Salivary Microbiota Associated with Immunoglobulin A Nephropathy

This study aimed at investigating the salivary microbiota of 28 patients affected by immunoglobulin A nephropathy (IgAN). Fourteen healthy volunteers (HC) were used as control. Compared to HC, the number of some cultivable bacteria groups (e.g., total anaerobes) significantly (P < 0.05) decreased in the salivary samples of IgAN patients. Total bacteria from salivary samples of IgAN patients and HC subjects were analyzed by pyrosequencing of 16S rRNA gene. Paired t test showed no significant (P > 0.05) differences of alpha-diversity parameters (OTU, ACE, Chao1, and Shannon index) between the salivary samples of HC and IgAN patients. The difference for the community structure was further analyzed using three phylogeny-based beta-diversity measures. Compared to HC, the ratio between Firmicutes/Proteobacteria markedly decreased in IgAN patients. Gemella haemolysins, Granulicatella adiacens, and Veillonella parvula were positively associated (P < 0.05) with HC. Within the phylum Bacteroidetes, Prevotella species (Prevotella nigrescens, Prevotella intermedia, Prevotella pallens, and Prevotella salivae) were the highest in HC. The only exception was for Prevotella aurantiaca. Compared to HC, the percentage of abundance of some species, belonging to Pasteurellaceae family (e.g., Haemophylus parainfluenzae), increased in IgAN patients. Fusobacteriaceae (Fusobacterium) and Corynebacterium sp. also differed between the salivary samples of HC and IgAN patients.