The present invention relates to a microbial strain, particularly to Bifidobacterium animalis capable of well tolerating gastric acid, wherein the Bifidobacterium animalis CG-B1 is preserved in the China General Microbiological Culture Collection Center on September 05, 2016, and has the preservation number of CGMCCNo.12943. According to the present invention, the product is derived from the intestinal tract of the healthy old man with 100 years old; the animal test results prove that the product can promote the intestinal peristalsis of mice with constipation, can relieve the constipation symptoms of mice, can significantly alleviate the ulcerative colitis in mice, can reduce intestinal inflammation, can reduce serum inflammatory cytokines, can improve intestinal barrier integrity by improving the expression of intestinal tight junction protein, and can prevent and improve type II diabetes; and the product is suitable for food, medicineand/or health care products.