SSRI Antidepressants May Be More Effective With Probiotic Supplement, Study Shows

We’ve long known the connection between the gut and the brain with depression, so much so that the phrase, “the gut is the second brain,” has become commonplace in American culture. With so many people having clinical depression – about 5% of U.S. adults according to the CDC, – figuring out ways to improve SSRI medication outcomes is imperative.

Hashemi-Mohammadabad et al. (2024) recently published their findings from a double-blind trial between the use of probiotics with antidepressant SSRI medications and simply the medication on female depression and sexual function. They found that the women who took the probiotic supplement had significant improvements after two months compared to the antidepressant-alone group regarding depression rating and sexual function.

There were many different types of SSRI medications used (fluoxetine, sertraline, fluvoxamine, citalopram, escitalopram, paroxetine). The probiotic prescribed was LactoFem^® . Participants took three self-report questionnaires prior to and post treatment: the Female Sexual Function Index, the Larson questionnaire (sexual satisfaction), and the Hamilton Depression Rating Scale.

The researchers found that participants who took the probiotic had significantly improved self-reports compared to the control group on all questions in the Female Sexual Function Index. These participants also had significantly better improvements on the depression scale total and the sexual satisfaction scale total two months after treatment.

This study shows the promise of mutual prescription regarding probiotic supplements and SSRIs for depression. However, it is important to note that this was not a placebo-controlled study. It is very possible that the noted effects of the probiotic arose from expectation effects by the participants. A recent meta-analysis found mixed beneficial impacts of probiotic supplements regarding depression. That same analysis noted that all studies that tested the gut microbiota as well as depression found no significant differences in the gut microbiota levels pre- and post- supplementation. Another study found that LactoFem^® specifically did not change the vaginal microflora, which is an important indicator of female health and sexual functioning.

So, should you take a probiotic to help your depression? Maybe.

Will eating differently make you feel better? More likely.

A recent study done with mice found that dietary change – specifically incorporating a transitory diet prior to a full diet change – improved the Lactobacillus (one of the key gut microbiota associated with depression) levels the most. There was no difference in levels with a probiotic supplement or without one.