Sarecycline is a narrow-spectrum tetracycline-class antibiotic indicated for treatment of moderate-to-severe acne vulgaris. In vitro studies demonstrated reduced activity of sarecycline when compared to minocycline against clinically relevant enteric microbiota. In this animal model study, we compared the in vivo effects of sarecycline, doxycycline and minocycline on the gut microbiota of healthy mice. Mice were divided into 4 treatment groups (n=10 per group): (a) Sarecycline 10 mg/kg. (b) Doxycycline 5 mg/kg. (c) Minocycline 5 mg/kg. (d) Control (saline). Beginning on day 1, individual mice received 200 µl of antibiotics or saline by oral gavage, once a day for 7 days. Fecal samples were collected on Days 0, 1, 7, 10 and 13, stored in sterile MPbio 2ml lysis tubes containing ~300 mg of 100 µm diameter glass beads with 1 mL of the InhibitEX lysis buffer. DNA extraction and amplification was performed, followed by library preparation and sequencing. 16s-targeted sequencing output was normalized and converted to relative abundance. Alpha diversity (Shannon Index) was calculated, and core microbiome was assessed. Heatmaps used to visualize core microbiome, values transformed to z-score per species across all samples. Microbial abundance of the core microbiota at baseline vs. Day 13 showed that many species including several Lactobacillus and Prevotella spp. were unchanged following 10 mg/kg sarecycline compared to either minocycline or doxycycline treatments. Shannon diversity indices at all taxonomic levels demonstrated a rapid decrease in diversity for doxycycline (5 mg/kg) and minocycline (5 mg/kg). In contrast: sarecycline treatment showed only a modest effect on diversity, similar to saline treated control animals. Taken together these data indicate that the narrow-spectrum sarecycline may have limited impact on the murine gut microbiome compared to other broad-spectrum tetracyclines such as minocycline and doxycycline.

LB011 - Impact of Tetracycline-class Antibiotics on the Gut Microbiome: A Comparative Animal Model Study

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.