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Rosacea patients show distinctive microbiota in stool samples

Key clinical point: Rosacea patients showed a distinct fecal microbial community structure compared with controls.

Major finding: Stool samples from patients with rosacea were significantly enriched with Rhabdochlamydia, CF231, Bifidobacterium, Sarcina, and Ruminococcus compared with controls.

Study details: The data come from a case-control study of 11 rosacea patients and 110 matched controls.

Disclosures: The study was supported by the Ministry of Science and Technology, Taiwan, and Taichung Veterans General Hospital, Taiwan. The researchers had no financial conflicts to disclose.


"In the past decade, an plethora of papers has reported the co-occurrence of rosacea with a variety of systemic diseases. This has followed on the heels of data showing a clear relationship between psoriasis and cardiovascular disease. Reported rosacea comorbidities have included neurologic, cardiovascular, autoimmune and solid tumors. The strongest evidence thus far is the association between rosacea and gastrointestinal disorders, particularly inflammatory bowel disease. The link between them, however, is unknown; is the association genetic, environmental, based on a common pathophysiology or is it simply two common disorders occurring in a cohort of patients who are merely aging? Many gastrointestinal diseases (most notably small intestinal bacterial overgrowth (SIBO) and C. difficile diarrhea) are clearly associated with a marked dysbiosis; the gut microbiome has therefore become an area of interest in rosacea. Thus far, studies have demonstrated variable alterations in microbial richness, diversity and distinct species over- and under-abundance. However, no consistent answers have arisen. Considering that dietary habits can alter the intestinal microflora, it is possible that there will be no cross-cultural similarities and that putative associations of gut health with rosacea will be confined to narrow geographic constraints."

Hilary Baldwin, MD
Medical Director, Acne Treatment and Research Center
Brooklyn, New York
Clinical Associate Professor, Robert Wood Johnson Medical Center
Newark, New Jersey


Chen YJ et al. J Formos Med Assoc. 2020 May 20. doi: 10.1016/j.jfma.2020.04.034.