Alterations in Skin Microbiomes of Patients With Cirrhosis

Patients with cirrhosis have intestinal dysbiosis and are prone to itching and skin or soft-tissue infections. The skin microbiome, and its relationship with intestinal microbiome, have not been characterized. We investigated alterations in skin microbiota of patients with cirrhosis and their association with intestinal microbiota and modulators of itch.

We collected skin swabs at 7 sites and blood and stool samples from 20 healthy individuals (control subjects; mean age, 59 years) and 50 patients with cirrhosis (mean age, 61 years; mean model for end-stage disease score, 12; 20 with decompensation). Skin and stool samples were analyzed by 16s rRNA sequencing and serum samples were analyzed by liquid chromatography and mass spectrometry for levels of bile acids (BAs) and by an ELISA for autotaxin (an itch modulator). Participants were analyzed by the visual analog itch scale (VAS, 0-10,10 = maximum intensity). Data were compared between groups (cirrhosis vs control subjects, with vs without decompensation, VAS 5 or higher vs less than 5). Correlation networks between serum levels of BAs and skin microbiomes were compared between patients with cirrhosis with vs without itching.

The composition of microbiomes at all skin sites differed between control subjects and patients with cirrhosis and between patients with compensated vs decompensated cirrhosis. Skin microbiomes of patients with cirrhosis (especially those with decompensation) contained a higher relative abundance of Gammaproteobacteria, Streptococaceae, and Staphylococcaceae, and fecal microbiomes contained a higher relative abundance of Gammaproteobacteria, than control subjects. These bacterial taxa were associated with serum levels of autotaxin and BAs, which were higher in patients with VAS scores ≥5. Based on network statistics, microbial and BA interactions at all sites were more complex in patients with greater levels of itching in the shin, the most common site of itch.

We identified alterations in skin microbiome of patients with cirrhosis (in Gammaproteobacteria, Streptococcaceae, and Staphylococcaceae)-especially in patients with decompensation; fecal microbiomes of patients with cirrhosis had a higher relative abundance of Gammaproteobacteria than control subjects. These specific microbial taxa are associated with itching intensity and itch modulators, such as serum levels of BAs and autotaxin.