in rats and H9c2 cardiomyocytes injury models. Cardiac injury was assessed using hemodynamic indices, cardiac injury biomarkers, and oxidative stress markers. Cell counting kit-8 (CCK-8) method and high-content analysis were used to investigate the effects of HG on the cell proliferation, morphology and mitochondrial function of H9c2 cardiomyocytes. 16S rDNA sequencing analysis, untargeted metabolomics, and network pharmacology were performed to identify the multi-target and multi-pathway mechanisms of HG in treating HF. Furthermore, reverse transcription quantitative polymerase chain reaction (RT-qPCR), immunohistochemistry, and Western Blotting was used to investigate its intervention on the nuclear factor erythroid 2-related factor 2 (Nrf2)/glutathione peroxidase 4 (GPX4) ferroptosis pathway.

RESULTS

HG alleviated DOX-mediated myocardial injury by enhancing cardiac and mitochondrial function, reducing oxidative stress levels, and promoting cell proliferation. Effects of HG on changes in the gut microbiota of rats is characterized by a low abundance of Firmicutes and Proteobacteria, along with a high abundance of Bacteroidetes and Actinobacteria, indicating an improvement in DOX-induced dysbiosis. Untargeted metabolomics combined with network pharmacology showed that HG exerted anti-HF effects by regulating eight metabolites, eight pathways, and interacting with ferroptosis-related targets. Molecular biology studies revealed its cardioprotective effects via regulating the Nrf2/GPX4 ferroptosis pathway.

CONCLUSION

HG could inhibit ferroptosis and protect against HF by regulating the Nrf2/GPX4-mediated "mitochondrial-ferroptosis" pathway, offering a potential treatment strategy for HF.

Cardiac function of colorectal cancer mice is remotely controlled by gut microbiota: regulating serum metabolites and myocardial cytokines

Several studies have indicated that the dysregulation of microbial metabolites and the inflammatory environment resulting from microbial dysbiosis may contribute to the occurrence and progression of cardiovascular diseases. Therefore, restoring the disordered gut microbiota in patients with colorectal cancer by fecal microbiota transplantation (FMT) has the potential to reduce the incidence of cardiac disease. In this study, we identified cardiac dysfunction in azomethane and dextran sodium sulfate-induced colorectal cancer mice. Intestinal microbes from healthy mice were transferred to colorectal cancer mice, which vastly reversed the disorder of the gut microbiota and effectively alleviated cardiac dysfunction. Moreover, FMT regulated the expression of serum metabolites such as uridine triphosphate (UTP), tiamulin, andrographolide, and N-Acetyl-D-glucosamine, as well as cytokines like TGF-β, IRF5, and β-MHC in the heart. These findings uncover that the disturbed gut microbiota causes cardiac dysfunction in colorectal cancer mice by modulating the expression of serum metabolites and cytokines, which could be alleviated by treatment with FMT.

Interaction Between Gut-Heart Axis in Sepsis-Induced Cardiomyopathy

The gut microbiota and its metabolites profoundly influence cardiac function, emerging as critical players in the pathophysiology of Sepsis-Induced Cardiomyopathy (SIC). Conversely, therapeutic interventions for SIC and the resultant cardiac alterations can reciprocally modulate gut microbial composition and function. To systematically elucidate this complex bidirectional relationship during SIC, this review delineates two key aspects: the 'forward gut-heart axis', defined as influences originating from the gut microbiota and its metabolites directed towards the cardiovascular system, and the 'reverse gut-heart axis', encompassing the reciprocal effects of cardiovascular drugs and cardiac factors on the gut microbiota. Furthermore, we explore potential therapeutic strategies for SIC centered on the targeted modulation of this intricate gut-heart interplay.

Fecal microbiota transplantation for hypertension: an exploratory, multicenter, randomized, blinded, placebo-controlled trial

BACKGROUND

On the basis of the contribution of the gut microbiota to hypertension development, a novel strategy involving fecal microbiota transplantation (FMT) has been proposed to treat hypertension, but its efficacy has not been investigated in the clinic.

METHODS

In a randomized, blinded, placebo-controlled clinical trial (2021/03-2021/12, ClinicalTrials.gov, NCT04406129), hypertensive patients were recruited from seven centers in China, and received FMT or placebo capsules orally at three visits. The patients were randomized at a 1:1 ratio in blocks of four and stratified by center by an independent statistician. The intention-to-treat principle was implemented, as all randomized participants who received at least one intervention were included. The primary outcome was the decrease in office systolic blood pressure (SBP) from baseline to the day 30 visit. Adverse events (AEs) were recorded through the 3-month follow-up to assess safety measures. Alterations in BP, the fecal microbiome, and the plasma metabolome were assessed via exploratory analyses.

RESULTS

This study included 124 patients (mean age 43 years, 73.4% men) who received FMT (n = 63) or placebo (n = 61) capsules. The numbers of participants who experienced AEs (13 (20.6%) vs. 9 (14.8%), p = 0.39) and the primary outcome (6.28 (11.83) vs. 5.77 (10.06) mmHg, p = 0.62) were comparable between the groups. The FMT group presented a decrease in SBP after 1 week of FMT, with a between-arm difference of - 4.34 (95% CI, - 8.1 to - 0.58; p = 0.024) mmHg, but this difference did not persist even after repeated intervention. After FMT, shifts in microbial richness and structure were identified and the abundance of the phyla Firmicutes and Bacteroidetes was altered. Decreases in the abundances of Eggerthella lenta, Erysipelatoclostridium ramosum, Anaerostipes hadrus, Gemella haemolysans, and Streptococcus vestibularis and increases in the abundances of Parabacteroides merdae, Prevotella copri, Bacteroides galacturonicus, Eubacterium sp. CAG 180, Desulfovibrio piger, Megamonas hypermegale, Collinsella stercoris, Coprococcus catus, and Allisonella histaminiformans were identified and correlated with office SBP. Those species were also correlated with responding and inversely office SBP-associated metabolites including tyrosine, glutamine, aspartate, phenylalanine, methionine, serine, sarcosine, and/or asparagine.

CONCLUSIONS

Safety but unsustainable BP reduction was observed in the first trial of the effects of FMT on hypertension. Additional intervention studies on specific microbes with metabolite-targeting and BP-modulating features are needed. Video Abstract.

Aging at the Crossroads of Organ Interactions: Implications for the Heart

Aging processes underlie common chronic cardiometabolic diseases such as heart failure and diabetes. Cross-organ/tissue interactions can accelerate aging through cellular senescence, tissue wasting, accelerated atherosclerosis, increased vascular stiffness, and reduction in blood flow, leading to organ remodeling and premature failure. This interorgan/tissue crosstalk can accelerate aging-related dysfunction through inflammation, senescence-associated secretome, and metabolic and mitochondrial changes resulting in increased oxidative stress, microvascular dysfunction, cellular reprogramming, and tissue fibrosis. This may also underscore the rising incidence and co-occurrence of multiorgan dysfunction in cardiometabolic aging in the population. Examples include interactions between the heart and the lungs, kidneys, liver, muscles, and brain, among others. However, this phenomenon can also present new translational opportunities for identifying diagnostic biomarkers to define early risks of multiorgan dysfunction, gain mechanistic insights, and help to design precision-directed therapeutic interventions. Indeed, this opens new opportunities for therapeutic development in targeting multiple organs simultaneously to disrupt the crosstalk-driven process of mutual disease acceleration. New therapeutic targets could provide synergistic benefits across multiple organ systems in the same at-risk patient. Ultimately, these approaches may together slow the aging process itself throughout the body. In the future, with patient-centered multisystem coordinated approaches, we can initiate a new paradigm of multiorgan early risk prediction and tailored intervention. With emerging tools including artificial intelligence-assisted risk profiling and novel preventive strategies (eg, RNA-based therapeutics), we may be able to mitigate multiorgan cardiometabolic dysfunction much earlier and, perhaps, even slow the aging process itself.

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

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

The role of gut microbiota in cardiovascular diseases and their potential as novel therapeutic targets

Cardiovascular diseases (CVDs) including heart failure (HF) is a major health, medical and social issue that needs to be resolved in Japan's super-aged society. Recent clinical and basic studies suggest that the gut microbiota and their metabolites play critical roles in the onset and progression of CVDs. We explored changes in gut microbiota composition and metabolite levels among Japanese patients to investigate their association with CVDs. Changes in specific bacteria were observed, with a decrease in phylum Bacteroidetes and increases in order Lactobacillus or genus Streptococcus in coronary artery disease patients. For HF patients, a reduction in phylum Bacteroidetes and increases in phylum Actinobacteria (e.g. Bifidobacterium) and Proteobacteria (e.g. Escherichia, Shigella, and Klebsiella) were noted. Elevated levels of gut microbiota-associated metabolites, such as trimethylamine N-oxide (TMAO) and indoxyl sulfate, were observed in CVD patients, suggesting potential effects on organ functions. Many studies have linked higher plasma TMAO levels to worse prognoses in CVDs, including HF and renal failure. However, the clinical significance and therapeutic potential of these findings require further investigation. In this manuscript, the author aims to review the current status of research on gut microbiota in CVDs, with a primary focus on the microbes themselves and their related metabolites. Further research is essential to comprehensively understand these intricacies and establish clear cause-and-effect relationships, ultimately paving the way for the development of innovative therapies for CVDs.

Gut microbiota-derived short-chain fatty acids and their role in human health and disease

Short-chain fatty acids (SCFAs) are a group of organic compounds produced by the fermentation of dietary fibre by the human gut microbiota. They play diverse roles in different physiological processes of the host with implications for human health and disease. This Review provides an overview of the complex microbial metabolism underlying SCFA formation, considering microbial interactions and modulating factors of the gut environment. We explore the multifaceted mechanistic interactions between SCFAs and the host, with a particular focus on the local actions of SCFAs in the gut and their complex interactions with the immune system. We also discuss how these actions influence intestinal and extraintestinal diseases and emerging therapeutic strategies using SCFAs.

Nuclear Magnetic Resonance Analysis Seeking for Metabolic Markers of Hypertension in Human Serum

Hypertension is a highly prevalent medical condition that occurs when blood pressure is too high, which greatly increases the risk of developing other cardiovascular diseases and is generally associated with higher rates of morbidity and mortality. Due to the silent/asymptomatic nature of hypertension, although the methods currently available to diagnose it are easy, they generally do not allow for an early diagnosis and an efficient prognosis to avoid irreversible damage in the medium or long term. In fact, an early diagnosis of hypertension would be crucial to decrease hypertension-associated mortality. Since metabolomics using NMR can provide a global measurement of various serum metabolites, it is very suitable for detecting novel biomarkers. We therefore analyzed serum metabolomic profiles among normotensive and hypertensive elderly individuals by NMR and identified new potential biomarkers for hypertension and associated diseases. We found higher levels of acetate, formate, and glycerol, and lower levels of glutamine, glycine, and sarcosine in individuals with hypertension. Therefore, these metabolites could be used for early diagnosis of hypertension to avoid comorbidities derived from hypertension and associated mortality.

Gut microbiota-dependent increase in phenylacetic acid induces endothelial cell senescence during aging

Endothelial cell senescence is a key driver of cardiovascular aging, yet little is known about the mechanisms by which it is induced in vivo. Here we show that the gut bacterial metabolite phenylacetic acid (PAA) and its byproduct, phenylacetylglutamine (PAGln), are elevated in aged humans and mice. Metagenomic analyses reveal an age-related increase in PAA-producing microbial pathways, positively linked to the bacterium Clostridium sp. ASF356 (Clos). We demonstrate that colonization of young mice with Clos increases blood PAA levels and induces endothelial senescence and angiogenic incompetence. Mechanistically, we find that PAA triggers senescence through mitochondrial H2O2 production, exacerbating the senescence-associated secretory phenotype. By contrast, we demonstrate that fecal acetate levels are reduced with age, compromising its function as a Sirt1-dependent senomorphic, regulating proinflammatory secretion and redox homeostasis. These findings define PAA as a mediator of gut-vascular crosstalk in aging and identify sodium acetate as a potential microbiome-based senotherapy to promote healthy aging.

Mechanisms of Acetate in Alleviating SETDB1-Linked Neuroinflammation and Cognitive Impairment in a Mouse Model of OSA

Background

Microglia-mediated neuroinflammation is crucial for obstructive sleep apnea (OSA)-induced cognitive impairment. We aimed to investigate roles of acetate (ACE) and SET domain bifurcated histone lysine methyltransferase 1 (SETDB1) in neuroinflammation of OSA.

Methods

After C57BL/6J mice were exposed to OSA-associated intermittent hypoxia (IH) or normoxia for four weeks, the composition of the gut microbiota (GM) and the levels of serum short-chain fatty acids (SCFAs) were measured by 16S rRNA and GC-MS methods, respectively. To assess the effect of ACE on IH mice, glyceryl triacetate (GTA) was gavaged in IH-exposed mice and the cognitive function, microglial activation, and hippocampal neuronal death were examined. Moreover, ACE-treated BV2 microglia cells were also utilized for further mechanistic studies.

Results

IH disrupts the gut microbiome, reduces microbiota-SCFAs, and impairs cognitive function. Gavage with GTA significantly mitigated these cognitive deficits. Following IH exposure, we observed substantial increases in SETDB1 both in vivo and in vitro, along with elevated levels of histone H3 lysine 9 trimethylation (H3K9me3). Genetic or pharmacological inhibition of SETDB1 in microglia led to decreased induction of proinflammatory factors, as well as reduced reactive oxygen species (ROS) generation. Mechanistically, SETDB1 was found to upregulate the transcription factors p-signal transducer and activator of transcription 3 (p-STAT3) and p-NF-κB. In vitro, ACE supplementation effectively repressed high SETDB1 and H3K9me3 levels, thereby inhibiting microglial pro-inflammatory responses induced by IH. In vivo, ACE supplementation significantly reduced hippocampal levels of p-STAT3, p-NF-κB, and pro-inflammatory cytokines while also protecting neuronal integrity.

Conclusion

This study provides the first evidence that H3K9 methyltransferase SETDB1 promotes microglial pro-inflammatory response distinct from its previously shown role in macrophages. Our findings also identify ACE supplementation as a promising dietary intervention for OSA-related cognitive impairment with SETDB1 serving as both a mechanistic biomarker and potential therapeutic target.

Lentinan alleviates angiotensin II-induced myocardial remodeling through LMP7-SOCS3 signaling

Myocardial remodeling is a major pathological mechanism causing heart failure. As a critical negative modulator of cardiac remodeling, suppressor of cytokine signaling 3 (SOCS3) is regulated by immunoproteasome subunit large multifunctional peptidase 7 (LMP7). Lentinan (LNT), a β-polysaccharide extracted from Lentinus edodes, has anti-inflammatory and antioxidant properties. However, the role and molecular mechanisms of LNT in angiotensin II (Ang II)-triggered myocardial remodeling are unclear. Myocardial remodeling was established using Ang II infusion (1000 or 200 ng/kg/min) for 2 weeks. Cardiomyocytes and cardiac fibroblasts were triggered by Ang II. LNT was administered daily by oral gavage to mice starting 1 day before Ang II or saline treatment. Here, we found that LNT supplementation dose-dependently ameliorated Ang II-triggered myocardial dysfunction and remodeling (hypertrophy, fibrosis, inflammation, and superoxide production). Mechanistically, LNT suppressed SOCS3 protein degradation by downregulating immunoproteasome LMP7 activity and expression, thereby inactivating downstream signaling, such as STAT3, ERK, AKT, NF-κB, and TGF-β. Conversely, SOCS3 knockdown significantly blocked the protective effect of LNT on myocardial remodeling in Ang II-infused mice. Together, our findings suggest that LNT may be a new therapeutic approach for myocardial remodeling and heart failure.

Diabetes mellitus secondary to endocrine diseases: a position statement of the working group of the club of the Italian society of endocrinology (SIE)-Nutrition hormones and metabolism

PURPOSE

This position statement addressed the limited scientific literature on the management of diabetes mellitus secondary to endocrinopathies, despite its frequent occurrence in hormonal diseases such as acromegaly, Cushing's syndrome, primary hyperaldosteronism, pheochromocytoma, hyperthyroidism, and neuroendocrine tumors. The aim was to review the pathophysiological mechanisms, clinical features, and management strategies, focusing on nutritional and pharmacological approaches.

METHODS

A comprehensive review of existing literature was conducted regarding studies on diabetes secondary to endocrinopathies and the effects of treatments for these conditions, such as somatostatin analogues and pancreatic surgery. Particular emphasis was placed on understanding glucose metabolism derangements and the interplay between endocrine excess and therapeutic interventions.

RESULTS

Secondary diabetes arises not only from hormone excess but also as a consequence of treatments for endocrine disorders. For instance, somatostatin analogues, while effective in resolving hormone hypersecretion, impair glucose metabolism by inhibiting pancreatic insulin secretion. Similarly, pancreatic surgery for neuroendocrine tumors often exacerbates glycemic disturbances. The management of secondary diabetes requires a multidisciplinary approach that includes treating the underlying endocrine disorder, tailoring antidiabetic therapy, and optimizing nutritional strategies to mitigate metabolic disruptions.

CONCLUSION

Diabetes secondary to endocrinopathies presents unique challenges due to its complex etiology and the metabolic effects of treatments. This position statement underscores the importance of an integrated management approach, offering guidance for clinicians in addressing this multifaceted condition. Further research is needed to develop evidence-based guidelines for optimal care.

"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.

Effects of high-dose glucocorticoids on gut microbiota in the treatment of Graves' ophthalmopathy

Many studies indicate the gut microbiome is associated with diseases caused by administering high-dose glucocorticoids (GCs), such as hypertension, hyperglycemia, and osteoporosis. However, the association between intestinal flora and the use of high-dose GCs remains elusive. We aimed to characterize gut microbiome in Graves' ophthalmopathy (GO) patients after administering high-dose GCs. In this study, 20 primary GO patients were recruited. The differences in gut microbiota of GO patients before and after administering high-dose GCs were analyzed by 16S rDNA sequencing technology. Untargeted metabolomic analysis was used to examine the differences in gut metabolites between two groups. There were significant differences in α and β diversities of gut microbiota in GO patients before and after administering high-dose GCs. The random forest analysis indicated that three intestinal bacteria (Faecalibacterium, Streptococcus, and Prevotella) could distinguish the two groups with the highest accuracy, which was proven by receiver operator characteristic curve and linear discriminant analysis effect size analysis. The short-chain fatty acid-producing ability in GO patients' gut after high-dose GC administration was significantly decreased. The 5-hydroxytryptamine levels significantly increased in the gut of GO patients after administering high-dose GCs. Our study suggests that high-dose GC administration causes the changes in gut microbiome and metabolites. Moreover, the altered flora and metabolites are related to hypertension, hyperglycemia, and osteoporosis. These findings can help understand the development of side effects caused by high-dose GCs and can be further used to develop potential probiotics to facilitate the prevention for those side effects.IMPORTANCEFor the first time, we revealed that gut microbiome and metabolome in Graves' ophthalmopathy patients after high-dose glucocorticoid (GC) administration significantly changed, and the altered flora and metabolites are related to hypertension, hyperglycemia, and osteoporosis. These findings can help understand the development of side effects caused by high-dose GCs and can be further used to develop potential probiotics to facilitate the prevention for those side effects.

Gut Microbiota Metabolites and Chronic Diseases: Interactions, Mechanisms, and Therapeutic Strategies

The gut microbiota, shaped by factors such as diet, lifestyle, and genetics, plays a pivotal role in regulating host metabolism, immune function, and overall health. The diversity and balance of the gut microbiota are closely linked to the onset and progression of various chronic diseases. A growing body of evidence has demonstrated that alterations in the composition, function, and metabolites of the gut microbiota are significantly associated with cardiovascular diseases, including hypertension, atherosclerosis, and heart failure; metabolic disorders such as obesity, type 2 diabetes, and metabolic dysfunction-associated steatotic liver disease; and gastrointestinal conditions like inflammatory bowel disease and colorectal cancer. Despite substantial advances in microbiome research, challenges remain in fully elucidating the causal relationships between the gut microbiota and disease, as well as in translating these insights into clinical applications. This review aims to investigate the regulatory pathways via which the gut microbiota affects cardiovascular health, metabolic function, and gastrointestinal disease. Additionally, it highlights emerging strategies for the prevention and treatment of these chronic conditions, focusing on microbiota-targeted therapies and personalized dietary interventions as promising approaches for improving health outcomes.

Key Insights into Gut Alterations in Metabolic Syndrome

Over time, extensive research has underscored the pivotal role of gut microbiota in the onset and progression of various diseases, with a particular focus on fecal microbiota transplantation (FMT) as a potential therapeutic approach. The practice of transferring fecal matter from a healthy donor to a patient provides valuable insights into how alterations in gut microbiota can impact disease development and how rectifying dysbiosis may offer therapeutic benefits. Re-establishing a balanced symbiotic relationship in the gastrointestinal tract has shown positive results in managing both intestinal and systemic conditions. Currently, one of the most pressing global health issues is metabolic syndrome-a cluster of conditions that includes insulin resistance, lipid imbalances, central obesity and hypertension. In this context, FMT has emerged as a promising strategy for addressing key components of metabolic syndrome, such as improving insulin sensitivity, body weight and lipid profiles. However, further well-structured studies are needed to refine treatment protocols and establish the long-term safety and efficacy of this intervention.

Understanding Hypertension: A Metabolomic Perspective

Metabolomics approaches, such as Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS), have emerged as powerful tools for studying cardiovascular diseases (CVD), including hypertension. The use of biological fluids, like plasma and serum, has garnered significant interest due to their accessibility and potential in elucidating disease mechanisms. This review aims to summarize the current literature on the application of metabolomics techniques (FTIR, NMR, and MS) in the study of hypertension, focusing on their contributions to understanding disease pathophysiology, biomarker discovery, and therapeutic advancements. A comprehensive analysis of metabolomic studies was performed, with a particular emphasis on the diversity of altered metabolites associated with systolic blood pressure (SBP), diastolic blood pressure (DBP), and sex-related differences. Metabolomics techniques, including FTIR, NMR, and MS, provide comprehensive insights into the biochemical alterations underlying hypertension, such as amino acid and fatty acid metabolism impairment or inflammation and oxidative stress processes. This review underscores their role in advancing biomarker identification, deepening our understanding of disease mechanisms, and supporting the development of targeted therapeutic strategies. The integration of these tools highlights their potential in personalized medicine and their capacity to improve clinical outcomes.

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.

Inulin Diet Alleviates Abdominal Aortic Aneurysm by Increasing Akkermansia and Improving Intestinal Barrier

Background/Objectives: Previous studies have shown varying efficacy of high-fiber diets containing different ingredients in abdominal aortic aneurysms (AAAs). This study aimed to identify which high-fiber diet protects against AAA in mice and elucidate the underlying mechanisms. Methods: This study compared inulin, cellulose, and chow diets in terms of their impact on aneurysm enlargement, elastin degradation, matrix metalloproteinase 2 and 9 expressions, CD3+ T cell and CD68+ macrophage infiltration, and macrophage differentiation. It also examined gut microbiota composition, focusing on Akkermansia, and evaluated intestinal barrier function and systemic inflammatory response. Results: The inulin diet, but not the cellulose diet, compared with the chow diet, reduced aneurysm enlargement, elastin degradation, matrix metalloproteinase 2 and 9 expressions, CD3+ T cell and CD68+ macrophage infiltration, and skewed macrophage towards M2 differentiation. The inulin diet enriched Akkermansia in both the small and large intestine. The inulin diet also enhanced the intestinal barrier by augmenting goblet cells, upregulating the gene related to the epithelial barrier and antibacterial peptides in the small intestine, and reducing circulating lipopolysaccharide and interleukin-1β levels. The inulin diet lowered the proportion of Ly6Chi monocytes and C-C chemokine receptor 2 expression on these cells in the bone marrow, reducing aneurysm infiltration. Administering Akkermansia to AAA mice decreased intestinal permeability and mitigated AAA. Conclusions: A diet rich in fermentable fiber inulin, as opposed to cellulose, alleviates AAA in mice. This beneficial effect is attributed to the enhanced presence of Akkermansia bacteria and improvement of the intestinal barrier.

The Gut-Heart Axis and Its Role in Doxorubicin-Induced Cardiotoxicity: A Narrative Review

Doxorubicin is a widely used chemotherapy for the treatment of several types of cancer. However, its application is restricted due to adverse effects, particularly cardiotoxicity, which can progress to heart failure-a chronic and debilitating condition. Several mechanisms have been identified in the pathophysiology of doxorubicin-induced cardiotoxicity, including oxidative stress, mitochondrial dysfunction, inflammation, and disruption of collagen homeostasis. More recently, dysbiosis of the gut microbiota has been implicated in the development and perpetuation of cardiac injury. Studies have reported alterations in the composition and abundance of the microbiota during doxorubicin treatment. Therefore, as of recent, there is a new field of research in order to develop strategies involving the gut microbiota to prevent or attenuate cardiotoxicity since there is no effective therapy at the moment. This narrative review aims to provide an update on the role of gut microbiota and intestinal permeability in the pathophysiology of cardiovascular diseases, and more specifically doxorubicin-induced cardiotoxicity. Additionally, it seeks to establish a foundation for future research targeting gut microbiota to alleviate cardiotoxicity.

Lacto-Fermented Fruits and Vegetables: Bioactive Components and Effects on Human Health

Lacto-fermented fruits and vegetables (FVs) such as kimchi, sauerkraut, and fermented olives and nonalcoholic juices have a long history as dietary staples. Herein, the production steps and microbial ecology of lacto-fermented FVs are discussed alongside findings from human and laboratory studies investigating the health benefits of these foods. Lacto-fermented FVs are enriched in beneficial live microbes and bioactive compounds, including lactic and acetic acids, phenolic compounds, bacteriocins, and amino acid derivatives such as indole-3-lactic acid, phenyl-lactic acid, and γ-aminobutyric acid. At least 11 human studies have been performed on kimchi, whereas others have been investigated in only one or two trials. Besides exploring the health benefits, it is imperative to ensure that these foods made either commercially or at home have minimal risk for foodborne illness and exposure to undesired compounds like biogenic amines. Development of starter-culture strains and production protocols can lead to lacto-fermented FVs designed for specific health benefits.

Deciphering the causality of gut microbiota, circulating metabolites and heart failure: a mediation mendelian

Background

Growing evidence suggesting a connection between the gut microbiome, plasma metabolites, and the development of heart failure (HF). However, the causality of this relationship remains to be fully elucidated.

Methods

Utilizing summary statistics from extensive genome-wide association studies (GWAS), we investigated the interplay among the gut microbiome, 1,400 plasma metabolites and heart failure. We conducted bidirectional Mendelian randomization (MR) analyses and MR mediation analysis to discern the causality within these relationships. The inverse variance-weighted (IVW) method served as our primary analytical approach, supported by various MR methods and sensitivity analyses.

Results

We revealed casual relationships between nine microbial groups/pathways and heart failure. Additionally, 15 metabolites exhibited casual links with HF, with eight exerting protective effects. Through two-step MR analysis we also identified the metabolite, Campesterol, mediated the increasing risk from gut microbiota to HF and a metabolite ratio played the converse role.

Conclusion

This investigation has provided robust evidence supporting the causal links between the gut microbiome, plasma metabolites, and heart failure. The findings enhance our comprehension of the role of circulating metabolites and offer significant insights for future etiological research and therapeutic development in heart failure.

Protective Effect of Dietary Fiber on Blood Pressure and Vascular Dysfunction Through Regulation of Sympathetic Tone and Immune Response in Genetic Hypertension

The mechanisms underlying the antihypertensive effect of dietary fibers remain poorly understood. This study investigates whether dietary fiber supplementation can prevent cardiovascular damage and high blood pressure in a genetic model of neurogenic hypertension. Six-week-old male spontaneously hypertensive rats (SHR) and their respective normotensive control, Wistar Kyoto rats (WKY), were divided into four groups: Untreated WKY, untreated SHR, SHR treated with resistant starch (SHR + RS), and SHR treated with inulin-type fructans (SHR + ITF) for 12 weeks. Additionally, a faecal microbiota transplantation (FMT) experiment was conducted, transferring faecal content from treated SHR donors to recipient SHRs. A diet rich in RS fiber reduced vascular oxidative stress, inflammation, and high blood pressure. These protective effects were associated with a reshaped gut microbiota, leading to increased short-chain fatty acid production, reduced endotoxemia, decreased sympathetic activity, and a restored balance between Th17 and Treg lymphocytes in mesenteric lymph nodes and aorta. Elevated plasma levels of acetate and butyrate in the SHR + RS group correlated with increased expression of aortic GPR41, GRP43 and PPARδ. Conversely, ITF treatment failed to prevent hypertension or endothelial dysfunction in SHR. FMT from the SHR + RS group to recipient SHR partially replicated these beneficial effects. This study highlights the antihypertensive benefits of dietary insoluble RS fiber, which are attributed to enhanced short-chain fatty acids production in the gut. This leads to improved gut permeability, reduced sympathetic tone, and diminished vascular T-cell accumulation. Therefore, dietary interventions with RS fiber may offer promising therapeutic strategies for preventing hypertension.

Diagnostic significance of the gut microbiota and its metabolites in cardiovascular risk assessment among patients with ulcerative colitis

Cardiovascular diseases (CVDs) rank among the leading causes of mortality. Studies suggest that ulcerative colitis (UC) is associated with an increased risk of CVDs. Gut microbiota and its metabolites play a pivotal role in the development of cardiovascular pathologies, including through the proatherogenic effects of trimethylamine N-oxide (TMAO) and disruptions in intestinal permeability. Objective: To evaluate the diagnostic value of markers characterizing gut microbiota metabolism and intestinal permeability in UC patients in the context of arterial hypertension (AH) risk. Materials and Methods. The study included 80 UC patients divided into two groups: those with UC and AH (Group 1) and those without AH (Group 2). TMAO levels in blood, zonulin, and short-chain fatty acids (SCFAs) in stool were assessed. Quantitative features with an alternative distribution were described using the median (Me), upper, and lower quartiles (P25, P75). The Mann-Whitney test and Bayesian approach were applied to evaluate diagnostic significance. Results. A significant increase in TMAO (1473.4 ng/mL vs. 785.02 ng/mL, p=0.01) and zonulin levels (318.42 ng/g vs. 164.22 ng/g, p=0.039) was observed in Group 1. Reduced acetic acid levels and anaerobic index were noted in the AH group, indicating gut microbiota imbalance. Conclusion. UC is a systemic inflammatory disease associated with an increased risk of CVDs. Investigating gut microbiota and its metabolites provides new opportunities for the prevention and treatment of cardiovascular complications in UC patients.

Interactions between Gut Microbiota, Host Circadian Rhythms, and Metabolic Diseases

The circadian rhythm arises endogenously from genetically encoded molecular clocks, wherein the components collaborate to induce cyclic fluctuations, occurring approximately every 24 h. The rhythms synchronize biological processes with regular and predictable environmental patterns to guarantee the host metabolism and energy homeostasis function and well-being. Disruptions to circadian rhythms are widely associated with metabolic disorders. Notably, microbial rhythms are influenced by both the host's intrinsic circadian clock and external rhythmic factors (i.e., light-dark cycle, diet patterns, and diet composition), which affect the structure of microbial communities and metabolic functions. Moreover, microbiota and the metabolites also reciprocally influence host rhythms, potentially impacting host metabolic function. This review aimed to explore the bidirectional interactions between the circadian clock, factors influencing host-microbial circadian rhythms, and the effects on lipid metabolism and energy homeostasis.

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

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

Antihypertensive effects of rice peptides involve intestinal microbiome alterations and intestinal inflammation alleviation in spontaneously hypertensive rats

Gut dysbiosis serves as an underlying risk factor for the development of hypertension. The resolution of this dysbiosis has emerged as a promising strategy in improving hypertension. Food-derived bioactive protein peptides have become increasingly more attractive in ameliorating hypertension, primarily due to their anti-inflammatory and anti-oxidant activities. However, the regulatory mechanisms linking rice peptides (RP), gut dysbiosis, and hypertension remain to be fully elucidated. In our study, male spontaneously hypertensive rats (SHR) were fed with chow diet and concomitantly treated with ddH2O (Ctrl) or varying doses of rice peptides (20, 100, or 500 mg (kg bw day)-1 designated as low-dose RP, LRP; medium-dose RP, MRP; high-dose RP, HAP) or captopril (Cap) by intragastric administration. Wistar-Kyoto (WKY) rats served as the normotensive control group and were orally administered with ddH2O. We observed beneficial effects of RP in lowering blood pressure and ameliorating cardiovascular risk profiles, as evidenced by improvements in glucolipid metabolic disorders, hepatic and renal damage, left ventricular hypertrophy and endothelial dysfunction in hypertensive rats. More importantly, we found that RP attenuated intestinal pathological damage, improved impaired intestinal barrier, and reduced intestinal inflammation by inhibiting the HMGB1-TLR4-NF-κB pathway. Notably, multi-omics integrative analyses have revealed that RP altered the composition and function of the gut microbiota. This is exemplified by the observed enrichment of beneficial bacterial constituents, such as g_Lactobacillus, g_Lactococcus, s_Lactobacillus_intestinalis, and Lactococcus lactis, and elevated production of microbiota-derived short-chain fatty acid metabolites. Collectively, these studies suggest that the hypotensive effects of RP may be associated with modulation of the gut microbiota and its short-chain fatty acids metabolites. This implicates the microbiota-gut-HMGB1-TLR4-NF-κB axis as a novel venue for the amelioration of hypertension and its complications.

Role of Gut Microbial Metabolites in Ischemic and Non-Ischemic Heart Failure

The effect of the gut microbiota extends beyond their habitant place from the gastrointestinal tract to distant organs, including the cardiovascular system. Research interest in the relationship between the heart and the gut microbiota has recently been emerging. The gut microbiota secretes metabolites, including Trimethylamine N-oxide (TMAO), short-chain fatty acids (SCFAs), bile acids (BAs), indole propionic acid (IPA), hydrogen sulfide (H2S), and phenylacetylglutamine (PAGln). In this review, we explore the accumulating evidence on the role of these secreted microbiota metabolites in the pathophysiology of ischemic and non-ischemic heart failure (HF) by summarizing current knowledge from clinical studies and experimental models. Elevated TMAO contributes to non-ischemic HF through TGF-ß/Smad signaling-mediated myocardial hypertrophy and fibrosis, impairments of mitochondrial energy production, DNA methylation pattern change, and intracellular calcium transport. Also, high-level TMAO can promote ischemic HF via inflammation, histone methylation-mediated vascular fibrosis, platelet hyperactivity, and thrombosis, as well as cholesterol accumulation and the activation of MAPK signaling. Reduced SCFAs upregulate Egr-1 protein, T-cell myocardial infiltration, and HDAC 5 and 6 activities, leading to non-ischemic HF, while reactive oxygen species production and the hyperactivation of caveolin-ACE axis result in ischemic HF. An altered BAs level worsens contractility, opens mitochondrial permeability transition pores inducing apoptosis, and enhances cholesterol accumulation, eventually exacerbating ischemic and non-ischemic HF. IPA, through the inhibition of nicotinamide N-methyl transferase expression and increased nicotinamide, NAD+/NADH, and SIRT3 levels, can ameliorate non-ischemic HF; meanwhile, H2S by suppressing Nox4 expression and mitochondrial ROS production by stimulating the PI3K/AKT pathway can also protect against non-ischemic HF. Furthermore, PAGln can affect sarcomere shortening ability and myocyte contraction. This emerging field of research opens new avenues for HF therapies by restoring gut microbiota through dietary interventions, prebiotics, probiotics, or fecal microbiota transplantation and as such normalizing circulating levels of TMAO, SCFA, BAs, IPA, H2S, and PAGln.

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.

Integrative approaches to atrial fibrillation prevention and management: Leveraging gut health for improved cardiovascular outcomes in the aging population

Atrial fibrillation (AF) is a prevalent clinical arrhythmia associated with a high incidence and severe complications such as cerebral embolism and heart failure. While the etiology and pathogenesis of AF involve numerous factors, recent research emphasizes the significant role of intestinal microbiota imbalance in the emergence and progression of AF, particularly among older adults. This review investigates the mechanisms by which intestinal flora and their metabolites contribute to the onset of AF in the elderly, highlighting novel interactions between gut health and cardiac function. Current literature often overlooks these critical connections, indicating a substantial research gap in understanding how dysbiosis may exacerbate AF and hinder recovery. Furthermore, exploring the bidirectional relationship between the gut microbiome and systemic inflammation in the context of AF provides a unique perspective that has yet to be thoroughly investigated. Future research should focus on longitudinal studies assessing gut microbiota composition and function in AF patients and consider probiotics or prebiotics as potential adjunctive therapies for mitigating AF. This comprehensive approach may pave the way for innovative treatments integrating cardiology with gastroenterology, enhancing patient outcomes through a holistic understanding of health.

The effect of high-fiber diet based on gut microbiota in patients with chronic heart failure

This research explored the effect of a high-fiber diet based on gut microbiota on patients with chronic heart failure (HF). Patients with chronic HF, who had undergone a dietary survey indicating a daily dietary fiber intake of less than 15 g/day, were divided into the control and study groups (n = 50). In addition to conventional heart failure treatment, the study group received dietary guidance, while the control group did not receive any dietary guidance and maintained their usual low-fiber dietary habits. After 1 yr intervention, the daily dietary fiber intake, abundance of gut microbiota, plasma trimethylamine N-oxide (TMAO), albumin (ALB), prealbumin (PA), transferrin (TF), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), left ventricular ejection fraction (LVEF), left ventricular end-diastolic index (LVEDVI), and left ventricular end-systolic volume index (LVESVI), Barthel index (BI), and 6 min walking distance (6 MWD) were compared. After the intervention, in both groups, the daily dietary fiber intake increased and the abundance of Firmicutes, Proteobacteria, Actinobacteria, and Fusobacteria decreased and that of Bacteroides increased; the plasma TMAO decreased; serum ALB, PA, and TF levels increased; serum CRP, TNF-α, IL-6, and IL-8 levels decreased, and the change was greater in the study group; LVEF elevated, LVEDVI and LVESVI reduced, and the differences between both groups were not significant; BI and 6 MWD elevated, and the study group was higher than the control group. High-fiber diet positively regulates the composition of gut microbiota, nutritional status, and microinflammatory level in patients with chronic HF, thereby improving patients' quality of life.NEW & NOTEWORTHY Traditional heart failure (HF) treatment primarily focuses on medications and surgery, whereas this study explores the improvement effects of a diet high in dietary fiber on patients with chronic HF from the perspective of gut microbiota, providing a new perspective for HF treatment.

Interplay of gut microbiota in Kawasaki disease: role of gut microbiota and potential treatment strategies

Kawasaki disease (KD) is an acute systemic immune vasculitis with predominant involvement of the medium and small arteries. It mostly affects pediatric patients, representing the most common form of pediatric vasculitis in children less than 5 years old. Numerous diseases, especially those related to the immune system, have established links with the intestinal flora. Recent studies have investigated the intestinal flora changes throughout the management of KD. There was gut microbiota dysbiosis in pediatric KD at the acute phase, particularly the downregulation of short-chain fat acids-producing microbiota and the over-proliferation of opportunistic pathogens. The relationship between the response to therapies in individuals with KD and specific microbiota remains uncertain. Targeted microbial supplements and dietary regulation may serve as potential measures to alleviate KD complications and thus improve prognosis. This review provides an overview of the current understanding of the interplay of the gut microbiota and KD. Furthermore, it discusses the possibility of altering the gut microbiota to reinstate a healthy condition.

Microbiome-Based Therapeutics for Salt-Sensitive Hypertension: A Scoping Review

The purpose of this scoping review was to provide a comprehensive understanding of the current knowledge concerning the gut microbiome and SCFAs as emerging treatments for salt-sensitive hypertension. Relevant animal and human studies were identified via PubMed through August 2024. Twenty-four human (n = 9) and animal (n = 15) trials were included. Most human studies were observational (n = 6), aiming to compare gut microbiota differences between hypertensive and normotensive individuals. Three human studies evaluated microbiome-based interventions either via a sodium-restricted diet (n = 2) or prebiotic supplementation (n = 1). Fifteen animal trials involving either mice or rats were identified, all of which were interventional. These included dietary changes (n = 9), probiotic treatments (n = 1), postbiotic primarily bacterial metabolites (n = 4), and live biotherapeutic products (n = 4). All interventions were effective in decreasing blood pressure. Microbiome-based therapies as biologic modifiers for salt-sensitive hypertension are emerging. Substantial knowledge gaps remain, warranting further research to fully explore this promising therapeutic avenue.

Heart Failure and Gut Microbiota: What Is Cause and Effect?

Emerging evidence highlights the central role of gut microbiota in maintaining physiological homeostasis within the host. Disruptions in gut microbiota can destabilize systemic metabolism and inflammation, driving the onset and progression of cardiometabolic diseases. In heart failure (HF), intestinal dysfunction may induce the release of endotoxins and metabolites, leading to dysbiosis and exacerbating HF through the gut-heart axis. Understanding the relationship between gut microbiota and HF offers critical insights into disease mechanisms and therapeutic opportunities. Current research highlights promising potential to improve patient outcomes by restoring microbiota balance. In this review, we summarize the current studies in understanding the gut microbiota-HF connection and discuss avenues for future investigation.

Gut Microbiota Metabolites Sensed by Host GPR41/43 Protect Against Hypertension

BACKGROUND

Fermentation of dietary fiber by the gut microbiota leads to the production of metabolites called short-chain fatty acids, which lower blood pressure and exert cardioprotective effects. Short-chain fatty acids activate host signaling responses via the functionally redundant receptors GPR41 (G-protein-coupled receptor 41) and GPR43 (G-protein-coupled receptor 43), which are highly expressed by immune cells. Whether and how these receptors protect against hypertension or mediate the cardioprotective effects of dietary fiber remains unknown.

METHODS

Cardiovascular phenotype was assessed in untreated and Ang II (angiotensin II) treated hypertensive wild-type and GPR41/43 knockout (KO) double knockout male mice fed diets with different levels of fiber content. Some mice received TLR4 (toll-like receptor 4)-antagonist treatment and bone marrow chimeras. SNPs (single-nucleotide polymorphisms) associated with GPR41 and GPR43 expression were assessed in UK Biobank participants.

RESULTS

Untreated GPR41/43KO mice had unaltered blood pressure but had greater cardiac and renal collagen deposition with higher macrophage numbers in the kidney compared with wild-type mice. Ang II-treated GPR41/43KO mice showed higher systolic blood pressure, cardiorenal weights and collagen deposition, and increased gut permeability, which allows the translocation of gastrointestinal bacterial components such as lipopolysaccharides into the circulation. The use of an antagonist to the lipopolysaccharide receptor, TLR4, a potent proinflammatory signaling molecule, restored the cardiovascular phenotype in GPR41/43KO mice. The lack of GPR41/43 expression in the immune compartment was sufficient to lead to a worsened hypertensive phenotype. We also demonstrate that GPR41/43 is, at least partially, responsible for the blood pressure-lowering and cardioprotective effects of a high-fiber diet. Finally, using the UK Biobank, we provide translational evidence that variants associated with lower expression of both GPR41 and GPR43 are more prevalent in participants with hypertension.

CONCLUSIONS

Our findings highlight that lack of short-chain fatty acid-receptor signaling via both GPR41 and GPR43 increases risk of high blood pressure, suggesting treatments that target these receptors could be a novel strategy to prevent or treat hypertension.

Dietary Lipids, Gut Microbiota, and Their Metabolites: Insights from Recent Studies

Dietary lipid intake can influence the gut microbiota (GM) and their metabolites, such as short-chain fatty acids (SCFA) and bile acids, which are key mediators of health. The objective is to examine how dietary lipids' quantity and quality influence the GM and metabolite profiles. A literature review of 33 studies in animals and humans was performed on the effects of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), trans-fatty acids (TFAs), and sterols on GM composition and gut-derived metabolites. The results show that diets rich in MUFAs, n-3 PUFAs, and short-chain FAs have the potential to enhance beneficial bacteria and metabolites. In addition, trans-palmitoleic acid, conjugated linoleic acid, and phytosterols may also have potentially beneficial effects on GM, but more research is needed. Medium-chain FAs and n-6 PUFAs have variable effects on the GM. Conversely, intakes of high-fat diets, long-chain SFAs, industrial TFAs, and cholesterol disrupt GM balance. In conclusion, animal studies clearly demonstrate that dietary fats influence the GM and related metabolites. Yet, human studies are limited. Therefore, well-designed human studies that consider the whole diet and baseline health status are needed to better understand the effects of dietary lipids on GM.

Targeting gut S. aureofaciens Tü117 serves as a new potential therapeutic intervention for the prevention and treatment of hypertension

Currently, the regulation of specific gut microbial metabolism for the development and/or treatment of hypertension remains largely unexplored. Here, we show that α-lipomycin, produced by Streptomyces aureofaciens (S. aureofaciens) Tü117, is upregulated in the serum of high-salt diet (HSD) mice and patients with essential hypertension. α-lipomycin causes vasodilation impairment involving transient receptor potential vanilloid 4 (TRPV4)-mediated nitric oxide and endothelium-derived hyperpolarizing factor pathways in mice. We also find that Lactobacillus plantarum (L. plantarum) CCFM639 attenuates the increase in blood pressure (BP) potentially through inhibiting the proliferation of S. aureofaciens Tü117 in mice. An exploratory intervention trial indicates that L. plantarum CCFM639 supplementation reduces BPs in subjects newly diagnosed with pre-hypertension or stage 1 hypertension without antihypertensive medication. Our findings provide evidence for a role of S. aureofaciens Tü117-associated α-lipomycin elevation in the pathogenesis of HSD-induced hypertension, highlighting that targeting gut bacteria serves as a new therapeutic intervention for hypertension.

Metagenomic Sequencing Combined with Metabolomics to Explore Gut Microbiota and Metabolic Changes in Mice with Acute Myocardial Infarction and the Potential Mechanism of Allicin

Background

Acute myocardial infarction (AMI) is a significant contributor to global morbidity and mortality. Allicin exhibits promising therapeutic potential in AMI as a primary bioactive component derived from garlic; however, its underlying mechanisms remain incompletely elucidated.

Methods

Our study induced AMI in mice by ligating the left coronary artery, and administered allicin orally for 28 days. The cardioprotective effects of allicin treatment were comprehensively assessed using echocardiography, histopathological examinations, intestinal barrier function, and serum inflammatory factors. The potential mechanisms of allicin were elucidated through analysis of metagenomics and serum metabolomics. Network pharmacology (NP) was used to further investigate and validate the possible molecular mechanisms of allicin.

Results

Our findings revealed allicin's capacity to ameliorate cardiac impairments, improve intestinal barrier integrity, and reduce serum IL-18 and IL-1β levels after AMI. Further analysis demonstrated that the administration of allicin has the potential to ameliorate intestinal flora disorder following AMI by modulating the abundance of beneficial bacteria, such as g_Lactobacillus, g_Prevotella, g_Alistipes, and g_Limosilactobacillus, while reducing the abundance of harmful bacteria g_Parasutterella. Additionally, it exhibits the ability to enhance myocardial energy metabolism flexibility through modulating metabolites and key enzymes associated with the fatty acid metabolic pathway. Mechanistically, NP and in vivo experiments indicated that allicin might suppress pyroptosis and reduce inflammatory response via blocked activation of the NF-κB-mediated NLRP3/Caspase-1/GSDMD pathway. Moreover, Spearman correlation analysis suggested a significant association between the allicin-induced alterations in microbiota and metabolites with cardiac function and inflammatory cytokines.

Conclusion

Our study demonstrated that allicin alleviated myocardial injury and reduced inflammatory response by inhibiting the NF-κB-mediated NLRP3/Caspase-1/GSDMD pathway while remodeling microbiota disturbance, improving serum metabolic disorder, and enhancing the intestinal barrier. These research findings offer a novel perspective on the potential therapeutic value of allicin as an adjunctive dietary supplement to conventional treatments for AMI.

Short-Chain Fatty Acids and Their Metabolic Interactions in Heart Failure

Short-chain fatty acids (SCFAs), produced through fermentation of dietary fibers by gut bacteria, play a central role in modulating cardiovascular function and heart failure (HF) development. The progression of HF is influenced by intestinal barrier dysfunction and microbial translocation, where SCFAs serve as key mediators in the gut-heart axis. This review examines the complex metabolic interactions between SCFAs and other gut microbiota metabolites in HF, including their relationships with trimethylamine N-oxide (TMAO), aromatic amino acids (AAAs), B vitamins, and bile acids (BAs). We analyze the associations between SCFA production and clinical parameters of HF, such as left ventricular ejection fraction (LVEF), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and glomerular filtration rate (GFR). Gaining insights into metabolic networks offers new potential therapeutic targets and prognostic markers for managing heart failure, although their clinical significance needs further exploration.

Polysaccharides from Yupingfeng granules ameliorated cyclophosphamide-induced immune injury by protecting intestinal barrier

Immune injury is the main side effect caused by cyclophosphamide and the disruption of the intestinal barrier may be an important cause. Yupingfeng granules have been reported to have immunomodulatory effects and polysaccharides are important components of them. This study aimed to investigate the ameliorative effect of polysaccharides from Yupingfeng granules (YPFP) on cyclophosphamide induced immune injury and reveal their potential mechanisms based on its protective effect on the intestine. YPFP were isolated and preliminarily characterized. Pharmacodynamic evaluation revealed that YPFP treatment could effectively mitigate lesions of immune organs, ameliorate white blood cells and downregulate IL-10 level. Further, the protective effect of intestinal barrier on the basis of intestinal tight junctions, MUC-2, microflora, endogenous metabolites, pathways and immune cells was discussed to outline mechanisms. The results showed that YPFP repaired the integrity of intestinal epithelium, enhanced the abundance of Muribaculaceae_unclassified, Bacteroide and Muribaculum, downgraded the abundance of Lachnospiraceae_NK4A136_group, improved the excretion of lipids and bile acids especially 3-oxo-LCA, increased the content of SCFAs in feces and inhibited the expression of key proteins of PI3K-AKT and MAPK-JUN pathways. More importantly, Th17 and Treg balance was remodeled after YPFP administration, which might be related to certain differential metabolites and pathways enriched by metabolomics. This study provides a rich understanding of YPFP and lays a foundation for further development of Yupingfeng granules. It was shown for the first time that the immunomodulatory effect of YPFP might be involved in multiple mechanisms of intestinal homeostasis. YPFP could be regarded as an immunomodulator to alleviate immune damage caused by cyclophosphamide.

Integrated Microbiome and Metabolome Analysis Reveals Correlations Between Gut Microbiota Components and Metabolic Profiles in Mice With Mitoxantrone-Induced Cardiotoxicity

Purpose

Mitoxantrone (MTX) is largely restricted in clinical usage due to its significant cardiotoxicity. Multiple studies have shown that an imbalance in the gut-heart axis plays an important role in the development of cardiovascular disease (CVD). We aim to explore the possible correlations between gut microbiota (GM) compositions and cardiometabolic (CM) disorder in MTX-triggered cardiotoxicity mice.

Methods

MTX cumulative dose of 6 mg/kg was administered to healthy Kunming male mice to trigger cardiotoxicity, with 1 mg/kg twice weekly for a duration of 3 weeks. Plasma CK-MB and LDH levels were determined, and the heart tissue histopathology was assessed, followed by utilizing an integrated liquid chromatography-mass spectrometry (LC-MS)-based heart metabolomics study alongside the 16S ribosomal RNA (rRNA) sequencing method to assess MTX impact on GM and CM profiles in mice, establishing associations between GM and CM profiles through the Pearson correlation coefficient calculation.

Results

MTX caused CK-MB and LDH level elevations and cardiotoxicity in our mouse model. MTX primarily affected the processes of protein digestion and absorption, mineral absorption, membrane transport, production of aminoacyl-transfer RNA (tRNA), metabolism of nucleotides, lipids, and amino acids, as well as autophagy. Additionally, MTX increased Romboutsia, Enterococcus, and Turicibacter abundances and lowered norank_f__Muribaculaceae, Alistipes, Odoribacter, norank_f__Lachnospiraceae, norank_f__Ruminococcaceae, norank_f__Oscillospiraceae, unclassified_f__Ruminococcaceae, NK4A214_group, Colidextribacter, norank_f__norank_o__Clostridia_vadinBB60_group, Rikenella, and Anaerotruncus abundances. The correlation analyses showcased variations in the abundance of diverse flora, such as Romboutsia, Enterococcus, Turicibacter, and norank_f__Muribaculaceae, which were related to MTX-induced cardiac injury.

Conclusion

Our study supports the claim that MTX provokes cardiotoxicity by modifying CM and GM profiles. Our results offer new possibilities for controlling MTX-triggered cardiotoxicity.

Chemical interplay between gut microbiota and epigenetics: Implications in circadian biology

Circadian rhythms are intrinsic molecular mechanisms that synchronize biological functions with the day/night cycle. The mammalian gut is colonized by a myriad of microbes, collectively named the gut microbiota. The microbiota impacts host physiology via metabolites and structural components. A key mechanism is the modulation of host epigenetic pathways, especially histone modifications. An increasing number of studies indicate the role of the microbiota in regulating host circadian rhythms. However, the mechanisms remain largely unknown. Here, we summarize studies on microbial regulation of host circadian rhythms and epigenetic pathways, highlight recent findings on how the microbiota employs host epigenetic machinery to regulate circadian rhythms, and discuss its impacts on host physiology, particularly immune and metabolic functions. We further describe current challenges and resources that could facilitate research on microbiota-epigenetic-circadian rhythm interactions to advance our knowledge of circadian disorders and possible therapeutic avenues.

The oral-gut microbiota axis: a link in cardiometabolic diseases

The oral-gut microbiota axis plays a crucial role in cardiometabolic health. This review explores the interactions between these microbiomes through enteric, hematogenous, and immune pathways, resulting in disruptions in microbial balance and metabolic processes. These disruptions contribute to systemic inflammation, metabolic disorders, and endothelial dysfunction, which are closely associated with cardiometabolic diseases. Understanding these interactions provides insights for innovative therapeutic strategies to prevent and manage cardiometabolic diseases.

The gut-heart axis: a review of gut microbiota, dysbiosis, and cardiovascular disease development

Background

Cardiovascular diseases (CVDs) are a major cause of morbidity and mortality worldwide and there are strong links existing between gut health and cardiovascular health. Gut microbial diversity determines gut health. Dysbiosis, described as altered gut microbiota, causes bacterial translocations and abnormal gut byproducts resulting in systemic inflammation.

Objective

To review the current literature on the relationships between gut microbiota, dysbiosis, and CVD development, and explore therapeutic methods to prevent dysbiosis and support cardiovascular health.

Summary

Dysbiosis increases levels of pro-inflammatory substances while reducing those of anti-inflammatory substances. This accumulative inflammatory effect negatively modulates the immune system and promotes vascular dysfunction and atherosclerosis. High Firmicutes to Bacteroidetes ratios, high trimethylamine-n-oxide to short-chain fatty acid ratios, high indole sulfate levels, low cardiac output, and polypharmacy are all associated with worse cardiovascular outcomes. Supplementation with prebiotics and probiotics potentially alleviates some CVD risk. Blood and stool samples may be used in clinical practice to quantify and qualify gut bacterial ratios and byproducts, assess patients' risk for adverse cardiovascular outcomes, and track their gut health progress. Further research is required to set population-based cutoffs for normal and abnormal gut microbiota and byproduct ratios.

Dietary Interventions in Heart Failure With Preserved Ejection Fraction: A Scoping Review

Patients with heart failure with preserved ejection fraction (HFpEF) are burdened by multiple diet-sensitive comorbidities, including obesity and malnutrition. Despite this, a low percentage of patients with HFpEF have been enrolled in dietary intervention trials in heart failure and few dietary interventions have been conducted in HFpEF exclusively. This scoping review will examine available evidence regarding dietary interventions in patients with HFpEF, highlight existing gaps in knowledge, and discuss emerging dietary therapies in this population.