Background: Imbalances in gut microbiota are linked to chronic diseases, including heart failure, where shifts in microbial composition are evident in patients with reduced ejection fraction (HFrEF). This study compared gut microbiome profiles between HFrEF patients and healthy controls and explored potential links between microbiome composition and patient survival over 6 and 12 months.Methods: In this longitudinal case-control study, 20 HFrEF patients and 40 healthy controls were recruited, with stool samples collected for gut microbiome analysis. Patients were followed for six and twelve months to assess survival. Gut microbiome composition was analyzed using real-time PCR for specific bacterial taxa. Statistical analyses were performed using R to compare HFrEF and control groups and draw the ROC curve to predict survival at six and twelve months.Results: HFrEF patients showed a significantly lower abundance of all bacterial taxa, except for A. muciniphila. Decreased levels of Prevotella, F. prausnitzii, Firmicutes, and Bacteroides, as well as a lower Firmicutes/Bacteroidetes (F/B) ratio, were notable in HFrEF patients, with specific taxa correlating with clinical features like ascites and vitamin D levels. Most bacterial taxa and the F/B ratio could distinguish HFrEF patients from controls, though none effectively predicted survival outcomes at six or twelve months.Conclusion: The study demonstrates that patients with HFrEF exhibit a distinct gut microbiome profile compared to healthy individuals. While specific gut bacteria were effective in distinguishing HFrEF patients from healthy controls, their ability to predict survival outcomes was limited, highlighting the need for further research into the role of the gut microbiome in the progression and prognosis of heart failure.

Background: Imbalances in gut microbiota are linked to chronic diseases, including heart failure, where shifts in microbial composition are evident in patients with reduced ejection fraction (HFrEF). This study compared gut microbiome profiles between HFrEF patients and healthy controls and explored potential links between microbiome composition and patient survival over 6 and 12 months.Methods: In this longitudinal case-control study, 20 HFrEF patients and 40 healthy controls were recruited, with stool samples collected for gut microbiome analysis. Patients were followed for six and twelve months to assess survival. Gut microbiome composition was analyzed using real-time PCR for specific bacterial taxa. Statistical analyses were performed using R to compare HFrEF and control groups and draw the ROC curve to predict survival at six and twelve months.Results: HFrEF patients showed a significantly lower abundance of all bacterial taxa, except for A. muciniphila. Decreased levels of Prevotella, F. prausnitzii, Firmicutes, and Bacteroides, as well as a lower Firmicutes/Bacteroidetes (F/B) ratio, were notable in HFrEF patients, with specific taxa correlating with clinical features like ascites and vitamin D levels. Most bacterial taxa and the F/B ratio could distinguish HFrEF patients from controls, though none effectively predicted survival outcomes at six or twelve months.Conclusion: The study demonstrates that patients with HFrEF exhibit a distinct gut microbiome profile compared to healthy individuals. While specific gut bacteria were effective in distinguishing HFrEF patients from healthy controls, their ability to predict survival outcomes was limited, highlighting the need for further research into the role of the gut microbiome in the progression and prognosis of heart failure.