Despite significant progress in reducing cardiovascular disease (CVD) through modifications of classic CVD risk factors —smoking, diabetes mellitus, dyslipidemia, hypertension, and obesity—important residual risks remain to be managed. Recent discoveries linking the gut microbiome to cardiovascular health and disease have expanded our understanding. Understanding how dietary nutrients can affect health is a field of research where we are still in its early stages; we have only scratched the surface.
The gut microbiome, composed of diverse microorganisms, can utilize various compounds present in the digestive tract, such as trimethylamine N-oxide (TMAO), short-chain fatty acids, and primary and secondary bile acid pathways, to enter the circulatory system via intestinal cells. From there, they can modulate inflammatory activity, oxidative stress, and systemic thrombotic activity. The gut microbiome is currently being studied for its potential contribution to metabolic syndrome (which includes classic cardiovascular disease risk factors) and heart diseases such as heart failure, myocardial fibrosis, and coronary atherosclerosis.
Modulating the gut microbiome is a potential therapeutic strategy for various cardiovascular risk factors . Currently, it can be considered an adjunct to other therapies, without replacing established pharmacological treatments with sufficient scientific evidence.
What are probiotics?
According to the World Health Organization (WHO), probiotics are defined as live microorganisms, such as bacteria or yeasts, that, when administered orally in adequate amounts, confer a health benefit on the host. Optimal probiotic strains should be derived from human sources, inhibit acid and bile resistance, survive gastrointestinal transit, adhere to the intestinal epithelial cell membrane, and produce antibiotic substances to combat infections (ethanol, hydrogen peroxide, bacteriocins, and organic acids), all with the aim of stabilizing the intestinal microflora. It is imperative that probiotic products undergo comprehensive testing to identify and evaluate their dosage and safety.
What are prebiotics?
They are defined as the substrate specifically used by the gut microbiota , which produces beneficial effects for the host. All molecules classified as prebiotics fall into one of two categories: carbohydrates that can be metabolized by the gut flora or easily fermentable dietary fiber.
What are synbiotics?
They are formulas of probiotics and prebiotics, which can collectively exert a modulating effect on the intestinal microbiome.
Which probiotics are beneficial for cardiovascular health?
There are some systematic reviews and meta-analyses that have shown favorable, modest, and still insufficient results for probiotics in the context of cardiovascular risk factors; moreover, the overall body of evidence is less robust compared to that for gastrointestinal problems. Numerous studies have focused primarily on the impact of probiotics, prebiotics, and synbiotics on cardiovascular risk factors, including dyslipidemia, hypertension, and diabetes mellitus.
Probiotics in dyslipidemia
Dyslipidemia is a major risk factor for ischemic heart disease, the leading cause of death worldwide. Different strains of Lactobacillus plantarum and Lactobacillus reuterii have achieved significant reductions in LDL cholesterol levels in randomized clinical trials; however, these reductions have been modest compared to other well-established and potent therapies (statins, ezetimibe, bempedoic acid, PCSK9 inhibitors, or RNA technology, among others).
Probiotics in arterial hypertension
High blood pressure places greater strain on the heart, which responds by increasing its muscle mass (left ventricular hypertrophy). This hypertrophy can be detrimental in the long term because it can lead to angina or arrhythmias. Despite the genetic component of high blood pressure (which is often uncontrollable), reducing dietary salt, losing weight, and using various antihypertensive medications are well-established management strategies. In small studies, different strains of Lactobacillus plantarum have shown a modest reduction in systolic and diastolic blood pressure. Furthermore, in small clinical trials, some symbiotic formulas have demonstrated good blood pressure control in the management of mild preeclampsia during pregnancy.
Probiotics in diabetes mellitus
Diabetes mellitus (DM) is a highly prevalent disease associated with increased morbidity and mortality, primarily due to its cardiovascular (ischemic heart disease and heart failure) and renal complications, within the broad spectrum of cardio-renal-metabolic syndrome. Its non-pharmacological and, especially, pharmacological management (GLP-1 receptor agonists, DPP-4 inhibitors, SGLT2 inhibitors, among others) has evolved in recent years with significant results. Additionally, various strains of Lactobacillus and Bifidobacteria , as well as prebiotic compounds (e.g., oligofructose-enriched inulin), have shown promising results in improving metabolic control and the glycemic profile of these patients, particularly those who are overweight or obese.
Enteric-cardio-metabolic interaction is a broad and rapidly growing field of research. Increased research into the control of cardiovascular risk factors may allow for improved therapeutic approaches in the future.
By Dr. Ricardo Mori, specialist at UICAR