Gut Microbiota Alterations in Heart Failure Patients: Insights from a Systematic Review.

Background/Objectives: Heart failure (HF) is associated with chronic systemic inflammation, resulting in increased mortality. The intestinal microbiota can modulate systemic inflammation, and changes in the microbiota have been observed in patients with HF. Methods: A systematic search was performed in PubMed/MEDLINE up until July 2025 for studies comparing the intestinal microbiota between patients with HF and healthy controls (HCs). The PRISMA (Preferred Reporting Items for Systemic reviews and Meta-Analyses) criteria were used. The risk of bias was evaluated with the Newcastle-Ottawa scale for cross-sectional studies. Results: Fourteen studies with 1167 participants (550 patients with HF and 617 HC) were included. The patients with HF had less alpha and beta diversity compared with HC. In turn, the patients with HF presented an increase in proinflammatory bacteria belonging to the genera Streptococcus and Escherichia-Shigella, and a decrease in bacteria with anti-inflammatory effects, pertaining to the genera Faecalibacterium, Blautia and Lachnospira. Conclusions: Patients with HF present an altered intestinal microbiota, favoring the growth of bacteria that increase systemic inflammation through their metabolic activity. Modulation of the intestinal microbiota through different approaches is seen as a new therapeutic target in HF.