USE OF CAPSULAR POLYSACCHARIDE A FROM BACTEROIDES FRAGILIS AND IMMUNE CHECKPOINT INHIBITORS IN PREPARATION OF DRUGS FOR TREATING DIGESTIVE SYSTEM TUMORS

The use of capsular polysaccharide A from Bacteroides fragilis and immune checkpoint inhibitors in preparation of drugs for treating digestive system tumors. The capsular polysaccharide from Bacteroides fragilis is capsular polysaccharide A extracted from Bacteroides fragilis ZY-312 by means of the method provided by the present invention, the relative molecular weight is 70-90 kDa, and the binding lipid content is lower than 0.02% or the capsular polysaccharide A does not contain lipids. The capsular polysaccharide A from Bacteroides fragilis is used as a main active ingredient to prepare a pharmaceutical preparation, a pharmaceutical composition and other biological preparations, and the immune checkpoint inhibitors are combined to treat digestive system tumors, so that the response rate of the immune checkpoint inhibitors and the treatment effect can be increased, and side effects are reduced. L'utilisation de polysaccharide capsulaire A de Bacteroides fragilis et d'inhibiteurs de point de contrôle immunit