Jasmohan S. Bajaj
Researchers identified alterations in the skin microbiome of patients with cirrhosis that correlated with itching intensity and itch modulators, according to a recently published study.
“In cirrhosis there is evidence of a global mucosal-immune impairment illustrated by altered systemic immune activation, neutrophil dysfunction and changes in microbial composition,” Jasmohan S. Bajaj, MD, from the Virginia Commonwealth University, and colleagues wrote. “These microbial alterations span the stool, intestinal mucosa, ascites fluid, serum and the oral cavity. The study results demonstrate alterations in the skin microbial composition across the body in cirrhosis compared to healthy controls.”
The study comprised 20 controls and 50 patients with cirrhosis, including 20 patients with decompensated cirrhosis. Bajaj and colleagues noted significant differences in the skin microbiota among patients with cirrhosis compared with controls from all three skin areas: sebaceous, moist, and dry areas.
Patients with cirrhosis had higher potentially pathogenic taxa such as Staphylococcaceae and lower potentially commensal Actinobacteria in sebaceous areas compared with controls. Patients with decompensated cirrhosis and in those with visual analog itch scale (VAS) score of 5 had a higher relative abundance of Gammaproteobacteria compared with patients with compensated cirrhosis and those with less severe itching.
“We found significant differences in the stool and salivary microbiota in those with greater itching, which were different from the taxa that separated controls from cirrhosis, or compensated from decompensated cirrhosis,” the researchers wrote. “This implies that a specific signature of the microbial composition that is present in the gut could be associated with itching manifested in the skin.”
All study participants with a VAS score of 5 or higher had a higher abundance of Lactobacillaceae, Fusobacteriaceae and Eubacteriaceae, and lower Porphyromonadaceae in their stool. They also had a higher relative abundance of Enterococcaceae and lower constituents of Firmicutes, Actinobacteria Fusobacteria, and Synergistetes in their salivary microbiota.
The shin had the highest itch intensity among participants and had the highest number of interactions between serum bile acids and bacterial taxa. Streptococcoceae (r = 0.5; P = .001), Pseudomonadaceae (r = 0.43; P = .003), Alcaligenaceae (r = 0.3; P = .05) and Pasteurellaceae (r = 0.3; P = .05) also correlated with autotaxin levels in the shin.
“Pruritus is one of the most distressing complication of advanced liver disease and indeed a larger proportion of cirrhotics in our study reported a higher itching severity, duration and greater negative impact on their daily life compared to controls which was not related to the decompensation or the MELD score,” Bajaj and colleagues wrote. “Therefore, the differential correlations between skin microbiota, bile acids and autotaxin in those with greater itching may be an important aspect of the pathophysiology that needs further exploration.” – by Talitha Bennett
Disclosure: The authors report no relevant financial disclosures.