Oral pharmaceutical compositions containing rifamycin SV, or a pharmaceutically salt thereof, characterized in that they are formulated in a higher strength (about 600 mg/tablet) and in such a manner to obtain a modified profile of the rifamycin SV, or a pharmaceutically acceptable salt thereof, in the proximal portion of the intestine, i.e. in the small intestine (duodenum, jejunum and ileum). In one embodiment, the disclosed oral pharmaceutical compositions are used in the prevention and/or treatment in a subject of small intestine bacterial overgrowth (SIBO) and/or irritable bowel syndrome (IBS) and/or in the treatment of cholera. In one embodiment, the disclosed oral pharmaceutical compositions are used in the prevention and/or treatment in a subject of hepatic encephalopathy, hepatic cirrhosis, pouchitis and/or spontaneous bacterial perotinitis. In one embodiment, the disclosed oral pharmaceutical compositions are used in the prevention and/or treatment in a subject of non-alcoholic fatty liver disease, non-alcoholic fatty liver or non-alcoholic steatohepatitis.
