An increasing number of studies have focused on modulating the TME to mitigate tumor burden by microbial interventions.34–36 For instance, our previous studies have demonstrated that Akkermansia muciniphila effectively inhibits CRC tumorigenesis by inducing M1-like tumor-associated macrophages,37 and Bifidobacterium adolescentis was found to activate a cluster of Decorin+ macrophages, contributing to the suppression of CRC.17 In this study, we have first identified L. intestinalis as a tumor-suppressive strain and conclusively demonstrates its crucial functions in the TME. The gene discussed is DCN; the disease is colorectal carcinoma.