Salivary microbiota and inflammation-related proteins in patients with psoriasis

OBJECTIVE: The purpose of the present study was to characterize the composition of the salivary microbiota and quantify salivary levels of inflammation-related proteins (neutrophil gelatinase-associated lipocalin [NGAL] and transferrin) in patients with psoriasis and compare data to those obtained in patients with periodontitis and orally healthy controls, respectively.

MATERIALS AND METHODS: Stimulated saliva samples from patients with psoriasis (n = 27), patients with periodontitis (n = 58), and orally healthy controls (n = 52) were characterized by means of next-generation sequencing of the 16S rRNA gene. Salivary levels of NGAL and transferrin were quantified using immunoassays.

RESULTS: Linear discriminant effect size analysis showed that 52 (22 psoriasis-associated and 30 periodontitis-associated) and 21 (8 psoriasis-associated and 13 orally healthy control-associated) bacterial taxa differentiated the salivary microbiota in patients with psoriasis from that of patients with periodontitis and orally healthy controls, respectively. Significantly lower mean salivary levels of NGAL (psoriasis: 996 [std. error 320], periodontitis: 2,072 [295], orally healthy controls: 2,551 [345] ng/ml, p < .0001) and transferrin (psoriasis: 4.37 [0.92], periodontitis: 7.25 [0.88], orally healthy controls: 10.02 [0.94] ng/ml, p < .0001) were identified in patients with psoriasis.

CONCLUSIONS: Psoriasis associates with characteristics of the salivary microbiota and salivary levels of inflammation-related proteins, which are different from characteristics in patients with periodontitis and orally healthy controls, respectively.