A human-based study also considered the effect of non-antibiotic medications on the intestinal microbiome [Maier, L.; Pruteanu, M.; Kuhn, M.; Zeller, G.; et al. Extensive impact of non-antibiotic drugs on human gut bacteria. Nature Mar 29 2018, vol. 555; pp. 623-628]. While this study focused on human intestinal bacteria, it may be relevant because of its potential effects on animal species.

The research was performed at the German-based European Molecular Biology Laboratory. Evaluation of 1,100 marketed drugs and their effects on 40 representative intestinal bacteria demonstrated that 24% (more than 200 species) “inhibited growth of at least one bacterial strain in vitro.” Some medications, such as non-steroidal anti-inflammatory drugs, hormones, and proton pump inhibitors, exerted antibiotic-like effects, which has the potential to promote antibiotic resistance.