Vegetarianism, Microbiota and Cardiovascular health: Looking back, and forward

Mendelian Randomization Highlights Gut Microbiota of Short-chain Fatty Acids' Producer as Protective Factor of Cerebrovascular Disease

BACKGROUND

Recent research advancements have indicated a potential association between gut microbiota and cerebrovascular diseases, although the precise causative pathways and the directionality of this association remain to be fully elucidated.

OBJECTIVE

This study utilized a bidirectional two-sample Mendelian Randomization (MR) methodology to explore the causal impact of gut microbiota compositions on the risk of cerebrovascular disease.

METHODS

Genome-wide Association Study (GWAS) data pertaining to gut microbiota were obtained from the MiBioGen consortium. For Ischemic Stroke (IS), Transient Ischemic Attack (TIA), Vascular Dementia (VD), and Subarachnoid Hemorrhage (SAH), GWAS summary data were sourced from the FinnGen consortium, the IEU Open GWAS project, and the GWAS catalog, respectively.

RESULTS

Our MR analyses identified that specific bacterial strains, notably those involved in the production of Short-chain Fatty Acids (SCFAs), including Barnesiella, Ruminococcus torques group, and Coprobacter, serve as protective factors against IS, TIA, and SAH. Linkage Disequilibrium Score Regression (LDSC) analysis corroborated a significant genetic correlation between these gut microbiota strains and various forms of cerebrovascular disease. In contrast, reverse MR analysis failed to establish a bidirectional causal relationship between genetically inferred gut microbiota profiles and these cerebrovascular conditions.

CONCLUSION

This investigation has pinpointed particular strains of gut microbiota that play protective or detrimental roles in cerebrovascular disease pathogenesis. These findings offer valuable insights that could be pivotal for the clinical management, prevention, and treatment of cerebrovascular diseases.

Superfamily II helicases: the potential therapeutic target for cardiovascular diseases

Cardiovascular diseases (CVDs) still maintain high morbidity and mortality globally. Helicases, a unique class of enzymes, are extensively implicated in the processes of nucleic acid (NA) metabolism across various organisms. They play a pivotal role in gene expression, inflammatory response, lipid metabolism, and so forth. However, abnormal helicase expression has been associated with immune response, cancer, and intellectual disability in humans. Superfamily II (SFII) is one of the largest and most diverse of the helicase superfamilies. Increasing evidence has implicated SFⅡ helicases in the pathogenesis of multiple CVDs. In this review, we comprehensively review the regulation mechanism of SFⅡ helicases in CVDs including atherosclerosis, myocardial infarction, cardiomyopathies, and heart failure, which will contribute to the investigation of ideal therapeutic targets for CVDs.

Vegetarian diets and risk of all-cause mortality in a population-based prospective study in the United States

The popularity of vegetarian diets has increased the need for studies on long-term health outcomes. A limited number of studies, including only one study from a non-vegetarian population, investigated the risk of mortality with self-identified vegetarianism and reported inconsistent results. This study evaluated prospective associations between vegetarian diets and all-cause mortality among 117,673 participants from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial cohort study. Vegetarian diet status was self-identified on the questionnaire. Deaths were ascertained from follow-up questionnaires and the National Death Index database. Multivariable Cox regression models were used to estimate the risk of all-cause mortality in hazard ratio (HR) and 95% confidence intervals (CI). By diet group, there were 116,894 omnivores (whose diet does not exclude animal products), 329 lacto- and/or ovo-vegetarians (whose diet excludes meat, but includes dairy and/or eggs), 310 pesco-vegetarians (whose diet excludes meat except for fish and seafood) and 140 vegans (whose diet excludes all animal products). After an average follow-up of 18 years, 39,763 participants were deceased. The risk of all-cause mortality did not statistically significantly differ among the four diet groups. Comparing with the omnivore group, the HR (95% CI) were 0.81 (0.64-1.03) for pesco-vegetarian group, 0.99 (0.80-1.22) for lacto- and/or ovo-vegetarian group and 1.27 (0.99-1.63) for vegan group, respectively. Similarly, mortality risk did not differ when comparing lacto- and/or ovo-vegetarians plus vegans with meat/fish eaters (omnivores and pesco-vegetarians) (HR [95% CI] = 1.09 [0.93-1.28]). As this study is one of the two studies of vegetarianism and mortality in non-vegetarian populations, further investigation is warranted.

Low Greenhouse Gas Emission Self-Selective Diets and Risk of Metabolic Syndrome in Adults 40 and Older: A Prospective Cohort Study in South Korea

BACKGROUND

The food system accounts for ∼ 40 % of human-generated greenhouse gas (GHG) emissions. Meanwhile, daily diet selection also impacts human nutrition status and health.

OBJECTIVES

This study aimed to use the alternate Mediterranean Diet (aMED) score to evaluate the quality of a low-GHG emission diet and the association with risk of developing metabolic syndrome (MetS).

METHODS

A total of 41,659 healthy participants without MetS 40 y of age or older were selected from the Health Examinees Study, an ongoing cohort study in South Korea from 2004. A dietary GHG emissions database was compiled following a national project and literature review. MetS was defined according to the Adult Treatment Panel III criteria of the National Cholesterol Education Program. The participants were grouped into quintiles based on 2,000  kcal -standardized daily diet-GHG emissions (Q1: the lowest energy-adjusted diet-GHG emissions). A multivariable logistic regression model was used to analyze the risk for MetS at follow-up. The aMED score was used to assess the diet quality of the different diet-related GHG emission groups.

RESULTS

Females with lower energy-adjusted diet-related GHG emissions had significantly lower risks of developing MetS (p = 0.0043 ) than those with the highest energy-adjusted diet-related GHG emissions. In addition, the Q1 group, in comparison with the other groups, had a higher aMED score (3.02 for males and 3.00 for females), which indicated that the participants in this group had a diet that more closely matched the Mediterranean diet.

DISCUSSION

These findings provide a reference for dietary guidance and other policies aimed toward improving dietary intake and reducing diet-related GHG emissions in South Korea and worldwide. https://doi.org/10.1289/EHP12727.

Causal relationships between the gut microbiome, blood lipids, and heart failure: a Mendelian randomization analysis

AIMS

Studies have linked gut microbiome and heart failure (HF). However, their causal relationships and potential mediating factors have not been well defined. To investigate the causal relationships between the gut microbiome and HF and the mediating effect of potential blood lipids by using genetics.

METHODS AND RESULTS

We performed a bidirectional and mediation Mendelian randomization (MR) study using summary statistics from the genome-wide association studies of gut microbial taxa (Dutch Microbiome Project, n = 7738), blood lipids (UK Biobank, n = 115 078), and a meta-analysis of HF (115 150 cases and 1550 331 controls). We applied the inverse-variance weighted estimation method as the primary method, with several other estimators as complementary methods. The multivariable MR approach based on Bayesian model averaging (MR-BMA) was used to prioritize the most likely causal lipids. Six microbial taxa are suggestively associated with HF causally. The most significant taxon was the species Bacteroides dorei [odds ratio = 1.059, 95% confidence interval (CI) = 1.022-1.097, P-value = 0.0017]. The MR-BMA analysis showed that apolipoprotein B (ApoB) was the most likely causal lipid for HF (the marginal inclusion probability = 0.717, P-value = 0.005). The mediation MR analysis showed that ApoB mediated the causal effects of species B. dorei on HF (proportion mediated = 10.1%, 95% CI = 0.2-21.6%, P-value = 0.031).

CONCLUSION

The study suggested a causal relationship between specific gut microbial taxa and HF and that ApoB might mediate this relationship as the primary lipid determinant of HF.

Plant-based diet and its effect on coronary artery disease: A narrative review

Coronary artery disease (CAD), a primary component of cardiovascular diseases, is one of the top contributors to mortality rates worldwide. In 2021, dietary risk was estimated to be attributed to 6.58 million cardiovascular deaths. Plant-based diets (PBDs), which encourage higher consumption of plant foods and lower intake of animal-based foods, have been shown to reduce the risk of CAD by up to 29% when compared to non-vegetarian diets in a meta-analysis. This article aims to summarize the array of PBDs and compare them with conventional Western diets that include meat. We review the various proposed mechanisms for how the bioactive nutrients of PBDs aid in preventing atherosclerosis and CAD events, as well as other cardiac diseases. We conducted a detailed search of PubMed using our exclusive search strategy using the keywords plant-based diet, vegan diet, phytosterols, CAD, myocardial ischemia, and atherosclerosis. A total of 162 pertinent articles published within the past decade were identified for qualitative synthesis. To ensure the accuracy and reliability of our review, we included a total of 55 full-text, peer-reviewed articles that demonstrated the effects of plant-based diets on CAD and were written in English. We excluded animal studies, in vitro or molecular studies, and non-original data like editorials, letters, protocols, and conference abstracts. In this article, we emphasize the importance of dietary interventions, such as PBDs, to prevent CAD and their benefits on environmental sustainability. Integrating plant foods and whole grains into one's daily eating habits leads to an increase in the intake of nutrient-rich foods while reducing the consumption of processed food could not only prevent millions of premature deaths but also provide prevention against many chronic gastrointestinal and metabolic diseases.

The gut microbial metabolite trimethylamine N-oxide and cardiovascular diseases

Morbidity and mortality of cardiovascular diseases (CVDs) are exceedingly high worldwide. Researchers have found that the occurrence and development of CVDs are closely related to intestinal microecology. Imbalances in intestinal microecology caused by changes in the composition of the intestinal microbiota will eventually alter intestinal metabolites, thus transforming the host physiological state from healthy mode to pathological mode. Trimethylamine N-oxide (TMAO) is produced from the metabolism of dietary choline and L-carnitine by intestinal microbiota, and many studies have shown that this important product inhibits cholesterol metabolism, induces platelet aggregation and thrombosis, and promotes atherosclerosis. TMAO is directly or indirectly involved in the pathogenesis of CVDs and is an important risk factor affecting the occurrence and even prognosis of CVDs. This review presents the biological and chemical characteristics of TMAO, and the process of TMAO produced by gut microbiota. In particular, the review focuses on summarizing how the increase of gut microbial metabolite TMAO affects CVDs including atherosclerosis, heart failure, hypertension, arrhythmia, coronary artery disease, and other CVD-related diseases. Understanding the mechanism of how increases in TMAO promotes CVDs will potentially facilitate the identification and development of targeted therapy for CVDs.