Bifidobacterium longum with good intestinal tract colonizing ability and screening method and application of bifidobacterium longum

The invention relates to bifidobacterium longum with good intestinal tract colonizing ability. The bifidobacterium longum is named CCFM 729, the bifidobacterium longum is preserved in China General Microbiological Culture Collection Center, which is located at No.3, No.1 courtyard, Beichen West Road, Chaoyang District, Beijing, on May 28th, 2015, and the preservation number of the bifidobacterium longum is CGMCC No. 10932. The bifidobacterium longum has the advantages that the bifidobacterium longum CCFM 729 is initially derived from the excrement of one-week-old infants, in vitro experiments show that the bifidobacterium longum has acid resistance and bile salt resistance, cell experiments show that the bifidobacterium longum can well adhere to colon cancer cells HT-29, animal experiments show that the bifidobacterium longum can colonize in a mouse for 10 days even more than 10 days, and the bifidobacterium longum is good in intestinal tract colonizing ability, huge in application and commercial value, capable of being used to produce bifidobacterium powder, capable of being jointly fermented with streptococcus thermophilus and lactobacillus bulgaricus to produce yogurt, capable of being made into probiotics chocolate and the like, and promising in application prospect.