The well known interaction between antibiotics and gut microbiota have been reported in recent years, for example, some studies have shown that the antibiotic use (oral or intravenous) reduces and influences significantly the gut microbiota (Bartosch et al. 2004; Palmer et al. 2007; Iizumi et al. 2017). The change in gut microbiota composition and function depends on the type of antibiotic, the dose concentration and the period of time of the treatment. Antibiotics treatment not only affects microbiota imbalance but can also cause the gene expression, protein activity and metabolism of the gut microbiota that can lead to chronic human disorders such as asthma and irritable bowel syndrome (Figure 1; Francino 2016).
In 2015, a study found that the treatment of metformin in type 2 diabetes patients affects the composition of gut microbiota, in which reduction of butyrate-producing bacteria and an increase of Escherichia species was observed (Forslund et al. 2015). Some of the adverse effects of metformin treatment in 30% of diabetes patients are diarrhoea, nauseas and bloating and this might be related to the change in gut microbiota but the mechanism is not fully understood. This evidence suggests that not only antibiotic drugs can cause a microbiota imbalance in the gut but other drugs can cause this variation as well. For example, the consumption of proton pump inhibitors (PPIs) drugs have been found to be associated with changes in gut microbiota, causing a higher risk of enteric infections, more specifically with a 65% higher incidence of Clostridium difficile infections (Imhann et al. 2016; Jackson et al. 2016). In addition, the use of nonsteroidal anti-inflammatory drugs (NSAIDs) have been associated with changes in the gut microbiota and this modification can be related to the bleeding, inflammation and ulceration in the stomach and intestine caused by NSAIDS treatment. A recent study investigated the relative abundance of operational taxonomic units (OTUs) by types of different classes of medication. They found for example that the OTU of Enterobacteriaceae family was 32% higher with the medication of antidepressant citalopram (Fig. 2), as well as 20% higher with Naproxen treatment compared with patients not taking any mediation (0.7%), Figure 2 (Rogers & Aronoff 2016).
(Rogers & Aronoff 2016).
A new study argues that most of the drugs commercially available will influence the gut microbiota; the screen of 1,197 compounds monitoring the growth of 40 representative bacteria in the human gut showed that 24% of the drugs tested inhibited the bacteria growth of at least one species in vitro (Maier et al. 2018). All these results are suggesting that drugs are affecting the normal microbiota in the gut, however these changes might not be affecting human health. In addition, there is increasing interest in the interactions of drug-microbiome, in which bacteria can interact and modify the efficacy of drugs and their therapeutic effect (Willyard 2018). Future research needs to focus on detecting the drug-microbiota interactions for human disease, health and drug efficacy. We should not be surprised that these type of studies are included as a clinical trial before a drug is commercially available.
Blog written by Thalia Carreno Velazquez
Bartosch, S. et al., 2004. Characterization of bacterial communities in feces from healthy elderly volunteers and hospitalized elderly patients by using real-time PCR and effects of antibiotic treatment on the fecal microbiota. Applied and environmental microbiology, 70(6), pp.3575–81.
Forslund, K. et al., 2015. Disentangling type 2 diabetes and metformin treatment signatures in the human gut microbiota. Nature, 528(7581), pp.262–266.
Francino, M.P., 2016. Antibiotics and the human gut microbiome: Dysbioses and accumulation of resistances. Frontiers in Microbiology, 6(JAN), pp.1–11.
Iizumi, T. et al., 2017. Gut Microbiome and Antibiotics. Archives of Medical Research, 48(8), pp.727–734.
Imhann, F. et al., 2016. Proton pump inhibitors affect the gut microbiome. Gut, 65(5), pp.740–748.
Jackson, M.A. et al., 2016. Proton pump inhibitors alter the composition of the gut microbiota. Gut, 65(5), pp.749–756.
Maier, L. et al., 2018. Extensive impact of non-antibiotic drugs on human gut bacteria. Nature, 555(7698), pp.623–628.
Palmer, C. et al., 2007. Development of the Human Infant Intestinal Microbiota Y. Ruan, ed. PLoS Biology, 5(7), p.e177.
Rogers, M.A.M. & Aronoff, D.M., 2016. The influence of non-steroidal anti-inflammatory drugs on the gut microbiome. Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases, 22(2), p.178.e1-178.e9.
Willyard, C., 2018. When drugs unintentionally affect gut bugs. Nature Publishing Group, 17(6), pp.383–384.