Recolonizing Gut Microbiome for Mental Health

"... So many people with depression called wanting to take part in the study we felt we had an obligation to try."
"The literature that we're on to something has grown. But we're not Goop [wry reference to bizarrely stupid lifestyle brand]. We want to know if there's something here or not."
"We now think mental illness is essentially a brain illness, and it may be that it isn't."
"We really wanted to look at quite ill individuals and say we're going to take out the entire gut microbiome and introduce a new one and see if we can recolonize."
"Can you cause schizophrenia if you gave somebody stool from someone with schizophrenia? We don't know."
"I would love to be able to show this actually works and that's potentially game changing. We're not there yet. But I think we're getting there."
Dr. Valerie Taylor, chief of psychiatry, University of Calgary

Psycom

"Poop pill" therapy is being researched and tested on a number of fronts, and cancer is one of them, where the hope is that changing the gut microbiota may have a desired effect of shrinking tumours. Fecal microbiota transplantation is also being investigated for potential good news on the mental health front. Differentiating between depression and mental health had Dr. Taylor's laboratory researching the possible effectiveness of transferring microbiota through 'poop' from one body to another, specifically as it relates to the potential treatment of bipolar disorder.

Two years ago following that bipolar study -- the first such study to be conducted globally -- the call came to launch a follow-up study to test fecal transplants in people suffering from depression. In the works will be yet another, a third such study meant for people, who aside from suffering from depression, are also afflicted with irritable bowel syndrome. The controversial study of manipulating the gut to impact the mind has the world of psychiatry abuzz.

Researchers have published in the Canadian Journal of Psychiatry their findings that trillions of bacteria alive in the human gut are acknowledged to have a critical impact in gut-brain communication. The goal is to determine the success or lack of reaction in enhancing beneficial gut microbes -- with probiotics, fecal transplants or capsules of donor stool, or by adding sauerkraut or other fermented foods in the diet. Conventional therapies appear to have little impact on intractable depression; the hope is that new therapies based on altering gut microbes will succeed.

There is a recognized link among those suffering from depression and anxiety, according to studies, that gastro-intestinal problems are involved. People with depression appear to be possessed of a different gut flora as compared to people without. Serotonin, dopamine and other brain chemicals known to regulate mood are produced by intestinal bacteria. Direct connections exist through the vagus nerve which connects nerves in the gastrointestinal system to those in the brain.

At one time in the past, a procedure to excise the vagus nerve in the treatment of peptic ulcers resulted in those undergoing a "vagotomy" ending up with higher rates of psychiatric illness following surgery. While these initial studies are underway in the potential for achieving success with psychobiotics or poop transplants, it would be vastly premature to regard the process as fixed, as a replacement for current standard treatments. There must be an assurance that the therapy will result in donor bacteria attaching to the gut of the recipient, to begin with.

"We think mental illness is a brain illness, and it may be that it isn’t."Getty Images

Dr. Taylor feels that gut bacteria influence the immune system. Inflammation caused by stress can lead to conditions such as gut dysbiosis, linked with altered brain function. Some level of evidence exists that certain probiotics -- bifidobacterium and lactobacillus supplements -- can serve to improve mood, while results for anxiety have come out less firm in conclusion. Fermented, probiotic-containing foods appeared, through one small study, to protect against social anxiety disorder in those with higher-than-normal levels of neuroticism.

A near-perfect success rate in curing antibiotic-resistant Clostridium difficule, a hospital-acquired super bug has resulted through fecal transplants, leading Dr. Taylor to believe they produce a superior outcome at recolonizing the gut than probiotics. Animal studies demonstrate that when stool from depressed humans is transplanted into germ-free mice -- mice that have been raised in ultra-sterile environments, free of intestinal bugs -- the rodents then demonstrate depressive-appearing behaviours.

The hope: enhancing good gut microbes to solve intractable depression. Getty Images

"Humans aren't mice and mice aren't humans, but there's clearly a signal", Dr. Taylor explains. The Calgary depression studies are preparing to compare fecal tablets against a placebo whereas the bipolar study still underway in Toronto involves injecting specially-prepared stool from a donor into the colon of a recipient through a colonoscopy procedure. The trial is random, with some participants injected with donor feces, while others are re-infused with their own fecal matter.