Food & Mood researchers have published a new study investigating how FMT may be used in the real world for people experiencing depression.

Prior research has shown that people experiencing major depressive disorder have a different gut microbiota compared to people without depression. Some studies have also shown that changing the gut microbiota (e.g. probiotics, antibiotics and diet) may influence symptoms of depression and anxiety.

While probiotics are limited to only a small amount of bacterial strains, FMT may potentially offer a broader range of strains meaning it may deliver a wider range of changes within the gut microbiota.

Dr Jessica Green, the lead author of the paper, psychiatrist and PhD Candidate at the Food & Mood Centre, says “Faecal transplants are potentially the best way to modify intestinal microbiota because they carry a complete ecosystem of potentially beneficial microbes, rather than just a handful like probiotics.”

Until now, there have been no published controlled studies looking at FMT in people experiencing depression. Food & Mood researchers wanted to address this gap by exploring whether FMT is safe and tolerable.

The study recruited 15 adults with major depressive disorder and participants were randomly allocated to receive a total of 4 doses of active or placebo FMT over 4 consecutive days.

The treatment was delivered via an enema, a simple, painless procedure whereby a syringe delivers the microbiota transplant into the rectum.

The study attracted strong interest from the community, allowing the team to recruit participants and complete the study in a much shorter time frame than expected. “This highlights the huge need for alternative treatments for common mental illnesses such as depression,” says Dr Green.

By the end of the 8-week study, participants agreed that the enema was tolerable and they would be willing to have the treatment again if required. There were no serious adverse events reported in either group, and no differences in mild to moderate adverse events between groups.

While the study was not intended to measure clinical outcomes such as mental health or gastrointestinal symptoms, it was found that those who received the FMT treatment did have an improvement in gastrointestinal symptoms and quality of life.

The findings of this study support future research to further evaluate the effectiveness of FMT for people experiencing major depressive disorder. “Now that the team know that our protocol is safe and feasible, we are hopeful to run a larger study in the near future that will shed light on whether the poo transplants are efficacious at treating depression,” says Dr Green.

This research was supported by Wilson Foundation and Holobiome.

Sophie is an Associate Research Fellow and Accredited Practising Dietitian at the Food & Mood Centre, currently working on the HARMON-E trial.