Over 250 million people live with depression. Unfortunately, the drugs used to treat depression also kill beneficial gut bacteria, and this may cause unpleasant side effects, including nausea, vomiting or diarrhea. People may even stop taking their medication because of these effects.

In a new study published in Scientific Reports, scientists examined the antimicrobial properties of different antidepressant drugs on common gut microbes. Studies continuing from this research could enable us to minimize these unpleasant side effects. Looking at someone's gut bacteria might also allow clinicians to select the ideal antidepressant treatment.

The scientists grew common gut bacteria on petri dishes and added varying doses of different antidepressants to measure how the drugs affected these gut bacteria. They found that different types of antidepressants inhibited the growth of common, and important, gut bacteria, and that desipramine and aripiprazole had the greatest effects on the bacteria.

There is growing recognition that future clinical trials will need to assess the effects of drugs on gut microbes. Tracking these effects in large clinical samples could help us determine why some antidepressants cause digestive problems. Long-term, these discoveries could enable the development of better treatments for depression with fewer side effects.