It is well established that probiotics are beneficial for gut health, but did you know that probiotics can be good for your brain, too?
In this article, we review some of the scientific evidence that is blooming around the connection between gut flora and your brain health.
Wait… How is Gut Bacteria Related to Brain Diseases?
We tend to think about different organ systems as completely separate from one another. We think the digestive system is separate from the cardiovascular system and then that both of these are separate from the nervous system and the endocrine system.
This thinking helps us to feel a sense of causality.
For example, because probiotics “colonize” the gut, it is logical to think that it will affect digestion. It can take a while to wrap our head around the idea that what happens in our gut can also have an effect on our brain.
Of course, if we take a moment, the idea that all of our bodily systems are separate doesn’t actually make much sense.
The endocrine system (the system of hormones) helps to let the brain (part of the nervous system) know when we are feeling hungry or full (digestive system).
And, we know that certain healthy fats, like omega-3 fatty acids, enter the body through the digestive system, but then they benefit heart health.
So, in reality, the idea that probiotics can be good for your brain isn’t that far-fetched. And it’s true!
A recent study in Nature Reviews Neuroscience clearly shows that stomach bacteria actually communicate with the central nervous system through nerves and hormones to influence brain function and behavior.
“Good” bacteria can help make sure everything is working as well as possible. But “bad” gut bacteria can cause communication problems between the brain and the body!
How exactly do “good” bacteria (like those in probiotics) keep everything working as well as possible and prevent brain conditions? Well, that depends on what condition you are talking about.
Depression, anxiety, stress, mood, brain injuries and autism are all affected by “good” bacteria in different ways.
And we’ll get into the details in the next few paragraphs.
Benefits of Probiotics for Your Brain
1. Reducing Symptoms of Depression, Anxiety, and Stress
It is clear that stress can alter healthy gut bacteria.
People who experience chronic illnesses, for example, also tend to have a poor population of “good” gut bacteria, making way for the ones that cause sickness and inflammation.
Animal studies show how animals treated with probiotics (like a strain called L. rhamnosis) experienced positive changes in mood while control groups were more likely to have trouble regulating anxiety, mood, cognition, and even pain.
The mechanisms seem to have to do with something called GABA receptors in your brain.
GABA is the main central nervous system neurotransmitter (communicator for the nervous system). It is one of the main actors in helping making sure your body is working as it should.
Certain types of bacteria in the gut have the potential to alter GABA expression, reducing stress, anxiety, and depression. Bacteria can “communicate” with the brain via the gut-brain axis and the vagus nerve, and certain organisms may prove to be therapeutic in stress-related disorders.
2. Improving Mood
A 2015 study by Steenbergen et. al of Leiden University published an article in in Brain, Behavior and Immunity where they describe a clinical trial to test if a multi-species probiotic containing Bifidobacterium, Lactobacillus and Lactococcus strains had an effect on sad mood.
In the study, 40 participants were assigned either a control or a probiotic supplement to take over 4 weeks.
Researchers found that, compared to participants who received placebo intervention, participants who took the probiotic supplement dealt with sadness better.
These results show that there is great potential for probiotics to be included as part of a larger approach to improving mood, and, hopefully, one day, depression.
3. Preventing Infection After Traumatic Brain Injury Treatments and Surgeries
Taking probiotics has also been shown to be effective in preventing infection after brain surgery.
A systematic review of studies demonstrated that, after traumatic brain injuries, giving people probiotics together with proper nutrition helped reduce brain infections.
One study, in particular, indicated that not only was there a reduction in infection rates after the administration of probiotics, but patients also got to go home from the hospital earlier.
4. Easing the Symptoms of Autism
After several researchers established the relationship between microbiota and brain health, there was a growing interest in whether probiotics could also affect autism.
The connection seemed logical, since there are alterations in gut microbiota of people with autism when compared to the average population.
As of yet, the effects of good bacteria have only been examined in the lab. Initial results, however, are promising and demonstrate that probiotics can be good for the brain of people with autism, too!
For example, a review found that probiotics restored normal gut microbiota, reduced inflammation, restored intestinal epithelial barrier function and behavior symptoms in individuals with autism.
Best Probiotics for Brain Health
Scientists have demonstrated that there are multiple strains of probiotic bacteria that are beneficial for brain health. Most of them are from the Lactobacillis, Bifidobacterium, and Lactococcus families.
Some names to look out for include:
- Lactobacillus mamnosus
- Lactobacillus rhamnosus
- Bifidobacterium bifidum
- Lactobacillus acidophilus
- Lactobacillus brevis
- Bifidobacterium lactis
- Lactobacillus casei
- Lactobacillus salivarius
- Lactococcus lactis
There are dozens more strains of probiotic bacteria that may be beneficial, but more research is needed. It is important that you to talk to your doctor to discuss what strains and dosages may be best for you.
A best-seller on Amazon, Hyperbiotics Pro15 has a patented delivery system to the gut. This ensures that a significant portion of the probiotic population makes it to the right place. It contains five of the strains mentioned above.
This is a good option if you have never taken probiotics before, or if aren’t sure how your digestive system will react. It contains fewer strains of probiotics (six, to be exact), five of which are in the list above.
Take Home Message
There is growing evidence demonstrating that, in addition to promoting a healthy gut, probiotics can also be good for your brain.
Stomach bacteria affects the brain in ways scientists would have never imagined as little as ten years ago.
Thanks to recent research, we know that probiotics can help prevent infection after surgery from traumatic brain injuries, improve mood-related disorders and autism, and improve symptoms of stress-related anxiety and depression.
There is still a lot of research to do on the subject, but the initial findings are very promising.