CD4 and polyp of colon: 2 causal pathways were found to be associated with the mechanism of colon polyp development including RuminococcaceaeUCG002- CD24 on IgD- CD38- B cell- Colon polyp with a mediating effect of 6.20%; Eubacterium brachy- CD4 on CD28+ CD4+ T cell- Colon polyp, with a mediating effect of 12.11%.