The Microbiome and Blood Pressure: Can Microbes Regulate Our Blood Pressure?

Does maternal consumption of nutritive and non-nutritive sweeteners result in offspring hypertension?

The consumption of nutritive and non-nutritive sweeteners (NNS) has increased significantly in recent decades. The nutritional status of pregnant women plays a crucial role in determining the likelihood of their offspring developing hypertension in adulthood. While NNSs provide a sweet taste without adding to sugar intake, emerging evidence suggests that maternal consumption of not only nutritive sweeteners (such as fructose) but also NNS may lead to adverse outcomes in offspring, including hypertension. This review provides an overview of the latest research connecting maternal intake of sweeteners to the long-term risk of hypertension in offspring. We examine proposed mechanisms underlying the programming of offspring hypertension by sweeteners, encompassing oxidative stress, dysregulated nutrient sensing signals, abnormal renin-angiotensin system, transcriptome changes, and dysbiotic gut microbiota. Additionally, we outline preventive strategies that can help alleviate offspring hypertension programmed by maternal diets high in sweeteners. Recent advancements in understanding the mechanisms through which maternal consumption of nutritive and non-nutritive sweeteners contributes to offspring hypertension offer promise for addressing this widespread health concern at its developmental roots. Nonetheless, further research is needed to educate the public about the safety of sweetener consumption during pregnancy and lactation.

Type III Secretion System in Intestinal Pathogens and Metabolic Diseases

Modern lifestyle changes, especially the consumption of a diet high in salt, sugar, and fat, have contributed to the increasing incidence and prevalence of chronic metabolic diseases such as diabetes, obesity, and gout. Changing lifestyles continuously shape the gut microbiota which is closely related to the occurrence and development of metabolic diseases due to its specificity of composition and structural diversity. A large number of pathogenic bacteria such as Yersinia, Salmonella, Shigella, and pathogenic E. coli in the gut utilize the type III secretion system (T3SS) to help them resist host defenses and cause disease. Although the T3SS is critical for the virulence of many important human pathogens, its relationship with metabolic diseases remains unknown. This article reviews the structure and function of the T3SS, the disruption of intestinal barrier integrity by the T3SS, the changes in intestinal flora containing the T3SS in metabolic diseases, the possible mechanisms of the T3SS affecting metabolic diseases, and the application of the T3SS in the treatment of metabolic diseases. The aim is to provide insights into metabolic diseases targeting the T3SS, thereby serving as a valuable reference for future research on disease diagnosis, prevention, and treatment.

Consumption of processed meat but not red meat is associated with the incidence of hypertension: ELSA-Brasil cohort

OBJECTIVES

To verify the association between the consumption of red and processed meats and the incidence of hypertension in participants of the Longitudinal Study of Adult Health.

METHODS

This was a cohort with data from the baseline (2008-2010) and second wave (2012-2014) with 8,089 public workers of both sexes and different racial groups, with mean age of 49 ± 8 years (35-74 years old). Meat consumption (g/d) was estimated using a food frequency questionnaire and was divided into consumption tertiles. Hypertension was defined as systolic blood pressure ≥140 mm Hg and/or diastolic ≥90 mm Hg and/or antihypertensive medication. Cox proportional hazards models were used to estimate adjusted Hazard Ration (HRs) and 95% confidence interval (CI) for incident hypertension.

RESULTS

A total of 1186 incident cases of hypertension were identified. Even adjusting for confounders, such as urinary Na/K (sodium/potassium) ratio and BMI (body mass index), participants in the second (HR:1.19; 95% CI 1.03-1.30) and third (HR:1.30; 95% CI:1.11-1.53) tertile of processed meat consumption had a higher risk of developing hypertension than those in the first tertile. We did not find a significant association between red meat consumption and hypertension.

CONCLUSIONS

The increased risk of developing hypertension is associated with moderate and high consumption of processed meats but not with consumption of red meat.

From Microbes to Myocardium: A Comprehensive Review of the Impact of the Gut-Brain Axis on Cardiovascular Disease

Cardiovascular diseases (CVDs) remain the leading cause of morbidity and mortality worldwide despite advances in medical research and therapeutics. Emerging evidence suggests a significant role of the gut-brain axis, a complex communication network involving the gut microbiota, central nervous system, and cardiovascular system, in modulating cardiovascular health. The gut microbiota influences systemic inflammation, neurohumoral pathways, and metabolic processes, which are critical in the pathogenesis of CVD. Dysbiosis, or an imbalance in the gut microbiota, has been implicated in various cardiovascular conditions, including hypertension, atherosclerosis, and heart failure. This comprehensive review aims to elucidate the intricate relationship between the gut microbiome, brain, and cardiovascular system, highlighting the mechanisms by which gut-derived signals affect cardiovascular function. Key microbial metabolites, such as short-chain fatty acids (SCFAs) and trimethylamine N-oxide (TMAO), and their impact on vascular health and blood pressure regulation are discussed. Furthermore, the review explores potential therapeutic strategies targeting the gut-brain axis, including probiotics, prebiotics, dietary modifications, and pharmacological interventions, to improve cardiovascular outcomes. Despite promising findings, the field faces challenges such as individual variability in microbiome composition, complexities in gut-brain interactions, and the need for robust clinical trials to establish causality. Addressing these challenges through interdisciplinary research could pave the way for innovative, personalized therapeutic approaches. This review provides a comprehensive understanding of the gut-brain-cardiovascular axis, underscoring its potential as a novel target for preventing and treating CVD.

Metabolic dysfunction-associated steatotic liver disease and cardiovascular risk: a comprehensive review

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously termed nonalcoholic fatty liver disease (NAFLD), poses a significant global health challenge due to its increasing prevalence and strong association with cardiovascular disease (CVD). This comprehensive review summarizes the current knowledge on the MASLD-CVD relationship, compares analysis of how different terminologies for fatty liver disease affect cardiovascular (CV) risk assessment using different diagnostic criteria, explores the pathophysiological mechanisms connecting MASLD to CVD, the influence of MASLD on traditional CV risk factors, the role of noninvasive imaging techniques and biomarkers in the assessment of CV risk in patients with MASLD, and the implications for clinical management and prevention strategies. By incorporating current research and clinical guidelines, this review provides a comprehensive overview of the complex interplay between MASLD and cardiovascular health.

Akkermansia muciniphila as a Potential Guardian against Oral Health Diseases: A Narrative Review

The oral microbiome is a diverse ecosystem containing a community of symbiotic, commensal, and pathogenic microorganisms. One key microorganism linked to periodontal disease (PD) is Porphyromonas gingivalis (P. gingivalis), a Gram-negative anaerobic bacterium known to have several virulence factors that trigger inflammation and immune evasion. On the other hand, Akkermansia muciniphila (A. muciniphila), a symbiotic bacterium, has been recently shown to play an important role in mitigating inflammation and reducing periodontal damage. In vivo and in vitro studies have shown that A. muciniphila decreases inflammatory mediators and improves immune responses, suggesting its role in mitigating PD and related inflammatory systemic conditions such as diabetes, hypertension, and obesity. This review discusses the anti-inflammatory effects of A. muciniphila, its impact on periodontal health, and its potential role in managing systemic diseases. The overall aim is to elucidate how this bacterium might help reduce inflammation, improve oral health, and influence broader health outcomes.

Evaluation of normalization methods for predicting quantitative phenotypes in metagenomic data analysis

Genotype-to-phenotype mapping is an essential problem in the current genomic era. While qualitative case-control predictions have received significant attention, less emphasis has been placed on predicting quantitative phenotypes. This emerging field holds great promise in revealing intricate connections between microbial communities and host health. However, the presence of heterogeneity in microbiome datasets poses a substantial challenge to the accuracy of predictions and undermines the reproducibility of models. To tackle this challenge, we investigated 22 normalization methods that aimed at removing heterogeneity across multiple datasets, conducted a comprehensive review of them, and evaluated their effectiveness in predicting quantitative phenotypes in three simulation scenarios and 31 real datasets. The results indicate that none of these methods demonstrate significant superiority in predicting quantitative phenotypes or attain a noteworthy reduction in Root Mean Squared Error (RMSE) of the predictions. Given the frequent occurrence of batch effects and the satisfactory performance of batch correction methods in predicting datasets affected by these effects, we strongly recommend utilizing batch correction methods as the initial step in predicting quantitative phenotypes. In summary, the performance of normalization methods in predicting metagenomic data remains a dynamic and ongoing research area. Our study contributes to this field by undertaking a comprehensive evaluation of diverse methods and offering valuable insights into their effectiveness in predicting quantitative phenotypes.

Microbial influence on blood pressure: unraveling the complex relationship for health insights

Hypertension, a critical global health concern, is characterized by persistent high blood pressure and is a major cause of cardiovascular events. This perspective explores the multifaceted implications of hypertension, its association with cardiovascular diseases, and the emerging role of the gut microbiota. The gut microbiota, a dynamic community in the gastrointestinal tract, plays a pivotal role in hypertension by influencing blood pressure through the generation of antioxidant, anti-inflammatory, and short-chain fatty acids metabolites, and the conversion of nitrates into nitric oxide. Antihypertensive medications interact with the gut microbiota, impacting drug pharmacokinetics and efficacy. Prebiotics and probiotics present promising avenues for hypertension management, with prebiotics modulating blood pressure through lipid and cholesterol modulation, and probiotics exhibiting a general beneficial effect. Personalized choices based on individual factors are crucial for optimizing prebiotic and probiotic interventions. In conclusion, the gut microbiota's intricate influence on blood pressure regulation offers innovative perspectives in hypertension therapeutics, with targeted strategies proving valuable for holistic blood pressure management and health promotion.

Nutritional Approaches Targeting Gut Microbiota in Oxidative-Stress-Associated Metabolic Syndrome: Focus on Early Life Programming

Metabolic syndrome (MetS) denotes a constellation of risk factors associated with the development of cardiovascular disease, with its roots potentially traced back to early life. Given the pivotal role of oxidative stress and dysbiotic gut microbiota in MetS pathogenesis, comprehending their influence on MetS programming is crucial. Targeting these mechanisms during the early stages of life presents a promising avenue for preventing MetS later in life. This article begins by examining detrimental insults during early life that impact fetal programming, ultimately contributing to MetS in adulthood. Following that, we explore the role of oxidative stress and the dysregulation of gut microbiota in the initiation of MetS programming. The review also consolidates existing evidence on how gut-microbiota-targeted interventions can thwart oxidative-stress-associated MetS programming, encompassing approaches such as probiotics, prebiotics, postbiotics, and the modulation of bacterial metabolites. While animal studies demonstrate the favorable effects of gut-microbiota-targeted therapy in mitigating MetS programming, further clinical investigations are imperative to enhance our understanding of manipulating gut microbiota and oxidative stress for the prevention of MetS.

Research progress on the correlation between gut microbiota and preeclampsia: microbiome changes, mechanisms and treatments

Preeclampsia is a specific disease during pregnancy and is a significant factor in the increased mortality in perinatal women. Gut microbiota, an intricate and abundant microbial community in the digestive tract, is crucial for host metabolism, immunity, and nutrient absorption. The onset and progression of preeclampsia are closely correlated with the changes in maternal gut microbiota. Research purpose was to compile the existing bits of present scientific data and to close the gap in the knowledge of changes in gut microbiota in preeclampsia and their association with preeclampsia. We searched studies from two electronic databases (PubMed and Web of Science) included from 2014 to 2023. This review is divided into three parts. In the first part, the author elaborates longitudinal differences of maternal gut microbiota during different gestation periods. In the second part, we discuss that gut microbiota can lead to the occurrence of preeclampsia by systemic immune response, influencing the release of active peptides, short-chain fatty acids, trimethylamine-N-oxide (TMAO) and other metabolites, vascular factors and Microorganism-immune axis. In the third part, we proposed that a high-fiber diet combined with drugs and microecological regulators may be therapeutic in enhancing or preventing the emergence and evolution of preeclampsia, which needs further exploration. Although the pathogenesis of preeclampsia is still nebulous and there is no clear and valid clinical treatment, our study provides new ideas for the pathogenesis, prevention and treatment of preeclampsia.

The potential links between human gut microbiota and cardiovascular health and disease - is there a gut-cardiovascular axis?

The gut-heart axis is an emerging concept highlighting the crucial link between gut microbiota and cardiovascular diseases (CVDs). Recent studies have demonstrated that gut microbiota is pivotal in regulating host metabolism, inflammation, and immune function, critical drivers of CVD pathophysiology. Despite a strong link between gut microbiota and CVDs, this ecosystem’s complexity still needs to be fully understood. The short-chain fatty acids, trimethylamine N-oxide, bile acids, and polyamines are directly or indirectly involved in the development and prognosis of CVDs. This review explores the relationship between gut microbiota metabolites and CVDs, focusing on atherosclerosis and hypertension, and analyzes personalized microbiota-based modulation interventions, such as physical activity, diet, probiotics, prebiotics, and fecal microbiota transplantation, as a promising strategy for CVD prevention and treatment.

Exploring a Complex Interplay: Kidney-Gut Axis in Pediatric Chronic Kidney Disease

The human intestinal microbiota is a highly intricate structure with a crucial role in promoting health and preventing disease. It consists of diverse microbial communities that inhabit the gut and contribute to essential functions such as food digestion, nutrient synthesis, and immune system development. The composition and function of the gut microbiota are influenced by a variety of factors, including diet, host genetics, and environmental features. In pediatric patients, the gut microbiota is particularly dynamic and vulnerable to disruption from endogenous and exogenous factors. Recent research has focused on understanding the interaction between the gut and kidneys. In individuals with chronic kidney disease, there is often a significant disturbance in the gut microbiota. This imbalance can be attributed to factors like increased levels of harmful toxins from the gut entering the bloodstream, inflammation, and oxidative stress. This review looks at what is known about the link between a child's gut-kidney axis, how dysbiosis, or an imbalance in the microbiome, affects chronic kidney disease, and what treatments, both pharmaceutical and non-pharmaceutical, are available for this condition.

Red Quinoa Hydrolysates with Antioxidant Properties Improve Cardiovascular Health in Spontaneously Hypertensive Rats

In recent years, quinoa has been postulated as an emerging crop for the production of functional foods. Quinoa has been used to obtain plant protein hydrolysates with in vitro biological activity. The aim of the present study was to evaluate the beneficial effect of red quinoa hydrolysate (QrH) on oxidative stress and cardiovascular health in an in vivo experimental model of hypertension (HTN) in the spontaneously hypertensive rat (SHR). The oral administration of QrH at 1000 mg/kg/day (QrHH) showed a significant reduction in SBP from baseline (-9.8 ± 4.5 mm Hg; p < 0.05) in SHR. The mechanical stimulation thresholds did not change during the study QrH groups, whereas in the case of SHR control and SHR vitamin C, a significant reduction was observed (p < 0.05). The SHR QrHH exhibited higher antioxidant capacity in the kidney than the other experimental groups (p < 0.05). The SHR QrHH group showed an increase in reduced glutathione levels in the liver compared to the SHR control group (p < 0.05). In relation to lipid peroxidation, SHR QrHH exhibited a significant decrease in plasma, kidney and heart malondialdehyde (MDA) values compared to the SHR control group (p < 0.05). The results obtained revealed the in vivo antioxidant effect of QrH and its ability to ameliorate HTN and its associated complications.

Melatonin and Kidney Health: From Fetal Stage to Later Life

Melatonin, an endogenous hormone mainly released at night by the pineal gland, has multifaceted biofunctions. Emerging evidence points to melatonin having a crucial role in kidney health and disease. As the prevalence of chronic kidney disease (CKD) is still rising, a superior strategy to advance global kidney health is needed to not just treat CKD, but prevent it early on. Adult kidney disease can have its origins in early life. This review aims to evaluate the recent literature regarding melatonin's effect on kidney development, its clinical uses in the early stage of life, animal models documenting preventive applications of melatonin on offspring's kidney-related disease, and a thorough summary of therapeutic considerations concerning melatonin supplementation.

Gut Microbiome in Post-COVID-19 Patients Is Linked to Immune and Cardiovascular Health Status but Not COVID-19 Severity

The composition of the gut microbiome stores the imprints of prior infections and other impacts. COVID-19 can cause changes in inflammatory status that persist for a considerable time after infection ends. As the gut microbiome is closely associated with immunity and inflammation, the infection severity might be linked to its community structure dynamics. Using 16S rRNA sequencing of stool samples, we investigated the microbiome three months after the end of the disease/infection or SARS-CoV-2 contact in 178 post-COVID-19 patients and those who contacted SARS-CoV-2 but were not infected. The cohort included 3 groups: asymptomatic subjects (n = 48), subjects who contacted COVID-19 patients with no further infection (n = 46), and severe patients (n = 86). Using a novel compositional statistical algorithm (nearest balance) and the concept of bacterial co-occurrence clusters (coops), we compared microbiome compositions between the groups as well as with multiple categories of clinical parameters including: immunity, cardiovascular parameters and markers of endothelial dysfunction, and blood metabolites. Although a number of clinical indicators varied drastically across the three groups, no differences in microbiome features were identified between them at this follow-up point. However, there were multiple associations between the microbiome features and clinical data. Among the immunity parameters, the relative lymphocyte number was linked to a balance including 14 genera. Cardiovascular parameters were associated with up to four bacterial cooperatives. Intercellular adhesion molecule 1 was linked to a balance including ten genera and one cooperative. Among the blood biochemistry parameters, calcium was the only parameter associated with the microbiome via a balance of 16 genera. Our results suggest comparable recovery of the gut community structure in the post-COVID-19 period, independently of severity or infection status. The multiple identified associations of clinical analysis data with the microbiome provide hypotheses about the participation of specific taxa in regulating immunity and homeostasis of cardiovascular and other body systems in health, as well as their disruption in SARS-CoV-2 infections and other diseases.

Dysbiotic microbiome variation in colorectal cancer patients is linked to lifestyles and metabolic diseases

BACKGROUND

Differences in the composition and diversity of the gut microbial communities among individuals are influenced by environmental factors. However, there is limited research on factors affecting microbiome variation in colorectal cancer patients, who display lower inter-individual variations than that of healthy individuals. In this study, we examined the association between modifiable factors and the microbiome variation in colorectal cancer patients.

METHODS

A total of 331 colorectal cancer patients who underwent resection surgery at the Department of Surgery, Seoul National University Hospital between October 2017 and August 2019 were included. Fecal samples from colorectal cancer patients were collected prior to the surgery. Variations in the gut microbiome among patients with different lifestyles and metabolic diseases were examined through the network analysis of inter-connected microbial abundance, the assessment of the Anna Karenina principle effect for microbial stochasticity, and the identification of the enriched bacteria using linear discrimination analysis effect size. Associations of dietary diversity with microbiome variation were investigated using the Procrustes analysis.

RESULTS

We found stronger network connectivity of microbial communities in non-smokers, non-drinkers, obese individuals, hypertensive subjects, and individuals without diabetes than in their counterparts. The Anna Karenina principle effect was found for history of smoking, alcohol consumption, and diabetes (with significantly greater intra-sample similarity index), whereas obesity and hypertension showed the anti-Anna Karenina principle effect (with significantly lower intra-sample similarity index). We found certain bacterial taxa to be significantly enriched in patients of different categories of lifestyles and metabolic diseases using linear discrimination analysis. Diversity of food and nutrient intake did not shape the microbial diversity between individuals (p_Procrustes>0.05).

CONCLUSIONS

Our findings suggested an immune dysregulation and a reduced ability of the host and its microbiome in regulating the community composition. History of smoking, alcohol consumption, and diabetes were shown to affect partial individuals in shifting new microbial communities, whereas obesity and history of hypertension appeared to affect majority of individuals and shifted to drastic reductions in microbial compositions. Understanding the contribution of modifiable factors to microbial stochasticity may provide insights into how the microbiome regulates effects of these factors on the health outcomes of colorectal cancer patients.

Narrative Review on the Effects of Oat and Sprouted Oat Components on Blood Pressure

Hypertension (HTN) is a major risk factor for cardiovascular disease (CVD) and cognitive decline. Elevations in blood pressure (BP) leading to HTN can be found in young adults with increased prevalence as people age. Oats are known to decrease CVD risk via an established effect of β-glucan on the attenuation of blood cholesterol. Many past studies on CVD and oats have also reported a decrease in BP; however, a thorough assessment of oats and BP has not been conducted. Moreover, oats deliver several beneficial dietary components with putative beneficial effects on BP or endothelial function, such as β-glucan, γ-amino butyric acid (GABA), and phytochemicals such as avenanthramides. We conducted a comprehensive search for systematic reviews, meta-analyses, and clinical intervention studies on oats and BP and identified 18 randomized controlled trials (RCTs) and three meta-analyses that supported the role of oats in decreasing BP. Emerging data also suggest oat consumption may reduce the use of anti-hypertensive medications. The majority of these studies utilized whole oats or oat bran, which include a vast array of oat bioactives. Therefore, we also extensively reviewed the literature on these bioactives and their putative effect on BP-relevant mechanisms. The data suggest several oat components, such as GABA, as well as the delivery of high-quality plant protein and fermentable prebiotic fiber, may contribute to the anti-HTN effect of oats. In particular, GABA is enhanced in oat sprouts, which suggests this food may be particularly beneficial for healthy BP management.

The potential impact of a probiotic: Akkermansia muciniphila in the regulation of blood pressure—the current facts and evidence

Akkermansia muciniphila (A. muciniphila) is present in the human gut microbiota from infancy and gradually increases in adulthood. The potential impact of the abundance of A. muciniphila has been studied in major cardiovascular diseases including elevated blood pressure or hypertension (HTN). HTN is a major factor in premature death worldwide, and approximately 1.28 billion adults aged 30–79 years have hypertension. A. muciniphila is being considered a next-generation probiotic and though numerous studies had highlighted the positive role of A. muciniphila in lowering/controlling the HTN, however, few studies had highlighted the negative impact of increased abundance of A. muciniphila in the management of HTN. Thus, in the review, we aimed to discuss the current facts, evidence, and controversy about the role of A. muciniphila in the pathophysiology of HTN and its potential effect on HTN management/regulation, which could be beneficial in identifying the drug target for the management of HTN.

Gut Microbiota Modulation as a Novel Therapeutic Strategy in Cardiometabolic Diseases

The human gut harbors microbial ecology that is in a symbiotic relationship with its host and has a vital function in keeping host homeostasis. Inimical alterations in the composition of gut microbiota, known as gut dysbiosis, have been associated with cardiometabolic diseases. Studies have revealed the variation in gut microbiota composition in healthy individuals as compared to the composition of those with cardiometabolic diseases. Perturbation of host-microbial interaction attenuates physiological processes and may incite several cardiometabolic disease pathways. This imbalance contributes to cardiometabolic diseases via metabolism-independent and metabolite-dependent pathways. The aim of this review was to elucidate studies that have demonstrated the complex relationship between the intestinal microbiota as well as their metabolites and the development/progression of cardiometabolic diseases. Furthermore, we systematically itemized the potential therapeutic approaches for cardiometabolic diseases that target gut microbiota and/or their metabolites by following the pathophysiological pathways of disease development. These approaches include the use of diet, prebiotics, and probiotics. With the exposition of the link between gut microbiota and cardiometabolic diseases, the human gut microbiota therefore becomes a potential therapeutic target in the development of novel cardiometabolic agents.

Maternal Acetate Supplementation Reverses Blood Pressure Increase in Male Offspring Induced by Exposure to Minocycline during Pregnancy and Lactation

Emerging evidence supports that hypertension can be programmed or reprogrammed by maternal nutrition. Maternal exposures during pregnancy, such as maternal nutrition or antibiotic use, could alter the offspring’s gut microbiota. Short-chain fatty acids (SCFAs) are the major gut microbiota-derived metabolites. Acetate, the most dominant SCFA, has shown its antihypertensive effect. Limited information exists regarding whether maternal acetate supplementation can prevent maternal minocycline-induced hypertension in adult offspring. We exposed pregnant Sprague Dawley rats to normal diet (ND), minocycline (MI, 50 mg/kg/day), magnesium acetate (AC, 200 mmol/L in drinking water), and MI + AC from gestation to lactation period. At 12 weeks of age, four groups (n = 8/group) of male progeny were sacrificed. Maternal acetate supplementation protected adult offspring against minocycline-induced hypertension. Minocycline administration reduced plasma acetic acid level, which maternal acetate supplementation prevented. Additionally, acetate supplementation increased the protein level of SCFA receptor G protein-coupled receptor 41 in the offspring kidneys. Further, minocycline administration and acetate supplementation significantly altered gut microbiota composition. Maternal acetate supplementation protected minocycline-induced hypertension accompanying by the increases in genera Roseburia, Bifidobacterium, and Coprococcus. In sum, our results cast new light on targeting gut microbial metabolites as early interventions to prevent the development of hypertension, which could help alleviate the global burden of hypertension.

The Gut Microbiota (Microbiome) in Cardiovascular Disease and Its Therapeutic Regulation

In the last two decades, considerable interest has been shown in understanding the development of the gut microbiota and its internal and external effects on the intestine, as well as the risk factors for cardiovascular diseases (CVDs) such as metabolic syndrome. The intestinal microbiota plays a pivotal role in human health and disease. Recent studies revealed that the gut microbiota can affect the host body. CVDs are a leading cause of morbidity and mortality, and patients favor death over chronic kidney disease. For the function of gut microbiota in the host, molecules have to penetrate the intestinal epithelium or the surface cells of the host. Gut microbiota can utilize trimethylamine, N-oxide, short-chain fatty acids, and primary and secondary bile acid pathways. By affecting these living cells, the gut microbiota can cause heart failure, atherosclerosis, hypertension, myocardial fibrosis, myocardial infarction, and coronary artery disease. Previous studies of the gut microbiota and its relation to stroke pathogenesis and its consequences can provide new therapeutic prospects. This review highlights the interplay between the microbiota and its metabolites and addresses related interventions for the treatment of CVDs.

Sodium Butyrate Modulates Blood Pressure and Gut Microbiota in Maternal Tryptophan-Free Diet-induced Hypertension Rat Offspring

Maternal nutrition, gut microbiome composition, and metabolites derived from gut microbiota are closely related to the development of hypertension in offspring. A plethora of metabolites generated from diverse tryptophan metabolic pathways show both beneficial and harmful effects. Butyrate, one of the short-chain fatty acids (SCFAs), has shown vasodilation effects. We examined whether sodium butyrate administration in pregnancy and lactation can prevent hypertension induced by a maternal tryptophan-free diet in adult progeny and explored the protective mechanisms. Pregnant Sprague-Dawley rats received normal chow (CN), tryptophan-free diet (TF), sodium butyrate 400 mg/kg/day in drinking water (CNSB), or TF diet plus sodium butyrate (TFSB) in pregnancy and lactation. Male offspring were sacrificed at the age of 16 weeks (n = 8 per group). Compared with normal chow, offspring exposed to the maternal tryptophan-free diet had markedly increased blood pressure, associated with activation of the renin-angiotensin system (RAS). Treatment with sodium butyrate rescued maternal TF-exposed offspring from hypertension. The protective effect of sodium butyrate is related to alterations to microbiome composition, increased renal expression of SCFA receptor G protein-coupled receptor 41 (GPR41) and GPR109A, and restoration of RAS balance. In summary, these results suggest that sodium butyrate protects against maternal TF-induced offspring hypertension, likely by modulating gut microbiota, its derived metabolites, and the RAS.

Novel Insights on Dietary Polyphenols for Prevention in Early-Life Origins of Hypertension: A Review Focusing on Preclinical Animal Models

Polyphenols are the largest group of phytochemicals with health benefits. Early life appears to offer a critical window of opportunity for launching interventions focused on preventing hypertension, as increasing evidence supports the supposition that hypertension can originate in early life. Although polyphenols have antihypertensive actions, knowledge of the potential beneficial action of the early use of polyphenols to avert the development of hypertension is limited. Thus, in this review, we first provide a brief summary of the chemistry and biological function of polyphenols. Then, we present the current epidemiological and experimental evidence supporting the early-life origins of hypertension. We also document animal data on the use of specific polyphenols as an early-life intervention to protect offspring against hypertension in adulthood and discuss underlying mechanisms. Continued research into the use of polyphenols to prevent hypertension from starting early in life will have far-reaching implications for future health.

Developmental and Early Life Origins of Hypertension: Preventive Aspects of Melatonin

Hypertension represents a major disease burden worldwide. Abundant evidence suggests that hypertension can originate in early life. Adverse programming processes can be prevented by early life intervention-namely, reprogramming-to avoid developing chronic diseases later in life. Melatonin is an endogenously produced hormone with a multifaceted biological function. Although melatonin supplementation has shown benefits for human health, less attention has been paid to exploring its reprogramming effects on the early life origins of hypertension. In this review, first, we discuss the physiological roles of melatonin in pregnancy, fetal development, and the regulation of blood pressure. Then, we summarize the epidemiological and experimental evidence for the early life origins of hypertension. This is followed by a description of the animal models used to examine early melatonin therapy as a reprogramming strategy to protect against the early life origins of hypertension. A deeper understanding of the developmental programming of hypertension and recent advances in early melatonin intervention might provide a path forward in reducing the global burden of hypertension.

Oxidative Stress-Induced Hypertension of Developmental Origins: Preventive Aspects of Antioxidant Therapy

Hypertension remains the leading cause of disease burden worldwide. Hypertension can originate in the early stages of life. A growing body of evidence suggests that oxidative stress, which is characterized as a reactive oxygen species (ROS)/nitric oxide (NO) disequilibrium, has a pivotal role in the hypertension of developmental origins. Results from animal studies support the idea that early-life oxidative stress causes developmental programming in prime blood pressure (BP)-controlled organs such as the brain, kidneys, heart, and blood vessels, leading to hypertension in adult offspring. Conversely, perinatal use of antioxidants can counteract oxidative stress and therefore lower BP. This review discusses the interaction between oxidative stress and developmental programming in hypertension. It will also discuss evidence from animal models, how oxidative stress connects with other core mechanisms, and the potential of antioxidant therapy as a novel preventive strategy to prevent the hypertension of developmental origins.

Early-Life Origins of Metabolic Syndrome: Mechanisms and Preventive Aspects

One of the leading global public-health burdens is metabolic syndrome (MetS), despite the many advances in pharmacotherapies. MetS, now known as "developmental origins of health and disease" (DOHaD), can have its origins in early life. Offspring MetS can be programmed by various adverse early-life conditions, such as nutrition imbalance, maternal conditions or diseases, maternal chemical exposure, and medication use. Conversely, early interventions have shown potential to revoke programming processes to prevent MetS of developmental origins, namely reprogramming. In this review, we summarize what is currently known about adverse environmental insults implicated in MetS of developmental origins, including the fundamental underlying mechanisms. We also describe animal models that have been developed to study the developmental programming of MetS. This review extends previous research reviews by addressing implementation of reprogramming strategies to prevent the programming of MetS. These mechanism-targeted strategies include antioxidants, melatonin, resveratrol, probiotics/prebiotics, and amino acids. Much work remains to be accomplished to determine the insults that could induce MetS, to identify the mechanisms behind MetS programming, and to develop potential reprogramming strategies for clinical translation.

Gut Microbiota in Adipose Tissue Dysfunction Induced Cardiovascular Disease: Role as a Metabolic Organ

The gut microbiome has emerged as a key regulator of host metabolism. Accumulating evidence has indicated that the gut microbiota is involved in the development of various human diseases. This association relies on the structure and metabolites of the gut microbiota. The gut microbiota metabolizes the diet ingested by the host into a series of metabolites, including short chain fatty acids, secondary bile acids, trimethylamine N-oxide, and branched-chain amino acids, which affects the physiological processes of the host by activating numerous signaling pathways. In this review, we first summarize the various mechanisms through which the gut microbiota influences adipose tissue dysfunction and metabolic processes that subsequently cause cardiovascular diseases, highlighting the complex interactions between gut microbes, their metabolites, and the metabolic activity of the host. Furthermore, we investigated the current status of clinical therapies for adipose tissue dysfunction directed at the gut microbiota. Finally, we discuss the challenges that remain to be addressed before this field of research can be translated to everyday clinical practice.

Administration with Quinoa Protein Reduces the Blood Pressure in Spontaneously Hypertensive Rats and Modifies the Fecal Microbiota

Despite the well-established role of quinoa protein as the source of antihypertensive peptides through in vitro enzymolysis, there is little evidence supporting the in vivo antihypertensive effect of intact quinoa protein. In this study, in vivo study on spontaneously hypertensive rats (SHRs) was conducted by administering quinoa protein for five weeks. Gastrointestinal content identification indicated that many promising precursors of bioactive peptides were released from quinoa protein under gastrointestinal processing. Quinoa protein administration on SHRs resulted in a significant decrease in blood pressure, a significant increase in alpha diversity, and microbial structure alternation towards that in non-hypertension rats. Furthermore, blood pressure was highly negatively correlated with the elevated abundance of genera in quinoa protein-treated SHRs, such as Turicibacter and Allobaculum. Interestingly, the fecal microbiota in quinoa protein-treated SHRs shared more features in the composition of genera with non-hypertension rats than that of the captopril-treated group. These results indicate that quinoa protein may serve as a potential candidate to lower blood pressure and ameliorate hypertension-related gut dysbiosis.

Cardiovascular Diseases of Developmental Origins: Preventive Aspects of Gut Microbiota-Targeted Therapy

Cardiovascular diseases (CVDs) can originate from early life. Accumulating evidence suggests that gut microbiota in early life is linked to CVDs in later life. Gut microbiota-targeted therapy has gained significant importance in recent decades for its health-promoting role in the prevention (rather than just treatment) of CVDs. Thus far, available gut microbiota-based treatment modalities used as reprogramming interventions include probiotics, prebiotics, and postbiotics. The purpose of this review is, first, to highlight current studies that link dysbiotic gut microbiota to the developmental origins of CVD. This is followed by a summary of the connections between the gut microbiota and CVD behind cardiovascular programming, such as short chain fatty acids (SCFAs) and their receptors, trimethylamine-N-oxide (TMAO), uremic toxins, and aryl hydrocarbon receptor (AhR), and the renin-angiotensin system (RAS). This review also presents an overview of how gut microbiota-targeted reprogramming interventions can prevent the developmental origins of CVD from animal studies. Overall, this review reveals that recent advances in gut microbiota-targeted therapy might provide the answers to reduce the global burden of CVDs. Still, additional studies will be needed to put research findings into practice.

Maternal Garlic Oil Supplementation Prevents High-Fat Diet-Induced Hypertension in Adult Rat Offspring: Implications of H2S-Generating Pathway in the Gut and Kidneys

SCOPE

Perinatal high-fat (HF) diet induces hypertension in adult offspring. Garlic, a naturally dietary source of Hydrogen sulfide (H2 S) donor, has been shown benefits in hypertension. The article examines whether maternal garlic oil supplementation can prevent hypertension induced by HF diet and elucidate its protective effects.

METHODS AND RESULTS

Pregnant rats are given either a normal diet or HF diet. Rat dams are given garlic oil or vehicle daily by oral gavage at 100 mg kg-1 day-1 during pregnancy and lactation. Male offspring are sacrificed at 16 weeks of age. Garlic oil supplementation during pregnancy and lactation protected against hypertension induced by HF diet in adult male offspring. The beneficial effects of garlic oil are associated with increased renal mRNA expression and activity of H2 S-generating enzymes, increased NO bioavailability, increased plasma short chain fatty acid levels, and alterations of gut microbiota composition. Garlic oil supplementation increases abundance of genus Lactobacillus, but decreases genera Turicibacter and Staphylococcus.

CONCLUSION

The data reveals associations between H2 S-generating pathway in the gut and kidneys, NO system, gut microbiota, and microbiota-derived metabolites in hypertension induced by HF intake and provide insight to garlic oil as a hypertension reprogramming strategy for further translational research.

Animal Models for DOHaD Research: Focus on Hypertension of Developmental Origins

Increasing evidence suggests that fetal programming through environmental exposure during a critical window of early life leads to long-term detrimental outcomes, by so-called developmental origins of health and disease (DOHaD). Hypertension can originate in early life. Animal models are essential for providing convincing evidence of a causal relationship between diverse early-life insults and the developmental programming of hypertension in later life. These insults include nutritional imbalances, maternal illnesses, exposure to environmental chemicals, and medication use. In addition to reviewing the various insults that contribute to hypertension of developmental origins, this review focuses on the benefits of animal models in addressing the underlying mechanisms by which early-life interventions can reprogram disease processes and prevent the development of hypertension. Our understanding of hypertension of developmental origins has been enhanced by each of these animal models, narrowing the knowledge gap between animal models and future clinical translation.

Maternal microbiome in preeclampsia pathophysiology and implications on offspring health

Preeclampsia is a devastating hypertensive pregnancy disorder that currently affects 2%–8% of pregnancies worldwide. It is associated with maternal and fetal mortality and morbidity and adverse health outcomes both in mom and offspring beyond pregnancy. The pathophysiology is not completely understood, and there are no approved therapies to specifically treat for the disease, with only few therapies approved to manage symptoms. Recent advances suggest that aberrations in the composition of the microbiome may play a role in the pathogenesis of various diseases including preeclampsia. The maternal and uteroplacental environments greatly influence the long‐term health outcomes of the offspring through developmental programming mechanisms. The current review summarizes recent developments on the role of the microbiome in adverse pregnancy outcomes with a focus on preeclampsia. It also discusses the potential role of the maternal microbiome in fetal programming; explores gut‐targeted therapeutics advancement and their implications in the treatment of preeclampsia.

Bifidobacterium reduction is associated with high blood pressure in children with type 1 diabetes mellitus

Children with Type 1 diabetes mellitus (T1DM) have an elevated risk of abnormal blood pressure (BP) measurements and patterns. Both hypertension and T1DM are well-known risk factors for cardiovascular disease and kidney failure. The human microbiome has been linked to both diabetes and hypertension, but the relationship between the gut microbiome and BP in children with T1DM is not well-understood. In this cross-sectional study, we examined the relationship between resting office BP and gut microbiota composition, diversity, and richness in children with T1DM and healthy controls. We recruited 29 pediatric subjects and divided them into three groups: healthy controls (HC, n = 5), T1DM with normal BP (T1DM-Normo, n = 17), and T1DM with elevated BP (T1DM-HBP, n = 7). We measured the BP, dietary and clinical parameters for each subject. We collected fecal samples to perform the 16s rDNA sequencing and to measure the short-chain fatty acids (SCFAs) level. The microbiome downstream analysis included the relative abundance of microbiota, alpha and beta diversity, microbial markers using Linear Discriminant effect size analysis (LEfSe), potential gut microbial metabolic pathways using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) and metabolic pathways validation using Statistical Inference of Associations between Microbial Communities And host phenotype (SIAMCAT) machine learning toolbox. Our study results showed that T1DM-HBP group had distinct gut microbial composition (at multiple taxonomic levels) and reduced diversity (richness and abundance) compared with T1DM-Normo and HC groups. Children with T1DM-HBP showed a significant reduction of Bifidobacterium levels (especially B. adolescentis, B. bifidum, and B. longum) compared to the T1DM-Normo group. We also observed unique gut-microbial metabolic pathways, such as elevated lipopolysaccharide synthesis and glutathione metabolism in children with T1DM-HBP compared to T1DM-Normo children. We can conclude that the reduction in the abundance of genus Bifidobacterium could play a significant role in elevating the BP in pediatric T1DM subjects. More studies are needed to corroborate our findings and further explore the potential contributing mechanisms we describe.

Preventive Aspects of Early Resveratrol Supplementation in Cardiovascular and Kidney Disease of Developmental Origins

The increase in the incidence of cardiovascular diseases (CVDs) and kidney disease has stimulated research for strategies that could prevent, rather than just treat, both interconnected disorders. Resveratrol, a polyphenolic compound with pleiotropic biofunctions, has shown health benefits. Emerging epidemiological data supports that early life environmental insults are regarded as increased risks of developing CVDs and kidney disease in adulthood. Conversely, both disorders could be reversed or postponed by shifting interventions from adulthood to earlier stage by so-called reprogramming. The purpose of this review is first to highlight current epidemiological studies linking cardiovascular and renal programming to resulting CVD and kidney disease of developmental origins. This will be followed by a summary of how resveratrol could exert a positive influence on CVDs and kidney disease. This review also presents an overview of the evidence documenting resveratrol as a reprogramming agent to protect against CVD and kidney disease of developmental origins from animal studies and to outline the advances in understanding the underlying molecular mechanisms. Overall, this review reveals the need for future research to further clarify the reprogramming effects of resveratrol before clinical translation.

Maternal resveratrol therapy protected adult rat offspring against hypertension programmed by combined exposures to asymmetric dimethylarginine and trimethylamine-N-oxide

Resveratrol, a phytochemical, has shown antioxidant properties and potential benefits in hypertension. Asymmetric dimethylarginine (ADMA)-related nitric oxide deficiency and gut microbiota-derived metabolite trimethylamine-N-oxide (TMAO) have been linked to hypertension. We aimed to test whether maternal resveratrol therapy would protect adult offspring against hypertension programmed by prenatal exposure to ADMA and TMAO. Pregnant Sprague-Dawley rats received ADMA 10 mg/kg/day (A), TMAO 0.65 mg/hr (T), ADMA+TMAO (AT), or vesicle (CV). One group of ADMA+TMAO-exposed rats received 50 mg/L of resveratrol in drinking water during pregnancy and lactation periods (ATR). Male offspring (n = 8/group) were assigned to five groups: CV, A, T, AT, and ATR. Rats were killed at 12 weeks of age. ADMA exposure caused the elevation of blood pressure in 12-week-old male offspring, which was exacerbated by TMAO exposure. Treatment with resveratrol rescued hypertension programmed by combined ADMA and TMAO exposure. This was accompanied by alterations in the compositions of gut microbiota and increased fecal butyrate levels. Both the abundance of the butyrate-producing genera Lachnospiraceae and Ruminococcaceae were augmented by resveratrol. Meanwhile, resveratrol therapy significantly increased the abundance of the Cyanobiaceae and Erysipelotrichaceae families. Moreover, the protective effects of resveratrol were related to the mediation of the renin-angiotensin system . Our data provide new insights into the protective mechanisms of resveratrol against hypertension programmed by ADMA and TMAO, including regulation of gut microbiota and their metabolites, the renin-angiotensin system, and nitric oxide pathway. Resveratrol might be a potential reprogramming strategy to protect against the hypertension of developmental origins.

Recognizing the Benefits of Pre-/Probiotics in Metabolic Syndrome and Type 2 Diabetes Mellitus Considering the Influence of Akkermansia muciniphila as a Key Gut Bacterium

Metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM) are diseases that can be influenced by the structure of gut microbiota, whose improvement is often neglected in metabolic pathology. This review highlights the following main aspects: the relationship between probiotics/gut microbes with the pathogenesis of MetS, the particular positive roles of Akkermansia muciniphila supplementation in the onset of MetS, and the interaction between dietary polyphenols (prebiotics) with gut microbiota. Therefore, an extensive and in-depth analysis of the often-neglected correlation between gut microbiota and chronic metabolic diseases was conducted, considering that this topic continues to fascinate and stimulate researchers through the discovery of novel strains and their beneficial properties.

Altered Gut Microbiota and Its Metabolites in Hypertension of Developmental Origins: Exploring Differences between Fructose and Antibiotics Exposure

Gut microbiota-derived metabolites, in particular short chain fatty acids (SCFAs) and their receptors, are linked to hypertension. Fructose and antibiotics are commonly used worldwide, and they have a negative impact on the gut microbiota. Our previous study revealed that maternal high-fructose (HF) diet-induced hypertension in adult offspring is relevant to altered gut microbiome and its metabolites. We, therefore, intended to examine whether minocycline administration during pregnancy and lactation may further affect blood pressure (BP) programmed by maternal HF intake via mediating gut microbiota and SCFAs. Pregnant Sprague-Dawley rats received a normal diet or diet containing 60% fructose throughout pregnancy and lactation periods. Additionally, pregnant dams received minocycline (50 mg/kg/day) via oral gavage or a vehicle during pregnancy and lactation periods. Four groups of male offspring were studied (n = 8 per group): normal diet (ND), high-fructose diet (HF), normal diet + minocycline (NDM), and HF + minocycline (HFM). Male offspring were killed at 12 weeks of age. We observed that the HF diet and minocycline administration, both individually and together, causes the elevation of BP in adult male offspring, while there is no synergistic effect between them. Four groups displayed distinct enterotypes. Minocycline treatment leads to an increase in the F/B ratio, but decreased abundance of genera Lactobacillus, Ruminococcus, and Odoribacter. Additionally, minocycline treatment decreases plasma acetic acid and butyric acid levels. Hypertension programmed by maternal HF diet plus minocycline exposure is related to the increased expression of several SCFA receptors. Moreover, minocycline- and HF-induced hypertension, individually or together, is associated with the aberrant activation of the renin-angiotensin system (RAS). Conclusively, our results provide a new insight into the support of gut microbiota and its metabolite SCAFs in the developmental programming of hypertension and cast new light on the role of RAS in this process, which will help prevent hypertension programmed by maternal high-fructose and antibiotic exposure.

Efficacy of synbiotic interventions on blood pressure: a systematic review and meta-analysis of clinical trials

PURPOSE

The present systematic review and meta-analysis aimed to evaluate the effect of synbiotic interventions on blood pressure levels in adults.

METHODS

A systematic literature search was conducted in the databases of MEDLINE, Scopus, Web of Science, and Cochrane through March 2020 to identify all randomized control trials (RCTs) investigating the effects of synbiotic interventions on blood pressure parameter, including systolic (SBP) and diastolic blood pressure (DBP). Grading of Recommendations Assessment, Development and Evaluation (GRADE) scale was used to assess the certainty of evaluated outcomes and determine the strength of recommendations.

RESULTS

Eleven RCTs were included in the meta-analysis. Synbiotic interventions significantly reduced SBP (-3.02 mmHg; 95% CI: -4.84, -1.21; I² = 55%) without changing DBP levels (-0.57 mmHg; 95% CI: -1.78, 0.64; I² = 50%). Subgroup analyses revealed that the SBP-lowering effects of synbiotic interventions were more pronounced wherein trials were longer (≥12 weeks), synbiotic interventions were administrated as a supplement, and participants were younger (<50 years old). Also, a significant improvement in both SBP and DBP levels was evident in subgroups with a lower (<30 kg/m²) body mass index.

CONCLUSIONS

Synbiotic interventions may significantly improve SBP levels in adults.

Preventing Developmental Origins of Cardiovascular Disease: Hydrogen Sulfide as a Potential Target?

The cardiovascular system can be programmed by a diversity of early-life insults, leading to cardiovascular disease (CVD) in adulthood. This notion is now termed developmental origins of health and disease (DOHaD). Emerging evidence indicates hydrogen sulfide (H₂S), a crucial regulator of cardiovascular homeostasis, plays a pathogenetic role in CVD of developmental origins. Conversely, early H₂S-based interventions have proved beneficial in preventing adult-onset CVD in animal studies via reversing programming processes by so-called reprogramming. The focus of this review will first summarize the current knowledge on H₂S implicated in cardiovascular programming. This will be followed by supporting evidence for the links between H₂S signaling and underlying mechanisms of cardiovascular programming, such as oxidative stress, nitric oxide deficiency, dysregulated nutrient-sensing signals, activation of the renin–angiotensin system, and gut microbiota dysbiosis. It will also provide an overview from animal models regarding how H₂S-based reprogramming interventions, such as precursors of H₂S and H₂S donors, may prevent CVD of developmental origins. A better understanding of cardiovascular programming and recent advances in H₂S-based interventions might provide the answers to bring down the global burden of CVD.

The influence of gut microbiota in cardiovascular diseases-a brief review

Lately, the gut microbiota has emerged as an important mediator of the development and the outcomes of certain diseases. It's well known that the gut microbiota plays an important role in maintaining human health. Still far from being completely understood and analyzed is the complexity of this ecosystem, although a close relationship between the gut microbiota and cardiovascular diseases (CVD) has been established. A loss of diversity in the microbiota will lead to physiological changes, which can improve inflammatory or infection states like atherosclerosis and hypertension, the basic pathological process of CVD. Targeting the gut microbiota and its metabolites are new and promising strategies for the treatment and prognosis of CVD.

A cross-talk between gut microbiome, salt and hypertension

Cardiac disorders contribute to one of the major causes of fatality across the world. Hypertensive patients, even well maintained on drugs, possess a high risk to cardiovascular diseases. It is, therefore, highly important to identify different factors and pathways that lead to risk and progression of cardiovascular disorders. Several animals and human studies suggest that taxonomical alterations in the gut are involved in the cardiovascular physiology. In this article, with the help of various experimental evidences, we suggest that the host gut-microbiota plays an important in this pathway. Short chain fatty acids (SCFAs) and Trimethyl Amine -n-Oxide (TMAO) are the two major products of gut microbiome. SCFAs present a crucial role in regulating the blood pressure, while TMAO is involved in pathogenesis of atherosclerosis and other coronary artery diseases, including hypertension. We prove that there exists a triangular bridge connecting the gap between dietary salt, hypertension and gut microbiome. We also present some of the dietary interventions which can regulate and control microbiota that can prevent cardiovascular complications.We strongly believe that this article would improve the understanding the role of gut microbiota in hypertension, and will be helpful in the development of novel therapeutic strategies for prevention of hypertension through restoring gut microbiome homeostasis in the near future.

The role of dietary nitrate and the oral microbiome on blood pressure and vascular tone

There is increasing evidence for the health benefits of dietary nitrates including lowering blood pressure and enhancing cardiovascular health. Although commensal oral bacteria play an important role in converting dietary nitrate to nitrite, very little is known about the potential role of these bacteria in blood pressure regulation and maintenance of vascular tone. The main purpose of this review is to present the current evidence on the involvement of the oral microbiome in mediating the beneficial effects of dietary nitrate on vascular function and to identify sources of inter-individual differences in bacterial composition. A systematic approach was used to identify the relevant articles published on PubMed and Web of Science in English from January 1950 until September 2019 examining the effects of dietary nitrate on oral microbiome composition and association with blood pressure and vascular tone. To date, only a limited number of studies have been conducted, with nine in human subjects and three in animals focusing mainly on blood pressure. In general, elimination of oral bacteria with use of a chlorhexidine-based antiseptic mouthwash reduced the conversion of nitrate to nitrite and was accompanied in some studies by an increase in blood pressure in normotensive subjects. In conclusion, our findings suggest that oral bacteria may play an important role in mediating the beneficial effects of nitrate-rich foods on blood pressure. Further human intervention studies assessing the potential effects of dietary nitrate on oral bacteria composition and relationship to real-time measures of vascular function are needed, particularly in individuals with hypertension and those at risk of developing CVD.

Perinatal Resveratrol Therapy Prevents Hypertension Programmed by Maternal Chronic Kidney Disease in Adult Male Offspring: Implications of the Gut Microbiome and Their Metabolites

The gut microbiota plays a critical role in kidney disease and hypertension; however, whether maternal chronic kidney disease (CKD)-induced offspring hypertension is associated with alterations of the microbiota and microbial metabolites remains elusive. Using rat as an animal model, we conducted a maternal adenine-induced CKD model to examine whether adult male offspring develop hypertension and kidney disease. As resveratrol has antioxidant and prebiotic properties, we also aimed to elucidate whether its use in pregnancy and lactation can benefit hypertension programmed by maternal CKD via mediation of the gut microbiota and oxidative stress. Female Sprague-Dawley rats received regular chow (C) or chow supplemented with 0.5% adenine (CKD) from 3 weeks before pregnancy until lactation. One group of the adenine-induced CKD pregnant rats received resveratrol (R; 50 mg/L) in drinking water during gestation and lactation. Male offspring were divided into three groups: C, CKD, and CKD+R. The microbial metabolites analyzed were short chain fatty acids (SCFAs) in feces and trimethylamine (TMA)/trimethylamine N-oxide (TMAO) in plasma. We found perinatal resveratrol therapy protected against maternal CKD-induced hypertension in adult male offspring. The overall microbial compositions and diversity of bacterial community in the three groups were different. Resveratrol therapy increased α-diversity, decreased the Firmicutes to Bacteroidetes ratio, and increased the abundance of the genera Lactobacillus and Bifidobacterium. Perinatal resveratrol therapy increased plasma TMA levels but decreased the plasma TMAO-to-TMA ratio. Although resveratrol had negligible effect on fecal concentrations of SCFAs, it increased G-protein coupled receptor-41 (GPR41) protein levels in the offspring’s kidneys. Additionally, resveratrol therapy increased plasma levels of L-arginine and the L-arginine-to-ADMA ratio (AAR), and decreased oxidative stress. Overall, the protective effects of resveratrol against programmed hypertension are related to gut microbiome remodeling, including an increased abundance of beneficial microbes, mediation of the TMA-TMAO pathway, and alterations of SCFA receptors. Our results highlighted that targeting the microbiome and their metabolites might be potential therapeutic strategies to prevent maternal CKD-induced adverse pregnancy and offspring outcomes.

Developmental Programming and Reprogramming of Hypertension and Kidney Disease: Impact of Tryptophan Metabolism

The concept that hypertension and chronic kidney disease (CKD) originate in early life has emerged recently. During pregnancy, tryptophan is crucial for maternal protein synthesis and fetal development. On one hand, impaired tryptophan metabolic pathway in pregnancy impacts fetal programming, resulting in the developmental programming of hypertension and kidney disease in adult offspring. On the other hand, tryptophan-related interventions might serve as reprogramming strategies to prevent a disease from occurring. In the present review, we aim to summarize (1) the three major tryptophan metabolic pathways, (2) the impact of tryptophan metabolism in pregnancy, (3) the interplay occurring between tryptophan metabolites and gut microbiota on the production of uremic toxins, (4) the role of tryptophan-derived metabolites-induced hypertension and CKD of developmental origin, (5) the therapeutic options in pregnancy that could aid in reprogramming adverse effects to protect offspring against hypertension and CKD, and (6) possible mechanisms linking tryptophan metabolism to developmental programming of hypertension and kidney disease.

Association between hypertension, oral microbiome and salivary nitric oxide: A case-control study

BACKGROUND

Nitric oxide (NO) produced in the oral cavity is a powerful resource for the human body, especially when NO-syntethase production is not adequate. The role of oral microbiome in determining blood pressure levels has been linked to the active role of some bacterial species involved in the nitro-reducing process. In the present study we investigated the correlation between selected oral microbiome characteristics, nitric oxide (NO) concentration in saliva and their association with hypertension.

METHODS

A case-control study including 48 (25 normotensive and 23 hypertensive subjects), subjects between 50 and 70 years old, was carried out at the dental clinic of an Italian teaching hospital. Characteristics of participants have been evaluated by means of a physical examination, and by an assisted interview. A real-time polymerase chain reaction in samples of saliva and plaque was used to detect Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Tannerella forsythia, Porphyromonas gingivalis, Treponema denticola, Streptococcus mutans, Streptococcus sanguinis, Veillonella dispar and Neisseria subflava as well as total bacterial count. Nitric oxide in saliva was evaluated by the ELISA method.

RESULTS

Normotensive subjects, compared with hypertensive subjects, had significantly higher concentration of NO (165.77 ± 61.7 vs 57.49 ± 19.61 μmol/l; p = 0.023), and higher bacterial concentration of the supragingival plaque (4.73E+07 ± 4.33+07 vs 4.02E+07 ± 4.00+07; p = 0.024). Bacterial species, usually associated to good oral health status, such as Neisseria subflava, were significantly more present in normotensive subjects than in hypertensive ones (9090.88 ± 5481.49 vs 4791.35 ± 4349.37; p < 0.001). considering the concentration of bacteria as a biomarker of the development of hypertension.

CONCLUSIONS

The results support the association between hypertension, oral microbiome and salivary nitric oxide, in fact do the results allow us to establish any biomarkers (microbial or biochemical, NO) that allow early therapeutic intervention.

Interplay between dietary phenolic compound intake and the human gut microbiome in hypertension: A cross-sectional study

In the present study, potential associations between dietary phenolic compounds (PCs), gut microbiota composition and targeted faecal metabolites were identified in a cross-sectional study including grade 1 hypertensive (HT) and normotensive (NT) subjects. We performed comprehensive quantification of PC intake, together with 16S rRNA gene sequencing of the gut microbiota, and faecal and plasma short-chain fatty acids (SCFAs) determination. The results showed multiple-way relationships between PCs from several plant-based foods and 25 bacterial taxa previously defined as discriminant biomarkers among groups. Remarkably, coffee PCs were positively associated with systolic and diastolic blood pressure, faecal SCFAs, Bacteroides plebeius and Bacteroides coprocola in HT and negatively associated with Faecalibacterium prausnitzii and Christensenellaceae R-7 in NT. Olive fruit PCs were positively associated with Ruminococcaceae UCG-010, Christensenellaceae R-7 and plasma SCFAs in NT. These interplays with discriminant bacterial taxa in HT and NT subjects highlight the potential role of specific PCs as gut microbiome modulators in either the pathogenesis or prevention of hypertension.

Antihypertensive agents: a long way to safe drug prescribing in children

Recently updated clinical guidelines have highlighted the gaps in our understanding and management of pediatric hypertension. With increased recognition and diagnosis of pediatric hypertension, the use of antihypertensive agents is also likely to increase. Drug selection to treat hypertension in the pediatric patient population remains challenging. This is primarily due to a lack of large, well-designed pediatric safety and efficacy trials, limited understanding of pharmacokinetics in children, and unknown risk of prolonged exposure to antihypertensive therapies. With newer legislation providing financial incentives for conducting clinical trials in children, along with publication of pediatric-focused guidelines, literature available for antihypertensive agents in pediatrics has increased over the last 20 years. The objective of this article is to review the literature for safety and efficacy of commonly prescribed antihypertensive agents in pediatrics. Thus far, the most data to support use in children was found for angiotensin-converting enzyme inhibitors (ACE-I), angiotensin receptor blockers (ARB), and calcium channel blockers (CCB). Several gaps were noted in the literature, particularly for beta blockers, vasodilators, and the long-term safety profile of antihypertensive agents in children. Further clinical trials are needed to guide safe and effective prescribing in the pediatric population.

Early Origins of Hypertension: Should Prevention Start Before Birth Using Natural Antioxidants?

Hypertension may originate in early life. Reactive oxygen species (ROS) generated due to the exposure of adverse in utero conditions causes developmental programming of hypertension. These excessive ROS can be antagonized by molecules which are antioxidants. Prenatal use of natural antioxidants may reverse programming processes and prevent hypertension of developmental origin. In the current review, firstly we document data on the impact of oxidative stress in hypertension of developmental origin. This will be followed by effective natural antioxidants uses starting before birth to prevent hypertension of developmental origin in animal models. It will also discuss evidence for the common mechanisms underlying developmental hypertension and beneficial effects of natural antioxidant interventions used as reprogramming strategies. A better understanding of the reprogramming effects of natural antioxidants and their interactions with common mechanisms underlying developmental hypertension is essential. Therefore, pregnant mothers and their children can benefit from natural antioxidant supplementation during pregnancy in order to reduce their risk for hypertension later in life.

Maternal Adenine-Induced Chronic Kidney Disease Programs Hypertension in Adult Male Rat Offspring: Implications of Nitric Oxide and Gut Microbiome Derived Metabolites

Maternal chronic kidney disease (CKD) during pregnancy causes adverse fetal programming. Nitric oxide (NO) deficiency, gut microbiota dysbiosis, and dysregulated renin-angiotensin system (RAS) during pregnancy are linked to the development of hypertension in adult offspring. We examined whether maternal adenine-induced CKD can program hypertension and kidney disease in adult male offspring. We also aimed to identify potential mechanisms, including alterations of gut microbiota composition, increased trimethylamine-N-oxide (TMAO), reduced NO bioavailability, and dysregulation of the RAS. To construct a maternal CKD model, female Sprague-Dawley rats received regular chow (control group) or chow supplemented with 0.5% adenine (CKD group) for 3 weeks before pregnancy. Mother rats were sacrificed on gestational day 21 to analyze placentas and fetuses. Male offspring (n = 8/group) were sacrificed at 12 weeks of age. Adenine-fed rats developed renal dysfunction, glomerular and tubulointerstitial damage, hypertension, placental abnormalities, and reduced fetal weights. Additionally, maternal adenine-induced CKD caused hypertension and renal hypertrophy in adult male offspring. These adverse pregnancy and offspring outcomes are associated with alterations of gut microbiota composition, increased uremic toxin asymmetric and symmetric dimethylarginine (ADMA and SDMA), increased microbiota-derived uremic toxin TMAO, reduced microbiota-derived metabolite acetate and butyrate levels, and dysregulation of the intrarenal RAS. Our results indicated that adenine-induced maternal CKD could be an appropriate model for studying uremia-related adverse pregnancy and offspring outcomes. Targeting NO pathway, microbiota metabolite TMAO, and the RAS might be potential therapeutic strategies to improve maternal CKD-induced adverse pregnancy and offspring outcomes.