Gut Microbiome Imbalance Linked to Vascular Disease Risk, Review Suggests

A recent narrative review of existing scientific literature has examined potential associations between the composition of the gut microbiome and the development of vascular diseases, including atherosclerosis and peripheral artery disease (PAD). The review suggests that an imbalance in gut bacteria may be a factor influencing vascular health alongside established risk factors.

The central focus is on gut dysbiosis—an imbalance in gut microbial communities—and its potential role in vascular damage.

Observed Microbial Patterns in Disease

The review reported consistent differences in the gut bacteria of individuals with vascular disease compared to those without.

Elevated Levels of Potentially Harmful Bacteria:

• Enterobacteriaceae
• Streptococcus spp.
• Lachnoclostridium
• Family XI

Reduced Levels of Beneficial Bacteria:

• Roseburia
• Faecalibacterium
• Coprococcus
• Ruminococcaceae

How Gut Bacteria May Influence Vascular Health

The review centered its discussion on two key groups of bacterial metabolites.

• Production: Generated from compounds in red meat and other animal-derived foods via gut microbial metabolism and liver processing.
• Proposed Associations: Higher TMAO levels are linked in studies to factors that increase vascular risk, including endothelial dysfunction, inflammation, and increased platelet reactivity.

• Production: Created by beneficial gut bacteria during the fermentation of dietary fiber.
• Proposed Associations: These metabolites (acetate, propionate, butyrate) are described as potentially protective, associated with anti-inflammatory effects, better insulin sensitivity, improved endothelial function, and lower vascular risk.

Specific Focus on Peripheral Artery Disease (PAD)

The review highlighted growing research into direct links between the gut microbiome and PAD.

• Bacteria Associated with Lower PAD Risk: Coprococcus 2 and certain Ruminococcaceae subtypes.
• Bacteria Associated with Greater PAD Risk: Lachnoclostridium and Family XI.

The proposed pathways connecting gut dysbiosis to PAD include reduced production of protective SCFAs, increased pro-inflammatory signaling, impaired nitric oxide activity, and elevated TMAO levels.

Potential Interventions and Research Status

The review discussed several investigational strategies aimed at modifying the gut microbiome.

• Dietary Approaches: Patterns like the Mediterranean diet may support beneficial bacteria while limiting red meat (a source of TMAO precursors).
• Microbial Supplements: This includes probiotics (e.g., Lactobacillus rhamnosus GG for potentially lowering TMAO) and prebiotics.
• Microbial Transfer: Fecal microbiota transplantation (FMT) is noted as a more invasive potential strategy.

The review explicitly states that these microbiome-targeted interventions are not established tools for vascular disease prevention or treatment.

Current Evidence Status: The supporting evidence is largely observational or from small-scale studies. The conclusion calls for longer-term, robust clinical trials to determine the efficacy and safety of such approaches.

Reference: Smółka L et al. The impact of the gut microbiome on the development of atherosclerosis and peripheral arterial disease: A narrative review. Przegl Epidemiol. 2025;79(4):580-594.