Associations between acne and gastrointestinal comorbidities suggest that microbial dysbiosis and intestinal permeability may promote inflammatory acne, a condition often managed with oral antibiotics.

We performed a case-control study to investigate the skin and gut microbiota in 8 acne patients before and after receiving oral minocycline compared to controls matched by age ±5 years, sex, and race.

DNA was extracted from stool samples and facial skin swabs. Sequencing of the V3V4 region of the bacterial 16S rRNA gene was performed using Illumina MiSeq and analyzed using QIIME/MetaStats 2.0 software.

Acne patients included 7 female and 1 male, ages 20~32. Shannon diversity was not significantly different between the skin (p=0.153) or gut (p<0.999) microbiota of acne patients before and after antibiotics. The gut microbiota in pre-antibiotic acne patients compared to acne-free controls was depleted in probiotics Lactobacillus iners (p=0.001), Lactobacillus zeae (p=0.001), and Bifidobacterium animalis (p=0.026). After antibiotics, the gut microbiota of acne patients was depleted in Lactobacillus salivarius (p=0.001), Bifidobacterium adolescentis (p=0.002), Bifidobacterium pseudolongum (p=0.010), and Bifidobacterium breve (p=0.042), while the skin microbiota was enriched in probiotics Bifidobacterium longum (p=0.028) and Leuconostoc mesenteroides (p=0.029) and depleted in Staphylococcus epidermidis (p=0.009) and Prevotella nigrescens (p=0.028). At the phylum level, significant enrichment of Bacteroidetes in stool of acne patients following antibiotic treatment (p=0.033) led to a decreased Firmicutes to Bacteroidetes ratio.

Minocycline produces significant derangements in the microbiota of the skin and gut, including many probiotic species, highlighting the potential for more targeted antimicrobial treatments for acne.