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Cardiovascular Health

Gut Health & Cardiometabolic Conditions

Reading Time: 5 minutes
Updated on: December 13, 2024

Research suggests, with increasing evidence, that the gut microbiome has a strong correlation with the occurrence, progression, and treatment of cardiovascular diseases.1 Scientists speculate that gut microbiota dysbiosis, including an impaired mucosal barrier, gut microbiota–generated metabolites, and the related signaling pathway, may serve as explanations for some of the mechanisms about the occurrence and development of cardiovascular diseases.1 What is the latest research, and how does a functional medicine and whole health approach address intestinal integrity and the gut microbiome as potential components of cardiometabolic dysfunction?

In the following video, IFM educator Shilpa P. Saxena, MD, IFMCP, discusses how gut health and the microbiome impact cardiovascular health. 

(Video Time: 02:00) Dr. Saxena is an IFM Certified Practitioner and a board-certified family physician who is a faculty member with IFM and chief medical officer at Forum Health, a nationwide provider of personalized health services. In addition to over 15 years of progressive patient care in her medical practices, Dr. Saxena teaches physicians around the globe, sharing her expertise and commitment for professional growth.


Gut Microbiota Composition, Mechanisms, & Metabolism

A large cross-sectional study published in 2023 of 8,973 participants aged 50 to 65 suggests a link between certain bacteria living in the gut (taken by fecal sample) and coronary atherosclerotic plaques.2 Sixty-four species were associated with a coronary artery calcium score independent of cardiovascular risk factors, with the strongest associations observed for Streptococcus anginosus and Streptococcus oralis subsp oralis.Another large-scale study with 893 participants suggests that certain families of gastrointestinal (GI) bacteria can either positively or negatively affect cardiovascular health.3 Different compositions in the gut microbiome were correlated to both BMI and lipid levels, independent of genetics, age, and gender. Lower levels of bacterial families Christensenellaceae and Rikenellaceae, class Mollicutes, genus Dehalobacterium, and kingdom Archaea correlated with high BMI. The researchers estimated that 4.5-6% of BMI, triglyceride, and HDL variations could be explained by these variations in the microbiome, independent of other risk factors.3

One mechanism by which the microbiome may affect cardiometabolic health is through generation of metabolites that alter host physiology4-6 and influence metabolic inflammation.7 After performing 16S rRNA gene sequencing in 531 Finnish men, researchers found gut microbiota correlated with fasting serum levels in fatty acids, amino acids, lipids, and glucose, as well as with levels of trimethylamine N-oxide (TMAO), a metabolite associated with coronary artery disease and stroke.8 Recent systematic reviews have associated high circulating levels of TMAO with cardiometabolic disorders in adults,9 as well as both major adverse cardiovascular events and all-cause mortality.10 The microbiome may also influence remote body sites through alterations of pathways such as the short-chain fatty acids and bile acids pathways.4,11

The gut microbiome is also known to affect metabolism and may contribute to insulin resistance and metabolic syndrome.8,12 In individuals with metabolic syndrome, arterial stiffness predicts cardiovascular risk.13 In a study of 617 women, analysis of the microbiome accounted for 8.3% of the variation in arterial stiffness, while visceral adiposity and insulin resistance only accounted for 1.8%. Examining the microbial makeup showed that butyrate-producing Ruminococcaceae bacteria were negatively correlated with arterial stiffness.13

GLP-1 HORMONE & THE MICROBIOME

Glucagon-like peptide 1 (GLP-1) is a gut hormone secreted from the GI tract after food ingestion. While this hormone promotes satiation and satiety, it also plays a role in metabolism by stimulating insulin secretion.14 Gut microbiota–derived metabolites, including SCFAs from dietary fiber fermentation, stimulate GLP-1 secretion.15 Dietary approaches that include increased fiber consumption have been reported as a way to naturally boost GLP-1 and promote healthy metabolic function.16 GLP-1 agonist medications work by mimicking this hormone to help patients with chronic metabolic diseases such as type 2 diabetes through the management of blood sugar levels and the maintenance of healthy weight. 

Fecal Transfers 

Fecal microbiota transplantation (FMT) may affect the course of some cardiometabolic diseases, including metabolic syndrome, obesity, and type 2 diabetes (T2D).17-19 A recent clinical trial suggests that a single oral FMT administration, coupled with daily low-fermentable fiber supplementation, may improve insulin sensitivity and microbial diversity in people with severe obesity and metabolic syndrome.20 Another small 2017 human study (n=38) investigated the effect of lean donor (allogenic) versus own (autologous) FMT to male recipients with metabolic syndrome.21 Results after the allogenic FMT indicated a significant improvement in insulin sensitivity at six weeks, accompanied by altered microbiota composition.21 However, the benefits and microbiota composition changes were short-term, returning to baseline measurements at 18 weeks. Investigators noted that participants did not deviate from their regular lifestyle practices, including diet, during the study and that this may have impacted the FMT benefit.21 Studies continue to explore the potential cardiometabolic health benefits of FMT among different populations. 

Dietary Impacts & the Functional Medicine Approach

This research is exciting in part because the microbiome changes rapidly in response to diet,22 making nutrition an important part of the microbiome-cardiometabolic equation. For example, research suggests that the Mediterranean diet and other diets naturally rich in polyphenols and/or long-chain n-3 polyunsaturated fatty acids may significantly increase gut microbial diversity and bifidobacteria concentrations, potentially impacting glucose and lipid metabolism.23,24

Within the functional medicine model, nutritional interventions are a cornerstone of therapeutic strategies used to address chronic diseases such as CVDs and metabolic disorders. Treating the gut using diet, probiotics, prebiotic foods, and other therapies may help reduce risks for many cardiometabolic patients. IFM’s Cardiometabolic Food Plan is one therapeutic resource that is easily personalized and helps to support cardiac and metabolic health, in part by affecting the microbiome. 

A functional medicine approach is a whole health approach that considers gut health when assessing and supporting cardiometabolic function. Learn more about cardiometabolic conditions and clinical applications that support your patient’s health journey at IFM’s upcoming Cardiometabolic Functional Medicine Advanced Practice Module® (APM).

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REFERENCES
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  2. Sayols-Baixeras S, Dekkers KF, Baldanzi G, et al. Streptococcus species abundance in the gut is linked to subclinical coronary atherosclerosis in 8973 participants from the SCAPIS cohort. Circulation. 2023;148(6):459-472. doi:10.1161/circulationaha.123.063914
  3. Fu J, Bonder MJ, Cenit MC, et al. The gut microbiome contributes to a substantial proportion of the variation in blood lipids. Circ Res. 2015;117(9):817-824. doi:10.1161/CIRCRESAHA.115.306807
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