It is known that ART is able to restore the CD4+ T cell count and suppress the HIV viremia in most PLWH; however, several manifestations of the HIV infection can still appear in these patients, especially signs related to residual inflammation, affecting the gut and oral microbiotas, contributing to dysbiosis and to the pathogenesis of related diseases (Coker et al., 2021). Here, CD4 is linked to HIV infectious disease.