In the correlation between genus Blautia and MDS, two specific mediators were distinguished, including CD4 +T cell %leukocyte (mediation effect: 0.104; 95% CI − 0.047,0.256) and CD45 on CD33 + HLA DR + WHR (mediation effect: − 0.066; 95% CI − 0.397, 0.265). The gene discussed is CD4; the disease is myelodysplastic syndrome.