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Alterations of gut microbiota are associated with blood pressure: a cross-sectional clinical trial in Northwestern China.
Lv, J, Wang, J, Yu, Y, Zhao, M, Yang, W, Liu, J, Zhao, Y, Yang, Y, Wang, G, Guo, L, et al
Journal of translational medicine. 2023;21(1):429
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Hypertension (HTN) is a complex and modifiable risk factor for cardiovascular diseases (CVDs) and stroke, while a diverse range of endogenous and environmental factors contribute to both HTN onset and progression. The adult gut microbiota (GM) consists of trillions of microorganisms and maintains the gut immunity and whole-body homeostasis. The aim of this study was to investigate the GM characteristics in HTN subjects in Northwestern China, and evaluate the associations of GM with blood pressure levels based on sex differences. This study was a cross-sectional study. Participants were randomly selected for the HTN and control groups. A total of 36 HTN subjects (24 females and 12 males) and 18 controls (9 females and 9 males) were randomly selected for metagenomic analysis. Results showed a positive association between GM characteristics and alterations and HTN in both females and males. Thus, GM dysbiosis underlies HTN pathogenesis. Authors conclude that further studies are needed to elucidate the underlying mechanisms and potential therapeutic interventions targeting GM for HTN prevention and management
Abstract
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/ .
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The Gut Microbiota (Microbiome) in Cardiovascular Disease and Its Therapeutic Regulation.
Rahman, MM, Islam, F, -Or-Rashid, MH, Mamun, AA, Rahaman, MS, Islam, MM, Meem, AFK, Sutradhar, PR, Mitra, S, Mimi, AA, et al
Frontiers in cellular and infection microbiology. 2022;12:903570
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Cardiovascular disease (CVD) accounts for 31% of all-cause mortality worldwide. Irregularities in the composition of intestinal microbial composition, genetic factors, nutrition, metabolic irregularities, and smoking are among the potential causes of CVD. Intestinal permeability and translocation of endotoxins and bacterial metabolites to systemic circulation may trigger an immune response and inflammation, which may increase the risk of CVD. Synthesis of bacterial metabolites such as trimethylamine N-oxide (TMAO) by choline-inducing gut bacteria and reduced consumption of dietary TMAO precursors may elevate the CVD risk. This review explores the latest research on the role of gut microbiota in the development of atherosclerosis and CVD, as well as potential strategies to prevent CVD by targeting TMAO-producing gut bacteria. Elevated levels of TMAO in the bloodstream can lead to the buildup of cholesterol and ultimately result in atherosclerosis. However, consuming probiotics and fibre-rich foods can help regulate gut bacteria, reduce inflammation, and improve lipid profiles, all of which contribute to better cardiovascular health. More future robust studies are required to examine the mechanistic insights and confirm whether TMAO can serve as a biomarker for preventing CVD through the therapeutic modulation of intestinal bacteria.
Abstract
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.
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Gut microbiota alterations associated with reduced bone mineral density in older adults.
Das, M, Cronin, O, Keohane, DM, Cormac, EM, Nugent, H, Nugent, M, Molloy, C, O'Toole, PW, Shanahan, F, Molloy, MG, et al
Rheumatology (Oxford, England). 2019;58(12):2295-2304
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Osteoporosis, characterised by reduced bone density or ‘brittle bones’ affects a significant number of individuals over the age of 50 worldwide. Contributing factors include calcium and vitamin D deficiency and the presence of other inflammatory conditions. The composition of gut bacteria, the gut microbiome, plays an important role in immune activity and changes in composition have been associated with other inflammatory conditions. This cohort study of 181 individuals at high risk of reduced bone density and fractures, aimed to determine whether different gut microbiota composition is associated with bone density. Dexa scans and faecal samples were used as part of the assessment and confounding factors of diet, BMI, supplementation and medication were included in the analysis. The authors of the study found 6 species of gut bacteria that were significantly altered in numbers in the groups with osteoporosis and osteopenia, after controlling for confounding factors, and suggest that they could be used as markers of disease risk or progression and as a therapeutic target. Nutrition Practitioners working with bone density can focus on supporting the gut microbiome as part of their nutrition protocols.
Abstract
OBJECTIVE To investigate compositional differences in the gut microbiota associated with bone homeostasis and fractures in a cohort of older adults. METHODS Faecal microbiota profiles were determined from 181 individuals with osteopenia (n = 61) or osteoporosis (n = 60), and an age- and gender-matched group with normal BMD (n = 60). Analysis of the 16S (V3-V4 region) amplicon dataset classified to the genus level was used to identify significantly differentially abundant taxa. Adjustments were made for potential confounding variables identified from the literature using several statistical models. RESULTS We identified six genera that were significantly altered in abundance in the osteoporosis or osteopenic groups compared with age- and gender-matched controls. A detailed study of microbiota associations with meta-data variables that included BMI, health status, diet and medication revealed that these meta-data explained 15-17% of the variance within the microbiota dataset. BMD measurements were significantly associated with alterations in the microbiota. After controlling for known biological confounders, five of the six taxa remained significant. Overall microbiota alpha diversity did not correlate to BMD in this study. CONCLUSION Reduced BMD in osteopenia and osteoporosis is associated with an altered microbiota. These alterations may be useful as biomarkers or therapeutic targets in individuals at high risk of reductions in BMD. These observations will lead to a better understanding of the relationship between the microbiota and bone homeostasis.