World-first study highlights the feasibility of using faecal transplants for the treatment of mental disorders

A new Deakin-led study has uncovered how human microbiota transfer therapy could work in the real world as a future treatment for depression.

Lead author of the new paper and PhD Candidate at the Food & Mood Centre, Dr Jess Green says the findings are an important leap forward in an under-researched area.

The publication marks the first published controlled human evidence supporting the feasibility, safety and acceptability of faecal transplants for the treatment of a mental disorder.

The evidence linking mental health with the microbiota that live symbiotically in our gut (“the gut-brain-microbiome axis”) is very compelling. Researchers wanted to explore the question of whether interventions that modify the microbiota might be used to treat mental disorders.

“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. You might think of it as a complete probiotic,” says Dr Green.

Moving Moods

The team adopted the gold standard in medical research, a randomised control trial (RCT), to split participants into two groups – treatment and placebo. Participants with moderate to severe major depressive disorder were randomised to either receive faecal transplants (treatment) via enema or a placebo enema (control).

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

There was strong interest from the public, with the team completing their recruitment in just 2 months, despite allowing for 6 months to reach their modest target of 15. However, in just 8 weeks they received over 160 expressions of interest from people.

“This highlights the huge need for alternative treatments for common mental illnesses such as depression,” says Dr Green.

A future mental health treatment?

Importantly, the study showed the appeal and viability of the treatment for those with moderate to severe depression. All participants who completed the feedback survey reported that the enema delivery was tolerable and that they would have the treatment again.

“It is so exciting to work with new and promising treatments for depression, an area of great need, when there have been few major advances in this field for close to 70 years”

– Dr Jess Green

 The study also found significant improvements in gastrointestinal symptoms and near-significant improvements in quality of life in participants who received active FMT compared to the placebo.

The future of FMT

The success of this study paves the way for further research in this area using the same (or a similar) protocol. However, despite the promising outcomes, more research is urgently needed.

“There are numerous barriers to conducting research like this. It is expensive, the transplants need to meet rigorous regulatory standards, and the project is highly multidisciplinary requiring a broad team of experts to carry out,”

“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.

The team are currently trying to obtain funding from the government for this research in collaboration with Lifeblood and their new national Stool Bank.

This research was supported by Wilson Foundation and Holobiome.

Find out more about the Food & Mood Centre here.

Follow Dr Jess Green on Twitter here and the Food & Mood Centre here.