Immunization with beneficial bacteria makes brain more stress resilient, study shows
Immunization with beneficial bacteria can have long-lasting anti-inflammatory effects on the brain, making it more resilient to the physical and behavioral effects of stress, according to new research by University of Colorado Boulder scientists.
The findings, if replicated in clinical trials could ultimately lead to new probiotic-based immunizations to protect against posttraumatic stress disorder (PTSD) and anxiety or new treatments for depression, the authors say.
“We found that in rodents this particular bacterium, Mycobacterium vaccae, actually shifts the environment in the brain toward an anti-inflammatory state,” said lead author Matthew Frank, a senior research associate in the Department of Psychology and Neuroscience. “If you could do that in people, it could have broad implications for a number of neuroinflammatory diseases.”
Anxiety, PTSD and other stress-related mental disorders impact as many as one in four people in their lifetime. Mounting research suggests that stress-induced brain inflammation can boost risk of such disorders, in part by impacting mood-influencing neurotransmitters like norepinephrine or dopamine.
“There is a robust literature that shows if you induce an inflammatory immune response in people, they quickly show signs of depression and anxiety,” said Frank. “Just think about how you feel when you get the flu.”
Research also suggests that trauma, illness or surgery can sensitize certain regions of the brain, setting up a hair-trigger inflammatory response to subsequent stressors which can lead to mood disorders and cognitive decline.
“We found that Mycobacterium vaccae blocked those sensitizing effects of stress too, creating a lasting stress-resilient phenotype in the brain,” Frank said.
A previous CU Boulder study, published in the Proceedings of the National Academy of Sciences (PNAS), found that mice injected with a heat-killed preparation of M. vaccae and then placed with a larger aggressive male for 19 days exhibited less anxiety-like behavior and were less likely to suffer colitis or inflammation in their peripheral tissues.
For the new study, published this week in the journal Brain, Behavior and Immunity, Frank and senior author Christopher Lowry, an associate professor in integrative physiology, set out to find out what exactly M. vaccae does in the brain.
Male rats injected with the bacterium three times, one week apart, had significantly higher levels of the anti-inflammatory protein interleukin-4 in the hippocampus — a brain region responsible for modulating cognitive function, anxiety and fear — eight days after the final injection.
After exposure to a stressor, the immunized animals also showed lower levels of a stress-induced protein, or alarmin, called HMGB1, believed to play a role in sensitizing the brain to inflammation, and higher expression of CD200R1, a receptor key for keeping glial cells (the brain’s immune cells) in an anti-inflammatory state.
The immunized rats, as in the first study, exhibited less anxious behavior after stress.
“If you look at the field of probiotics generally, they have been shown to have strong effects in the domains of cognitive function, anxiety and fear,” said Lowry. “This paper helps make sense of that by suggesting that these beneficial microbes, or signals derived from these microbes, somehow make their way to the hippocampus, inducing an anti-inflammatory state.”
Lowry envisions a day when M. vaccae (which was first isolated from the mud on the shores of Lake Kyoga in Uganda) could be administered to people at high risk of PTSD – such as soldiers preparing to be deployed or emergency room workers – to buffer the effects of stress on the brain and body. It could also possibly be used to prevent sepsis-induced cognitive impairment.
Meanwhile, Lowry is working with researchers at University of Colorado Denver on a study exploring whether veterans with PTSD can benefit from an oral probiotic consisting of a different bacterial strain, Lactobacillus reuteri.
“More research is necessary, but it’s possible that other strains of beneficial bacteria or probiotics may have a similar effect on the brain,” he said.
Learn more: Is a stress shot on the horizon?
The Latest on: Stress
[google_news title=”” keyword=”stress” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Stress
- How Chronic Stress Can Drive Junk Food Consumptionon June 9, 2023 at 1:40 am
According to new research from the Garvan Institute of Medical Research and UNSW Sydney done in mice, stress combined with calorie-dense ‘comfort’ food creates changes in the brain. These changes can ...
- How stress is damaging our workforceon June 8, 2023 at 7:29 pm
That go-go-go mentality at work? It can undermine everything from productivity, to mental and physical health.
- Elliot Page says he got shingles filming Inception due to stress of feeling 'out of place'on June 8, 2023 at 6:25 pm
"In a cast full of cis men, I did not understand the role I found myself in," Page writes in his new memoir Pageboy.
- Veterans hike 100 miles to raise awareness on post-traumatic stress disorderon June 8, 2023 at 3:32 pm
KSHB 41 reporter Abby Dodge walked with veterans from across the nation are taking steps to educate the public about PTSD through a 100-mile hike from Whiteman Air Force Base to Fort Leavenworth.
- Clarence Page: Migrant crisis gives Chicago diversity a stress teston June 8, 2023 at 12:16 pm
America’s latest migrant crisis has come to Chicago and, in an unfortunately Chicago-style way, threatens to reopen old divisions over race, ethnicity and whether new arrivals might be getting helped ...
- This Week In Credit Card News: SEC Cracks Down On Crypto; Buy Now, Pay Later Causing Stress To Consumerson June 8, 2023 at 12:02 pm
U.S. Tightens Crackdown on Crypto with Lawsuits Against Coinbase, Binance ...
- Ten ways to reduce stress on your beef cattle operationon June 8, 2023 at 11:43 am
Quality colostrum and vaccination can get animals off to a great start, but even in a vaccinated animal, stress can compromise their immune system and make them susceptible to respiratory disease. “We ...
- How chronic stress drives the brain to crave comfort foodon June 8, 2023 at 8:00 am
When you're stressed, a high-calorie snack may seem like a comforting go-to. But this combination has an unhealthy downside. According to Sydney scientists, stress combined with calorie-dense comfort ...
- Buy Now, Pay Later Is Boosting Sales. But Signs of Users’ Stress Are Emerging.on June 7, 2023 at 1:30 am
Companies like Overstock.com that have seen a surge in BNPL use aren’t expressing concern about a drop-off in sales, but academics warn that spending patterns suggest consumers are struggling and ...
via Bing News