The degrees of clinical severity or the parameters of PLHIV that were included in the gut microbiome analyses were based on CD4+ and CD8+ T-cell counts [26,27,30,33], immune reconstitution [24], serum cytokine levels [25,26,31,33], the chronicity of HIV infection [36], and the route of HIV transmission [23]. The gene discussed is CD4; the disease is HIV infectious disease.