Hamilton researchers are working on a gut feeling that may be not just a cure for mental health issues like post-traumatic stress disorder (PTSD), but a possible preventative treatment as well.

And the United States Navy is funding their research, to the tune of $1.5 million.

Doctors John Bienenstock and Paul Forsythe of the McMaster University brain-body institute are looking into bacteria in the stomach and their effects on the brain and a person’s mood.

'You can’t expect that your Activia (yogurt) is going to solve your mental depression… It hasn’t got to that stage.'- Dr. John Bienenstock

In their preliminary studies on mice, they’ve shown that what bacteria are in a mouse’s gut can have a major impact on a mouse’s mood or demeanor. They’ve also shown they can control the mood in anxious mice, calming stressed mice with a month of eating bacteria found in the stomach of calm mice.

While the idea sounds futuristic, the research, Bienenstock said, is still in the present.

“The (US) Navy is interested in sleep deprivation and circadian rhythm changes which are known to be highly stressful and may be one of the promoting features of PTSD,” said Forsythe from his office inside St. Joseph’s Healthcare.

Getting ahead of the science

“It’s suddenly become very popular to think that you can go and change your whole behaviour by changing your diet and changing the bugs,” added Bienenstock, describing probiotics. “It’s not as simple as that. The lay view of this is slightly ahead of the science before we can go diving into the clinical side.”

“You can’t just go to the health foods store and pick it up,” Bienenstock said. “You can’t expect that your Activia (yogurt) is going to solve your mental depression… It hasn’t got to that stage.”

While they’re cautious of what they know right now, Bienenstock and Forsythe know that the potential of their stomach science could lead to daily doses of the right bacteria.

Bacteria and pathways

Bienenstock said their preliminary work has shown that changes to what bacteria are in the gut can have an effect on the brain. He also said that Forsythe showed that pathway from the nerves in the stomach to signals in the brain can be cut by snipping the vagus nerve – which can act as an information highway to the brain from inside of a body.

They’re looking at identifying certain bacteria and pathways, and how they can be used to curb stress or even prevent it.

Specifically, they’ll be using calm mice bacteria put into a mouse that has been subjected to a “social defeat” stressor, a common model to stress mice by introducing them to a larger, more aggressive mouse.

The smaller mouse has long-term effects of stress of the larger mouse.

“(The) long term effects which are, if you dare make the comparison, similar the long term effects of PTSD, and that’s the whole idea,” Bienenstock said.