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Common Drugs Affect Composition, Function of the Gut Microbiome

November 01, 2019

By Megan Brooks

NEW YORK (Reuters Health) - Proton-pump inhibitors, metformin and several other commonly used drugs markedly alter the taxonomic structure and metabolic function as well as antibiotic-resistance genes in the gut microbiome, according to a study from the Netherlands.

The changes observed could increase the risk of intestinal infections, obesity and other disorders, the authors note in an abstract presented October 23 at United European Gastroenterology (UEG) Week 2019 in Barcelona.

"It is a bit early to draw conclusions in terms of clinical implications or health effects in the short and long term," lead author Arnau Vich Vila from University Medical Center Groningen cautioned in an email to Reuters Health.

"The immediate implication of our study is to create awareness on the potential effects of medication on the gut microbiota, pointing out certain mechanisms that need further investigation. We also want to highlight that the use of medications such as antacids (proton-pump inhibitors) should be only used when a health professional indicates so," Vich Vila told Reuters Health.

The researchers studied relations between 41 commonly used drug categories and gut microbial changes in the general population and in patients with inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). They performed metagenomics sequencing on 1,883 fresh frozen fecal samples.

Of the 41 drug categories, 18 were associated with changes in gut-microbiota composition and/or function, with proton-pump inhibitors, metformin, antibiotics and laxatives having the greatest impact, they report.

After correcting for polypharmacy, seven drug categories remained significantly associated with changes in 46 intestinal taxa and pathways.

For example, the gut microbiota of proton-pump inhibitors users showed increased abundance of upper-gastrointestinal-tract bacteria and increased fatty acid production, while metformin users had higher levels of Escherichia coli.

In addition, the use of selective serotonin-reuptake inhibitor (SSRI) antidepressants in patients with IBS was associated with an abundance of the potentially harmful bacteria species Eubacterium ramulus.

The use of oral steroids was associated with high levels of methanogenic bacteria which has been associated with obesity and an increase in BMI.

An increase in antibiotic-resistance mechanisms related to eight different medication categories was also observed.

"We are currently conducting follow-ups studies to see any potential links between medication exposure, gut microbiota and the development of adverse events," Vich Vila told Reuters Health. "So far, epidemiological and clinical studies have shown that the prolonged use of certain medications can have side effects. In the future, we will like to determine if these side effects are mediated via the gut microbiota and if so, explore if we can design strategies to prevent this from happening."

The study had no specific funding and the authors have declared no conflicts of interest.


UEG Week 2019.

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