The relative abundance of Streptococcus negatively correlated with the levels of IL-1β, IL-4, IL-6, IL-7, IL-8, IL-12p70, IL-17, G-CSF, IFN-γ and TNF-α, while the relative abundance of Veillonella and Prevotella/Porphyromonas (OTU93) positively correlated with the IgA level in the saliva of patients with PBC. The gene discussed is IL17A; the disease is primary biliary cholangitis.