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

The role of short-chain fatty acids produced by gut microbiota in the regulation of pre-eclampsia onset

Background

Preeclampsia (PE) is a common pregnancy-related disorder characterized by disrupted maternal-fetal immune tolerance, involving diffuse inflammatory responses and vascular endothelial damage. Alterations in the gut microbiota (GM) during pregnancy can affect intestinal barrier function and immune balance.

Aims and purpose

This comprehensive review aims to investigate the potential role of short-chain fatty acids (SCFAs), essential metabolites produced by the GM, in the development of PE. The purpose is to examine their impact on colonic peripheral regulatory T (Treg) cells, the pathogenic potential of antigen-specific helper T (Th) cells, and the inflammatory pathways associated with immune homeostasis.

Key insights

An increasing body of evidence suggests that dysbiosis in the GM can lead to alterations in SCFA levels, which may significantly contribute to the development of PE. SCFAs enhance the number and function of colonic Treg cells, mitigate the pathogenic potential of GM-specific Th cells, and inhibit inflammatory progression, thereby maintaining immune homeostasis. These insights highlight the potential significance of GM dysregulation and SCFAs produced by GM in the pathogenesis of PE. While the exact causes of PE remain elusive, and definitive clinical treatments are lacking, the GM and SCFAs present promising avenues for future clinical applications related to PE, offering a novel approach for prophylaxis and therapy.

Alterations of gut microbiota are associated with blood pressure: a cross-sectional clinical trial in Northwestern China

BACKGROUND

The human gut microbiota (GM) is involved in the pathogenesis of hypertension (HTN), and could be affected by various factors, including sex and geography. However, available data directly linking GM to HTN based on sex differences are limited.

METHODS

This study investigated the GM characteristics in HTN subjects in Northwestern China, and evaluate the associations of GM with blood pressure levels based on sex differences. A total of 87 HTN subjects and 45 controls were recruited with demographic and clinical characteristics documented. Fecal samples were collected for 16S rRNA gene sequencing and metagenomic sequencing.

RESULTS

GM diversity was observed higher in females compared to males, and principal coordinate analysis showed an obvious segregation of females and males. Four predominant phyla of fecal GM included Firmicutes, Bacteroidetes, Actinobacteria and Proteobacteria. LEfSe analysis indicated that phylum unidentified_Bacteria was enriched in HTN females, while Leuconostocaceae, Weissella and Weissella_cibaria were enriched in control females (P < 0.05). Functionally, ROC analysis revealed that Cellular Processes (0.796, 95% CI 0.620 ~ 0.916), Human Diseases (0.773, 95% CI 0.595 ~ 0.900), Signal transduction (0.806, 95% CI 0.631 ~ 0.922) and Two-component system (0.806, 95% CI 0.631 ~ 0.922) could differentiate HTN females as effective functional classifiers, which were also positively correlated with systolic blood pressure levels.

CONCLUSIONS

This work provides evidence of fecal GM characteristics in HTN females and males in a northwestern Chinese population, further supporting the notion that GM dysbiosis may participate in the pathogenesis of HTN, and the role of sex differences should be considered. Trial registration Chinese Clinical Trial Registry, ChiCTR1800019191. Registered 30 October 2018 - Retrospectively registered, http://www.chictr.org.cn/ .

The Association of Metabolomic Profiles of a Healthy Lifestyle with Heart Failure Risk in a Prospective Study

Lifestyle has been linked to the incidence of heart failure, but the underlying biological mechanisms remain unclear. Using the metabolomic, lifestyle, and heart failure data of the UK Biobank, we identified and validated healthy lifestyle-related metabolites in a matched case-control and cohort study, respectively. We then evaluated the association of healthy lifestyle-related metabolites with heart failure (HF) risk and the added predictivity of these healthy lifestyle-associated metabolites for HF. Of 161 metabolites, 8 were identified to be significantly related to healthy lifestyle. Notably, omega-3 fatty acids and docosahexaenoic acid (DHA) positively associated with a healthy lifestyle score (HLS) and exhibited a negative association with heart failure risk. Conversely, creatinine negatively associated with a HLS, but was positively correlated with the risk of HF. Adding these three metabolites to the classical risk factor prediction model, the prediction accuracy of heart failure incidence can be improved as assessed by the C-statistic (increasing from 0.806 [95% CI, 0.796-0.816] to 0.844 [95% CI, 0.834-0.854], p-value < 0.001). A healthy lifestyle is associated with significant metabolic alterations, among which metabolites related to healthy lifestyle may be critical for the relationship between healthy lifestyle and HF. Healthy lifestyle-related metabolites might enhance HF prediction, but additional validation studies are necessary.

Qishen granules regulate intestinal microecology to improve cardiac function in rats with heart failure

Introduction

Qishen Granule (QSG), a clinically approved traditional Chinese medicine, has been researched for treating heart failure (HF) for many years. However, the effect of QSG on intestinal microecology remains unconfirmed. Therefore, this study aimed to elucidate the possible mechanism of QSG regulating HF in rats based on intestinal microecological changes.

Methods

A rat model with HF induced by myocardial infarction was prepared by left coronary artery ligation. Cardiac functions were assessed by echocardiography, pathological changes in the heart and ileum by hematoxylin-eosin (HE) and Masson staining, mitochondrial ultrastructure by transmission electron microscope, and gut microbiota by 16S rRNA sequencing.

Results

QSG administration improved cardiac function, tightened cardiomyocytes alignment, decreased fibrous tissue and collagen deposition, and reduced inflammatory cell infiltration. Electron microscopic observation of mitochondria revealed that QSG could arrange mitochondria neatly, reduce swelling, and improve the structural integrity of the crest. Firmicutes were the dominant component in the model group, and QSG could significantly increase the abundance of Bacteroidetes and Prevotellaceae_NK3B31_group. Furthermore, QSG significantly reduced plasma lipopolysaccharide (LPS), improved intestinal structure, and recovered barrier protection function in rats with HF.

Conclusion

These results demonstrated that QSG was able to improve cardiac function by regulating intestinal microecology in rats with HF, suggesting promising therapeutic targets for HF.

Impact of the gut microbiota on angiotensin Ⅱ-related disorders and its mechanisms

The renin-angiotensin system (RAS) consists of multiple angiotensin peptides and performs various biological functions mediated by distinct receptors. Angiotensin II (Ang II) is the major effector of the RAS and affects the occurrence and development of inflammation, diabetes mellitus and its complications, hypertension, and end-organ damage via the Ang II type 1 receptor. Recently, considerable interest has been given to the association and interaction between the gut microbiota and host. Increasing evidence suggests that the gut microbiota may contribute to cardiovascular diseases, obesity, type 2 diabetes mellitus, chronic inflammatory diseases, and chronic kidney disease. Recent data have confirmed that Ang II can induce an imbalance in the intestinal flora and further aggravate disease progression. Furthermore, angiotensin converting enzyme 2 is another player in RAS, alleviates the deleterious effects of Ang II, modulates gut microbial dysbiosis, local and systemic immune responses associated with coronavirus disease 19. Due to the complicated etiology of pathologies, the precise mechanisms that link disease processes with specific characteristics of the gut microbiota remain obscure. This review aims to highlight the complex interactions between the gut microbiota and its metabolites in Ang II-related disease progression, and summarize the possible mechanisms. Deciphering these mechanisms will provide a theoretical basis for novel therapeutic strategies for disease prevention and treatment. Finally, we discuss therapies targeting the gut microbiota to treat Ang II-related disorders.

Intestinal fatty acid binding protein is associated with cardiac function and gut dysbiosis in chronic heart failure

Background

The gut microbiota in patients with chronic heart failure (HF) is characterized by low bacterial diversity and reduced ability to synthesize beneficial metabolites. These changes may facilitate leakage of whole bacteria or bacterial products from the gut into the bloodstream, which may activate the innate immune system and contribute to the low-grade inflammation seen in HF. In this exploratory cross-sectional study, we aimed to investigate relationships between gut microbiota diversity, markers of gut barrier dysfunction, inflammatory markers, and cardiac function in chronic HF patients.

Methods

In total, 151 adult patients with stable HF and left ventricular ejection fraction (LVEF) < 40% were enrolled. We measured lipopolysaccharide (LPS), LPS-binding protein (LBP), intestinal fatty acid binding protein (I-FABP), and soluble cluster of differentiation 14 (sCD14) as markers of gut barrier dysfunction. N-terminal pro-B-type natriuretic peptide (NT-proBNP) level above median was used as a marker of severe HF. LVEF was measured by 2D-echocardiography. Stool samples were sequenced using 16S ribosomal RNA gene amplification. Shannon diversity index was used as a measure of microbiota diversity.

Results

Patients with severe HF (NT-proBNP > 895 pg/ml) had increased I-FABP (p < 0.001) and LBP (p = 0.03) levels. ROC analysis for I-FABP yielded an AUC of 0.70 (95% CI 0.61-0.79, p < 0.001) for predicting severe HF. A multivariate logistic regression model showed increasing I-FABP levels across quartiles of NT-proBNP (OR 2.09, 95% CI 1.28-3.41, p = 0.003). I-FABP was negatively correlated with Shannon diversity index (rho = -0.30, p = <0.001), and the bacterial genera Ruminococcus gauvreauii group, Bifidobacterium, Clostridium sensu stricto, and Parasutterella, which were depleted in patients with severe HF.

Conclusions

In patients with HF, I-FABP, a marker of enterocyte damage, is associated with HF severity and low microbial diversity as part of an altered gut microbiota composition. I-FABP may reflect dysbiosis and may be a marker of gut involvement in patients with HF.

Conjugated bile acids are nutritionally re-programmable antihypertensive metabolites

BACKGROUND

Hypertension is the largest risk factor affecting global mortality. Despite available medications, uncontrolled hypertension is on the rise, whereby there is an urgent need to develop novel and sustainable therapeutics. Because gut microbiota is now recognized as an important entity in blood pressure regulation, one such new avenue is to target the gut-liver axis wherein metabolites are transacted via host-microbiota interactions. Knowledge on which metabolites within the gut-liver axis regulate blood pressure is largely unknown.

METHOD

To address this, we analyzed bile acid profiles of human, hypertensive and germ-free rat models and report that conjugated bile acids are inversely correlated with blood pressure in humans and rats.

RESULTS

Notably intervening with taurine or tauro-cholic acid rescued bile acid conjugation and reduced blood pressure in hypertensive rats. Subsequently, untargeted metabolomics uncovered altered energy metabolism following conjugation of bile acids as a mechanism alleviating high blood pressure.

CONCLUSION

Together this work reveals conjugated bile acids as nutritionally re-programmable anti-hypertensive metabolites.

Targeting intestinal microecology: potential intervention strategies of traditional Chinese medicine for managing hypertension

Hypertension has become one of the major public health problems in the world. At present, the pathogenesis of hypertension has still not been completely elucidated. In recent years, an increasing evidence shows that intestinal microecology is closely related to hypertension, which provides a new thinking for the prevention and treatment of hypertension. Traditional Chinese medicine (TCM) has unique advantages in the treatment of hypertension. Taking intestinal microecology as the target, it is possible to interpreting the scientific connotation of TCM prevention and treatment of hypertension by updating the treatment concept of hypertension, so as to improve the therapeutic effect. In our study, the clinical evidence for TCM treatment of hypertension was systematicly summarized. And the relationship among TCM, intestinal microecology and hypertension was analyzed. In addition, the methods by which TCM regulates intestinal microecology to prevent and treat hypertension were presented, to provide new research ideas for prevention and treatment of hypertension.

Gut microbiota and integrative traditional Chinese and western medicine in prevention and treatment of heart failure

BACKGROUND

Heart failure (HF) is the terminal stage of multiple cardiovascular diseases, with high mortality and morbidity. More and more studies have proved that gut microbiota may play a role in the process of HF, which is expected to become a new therapeutic target. The combination of traditional Chinese and Western medicine has vast therapeutic potential of complementation against HF.

PURPOSE

This manuscript expounds on the research progress of mechanisms of gut microbiota participating in the occurrence and prognosis of HF and the role of integrative traditional Chinese and Western medicine from 1987 to 2022. The combination of traditional Chinese and Western medicine in the prevention and treatment of HF from the perspective of gut microbiota has been discussed.

METHODS

Studies focusing on the effects and their mechanisms of gut microbiota in HF and the role of integrative traditional Chinese and Western medicine were identified and summarized, including contributions from February 1987 until August 2022. The investigation was carried out in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. We searched PubMed, Embase, Cochrane Library, CNKI, Wanfang, and VIP databases up to April 2023 by using the relevant keywords and operators.

RESULTS

A total of 34 articles were finally included in this review.16 RCTs and 13 basic researches, and 3 clinical research studies involving 7 relevant outcome indicators(cardiac function evaluation index, changes in gut microbiota, inflammatory factors, metabolites of gut microbiota, serum nutritional index protein, quality of life score, intestinal permeability and all-cause mortality). Compared with healthy controls, serum TNF-α and TMAO levels were significantly higher in patients with heart failure [MD = 5.77, 95%CI(4.97, 6.56), p < 0.0001; SMD = 1.92, 95%CI(1.70, 2.14), p < 0.0001]. Escherichia coli and Thick-walled bacteria increased significantly [SMD = -0.99, 95%CI(-1.38, -0.61), p < 0.0001, SMD = 2.58, 95%CI(2.23, 2.93), p < 0.0001];The number of bacteroides and lactobacillus decreased [SMD = -2.29, 95%CI(-2.54, -2.04), p < 0.0001; SMD = -1.55, 95%CI(-1.8, -1.3), p < 0.0001]. There was no difference in bifidobacterium [SMD = 0.16, 95%CI(-0.22, 0.54), p = 0.42]. In the published literature, it is not difficult to see that most of the results are studied and proved based on animal experiments or clinical trials, involving the cellular level, while the mechanism and mode of action of the molecular biology of traditional Chinese medicine are less elaborated, which is related to the characteristics of multi-components and multi-targets of traditional Chinese medicine. The above are the shortcomings of published literature, which can also be the direction of future research.

CONCLUSION

Heart failure patients have decreased beneficial bacteria such as Bacillus mimics and Lactobacillus in the intestinal flora and increased harmful flora like thick-walled flora. And increase the inflammatory response of the body and the expression of trimethylamine oxide (TMAO) in the serum. And The prevention and treatment of integrative traditional Chinese and Western medicine against heart failure based on gut microbiota and its metabolites is a promising research direction.

Characteristic Gut Bacteria in High Barley Consuming Japanese Individuals without Hypertension

BACKGROUND

Barley, a grain rich in soluble dietary fiber β-glucan, is expected to lower blood pressure. Conversely, individual differences in its effects on the host might be an issue, and gut bacterial composition may be a determinant.

METHODS

Using data from a cross-sectional study, we examined whether the gut bacterial composition could explain the classification of a population with hypertension risks despite their high barley consumption. Participants with high barley intake and no occurrence of hypertension were defined as "responders" (n = 26), whereas participants with high barley intake and hypertension risks were defined as "non-responders" (n = 39).

RESULTS

16S rRNA gene sequencing revealed that feces from the responders presented higher levels of Faecalibacterium, Ruminococcaceae UCG-013, Lachnospira, and Subdoligranulum and lower levels of Lachnoclostridium and Prevotella 9 than that from non-responders. We further created a machine-learning responder classification model using random forest based on gut bacteria with an area under the curve value of 0.75 for estimating the effect of barley on the development of hypertension.

CONCLUSIONS

Our findings establish a link between the gut bacteria characteristics and the predicted control of blood pressure provided by barley intake, thereby providing a framework for the future development of personalized dietary strategies.

Gut Microbiome-Based Management of Patients With Heart Failure: JACC Review Topic of the Week

Despite therapeutic advances, chronic heart failure (HF) is still associated with significant risk of morbidity and mortality. The course of disease and responses to therapies vary widely among individuals with HF, highlighting the need for precision medicine approaches. Gut microbiome stands to be an important aspect of precision medicine in HF. Exploratory clinical studies have revealed shared patterns of gut microbiome dysregulation in this disease, with mechanistic animal studies providing evidence for active involvement of the gut microbiome in development and pathophysiology of HF. Deeper insights into gut microbiome-host interactions in patients with HF promise to deliver novel disease biomarkers, preventative and therapeutic targets, and improve disease risk stratification. This knowledge may enable a paradigm shift in how we care for patients with HF, and pave the path toward improved clinical outcomes through personalized HF care.

Microbiota-related metabolites fueling the understanding of ischemic heart disease

Up-to-date knowledge of gut microbial taxa associated with ischemic heart disease (IHD). Microbial metabolites for mechanistic dissection of IHD pathology. Microbiome-based therapies in IHD prevention and treatment.

Changes in gut microbiota linked to a prevention of cardiac remodeling induced by hypertension in spontaneously hypertensive rats fed a pawpaw fruit diet

Objective

Dietary intake of fruit is associated with lower incidence of hypertension and cardiovascular risk. Papaya is a kind of delicious fruit and reported has dietary therapeutic effects, such as digestive stimulation and hypotensive efficacy. However, the mechanism of pawpaw involved have not been elucidated. Here, we illustrate that the effect of pawpaw on the gut microbiota and the prevention of cardiac remodeling.

Methods

Gut microbiome, cardiac structure/function, and blood pressure were examined in SHR and WKY groups. The intestinal barrier was tested with histopathologic; immunostaining and Western blot were used to measure the tight junction protein level; Gpr41 was tested by RT-PCR, and inflammatory factors were detected with ELISA.

Results

We observed a significant decrease in microbial richness, diversity, and evenness is the spontaneously hypertensive rat (SHR), in addition to an increased Firmicutes/Bacteroidetes (F/B) ratio. These changes were accompanied by decreased in acetate and butyrate-producing bacteria. Compared with SHR, treatment with pawpaw at the dosage of 10 g/kg for 12 weeks significantly reduced the blood pressure, cardiac fibrosis and cardiac hypertrophy, while the ratio of F/B decreased. We also found that the concentration of short-chain fatty acids (SCFAs) was increased in SHR fed with pawpaw compared with that in control group, while the gut barrier was restored and level of proinflammatory cytokines in the serum were decreased.

Conclusions

Pawpaw, rich of high fiber, led to changes in the gut microbiota that played a protective role in the development of cardiac remodeling. The potential mechanism of pawpaw may explained by the generation of one of the main metabolites of the gut microbiota, the short-chain fatty acid acetate, increasing tight junction protein level occluding to enhance the gut barrier for less releasing the inflammation cytokines, and upregulating G-protein-coupled receptor 41 (GPR41) to reduce blood pressure.

Effects of Probiotic Supplementation on Exercise and the Underlying Mechanisms

Long-term, high-intensity exercise can trigger stress response pathways in multiple organs, including the heart and lungs, gastrointestinal tract, skeletal muscle, and neuroendocrine system, thus affecting their material and energy metabolism, immunity, oxidative stress, and endocrine function, and reducing exercise function. As a natural, safe, and convenient nutritional supplement, probiotics have been a hot research topic in the field of biomedical health in recent years. Numerous studies have shown that probiotic supplementation improves the health of the body through the gut-brain axis and the gut-muscle axis, and probiotic supplementation may also improve the stress response and motor function of the body. This paper reviews the progress of research on the role of probiotic supplementation in material and energy metabolism, intestinal barrier function, immunity, oxidative stress, neuroendocrine function, and the health status of the body, as well as the underlying mechanisms.

Integrated Omic Analysis of Human Plasma Metabolites and Microbiota in a Hypertension Cohort

Hypertension is closely related to metabolic dysregulation, which is associated with microbial dysbiosis and altered host-microbiota interactions. However, plasma metabolite profiles and their relationships to oral/gut microbiota in hypertension have not been evaluated in depth. Plasma, saliva, subgingival plaques, and feces were collected from 52 hypertensive participants and 24 healthy controls in a cross-sectional cohort. Untargeted metabolomic profiling of plasma was performed using high-performance liquid chromatography-mass spectrometry. Microbial profiling of oral and gut samples was determined via 16S rRNA and metagenomic sequencing. Correlations between metabolites and clinic parameters/microbiota were identified using Spearman's correlation analysis. Metabolomic evaluation showed distinct clusters of metabolites in plasma between hypertensive participants and control participants. Hypertensive participants had six significantly increased and thirty-seven significantly decreased plasma metabolites compared to controls. The plasma metabolic similarity significantly correlated with the community similarity of microbiota. Both oral and gut microbial community composition had significant correlations with metabolites such as Sphingosine 1-phosphate, a molecule involved in the regulation of blood pressure. Plasma metabolites had a larger number of significant correlations with bacterial genera than fungal genera. The shared oral/gut bacterial genera had more correlations with metabolites than unique genera but shared fungal genera and metabolites did not show clear clusters. The hypertension group had fewer correlations between plasma metabolites and bacteria/fungi than controls at species level. The integrative analysis of plasma metabolome and oral/gut microbiome identified unreported alterations of plasma metabolites in hypertension and revealed correlations between altered metabolites and oral/gut microbiota. These observations suggested metabolites and microbiota may become valuable targets for therapeutic and preventive interventions of hypertension.

Gut Microbiota and Atrial Fibrillation: Pathogenesis, Mechanisms and Therapies

Over the past decade there has been an interest in understanding the role of gut microbiota in the pathogenesis of AF. A number of studies have linked the gut microbiota to the occurrence of traditional AF risk factors such as hypertension and obesity. However, it remains unclear whether gut dysbiosis has a direct effect on arrhythmogenesis in AF. This article describes the current understanding of the effect of gut dysbiosis and associated metabolites on AF. In addition, current therapeutic strategies and future directions are discussed.

The Implication of the Gut Microbiome in Heart Failure

Heart failure is a worldwide health problem with important consequences for the overall wellbeing of affected individuals as well as for the healthcare system. Over recent decades, numerous pieces of evidence have demonstrated that the associated gut microbiota represent an important component of human physiology and metabolic homeostasis, and can affect one's state of health or disease directly, or through their derived metabolites. The recent advances in human microbiome studies shed light on the relationship between the gut microbiota and the cardiovascular system, revealing its contribution to the development of heart failure-associated dysbiosis. HF has been linked to gut dysbiosis, low bacterial diversity, intestinal overgrowth of potentially pathogenic bacteria and a decrease in short chain fatty acids-producing bacteria. An increased intestinal permeability allowing microbial translocation and the passage of bacterial-derived metabolites into the bloodstream is associated with HF progression. A more insightful understanding of the interactions between the human gut microbiome, HF and the associated risk factors is mandatory for optimizing therapeutic strategies based on microbiota modulation and offering individualized treatment. The purpose of this review is to summarize the available data regarding the influence of gut bacterial communities and their derived metabolites on HF, in order to obtain a better understanding of this multi-layered complex relationship.

Gut microbiota dependant trimethylamine N-oxide and hypertension

The human gut microbiota environment is constantly changing and some specific changes influence the host's metabolic, immune, and neuroendocrine functions. Emerging evidence of the gut microbiota's role in the development of cardiovascular disease (CVD) including hypertension is remarkable. There is evidence showing that alterations in the gut microbiota and especially the gut-dependant metabolite trimethylamine N-oxide is associated with hypertension. However, there is a scarcity of literature addressing the role of trimethylamine N-oxide in hypertension pathogenesis. In this review, we discuss the impact of the gut microbiota and gut microbiota dependant trimethylamine N-oxide in the pathogenesis of hypertension. We present evidence from both human and animal studies and further discuss new insights relating to potential therapies for managing hypertension by altering the gut microbiota.

Is the Gut Microbiome Implicated in the Excess Risk of Hypertension Associated with Obstructive Sleep Apnea? A Contemporary Review

Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder and an established risk factor for cardiovascular diseases, including hypertension. The pathogenesis of elevated blood pressure (BP) in OSA is multifactorial, including sympathetic overdrive, vascular aberrations, oxidative stress, inflammation, and metabolic dysregulation. Among the mechanisms potentially involved in OSA-induced hypertension, the role of the gut microbiome is gaining increasing attention. Perturbations in the diversity, composition, and function of the gut microbiota have been causally linked to numerous disorders, and robust evidence has identified gut dysbiosis as a determinant of BP elevation in various populations. In this brief review, we summarize the current body of literature on the implications of altered gut microbiota for hypertension risk in OSA. Data from both preclinical models of OSA and patient populations are presented, and potential mechanistic pathways are highlighted, along with therapeutic considerations. Available evidence suggests that gut dysbiosis may promote the development of hypertension in OSA and may thus be a target for interventions aimed at attenuating the adverse consequences of OSA in relation to cardiovascular risk.

Engineered probiotics Clostridium butyricum-pMTL007-GLP-1 improves blood pressure via producing GLP-1 and modulating gut microbiota in spontaneous hypertension rat models

Hypertension is a significant risk factor of cardiovascular diseases (CVDs) with high prevalence worldwide, the current treatment has multiple adverse effects and requires continuous administration. The glucagon-like peptide-1 receptor (GLP-1R) agonists have shown great potential in treating diabetes mellitus, neurodegenerative diseases, obesity and hypertension. Butyric acid is a potential target in treating hypertension. Yet, the application of GLP-1 analogue and butyric acid in reducing blood pressure and reversing ventricular hypertrophy remains untapped. In this study, we combined the therapeutic capability of GLP-1 and butyric acid by transforming Clostridium butyricum (CB) with recombinant plasmid pMTL007 encoded with hGLP gene to construct the engineered probiotics Clostridium butyricum-pMTL007-GLP-1 (CB-GLP-1). We used spontaneous hypertensive rat (SHR) models to evaluate the positive effect of this strain in treating hypertension. The results revealed that the intragastric administration of CB-GLP-1 had markedly reduced blood pressure and improved cardiac marker ACE2, AT2R, AT1R, ANP, BNP, β-MHC, α-SMA and activating AMPK/mTOR/p70S6K/4EBP1 signalling pathway. The high-throughput sequencing further demonstrated that CB-GLP-1 treatments significantly improved the dysbiosis in the SHR rats via downregulating the relative abundance of Porphyromonadaceae at the family level and upregulating Lactobacillus at the genus level. Hence, we concluded that the CB-GLP-1 greatly improves blood pressure and cardiomegaly by restoring the gut microbiome and reducing ventricular hypertrophy in rat models. This is the first time using engineered CB in treating hypertension, which provides a new idea for the clinical treatment of hypertension.

Adult hypertensive rats are more prone to gut microflora perturbation and fibrosis in response to moderate restraint stress

Hypertension (HTN) is a common endpoint for numerous cardiovascular diseases, the prevalence of which has been quickly increasing due to a wide range of reasons. Previous research has found that following stress, ELISA and 16S rDNA sequencing indicated substantial changes in plasma cytokines or hormones, as well as alterations in gut microbiota in juvenile hypertensive rats. However, it remains still unclear how such interaction modifications affect microbial populations and organismal function. Stress-related hormones show a significant drop. Similar to earlier research, the stress group had dramatically increased release of pro-inflammatory cytokines such as IL-17. Importantly, a unified collection of tools that allows for deep and comprehensive colonic structural investigation has been developed. Stress may limit the transition of macrophages (Mφs) to M1Mφs while increasing the transfer to M2Mφs. Evidence highlighted that tight junction proteins were decreased along with enhancement in intestinal permeability. Morphological analysis revealed that the SHR-S group exhibited considerably higher levels of morphological alterations and fibrosis in colon, heart, and thoracic aorta tissues.Significant improvements in bacteria linked with short-chain fatty acid synthesis, such as Prevotella and Ruminococcus, were discovered by metagenomic analysis. Adult hypertensive rats are more susceptible to gut microbiota disruption and fibrosis as a result of mild restraint stress. This might contribute to some innovative ideas for HTN both treatment and prevention.

Early Growth Response-1: Friend or Foe in the Heart?

Cardiovascular disease is a major cause of mortality and morbidity worldwide. Early growth response-1 (Egr-1) plays a critical regulatory role in a range of experimental models of cardiovascular diseases. Egr-1 is an immediate-early gene and is upregulated by various stimuli including shear stress, oxygen deprivation, oxidative stress and nutrient deprivation. However, recent research suggests a new, underexplored cardioprotective side of Egr-1. The main purpose of this review is to explore and summarise the dual nature of Egr-1 in cardiovascular pathobiology.

Gut Failure: A Review of the Pathophysiology and Therapeutic Potentials in the Gut-Heart Axis

Despite considerable advances in the field, heart failure (HF) still poses a significant disease burden among affected individuals since it continues to cause high morbidity and mortality rates. Inflammation is considered to play a key role in disease progression, but the exact underlying pathophysiological mechanisms involved have not yet been fully elucidated. The gut, as a potential source of inflammation, could feasibly explain the state of low-grade inflammation seen in patients with chronic HF. Several derangements in the composition of the microbiota population, coupled with an imbalance between favorable and harmful metabolites and followed by gut barrier disruption and eventually bacterial translocation, could contribute to cardiac dysfunction and aggravate HF. On the other hand, HF-associated congestion and hypoperfusion alters intestinal function, thereby creating a vicious cycle. Based on this evidence, novel pharmaceutical agents have been developed and their potential therapeutic use has been tested in both animal and human subjects. The ultimate goal in these efforts is to reverse the aforementioned intestinal derangements and block the inflammation cascade. This review summarizes the gut-related causative pathways implicated in HF pathophysiology, as well as the associated therapeutic interventions described in the literature.

New insights on the impact of gut microbiota on premenstrual disorders. Will probiotics solve this mystery?

Premenstrual disorders (PMDs) refer to premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD), where both are characterized by physical and psychological changes occurring in the luteal phase of menstrual cycle. According to the available theories, there is no single accusation succeeded to explain the pathophysiology of PMDs. However, there is emerging evidence for the role of gut microbiota (GM) in PMDs, supported by the diverging impact of GM on our body systems. The direct secretory function of GM and their integration in hormonal, neurotransmitters and bioactive compounds secretion and activity reinforce this speculation. Moreover, the bidirectional relation between GM and steroid hormones and the impact of diet, drugs, and inflammation on both, GM and PMDs incidence and severity justify the need for more studies to determine the actual role of GM in PMDs and the possible potential of probiotics and prebiotics as therapeutic options.

Evaluation of the contribution of gut microbiome dysbiosis to cardiac surgery-associated acute kidney injury by comparative metagenome analysis

Introduction

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a common hospital-acquired AKI that carries a grave disease burden. Recently, gut-kidney crosstalk has greatly changed our understanding of the pathogenesis of kidney diseases. However, the relationship between gut microbial dysbiosis and CSA-AKI remains unclear. The purpose of this study was to investigate the possible contributions of gut microbiota alterations in CSA-AKI patients

Methods

Patients undergoing cardiac surgery were enrolled and divided into acute kidney injury (AKI) and Non-AKI groups. Faecal samples were collected before the operation. Shotgun metagenomic sequencing was performed to identify the taxonomic composition of the intestinal microbiome. All groups were statistically compared with alpha- and beta-diversity analysis, and linear discriminant analysis effect size (LEfSe) analysis was performed.

Results

A total of 70 individuals comprising 35 AKI and 35 Non_AKI were enrolled in the study. There was no significant difference between the AKI and Non_AKI groups with respect to the alpha-and beta-diversity of the Shannon index, Simpson or Chao1 index values except with respect to functional pathways (p &lt; 0.05). However, the relative abundance of top 10 gut microbiota in CSA-AKI was different from the Non_AKI group. Interestingly, both LEfSe and multivariate analysis confirmed that the species Escherichia coli, Rothia mucilaginosa, and Clostridium_innocuum were associated with CSA-AKI. Moreover, correlation heat map indicated that altered pathways and disrupted function could be attributed to disturbances of gut microbiota involving Escherichia_coli.

Conclusion

Dysbiosis of the intestinal microbiota in preoperative stool affects susceptibility to CSA-AKI, indicating the crucial role of key microbial players in the development of CSA-AKI. This work provides valuable knowledge for further study of the contribution of gut microbiota in CSA-AKI.

Role of the Gut Microbiome in the Development of Atherosclerotic Cardiovascular Disease

Atherosclerotic cardiovascular disease (ASCVD) is the primary cause of death globally, with nine million deaths directly attributable to ischemic heart diseases in 2020. Since the last few decades, great effort has been put toward primary and secondary prevention strategies through identification and treatment of major cardiovascular risk factors, including hypertension, diabetes, dyslipidemia, smoking, and a sedentary lifestyle. Once labelled “the forgotten organ”, the gut microbiota has recently been rediscovered and has been found to play key functions in the incidence of ASCVD both directly by contributing to the development of atherosclerosis and indirectly by playing a part in the occurrence of fundamental cardiovascular risk factors. Essential gut metabolites, such as trimethylamine N-oxide (TMAO), secondary bile acids, lipopolysaccharides (LPS), and short-chain fatty acids (SCFAs), have been associated with the extent of ischemic heart diseases. This paper reviews the latest data on the impact of the gut microbiome in the incidence of ASCVD.

Relationship between disorders of the intestinal microbiota and heart failure in infants with congenital heart disease

Purpose

There is a close relationship between the intestinal microbiota and heart failure, but no study has assessed this relationship in infants with congenital heart disease. This study aimed to explore the relationship between heart failure and intestinal microbiota in infants with congenital heart disease.

Methods

Twenty-eight infants with congenital heart disease with heart failure admitted to a provincial children’s hospital from September 2021 to December 2021 were enrolled in this study. A total of 22 infants without heart disease and matched for age, sex, and weight were selected as controls. Faecal samples were collected from every participant and subjected to 16S rDNA gene sequencing.

Results

The composition of the intestinal microbiota was significantly disordered in infants with heart failure caused by congenital heart disease compared with that in infants without heart disease. At the phylum level, the most abundant bacteria in the heart failure group were Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes, and the most abundant bacteria in the control group were Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes. At the genus level, the most abundant bacteria in the heart failure group were Enterococcus, Bifidobacterium, Subdoligranulum, Shigella, and Streptococcus, and the most abundant bacteria in the control group were Bifidobacterium, Blautia, Bacteroides, Streptococcus, and Ruminococcus. The alpha and beta diversities of the gut bacterial community in the heart failure group were significantly lower than those in the control group (p&lt;0.05). Compared with the control group, retinol metabolism was significantly downregulated in the heart failure group.

Conclusion

Heart failure in infants with congenital heart disease caused intestinal microbiota disorder, which was characterised by an increase in pathogenic bacteria, a decrease in beneficial bacteria, and decreases in diversity and richness. The significant downregulation of retinol metabolism in the intestinal microbiota of infants with heart failure may be related to the progression of heart failure, and further study of the underlying mechanism is needed.

Combined analysis of plasma metabolome and intestinal microbiome sequencing to explore jiashen prescription and its potential role in changing intestine–heart axis and effect on chronic heart failure

Background

Heart failure (HF) is a syndrome with global clinical and socioeconomic burden worldwide owing to its poor prognosis. Jiashen Prescription (JSP), a traditional Chinese medicine (TCM) formula, exhibits unambiguous effects on treating HF. Previously, we have reported that underlying mechanisms of JSP by an untargeted metabolomics approach, but the contribution of gut microbiota and metabolic interaction to the cardioprotective efficacy of JSP remains to be elucidated.

Materials and methods

Firstly, the rat model of heart failure was established by the permanent ligation of the left anterior descending coronary artery. The efficacy evaluation of JSP in treating HF rats was per-formed by left ventricular ejection fraction (LVEF). Then, 16S rRNA gene sequencing and LC/MS-based metabolomic analysis were utilized to explore the characteristics of cecal-contents microecology and plasma metabolic profile, respectively. After that, the correlation between intestinal micro-ecological characteristics and plasma metabolic characteristics was analyzed to explore the potential mechanism of the JSP treatment in HF.

Results

JSP could improve the cardiac function of heart failure rats and thus ameliorate heart failure via enhancing rat LVEF. Results of intestinal flora analysis revealed that JSP not only adjusted gut microbiota disturbances by enriching species diversity, reducing the abundance of pathogenic bacteria (such as Allobaculum, Brevinema), as well as increasing the abundance of beneficial bacteria (such as Lactobacillus, Lachnospiraceae_NK4A136_group), but also improved metabolic disorders by reversing metabolite plasma levels to normality. Through the conjoint analysis of 8 metabolites and the OTUs relative abundance data in the 16srRNA sequencing results by WGCNA method, 215 floras significantly related to the eight compounds were identified. The results of the correlation analysis demonstrated a significant association between intestinal microbiota and plasma metabolic profile, especially the significant correlation of Ruminococcaceae_UCG-014 and Protoporphyrin IX, Ruminococcaceae_UCG-005, Christensenellaceae_R-7_group and nicotinamide, dihydrofolic acid.

Conclusion

The present study illustrated the underlying mechanism of JSP to treat heart failure by affecting intestinal flora and plasma metabolites, provide a potential therapeutic strategy against heart failure.

A major mechanism for immunomodulation: Dietary fibres and acid metabolites

Diet and the gut microbiota have a profound influence on physiology and health, however, mechanisms are still emerging. Here we outline several pathways that gut microbiota products, particularly short-chain fatty acids (SCFAs), use to maintain gut and immune homeostasis. Dietary fibre is fermented by the gut microbiota in the colon, and large quantities of SCFAs such as acetate, propionate, and butyrate are produced. Dietary fibre and SCFAs enhance epithelial integrity and thereby limit systemic endotoxemia. Moreover, SCFAs inhibit histone deacetylases (HDAC), and thereby affect gene transcription. SCFAs also bind to 'metabolite-sensing' G-protein coupled receptors (GPCRs) such as GPR43, which promotes immune homeostasis. The enormous amounts of SCFAs produced in the colon are sufficient to lower pH, which affects the function of proton sensors such as GPR65 expressed on the gut epithelium and immune cells. GPR65 is an anti-inflammatory Gα_s-coupled receptor, which leads to the inhibition of inflammatory cytokines. The importance of GPR65 in inflammatory diseases is underscored by genetics associated with the missense variant I231L (rs3742704), which is associated with human inflammatory bowel disease, atopic dermatitis, and asthma. There is enormous scope to manipulate these pathways using specialized diets that release very high amounts of specific SCFAs in the gut, and we believe that therapies that rely on chemically modified foods is a promising approach. Such an approach includes high SCFA-producing diets, which we have shown to decrease numerous inflammatory western diseases in mouse models. These diets operate at many levels - increased gut integrity, changes to the gut microbiome, and promotion of immune homeostasis, which represents a new and highly promising way to prevent or treat human disease.

Nutritional implications in the mechanistic link between the intestinal microbiome, renin-angiotensin system, and the development of obesity and metabolic syndrome

Obesity and metabolic disorders represent a significant global health problem and the gut microbiota plays an important role in modulating systemic homeostasis. Recent evidence shows that microbiota and its signaling pathways may affect the whole metabolism and the Renin-Angiotensin System (RAS), which in turn seems to modify microbiota. The present review aimed to investigate nutritional implications in the mechanistic link between the intestinal microbiome, renin-angiotensin system, and the development of obesity and metabolic syndrome components. A description of metabolic changes was obtained based on relevant scientific literature. The molecular and physiological mechanisms that impact the human microbiome were addressed, including the gut microbiota associated with obesity, diabetes, and hepatic steatosis. The RAS interaction signaling and modulation were analyzed. Strategies including the use of prebiotics, symbiotics, probiotics, and biotechnology may affect the gut microbiota and its impact on human health.

The gut microbiome and hypertension

A large body of evidence has emerged in the past decade supporting a role for the gut microbiome in the regulation of blood pressure. The field has moved from association to causation in the last 5 years, with studies that have used germ-free animals, antibiotic treatments and direct supplementation with microbial metabolites. The gut microbiome can regulate blood pressure through several mechanisms, including through gut dysbiosis-induced changes in microbiome-associated gene pathways in the host. Microbiota-derived metabolites are either beneficial (for example, short-chain fatty acids and indole-3-lactic acid) or detrimental (for example, trimethylamine N-oxide), and can activate several downstream signalling pathways via G protein-coupled receptors or through direct immune cell activation. Moreover, dysbiosis-associated breakdown of the gut epithelial barrier can elicit systemic inflammation and disrupt intestinal mechanotransduction. These alterations activate mechanisms that are traditionally associated with blood pressure regulation, such as the renin-angiotensin-aldosterone system, the autonomic nervous system, and the immune system. Several methodological and technological challenges remain in gut microbiome research, and the solutions involve minimizing confounding factors, establishing causality and acting globally to improve sample diversity. New clinical trials, precision microbiome medicine and computational methods such as Mendelian randomization have the potential to enable leveraging of the microbiome for translational applications to lower blood pressure.

Acetate circumvents impaired metabolic switch in skeletal muscle of letrozole-induced PCOS rat model by suppression of PDK4/NLRP3

OBJECTIVES

Endocrine disorders in women of childbearing age, including polycystic ovarian syndrome (PCOS), have been linked to skeletal muscle insulin resistance with multiple post-receptor intracellular defects, disrupting metabolic flexibility. Short-chain fatty acids, such as acetate have been suggested as a metabolic modulator. However, the effects of acetate on aberrant metabolic switch in skeletal muscle of individuals with PCOS are unknown. This study therefore hypothesized that acetate would circumvent impaired metabolic switch in the skeletal muscle of a letrozole-induced PCOS rat model, probably by suppression of PDK4/NLRP3.

METHODS

Eight-wk-old female Wistar rats were assigned into three groups (n = 6), which received vehicle, letrozole (1 mg/kg), and letrozole plus acetate (200 mg/kg), respectively. The administrations were done by oral gavage for 21 d. .

RESULTS

Animals with PCOS had insulin resistance, increased testosterone, and leptin, as well as decreased adiponectin level. Additionally, the skeletal muscle was also characterized with increased lipid deposition, malondialdehyde, inflammatory mediators (nuclear factor-κB and tumor necrosis factor-α), lactate dehydrogenase, lactate/pyruvate ratio, HDAC and PDK 4 with corresponding decrease in glycogen synthesis, glutathione and NrF2. Besides, immunohistochemical evaluation showed severe expression of inflammasome and apoptosis in PCOS animals. Nonetheless, supplementation with acetate significantly attenuated these perturbations.

CONCLUSIONS

The present results demonstrate aberrant metabolic switch in the skeletal muscle of PCOS animals, which is accompanied by excessive inflammation, oxidative stress and elevated levels of histone deacetylase and PDK4. The results suggested that histone deacetylase inhibitor, acetate circumvents impaired metabolic switch in the skeletal muscle of PCOS rats by suppression of PDK4/NLRP3 inflammasome.

Short-chain fatty acids: possible regulators of insulin secretion

The benefits of gut microbiota-derived short-chain fatty acids (SCFAs) towards health and metabolism have been emerging since the past decade. Extensive studies have been carried out to understand the mechanisms responsible in initiating the functionalities of these SCFAs towards body tissues, which greatly involves the SCFA-specific receptors free fatty acid receptor 2 (FFAR2) and free fatty acid receptor 3 (FFAR3). This review intends to discuss the potential of SCFAs particularly in regulating insulin secretion in pancreatic β-cells, by explaining the production of SCFAs in the gut, the fate of each SCFAs after their production, involvement of FFAR2 and FFAR3 signalling mechanisms and their impacts on insulin secretion. Increased secretion of insulin after SCFAs treatments were reported in many studies, but contradicting evidence also exist in several other studies. Hence, no clear consensus was achieved in determining the true potential of SCFA in regulating insulin secretion. In this review, we explore how such differences were possible and hopefully be able to shed some perspectives in understanding SCFAs-signalling behaviour and preferences.

The role of gut-dependent molecule trimethylamine N-oxide as a novel target for the treatment of chronic kidney disease

Trimethylamine N-oxide (TMAO) is an intestinal uremic toxin molecule mainly excreted by the kidney. Therefore, the plasma TMAO concentration is significantly increased in chronic kidney disease (CKD) patients, and plasma TMAO can be cleared by dialysis. Furthermore, TMAO damage the kidney mainly through three mechanisms: oxidative stress, inflammation and endoplasmic reticulum stress. Clinical experiments have indicated that higher TMAO levels are strongly related to the elevated incidence and mortality of cardiovascular (CV) events in CKD patients. Moreover, experimental data have shown that high levels of TMAO directly aggravate atherosclerosis, thrombosis and enhance myocardial contractility, resulting in myocardial ischemia and stroke. Specially, there are currently four potential ways to reduce blood TMAO concentration or block the effect of TMAO, including reducing the intake of trimethylamine (TMA) precursors in the diet, regulating the intestinal flora to reduce TMA production, interrupting the role of flavin-dependent monooxygenase isoforms (FMOs) to reduce the generation of TMAO, and blocking the TMAO receptor protein kinase R-like endoplasmic reticulum kinase (PERK). We hope that more clinical studies and clinicians will focus on clinical treatment to reduce the concentration of TMAO and alleviate renal damage.

Exploring the Relevance between Gut Microbiota-Metabolites Profile and Chronic Kidney Disease with Distinct Pathogenic Factor

The intimate correlation of chronic kidney disease (CKD) with structural alteration in gut microbiota or metabolite profile has been documented in a growing body of studies. Nevertheless, a paucity of demonstrated knowledge regarding the impact and underlying mechanism of gut microbiota or metabolite on occurrence or progression of CKD is unclarified thus far. In this study, a liquid chromatography coupled-mass spectrometry and long-read sequencing were applied to identify gut metabolites and microbiome with statistically-discriminative abundance in diabetic CKD patients (n = 39), hypertensive CKD patients (n = 26), or CKD patients without comorbidity (n = 40) compared to those of healthy participants (n = 60). The association between CKD-related species and metabolite was evaluated by using zero-inflated negative binomial (ZINB) regression. The predictive utility of identified operational taxonomic units (OTUs), metabolite, or species-metabolite association toward the diagnosis of incident chronic kidney disease with distinct pathogenic factor was assessed using the random forest regression model and the receiver operating characteristic (ROC) curve. The results of statistical analyses indicated alterations in the relative abundances of 26 OTUs and 41 metabolites that were specifically relevant to each CKD-patient group. The random forest regression model with only species, metabolites, or its association differentially distinguished the hypertensive, diabetic CKD patients, or enrolled CKD patients without comorbidity from the healthy participants. IMPORTANCE Gut dysbiosis-altered metabolite association exhibits specific and convincing utility to differentiate CKD associated with distinct pathogenic factor. These results present the validity of pathogenesis-associated markers across healthy participants and high-risk population toward the early screening, prevention, diagnosis, or personalized treatment of CKD.

Gut Microbiota and Metabolome Changes in Three Pulmonary Hypertension Rat Models

Dysbiosis of the gut microbiota and metabolites is found in both pulmonary hypertension patients and pulmonary hypertension rodent models. However, the exact changes in gut microbiota during the development of pulmonary hypertension is unclear. The function of the gut microbiota is also ambiguous. Here, this study showed that the gut microbiota was disrupted in rats with hypoxia (Hyp)-, hypoxia/Sugen5416 (HySu)-, and monocrotaline (MCT)-induced pulmonary hypertension. The gut microbiota is dynamically changed during the development of Hyp-, HySu-, and MCT-induced rat pulmonary hypertension. The variation in the α diversity of the gut microbiota in Hyp-induced pulmonary hypertension rats was similar to that in rats with MCT-induced pulmonary hypertension and different from that in rats with HySu-induced pulmonary hypertension. In addition, six plasma biomarkers, His, Ala, Ser, ADMA, 2-hydroxybutyric acid, and cystathionine, were identified in Hyp-induced pulmonary hypertension rats. Furthermore, a disease-associated network connecting Streptococcus with Hyp-induced pulmonary hypertension-associated metabolites was described here, including trimethylamine N-oxide, Asp, Asn, Lys, His, Ser, Pro, and Ile.

Gut microbiota and myocardial fibrosis

Myocardial fibrosis (MF) is a pathophysiological condition that accompanies various myocardial diseases and comprises a damaged myocardial matrix repair process. Although fibrosis plays a vital role in repair, it ultimately alters cardiac systolic and diastolic functions. The gut microbiota is a complex and dynamic ecosystem with billions of microorganisms that produce bioactive compounds that influence host health and disease progression. Intestinal microbiota has been shown to correlate with cardiovascular disease, and dysbiosis of the intestinal microbiota is involved in the development of MF. In this review, we discuss the role of intestinal microbiota in the process of MF, including alterations in microbiota composition and the effects of metabolites. We also discuss how diet and medicines can affect cardiac fibrosis by influencing the gut microbiota, and potential future therapies targeting the gut-heart axis. A healthy gut microbiota can prevent disease, but dysbiosis can lead to various symptoms, including the induction of heart disease. In this review, we discuss the relevance of the gut-heart axis and the multiple pathways by which gut microbiota may affect cardiac fibrosis, including inflammatory factors, immune cells, and gut microbiota metabolites, such as trimethylamine-N-oxide (TMAO) and short-chain fatty acids (SCFAs). Finally, we discuss the involvement of gut microbiota in the treatment of cardiac fibrosis, including drugs, fecal microbiota transplantation, and oral probiotics or prebiotics. With future studies on the relationship between the heart and gut microbiota, we hope to find better ways to improve MF through the gut-heart axis.

Cardiac metabolism in HFpEF: from fuel to signalling

Heart failure (HF) is marked by distinctive changes in myocardial uptake and utilization of energy substrates. Among the different types of HF, HF with preserved ejection fraction (HFpEF) is a highly prevalent, complex, and heterogeneous condition for which metabolic derangements seem to dictate disease progression. Changes in intermediate metabolism in cardiometabolic HFpEF-among the most prevalent forms of HFpEF-have a large impact both on energy provision and on a number of signalling pathways in the heart. This dual, metabolic vs. signalling, role is played in particular by long-chain fatty acids (LCFAs) and short-chain carbon sources [namely, short-chain fatty acids (SCFAs) and ketone bodies (KBs)]. LCFAs are key fuels for the heart, but their excess can be harmful, as in the case of toxic accumulation of lipid by-products (i.e. lipotoxicity). SCFAs and KBs have been proposed as a potential major, alternative source of energy in HFpEF. At the same time, both LCFAs and short-chain carbon sources are substrate for protein post-translational modifications and other forms of direct and indirect signalling of pivotal importance in HFpEF pathogenesis. An in-depth molecular understanding of the biological functions of energy substrates and their signalling role will be instrumental in the development of novel therapeutic approaches to HFpEF. Here, we summarize the current evidence on changes in energy metabolism in HFpEF, discuss the signalling role of intermediate metabolites through, at least in part, their fate as substrates for post-translational modifications, and highlight clinical and translational challenges around metabolic therapy in HFpEF.

The Interaction of Gut Microbiota and Heart Failure with Preserved Ejection Fraction: From Mechanism to Potential Therapies

Heart failure with preserved ejection fraction (HFpEF) is a disease for which there is no definite and effective treatment, and the number of patients is more than 50% of heart failure (HF) patients. Gut microbiota (GMB) is a general term for a group of microbiota living in humans' intestinal tracts, which has been proved to be related to cardiovascular diseases, including HFpEF. In HFpEF patients, the composition of GMB is significantly changed, and there has been a tendency toward dysbacteriosis. Metabolites of GMB, such as trimethylamine N-oxide (TMAO), short-chain fatty acids (SCFAs) and bile acids (BAs) mediate various pathophysiological mechanisms of HFpEF. GMB is a crucial influential factor in inflammation, which is considered to be one of the main causes of HFpEF. The role of GMB in its important comorbidity-metabolic syndrome-also mediates HFpEF. Moreover, HF would aggravate intestinal barrier impairment and microbial translocation, further promoting the disease progression. In view of these mechanisms, drugs targeting GMB may be one of the effective ways to treat HFpEF. This review focuses on the interaction of GMB and HFpEF and analyzes potential therapies.

Circadian orchestration of host and gut microbiota in infection

Circadian rhythms are present in almost every organism and regulate multiple aspects of biological and physiological processes (e.g. metabolism, immune responses, and microbial exposure). There exists a bidirectional circadian interaction between the host and its gut microbiota, and potential circadian orchestration of both host and gut microbiota in response to invading pathogens. In this review, we summarize what is known about these intestinal microbial oscillations and the relationships between host circadian clocks and various infectious agents (bacteria, fungi, parasites, and viruses), and discuss how host circadian clocks prime the immune system to fight pathogen infections as well as the direct effects of circadian clocks on viral activity (e.g. SARS-CoV-2 entry and replication). Finally, we consider strategies employed to realign normal circadian rhythmicity for host health, such as chronotherapy, dietary intervention, good sleep hygiene, and gut microbiota-targeted therapy. We propose that targeting circadian rhythmicity may provide therapeutic opportunities for the treatment of infectious diseases.

Mineralocorticoid receptor blockade improved gut microbiota dysbiosis by reducing gut sympathetic tone in spontaneously hypertensive rats

Microbiota has a crucial role in the host blood pressure (BP) regulation. The present study analyzes whether the mineralocorticoid receptor antagonist spironolactone ameliorates the dysbiosic state in a genetic model of neurogenic hypertension. Twenty-week-old male Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were randomly allocated into three groups: untreated WKY, untreated SHR, and SHR treated with spironolactone for 5 weeks. Spironolactone restored the Firmicutes/Bacteroidetes proportion, and acetate-producing bacteria populations to WKY levels. Spironolactone reduced the percentage of intestinal aerobic bacteria. The amelioration of gut dysbiosis was linked to a reduction in the gut pathology, an enhanced colonic integrity, a reduced gut permeability and an attenuated sympathetic drive in the gut. Spironolactone was unable to reduce neuroinflammation and oxidative stress in the paraventricular nuclei in the hypothalamus. Spironolactone reduced the higher Th17 cells proportion in mesenteric lymph nodes and Th17 infiltration in aorta, improved aortic endothelial function and reduced systolic BP. This study demonstrates for the first time that spironolactone reduces gut dysbiosis in SHR. This effect could be related to its capability to improve gut integrity and pathology due to reduced sympathetic drive in the gut.

Dietary fiber and SCFAs in the regulation of mucosal immunity

Gut bacterial metabolites such as short-chain fatty acids (SCFAs) have important effects on immune cells and the gut. SCFAs derive from the fermentation of dietary fiber by gut commensal bacteria. Insufficient fiber intake thus compromises SCFA production and, as a consequence, the host's physiology (particularly immune functions). We propose that many Western diseases, including those associated with impaired mucosal responses such as food allergy and asthma, may be affected by insufficient fiber intake and reduced SCFA levels in the gut and blood. Insufficient fiber intake is 1 alternative, or contributor, on top of the "hygiene hypothesis" to the rise of Western lifestyle diseases, and the 2 ideas need to be reconciled. The mechanisms by which SCFAs influence immunity and gut homeostasis are varied; they include stimulation of G protein-coupled receptors (GPCRs), such as GPR43 or GPR41; inhibition of histone deacetylases (and hence, gene transcription changes); and induction of intracellular metabolic changes. SCFAs modulate at many different levels to alter mucosal homeostasis, including changes to gut epithelial integrity, increases in regulatory T-cell numbers and function, and decreased expression of numerous inflammatory cytokines. There is scope for preventing and/or treating diseases by using diets that alter SCFA levels.

Effects of probiotics on hypertension

Emerging data have suggested that probiotics had good potential in regulating intestinal flora and preventing hypertension. Some studies in human and animal models have demonstrated probiotic intervention could attenuate hypertension, regulate intestinal flora to increase the abundance of beneficial bacteria, and regulate intestinal microbial metabolites such as trimethylamine oxide, short-chain fatty acids, and polyphenols. However, there is still some debate as to whether probiotics exert effective benefits. These recently published reviews did not systematically expound on the heterogeneity between the effect and mechanism of probiotics with different types, doses, and carriers to exert antihypertensive effects, as well as the possible application of probiotics in the prevention and treatment of hypertension in food and clinic. Here we try to systematically review the association between hypertension and intestinal microflora, the effect of probiotics and their metabolites on hypertension, and the recent research progress on the specific mechanism of probiotics on hypertension. In addition, we also summarized the potential application of probiotics in antihypertension. Future challenges include elucidating the functions of metabolites produced by microorganisms and their downstream pathway or molecules, identifying specific strains, not just microbial communities, and developing therapeutic interventions that target hypertension by modulation of gut microbes and metabolites.

Liver Microbiome in Healthy Rats: The Hidden Inhabitants of Hepatocytes

The tumor and tissue microbiota of human beings have recently been investigated. Gut permeability is known as a possible resource for the positive detection of tissue bacteria. Herein, we report that microbiota were detected in high abundance in the hepatocytes of healthy rats and that they were shared with the gut microbiota to an extent. We assessed male Sprague Dawley (SD) rats for the 16S ribosomal ribonucleic acid (rRNA) gene. After the rats were sacrificed by blood drainage from the portal vein, we extracted total deoxyribonucleic acid (DNA) from their ileal and colonic contents and liver tissues. The V3–V4 region of the 16S rRNA gene was amplified by polymerase chain reaction (PCR) and sequenced using an Illumina HiSeq 2500 platform. Sequences were assigned taxonomically by the SILVA database. We also detected bacterial lipopolysaccharide (LPS) and lipoteichoic acid (LTA) in situ using immunofluorescence (IF) and western blotting and the 16S rRNA gene using fluorescent in situ hybridization (FISH). In the livers of six rats, we detected $\mathrm{54,867.50}\pm 6450.03$ effective tags of the 16S rRNA gene and clustered them into 1003 kinds of operational taxonomic units (OTUs; $805.67\pm 70.14$ , 729–893). Rats showed conservation of bacterial richness, abundance, and evenness. LPS and the 16S rRNA gene were detected in the nuclei of hepatocytes. The main function composition of the genomes of annotated bacteria was correlated with metabolism ( $79.92\pm 0.24\%$ ). Gram negativity was about 1.6 times higher than gram positivity. The liver microbiome was shared with both the small and large intestines but showed significantly higher richness and evenness than the gut microbiome, and the β-diversity results showed that the liver microbiome exhibited significantly higher similarity than the small and large intestines ( $P<0.05$ ). Our results suggest that the bacteria in the liver microbiome are hidden intracellular inhabitants in healthy rat livers.

Inflammatory Response: A Crucial Way for Gut Microbes to Regulate Cardiovascular Diseases

Gut microbiota is the largest and most complex microflora in the human body, which plays a crucial role in human health and disease. Over the past 20 years, the bidirectional communication between gut microbiota and extra-intestinal organs has been extensively studied. A better comprehension of the alternative mechanisms for physiological and pathophysiological processes could pave the way for health. Cardiovascular disease (CVD) is one of the most common diseases that seriously threatens human health. Although previous studies have shown that cardiovascular diseases, such as heart failure, hypertension, and coronary atherosclerosis, are closely related to gut microbiota, limited understanding of the complex pathogenesis leads to poor effectiveness of clinical treatment. Dysregulation of inflammation always accounts for the damaged gastrointestinal function and deranged interaction with the cardiovascular system. This review focuses on the characteristics of gut microbiota in CVD and the significance of inflammation regulation during the whole process. In addition, strategies to prevent and treat CVD through proper regulation of gut microbiota and its metabolites are also discussed.

Relationship between Nutrition, Lifestyle Habits and Laboratory Parameters in Hypertensive Patients with/without Cognitive Dysfunction

(1) Background: Cognitive dysfunction is a major concern in hypertensive patients. Lifestyle habits and nutrition influence laboratory parameters, with an impact on clinical course. The objective of the study was to evaluate nutrition and lifestyle habits in hypertensive patients with/without cognitive dysfunction and establish correlations to laboratory parameters.

MATERIAL AND METHODS

50 patients admitted to the Cardiovascular Rehabilitation Clinic in Târgu Mureș were enrolled in this study between March-June 2021. We evaluated their cognitive function, and they filled in a questionnaire about lifestyle and nutrition. Biochemical blood tests were performed using a Konelab Prime 60i analyzer. IBM-SPSS22 and GraphPad InStat3 were used for statistics.

RESULTS

Mean age of hypertensive patients (n = 50) was 70.42 ± 4.82 (SD) years, half of them had cognitive dysfunction. Zinc deficiency was present in 74% of the subjects. The subgroup with cognitive dysfunction had significantly higher BMI (p = 0.009) and microalbuminuria (p = 0.0479), as well as significantly lower magnesium intake (p = 0.032) and cholesterol intake (p = 0.022), compared to those with normal cognitive status.

CONCLUSIONS

Nutrition is in a close relationship with laboratory parameters; significant differences (microalbuminuria, cholesterol intake, BMI, etc.) are present between hypertensive patients with/without cognitive dysfunction. A healthy diet is important for the maintenance of metabolic balance, the achievement of optimal body weight, and the prevention of complications.

Crosstalk between Gut Microbiota and Host Immunity: Impact on Inflammation and Immunotherapy

Gut microbes and their metabolites are actively involved in the development and regulation of host immunity, which can influence disease susceptibility. Herein, we review the most recent research advancements in the gut microbiota-immune axis. We discuss in detail how the gut microbiota is a tipping point for neonatal immune development as indicated by newly uncovered phenomenon, such as maternal imprinting, in utero intestinal metabolome, and weaning reaction. We describe how the gut microbiota shapes both innate and adaptive immunity with emphasis on the metabolites short-chain fatty acids and secondary bile acids. We also comprehensively delineate how disruption in the microbiota-immune axis results in immune-mediated diseases, such as gastrointestinal infections, inflammatory bowel diseases, cardiometabolic disorders (e.g., cardiovascular diseases, diabetes, and hypertension), autoimmunity (e.g., rheumatoid arthritis), hypersensitivity (e.g., asthma and allergies), psychological disorders (e.g., anxiety), and cancer (e.g., colorectal and hepatic). We further encompass the role of fecal microbiota transplantation, probiotics, prebiotics, and dietary polyphenols in reshaping the gut microbiota and their therapeutic potential. Continuing, we examine how the gut microbiota modulates immune therapies, including immune checkpoint inhibitors, JAK inhibitors, and anti-TNF therapies. We lastly mention the current challenges in metagenomics, germ-free models, and microbiota recapitulation to a achieve fundamental understanding for how gut microbiota regulates immunity. Altogether, this review proposes improving immunotherapy efficacy from the perspective of microbiome-targeted interventions.

The Function and Therapeutic Potential of lncRNAs in Cardiac Fibrosis

Cardiac fibrosis remains an unresolved problem in cardiovascular diseases. Fibrosis of the myocardium plays a key role in the clinical outcomes of patients with heart injuries. Moderate fibrosis is favorable for cardiac structure maintaining and contractile force transmission, whereas adverse fibrosis generally progresses to ventricular remodeling and cardiac systolic or diastolic dysfunction. The molecular mechanisms involved in these processes are multifactorial and complex. Several molecular mechanisms, such as TGF-β signaling pathway, extracellular matrix (ECM) synthesis and degradation, and non-coding RNAs, positively or negatively regulate myocardial fibrosis. Long noncoding RNAs (lncRNAs) have emerged as significant mediators in gene regulation in cardiovascular diseases. Recent studies have demonstrated that lncRNAs are crucial in genetic programming and gene expression during myocardial fibrosis. We summarize the function of lncRNAs in cardiac fibrosis and their contributions to miRNA expression, TGF-β signaling, and ECMs synthesis, with a particular attention on the exosome-derived lncRNAs in the regulation of adverse fibrosis as well as the mode of action of lncRNAs secreted into exosomes. We also discuss how the current knowledge on lncRNAs can be applied to develop novel therapeutic strategies to prevent or reverse cardiac fibrosis.

Agaricus bisporus Polysaccharides Ameliorates Behavioural Deficits in D-Galactose-Induced Aging Mice: Mediated by Gut Microbiota

White button mushroom polysaccharide (WMP) has various health-promoting functions. However, whether these functions are mediated by gut microbiota has not been well explored. Therefore, this study evaluated the anti-aging capacity of WMP and its effects on the diversity and composition of gut microbiota in D-galactose-induced aging mice. WMP significantly improved locomotor activity and the spatial and recognition memory of the aging mice. It also alleviated oxidative stress and decreased the pro-inflammatory cytokine levels in the brain. Moreover, WMP increased α-diversity, the short-chain fatty acid (SCFA) level and the abundance of beneficial genera, such as Bacteroides and Parabacteroides. Moreover, its effect on Bacteroides at the species level was further determined, and the enrichments of B. acidifaciens, B. sartorii and B. stercorirosoris were found. A PICRUSt analysis revealed that WMP had a greater impact on the metabolism of carbon, fatty acid and amino acid, as well as the MAPK and PPAR signaling pathway. In addition, there was a strong correlation between the behavioral improvements and changes in SCFA levels and the abundance of Bacteroides, Parabacteroides, Mucispirillum and Desulfovibrio and Helicobacter. Therefore, WMP might be suitable as a functional foods to prevent or delay aging via the directed enrichment of specific species in Bacteroides.

A comparison of principal component analysis, partial least-squares, and reduced-rank regressions in the identification of dietary patterns associated with hypertension: YaHS-TAMYZ and Shahedieh cohort studies

Limited data exist on the advantage of data reduction hybrid methodologies for evaluating the relationship between dietary patterns (DPs) and chronic diseases and they have led to inconsistent results. This study aimed to investigate the association between DPs extracted using principal component analysis (PCA), partial least-squares (PLS), and reduced-rank regressions (RRRs) in identifying DPs associated with hypertension (HTN) risk. The current study was conducted in the context of two cohort studies accomplished in Iran. DPs were generated using PCA, PLS, and RRR methods. Log-binomial logistic regression test was used to assess the association between DPs and the risk of HTN. From a total of 12,403 included participants aged 20-70 years, 507 incident cases of confirmed HTN were identified. The PCA-DP2 was associated with HTN in the fully adjusted model (T3 vs. T1: RR: 0.737, 95% CI: 0.57-0.93, P trend = 0.013). The PLS-DP2 and HTN risk were inversely associated in the multivariate model (T3 vs. T1: RR: 0.704, 95% CI: 0.54-0.91, P trend = 0.013). The RRR-DP2 was associated with an increased risk of HTN (T3 vs. T1: RR: 1.412, 95% CI: 1.11-1.80, P trend = 0.007). Our findings suggest that the RRR method reveals stronger results in association with HTN risk. However, further investigations are required to confirm the association between DPs derived by PLS and RRR methods by incorporating biomarkers related to HTN as the response variables.