Worldwide, 1% to 2% of the general adult population have heart failure (HF), which is accompanied by reduced quality of life, high morbidity, mortality, and significant financial costs. Recently, the potential role of the gut in the pathophysiology of heart failure (HF) has recently begun to attract increased attention. In this context, the inventors demonstrated that treatment with Lactobbacillus reuteri ameliorates mice survival following myocardial infarction and that said treatment prevented the decrease of both cardiac function, (estimated by the % of ejection fraction) and cardiac remodeling. Moreover, the inventors show that ligands of aryl hydrocarbon receptor (AHR) that comprise some metabolites produced by Lactobacillus reuteri are also particularly suitable for the treatment of heart failure. Accordingly, the present invention relates to methods of treating heart failure in a subject in need thereof comprising administering to the subject an effective amount of Lactobacillus reuteri or at least one ligand of AHR.