CHICAGO – Research from the University of Washington School of Medicine in St. Louis found that isotretinoin, which has been prescribed to treat acne for decades, can alter the skin microbiome of acne patients to resemble more people with skin normal.
The researchers studied bacteria collected from facial skin samples at four times throughout the 10-month study.
The samples came from 17 patients, whose acne was treated with isotretinoin composed of eight untreated individuals. Of these eight, four had normal skin and four had acne.
Researchers found that isotretinoin therapy increases the diversity of microbes found in the skin. Through DNA sequencing, the researchers also identified four types of bacteria that flourished with isotretinoin treatment. None of them had previously been associated with improved acne.
Isotretinoin also reduced the total number of Propionibacterium bacteria, even when the treatment increased the diversity of individual types of this bacterium.
38% of isotretinoin-treated patients, who did not show this beneficial pattern in the Propionibacterium communities, are similar to the proportion of patients treated with isotretinoin in other studies that eventually required additional cycles of therapy.
The findings suggest that isotretinoin creates a "bottleneck" that selects beneficial communities of Propionibacteria and other bacteria that look healthy, thereby creating a microbial community of skin that reduces the chances of acne returning even when normal oil production returns to the skin after treatment stops.
"We see this happening here. After treatment, microbial communities shift to a mix of populations that appear to be healthier, and that change persists months after treatment, "said Makedonka Miterva, a senior author of the study and assistant director of the McDonnell Institute of Genome at the University of Washington. of medicine.
The researchers said it is important to understand how isotretinoin works in an effort to create new therapies that are more effective or have fewer side effects.
Because isotretinoin is known to cause birth defects, it should not be prescribed for women who are pregnant or are trying to become pregnant.
Women of reproductive age who take isotretinoin are prescribed birth control for the same reason.
The study was published Dec. 21 in the Journal of Investigative Dermatology.