CD4 and AIDS: As shown in Figure 6, higher plasma sCD14 and higher proportion of activated CD4+ T cells and CD8+ T cells were positively correlated with higher levels of metabolites in both AIDS and pre-AIDS patients, such as L-tryptophan (Figure 6A), while negatively correlated with the lower levels of metabolites, like pyridoxamine, niacinamide, nicotinamide riboside, ectoin, cinnamaldehyde, and fumaric acid (Figure 6B) (P<0.05).