Probiotics that treat anxiety and depression will be available within five years, scientists in Cork are predicting.
Ted Dinan, a professor of psychiatry at University College Cork, said probiotics for the brain — psychobiotics — have the potential to reduce mild to moderate depression.
He said scientists defined a psychobiotic as a live organism, and that when ingested in adequate amounts, it produced a health benefit in patients suffering from psychiatric illness.
Prof Dinan said there is around 1kg of bacteria in the adult gut, the same weight as the adult brain, and, without it, the brain does not develop normally.
Together with John Cryan, professor of anatomy and neuroscience at UCC, Prof Dinan led the brain-gut-microbiota axis team in the APC Microbiome Institute, which is based on campus.
“There is increasing evidence from our work at APC that alterations in gut microbes may predispose to mental-health problems,” said Prof Dinan.
“We have identified bacteria called psychobiotics which has a positive mental-health benefit.”
He said he expects other therapies for psychiatric conditions might emerge, including antibiotics targeting ‘bad’ bacteria or even faecal microbiota transplantation, a therapy currently confined to people with intractable clostridium difficile (C diff) infection.
Although many preparations of bacteria are now marketed as probiotics, the vast majority do nothing for us, said Prof Dinan.
While most do not make it past the stomach acid, a few have enormous implications for the future of psychiatric medication.
Prof Dinan, who was awarded the Melvin Ramsey Prize in 1995 for his research on the biology of stress, said the stress-reducing potential of a bacterium had already been tested in humans.
Prof Dinan said they found there was a statistically significant improvement in cognitive function, particularly memory. They also discovered that the probiotic actually modified brain activity.
Prof Cryan said studies are ongoing to try and prove certain bacteria have psychiobiotic effect.
Probiotics would be delivered in either a pill or drink and used mostly to treat mild to moderate depression.
“For people with severe mental illness they would have limited benefits,” he said.
Prof Dinan said some of the best probiotics, particularly for irritable bowel syndrome, were available in pill form because they could trick the stomach and get through it intact.
Prof Cryan said they had found a reduction in the diversity of the microbes in people with depression. “We want to find out if it is causal or not and are now at the stage of testing that through animal model systems.
“What we do know is reductions in diversity may predispose a person to certain changes in brain function. It is a paradigm shift in how we are thinking about treating the brain through the gut.”
Prof Dinan will present research on psychobiotics at the SynBio Future 12016 conference, ‘Future axioms in synthetic biology’, at UCC on Monday. The conference will be hosted by the world’s leading accelerator for synthetic biology and bio-tech start ups, IndieBio.
See today’s Feelgood for more on diet for mind and body
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