A study of more than 1,000 medications spanning all therapeutic classes showed that one in four non-antibiotic drugs inhibited the growth of at least one species of bacteria in the gut microbiome.
Investigators said these findings were unexpected and could help to improve understanding of the efficacy and side effects of existing drugs, and the largely “unnoticed” risk for the promotion of antibiotic resistance by non-antibiotic medications.
“The number of unrelated drugs that hit gut microbes as collateral damage was surprising,” study author Peer Bork, PhD, of the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, said in a press release. “Especially since we show that the actual number is likely to be even higher. This shift in the composition of our gut bacteria contributes to drug side-effects but might also be part of the drugs’ beneficial action.”
Bork and colleagues noted that several commonly used non-antibiotic drugs, including metformin, proton pump inhibitors, NSAIDs and atypical antipsychotics, have recently been linked to gut microbiota alterations, but the full extent of these effects was unclear. Therefore, they systematically profiled the effects of 1,197 commercially available drugs on 40 isolated strains of bacteria commonly represented in the human gut microbiome.
They found that 250 of the 923 non-antibiotic drugs tested inhibited the growth of at least one bacterial strain.
They also found that many non-antibiotic drugs resulted in antibiotic-like side effects, and bacterial resistance to antibiotics and human-targeted drugs appeared to correlate across species, suggesting that non-antibiotic drugs could promote antibiotic resistance.
“This is scary, considering that we take many non-antibiotic drugs in our life, often for long periods,” co-author Nassos Typas, PhD, also of EMBL, said in the press release. “Still, not all drugs will impact gut bacteria and not all resistance will be common. In some cases, resistance to specific non-antibiotics will trigger sensitivity to specific antibiotics, opening paths for designing optimal drug combinations.”
The investigators concluded that their work provides a comprehensive resource for research on drug-microbiome interactions in the future.
“This is just the beginning,” study co-author Kiran Patil, PhD, also of EMBL, said in the press release. “We don’t know yet how most of these drugs target microbes, how these effects manifest in the human host, and what the clinical outcomes are. We need to carefully study these relationships, as this knowledge could dramatically improve our understanding and the efficacy of existing drugs.”
The research team now plans to study these drug-microbiome interactions in complex gut microbial communities to better understand how the gut microbiota of different individuals might respond to the same drug, which could eventually help inform personalized therapeutic approaches, according to the press release. – by Adam Leitenberger
Disclosures: Healio Gastroenterology and Liver Disease was unable to confirm the authors’ relevant financial disclosures at the time of publication.