Oral pharmaceutical, nutraceutical, health foods and medical device compositions based on polysaccharides from Opuntia Ficus Indica cladodes in combination with other active substances are useful for the prevention or treatment of GERD (Gastro-Esophageal Reflux Disease), gastric esophagitis and related diseases (e.g. dyspepsia, esophagitis, esofageal tumour, gastro-intestinal symptoms, chronic pharyngitis, Barrett's esophagus, esophageal adenocarcinoma, GERD-related pulmonary symptoms).