The saliva microbiota in patients with psoriasis
Accumulating evidence supports an association between altered saliva microbiota and inflammatory diseases. However, the existing literature on the saliva microbiota in patients with psoriasis is limited. Yet, differences in prevalence of Candida species and abundance of several bacterial taxa in saliva have been found between patients and controls. This study aimed to investigate the differences in the composition and the functional potential of the saliva microbiota in patients with psoriasis compared with their cohabiting partners and healthy controls. Samples from 115 of 123 individuals qualified for statistical analysis; patients with psoriasis not receiving systemic anti-psoriatic treatment (n=47), cohabiting partners (n=21), and age-, sex- and BMI-matched healthy controls (n=47). One saliva sample was collected from each participant and analysed by shotgun metagenomic sequencing. A difference in the a-diversity of bacterial species was observed exclusively between patients and controls, showing lower diversity in patients (p=0.041). Variation in bacterial composition (ß-diversity) was shown to be influenced by smoking (p=0.001) and diet (p=0.025), but not by group status. When using a linear regression model adjusted for smoking and diet, we identified four bacterial classes and five species significantly different between the patient group and the partner and control group, respectively. One Kyoto Encyclopedia of Genes and Genomes module significantly differed between the psoriasis group and their partners. No differences in Candida abundance between the three groups were found. Comparison of the saliva microbiota at levels of bacterial diversity, composition, and predicted function indicates that psoriasis cases are characterized by dysbiosis.
Accumulating evidence supports an association between altered saliva microbiota and inflammatory diseases. However, the existing literature on the saliva microbiota in patients with psoriasis is limited. Yet, differences in prevalence of Candida species and abundance of several bacterial taxa in saliva have been found between patients and controls. This study aimed to investigate the differences in the composition and the functional potential of the saliva microbiota in patients with psoriasis compared with their cohabiting partners and healthy controls. Samples from 115 of 123 individuals qualified for statistical analysis; patients with psoriasis not receiving systemic anti-psoriatic treatment (n=47), cohabiting partners (n=21), and age-, sex- and BMI-matched healthy controls (n=47). One saliva sample was collected from each participant and analysed by shotgun metagenomic sequencing. A difference in the a-diversity of bacterial species was observed exclusively between patients and controls, showing lower diversity in patients (p=0.041). Variation in bacterial composition (ß-diversity) was shown to be influenced by smoking (p=0.001) and diet (p=0.025), but not by group status. When using a linear regression model adjusted for smoking and diet, we identified four bacterial classes and five species significantly different between the patient group and the partner and control group, respectively. One Kyoto Encyclopedia of Genes and Genomes module significantly differed between the psoriasis group and their partners. No differences in Candida abundance between the three groups were found. Comparison of the saliva microbiota at levels of bacterial diversity, composition, and predicted function indicates that psoriasis cases are characterized by dysbiosis.
Department of Dermatology and Allergi, Herlev and Gentofte