Recent studies show that gut microbiota strongly influences multiple sclerosis. These data suggest that the microbiota could have a direct effect on MS pathogenesis, although the mechanisms through which it modulates central nervous system (CNS) neuroinflammation and neurodegeneration are still poorly defined. The microbiota mediates its action principally through synthesizing specific metabolites that act as messengers in host functions, such as the modulation of the immune and nervous system, tissue repair, and stemness. The short-chain fatty acids (SCFAs- mainly acetate, propionate, and butyrate), produced by the fermentation of dietary fibers, are a class of microbial metabolites of primary importance for host physiology. Thus, the objective is to establish a mechanistic link between gut microbiota dysbiosis, reflected by a different level of SCFAs and SCFA-producing bacteria species, and neuroimmune alterations in MS. Preliminary data show a differential metabolomic profile in urine samples of MS patients compared to healthy controls. The authors now aim at deepening previous findings by analysing also the SCFAs concentration in the urines, plasma and CSF by GC-MS (their level turned out to be too low to be measured by NMR) and the microbiota composition by shotgun metagenomics analysis, to track changes in the abundance of SCFAs-producing bacteria species.

Inclusion Criteria:

- Volunteers that have preventively signed the informed consent to use their samples for additional studies.

Exclusion Criteria:

- None

20 healthy controls and 20 newly diagnosed not yet treated MS patients. Both HC and MS were recruited inside IRCCS San Raffaele. Both categories are composed of 50% females and 50% males. The age range for both categories is comprised between 28 and 65 years.