Animal experiment:

Mice[1]Indicated mice receive 200 mM Desaminotyrosine dissolved in Kool-Aid in the drinking water (control animals receive Kool-Aid alone). Indicated mice receive poly(IC) injections of 1 mg/kg for vancomycin, neomycin, ampicillin, and metronidazole (VNAM) treated mice or 5 mg/kg for all other mice intraperitoneally daily for 4 days, and then mice are scarified on day five at which time serum is collected[1].

Desaminotyrosine is a microbially associated metabolite protecting from influenza through augmentation of type I interferon signaling.

Wild-type mice produce nanomoles of Desaminotyrosine per gram of feces and have picomolar quantities of Desaminotyrosine in the serum. Desaminotyrosine (200 mM) treatment before influenza infection, protects from influenza by type I interferon (IFN) signaling, with no effect on weight loss or survival in mice with or without vancomycin, neomycin, ampicillin, and metronidazole (VNAM). Desaminotyrosine enhances type I IFN in macrophages via type I IFN amplification in mice[1].

[1]. Steed AL, et al. The microbial metabolite desaminotyrosine protects from influenza through type I interferon. Science. 2017 Aug 4;357(6350):498-502.