Adverse drug reactions caused by interactions with the microbiota?

Antibiotics are not the only therapeutic class to disrupt the intestinal microbiota, according to studies shedding new light on the mechanisms of interaction which may be involved in the adverse effects of many drugs.

 

“Antibiotics are not automatic”: this slogan, which aims to limit the consumption of antibiotics because of the bacterial resistance they create, could be applied to many other therapeutic classes in the light of the conclusions of this groundbreaking study published in the journal Nature.

The harmful effects of drugs on the intestinal microbiota

Antibiotics are far from being the only drugs to disrupt the intestinal microbiota. Recently, antidiabetic agents, proton pump inhibitors (treatment for gastric ulcer), nonsteroidal anti-inflammatory drugs and second-generation antipsychotics (treatment of bipolar disorder, schizophrenia, and other conditions), were linked to deteriorations in the composition of the microbiota, which could explain the digestive problems observed in many patients. This discovery led a German team to study the impact of the intake of a total of more than a thousand drugs, which had no a priori antimicrobial action, on strains of bacteria derived from the intestinal microbiota of healthy individuals.

A quarter of the drugs inhibited bacterial growth

In total, one in four of the drugs studied (especially second-generation antipsychotics) inhibited the growth of at least one bacterial strain, according to analyses carried out in vitro. The researchers stress that these results corroborate those obtained in vivo in several clinical studies. Simultaneously, the researchers demonstrated common mechanisms of bacterial resistance to the antibiotics and drugs tested. These elements could combine and contribute to the development of antibiotic resistance. For the authors, these discoveries open up new prospects for the control of antibiotic resistance as well as for the understanding of interactions between drugs and the microbiota which may explain the occurrence of adverse effects.

 

Sources:

Maier et al. Extensive impact of non-antibiotic drugs on human gut bacteria. Nature, vol. 555, p. 623-628