Through unspecific mechanism, the ingestion of the bicarbonates mineral waters in cure has sensible effects of amelioration on the allergic manifestation and on the installation of allergic tolerance too. From 29 bottled minerals waters exploited by the Romanian National Society of the Minerals Waters, 65,51% has the bicarbonate ion below 1000 mg/L, 27,5% between 1000-2000 mg/l and 6,89% over 3000 mg/l. The magnesium bicarbonate mineral waters speed the gastrointestinal transit on the people with chronic constipation, impede the resorbtion of the toxic food compounds including allergens etc. The hydro-mineral cure with amelioration effect on the chronic gastrointestinal diseases, impede the allergic crossing to the systemic circulation. Among the medicinal mineral water, on recommend the following: Sangeorz-Bai, Slanic- Moldova, Calimanesti, Olanesti, Borsec etc.