Abstract: The invention discloses a use of Bacillus coagulans BC198 or its metabolites for prevention or adjuvant treatment of intestinal lesion-related pathological changes or flora imbalance caused by chemotherapy, that is, by administering an effective amount of Bacillus coagulans BC198 to an individual receiving chemotherapy is capable of effectively improving disorders of weight loss, loss of appetite, diarrhea, shortening of length of large intestine, inflammation, intestinal tissues lesion and imbalance of intestinal flora caused by chemotherapeutic drugs, in other words, the Bacillus coagulans BC198 disclosed in the invention can be used as an adjuvant product, a dietetic food product for chemotherapy, or other compositions for improving side effects or enhancing therapeutic effects.