National Multicenter Interventional Study Aimed at Evaluating the Effect on the Intestinal Microbiota in Chronically Frail Patients Who Share Alterations in Intestinal Function.

Clinical survey conducted for research and study purposes, multicenter, focusing on ALS patients, elderly patients with chronic diseases, and pediatric patients with neurodevelopmental disorders. For each of the diseases treated, patients will be randomized into the two treatment arms (Study Group, GS; Control Group, GC) according to a block randomization, with a block size of 4 and an allocation ratio of 1:1. The randomization will be double-blind. * Study Group or GS: These subjects will be given an active symbiotic preparation consisting of two sticks of 1500mg each and of different colors. * Control group or GC:These subjects will be given a passive symbiotic preparation again consisting of two sticks of 1500mg each.