Tanja Todberg, Hannah Kaiser, Claus Zachariae, Alexander Egeberg, Anne-Sofie Halling, Lone Skov
DOI: 10.2340/00015555-3882

Advances in technology have led to an increased number of studies investigating the microbiome in patients with psoriasis. This systematic review examined data regarding the oral and gut microbiota in patients with psoriasis and/or psoriatic arthritis and the effect of probiotics on the microbiota and severity of psoriasis. Of 1,643 studies, 23 were included (22 observational, 1 interventional). Studies examined the microbiota using culture or 16S rRNA gene sequencing analysis. All culture-based studies identified an increased presence of oral Candida in patients with psoriasis, whereas small variations in the oral microbiota were found in a 16S rRNA gene-based study. All 16S rRNA gene sequencing based studies agreed that the gut microbiota of patients with psoriatic disease differed from that of healthy controls, but the results were heterogeneous. Probiotics were associated with a significant improvement in the severity of psoriasis, but did not change microbiota. Overall, studies lacked relevant inclusion criteria and baseline information. In conclusion, the role of the microbiota in patients with psoriasis requires further investigation using more robust methods.

Studies investigating the association between psoriasis and the microbiome have increased rapidly. This systematic review examined the role of the oral and gut microbiota and the effect of probiotics in patients with psoriasis and/or psoriatic arthritis. Twenty-three out of an initial total of 1,643 studies were included in the analysis. Of these, 22 studies were observational and 1 was interventional. The results showed increased presence of Candida in the oral cavity, and all studies examining the gut microbiota identified an altered microbiota in patients with psoriatic disease, but, overall, the results were heterogeneous. Probiotics were associated with a significant decrease in psoriasis severity, but the microbiota was unchanged. Further research is required into the role of the microbiome in patients with psoriasis.

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