For instance, Lactobacillus rhamnosus Probio‐M9 promotes the infiltration and activation of CTLs, inhibits Treg function, and enhances the anti‐PD‐1 tumor‐suppressive effect by increasing the abundance of Lactobacillus, Bifidobacterium animalis, and pyridoxine [101, 102]. The gene discussed is PDCD1; the disease is neoplasm.