scholarly journals Gut Microbiota in Hypertension and Atherosclerosis: A Review

Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2982 ◽  
Author(s):  
Barbara J. H. Verhaar ◽  
Andrei Prodan ◽  
Max Nieuwdorp ◽  
Majon Muller

Gut microbiota and its metabolites such as short chain fatty acids (SCFA), lipopolysaccharides (LPS), and trimethylamine-N-oxide (TMAO) impact cardiovascular health. In this review, we discuss how gut microbiota and gut metabolites can affect hypertension and atherosclerosis. Hypertensive patients were shown to have lower alpha diversity, lower abundance of SCFA-producing microbiota, and higher abundance of gram-negative bacteria, which are a source of LPS. Animal studies point towards a direct role for SCFAs in blood pressure regulation and show that LPS has pro-inflammatory effects. Translocation of LPS into the systemic circulation is a consequence of increased gut permeability. Atherosclerosis, a multifactorial disease, is influenced by the gut microbiota through multiple pathways. Many studies have focused on the pro-atherogenic role of TMAO, however, it is not clear if this is a causal factor. In addition, gut microbiota play a key role in bile acid metabolism and some interventions targeting bile acid receptors tend to decrease atherosclerosis. Concluding, gut microbiota affect hypertension and atherosclerosis through many pathways, providing a wide range of potential therapeutic targets. Challenges ahead include translation of findings and mechanisms to humans and development of therapeutic interventions that target cardiovascular risk by modulation of gut microbes and metabolites.

2021 ◽  
Vol 9 (10) ◽  
pp. 2013
Author(s):  
Noora Alhajri ◽  
Rubiya Khursheed ◽  
Mohammad Taher Ali ◽  
Tareq Abu Izneid ◽  
Oumaima Al-Kabbani ◽  
...  

It has become evident over the past several years that the intestinal microbial ecosystem plays a critical role in the development and prevention of cardiovascular diseases (CVDs) and other metabolic disorders, such as hypertension, obesity, diabetes mellitus, and metabolic syndrome. The intestinal microbiota ecosystem functions as a major virtual endocrine organ that interacts and responds to molecules’ signals within the host. Several meta-organismal pathways are involved in the gut–host interaction, including trimethylamine-N-oxide (TMAO) and short-chain fatty acids (SCFA). Host phenotype and cardiovascular diseases (CVDs) varying from hypertension, insulin resistance, and obesity to more specific inflammatory processes, such as atherosclerosis and hypercoagulability, have shown to be affected by the gut–host interaction. Additionally, several studies that involved animals and humans demonstrated a striking connection between the development of new CVDs and an imbalance in the gut microbiota composition along with the presence of their derived metabolites. Through this review article, we aim to evaluate the role of the normal gut microbiota ecosystem, its association with CVDs, effects of the therapies used to control and manage CVDs in the gut microbiota environment and explore potential therapeutic interventions to amplify disease outcomes in patients with CVDs.


2021 ◽  
pp. 1-54
Author(s):  
R.A.G. Pushpass ◽  
S. Alzoufairi ◽  
K.G. Jackson ◽  
J.A. Lovegrove

Abstract Beneficial effects of probiotic, prebiotic and polyphenol-rich interventions on fasting lipid profiles have been reported, with changes in the gut microbiota composition believed to play an important role in lipid regulation. Primary bile acids, which are involved in the digestion of fats and cholesterol metabolism, can be converted by the gut microbiota to secondary bile acids, some species of which are less well reabsorbed and consequently may be excreted in the stool. This can lead to increased hepatic bile acid neo-synthesis, resulting in a net loss of circulating low density lipoprotein. Bile acids may therefore provide a link between the gut microbiota and cardiovascular health. This narrative review presents an overview of bile acid metabolism and the role of probiotics, prebiotics and polyphenol-rich foods in modulating circulating cardiovascular disease (CVD) risk markers and bile acids. Although findings from human studies are inconsistent, there is growing evidence for associations between these dietary components and improved lipid CVD risk markers, attributed to modulation of the gut microbiota and bile acid metabolism. These include increased bile acid neo-synthesis, due to bile sequestering action, bile salt metabolising activity and effects of short chain fatty acids generated through bacterial fermentation of fibres. Animal studies have demonstrated effects on the FXR/FGF-15 axis and hepatic genes involved in bile acid synthesis (CYP7A1) and cholesterol synthesis (SREBP and HMGR). Further human studies are needed to determine the relationship between diet and bile acid metabolism and whether circulating bile acids can be utilised as a potential CVD risk biomarker.


2021 ◽  
Author(s):  
Ming-zhi Zhu ◽  
Fang Zhou ◽  
Jian Ouyang ◽  
Qi-ye Wang ◽  
Yi-long Li ◽  
...  

Combined use of epigallocatechin-3-gallate (EGCG) and caffeine in low doses exhibits marked anti-obesity synergy. The synergistic effect may be attributed to regulation of gut microbiota and BA metabolism.


2021 ◽  
Vol 9 (5) ◽  
pp. 1037
Author(s):  
Craig Resch ◽  
Mihir Parikh ◽  
J. Alejandro Austria ◽  
Spencer D. Proctor ◽  
Thomas Netticadan ◽  
...  

There is an increased interest in the gut microbiota as it relates to health and obesity. The impact of diet and sex on the gut microbiota in conjunction with obesity also demands extensive systemic investigation. Thus, the influence of sex, diet, and flaxseed supplementation on the gut microbiota was examined in the JCR:LA-cp rat model of genetic obesity. Male and female obese rats were randomized into four groups (n = 8) to receive, for 12 weeks, either (a) control diet (Con), (b) control diet supplemented with 10% ground flaxseed (CFlax), (c) a high-fat, high sucrose (HFHS) diet, or (d) HFHS supplemented with 10% ground flaxseed (HFlax). Male and female JCR:LA-cp lean rats served as genetic controls and received similar dietary interventions. Illumine MiSeq sequencing revealed a richer microbiota in rats fed control diets rather than HFHS diets. Obese female rats had lower alpha-diversity than lean female; however, both sexes of obese and lean JCR rats differed significantly in β-diversity, as their gut microbiota was composed of different abundances of bacterial types. The feeding of an HFHS diet affected the diversity by increasing the phylum Bacteroidetes and reducing bacterial species from phylum Firmicutes. Fecal short-chain fatty acids such as acetate, propionate, and butyrate-producing bacterial species were correspondingly impacted by the HFHS diet. Flax supplementation improved the gut microbiota by decreasing the abundance of Blautia and Eubacterium dolichum. Collectively, our data show that an HFHS diet results in gut microbiota dysbiosis in a sex-dependent manner. Flaxseed supplementation to the diet had a significant impact on gut microbiota diversity under both flax control and HFHS dietary conditions.


Author(s):  
Sik Yu So ◽  
Qinglong Wu ◽  
Kin Sum Leung ◽  
Zuzanna Maria Kundi ◽  
Tor C Savidge ◽  
...  

Emerging evidence links dietary fiber with altered gut microbiota composition and bile acid signaling in maintaining metabolic health. Yeast β-glucan (Y-BG) is a dietary supplement known for its immunomodulatory effect, yet its impact on the gut microbiota and bile acid composition remains unclear. This study investigated whether dietary forms of Y-BG modulate these gut-derived signals. We performed 4-week dietary supplementation in healthy mice to evaluate effects of different fiber composition (soluble vs particulate Y-BG) and dose (0.1 vs. 2%). We found that 2% particulate Y-BG induced robust gut microbiota community shifts with elevated liver Cyp7a1 mRNA abundance and bile acid synthesis. These diet-induced responses were notably different when compared to the prebiotic inulin, and included a marked reduction in fecal Bilophila abundance which we demonstrated as translatable to obesity in population-scale American Gut and TwinsUK clinical cohorts. This prompted us to test whether 2% Y-BG maintained metabolic health in mice fed 60% HFD over 13 weeks. Y-BG consistently altered the gut microbiota composition and reduced Bilophila abundance, with trends observed in improvement of metabolic phenotype. Notably, Y-BG improved insulin sensitization and this was associated with enhanced ileal Glpr1r mRNA accumulation and reduced Bilophila abundance. Collectively, our results demonstrate that Y-BG modulates gut microbiota community composition and bile acid signaling, but the dietary regime needs to be optimized to facilitate clinical improvement in metabolic phenotype in an aggressive high-fat diet animal model.


2019 ◽  
Vol 8 (1) ◽  
pp. 60
Author(s):  
Mohd Baasir Gaisawat ◽  
Chad W. MacPherson ◽  
Julien Tremblay ◽  
Amanda Piano ◽  
Michèle M. Iskandar ◽  
...  

Clostridium (C.) difficile-infection (CDI), a nosocomial gastrointestinal disorder, is of growing concern due to its rapid rise in recent years. Antibiotic therapy of CDI is associated with disrupted metabolic function and altered gut microbiota. The use of probiotics as an adjunct is being studied extensively due to their potential to modulate metabolic functions and the gut microbiota. In the present study, we assessed the ability of several single strain probiotics and a probiotic mixture to change the metabolic functions of normal and C. difficile-infected fecal samples. The production of short-chain fatty acids (SCFAs), hydrogen sulfide (H2S), and ammonia was measured, and changes in microbial composition were assessed by 16S rRNA gene amplicon sequencing. The C. difficile-infection in fecal samples resulted in a significant decrease (p < 0.05) in SCFA and H2S production, with a lower microbial alpha diversity. All probiotic treatments were associated with significantly increased (p < 0.05) levels of SCFAs and restored H2S levels. Probiotics showed no effect on microbial composition of either normal or C. difficile-infected fecal samples. These findings indicate that probiotics may be useful to improve the metabolic dysregulation associated with C. difficile infection.


2019 ◽  
Vol 64 (1) ◽  
pp. 1900789 ◽  
Author(s):  
Yang Zhang ◽  
Gerd Bobe ◽  
Johana S. Revel ◽  
Richard R. Rodrigues ◽  
Thomas J. Sharpton ◽  
...  

Methods ◽  
2018 ◽  
Vol 149 ◽  
pp. 49-58 ◽  
Author(s):  
Benjamin H. Mullish ◽  
Alexandros Pechlivanis ◽  
Grace F. Barker ◽  
Mark R. Thursz ◽  
Julian R. Marchesi ◽  
...  

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