Conversely, some species/strains such as B. infantis and B. bifidum have been linked to expansion of Foxp3+ regulatory T cells via IL-10 and TGF-β signaling, which may foster immune tolerance and attenuate ICI efficacy, particularly in chronic inflammatory states or tumor-specific contexts such as gastric cancer, where available data remain limited (142–144). The gene discussed is IL10; the disease is neoplasm.