The present invention relates to selected strains of bacteria belonging to the genus Lactobacillus and Bifidobacteria being able to maintaining a long-lasting homeostasis condition in a human body. Furthermore, the present invention relates to a composition, for example a food composition, a supplement product, a composition for a medical device or a pharmaceutical composition for use in the treatment of a long-lasting homeostasis condition in a human body; or for use in the treatment of renal failure, preferably acute or chronic; or for use in reducing uremic toxins, preferably of bacterial origin, such as indole and/or cresol.