Probiotics For Anxiety? The Gut Brain Connection

Mental health is just as important as physical health but too often we don’t treat them with equal measure. Part of the reason is the misconception that any mental disorder is a sign of weakness. This is simply not true. In fact, anxiety is quite normal and even necessary for survival when we’re facing a potentially dangerous situation.

The proverbial “fight or flight” response that fuels us with nervous energy is hardwired into our DNA since the days of our earliest ancestors who had to flee predators and fend for themselves. (1) Today, those same sort of tense and anxious feelings revolve around other challenges we confront—work, money, relationships, loss of a loved one, illness, injuries, etc.

According to the Anxiety and Depression Association of America, anxiety disorders are the most common mental illness in the United States affecting 40 million adults every year. Even though anxiety disorders are highly treatable, only 36.9% of those suffering receive treatment. (2) Improving those statistics requires educating people on how we can improve and maintain our own mental health just as we do our physical health.

To that end, one of the most promising (and surprising) developments of the last decade or so have been the beneficial effects that probiotics can have on mood, brain function, and anxiety symptoms. Sure, it might sound strange that the path to better mental health might actually begin with our gut, but sometimes fact is stranger than fiction.

What Are Probiotics?

Probiotics are the body’s good gut bacteria and yeast that help maintain balance, particularly when it comes to digestion and our immune system. This makes sense considering that 70-80% of immune cells are found in the human gut. (3) What’s more, a recent study published in 2019 further demonstrated how gut microbes are not only associated with intestinal disorders such as irritable bowel syndrome, but also with many other conditions including those affecting the nervous system. (4)

Sources Of Probiotics

Probiotics occur naturally in the body’s digestive system from the foods we eat—mostly dairy products like milk, yogurt, and cheese as well as fermented foods such as kimchi, pickles, sauerkraut, miso soup, tempeh, sourdough bread, kefir, and kombucha tea drinks. Of course, you can also find probiotic supplements in your local health food store or online outlets.

The Gut Brain Connection

Research supports a direct link between the gut microbiome (i.e. gastrointestinal system) and brain function (part of the central nervous system). This is known as the gut-brain axis or gut-brain connection. (5) These systems constantly communicate with each other and thus can affect the function (or dysfunction) of countless moving parts, notably with anxiety and depressive-like behaviors. (6)

Likewise, clinical studies published in 2017 demonstrated that an unhealthy gut microbiome negatively impacts the part of the brain that is responsible for stress and anxiety. (7) The report suggests that the microbiome is necessary for appropriate regulation of certain molecules in the brain that are implicated in anxiety-like behaviors. (7)

Probiotic Treatment Of Anxiety

While there’s plenty of evidence that supports the benefits of probiotics when it comes to gut health and immune function, (3) the jury is still out when it comes to treating anxiety disorders—at least for now. That’s because most studies have been conducted on animals and the only way to know for sure is to do more human studies.

That said, the potential is promising. A 2014 report on gut emotions showed that “probiotics attenuate anxiety and depressive-like behaviors in experimental animal models” (8) and a 2015 study demonstrated “for the first time, that a 4-week multispecies probiotic intervention has a positive effect on cognitive reactivity to naturally occurring changes in sad mood in healthy individuals not currently diagnosed with a depressive disorder.” (9)

Keep in mind that many of the positive effects of probiotics that reduce anxiety appear to be strain-specific. (6) There are billions of different probiotic strains, so just because one type makes your gut healthy doesn’t mean it will reduce anxiety. One study points specifically to Lactobacillus helveticus and Bifidobacterium longum as alleviating anxiety, depression, and stress on human subjects. (10)

On the other side of the argument, some warn that there is no real proof that probiotics can ease anxiety. In 2018, researchers from the University of Kansas published a report that reviewed data from 22 animal studies and 14 human clinical studies that found “Probiotics did not significantly reduce symptoms of anxiety in humans and did not differentially affect clinical and healthy human samples.” (11)

That said, the same scientists acknowledged that in terms of research, it’s all at a very preliminary stage and “further investigation of probiotic treatment for clinically relevant anxiety is warranted, particularly with respect to the probiotic species lactobacillus rhamnosus.” (12) Again, it’s all about finding the right probiotic strain to treat anxiety.

Side Effects Of Probiotics

Probiotics are considered safe to use and most people don’t experience side effects. However, there are some potential side effects including gas, bloating, and diarrhea. Also those with chronic illness or a compromised immune system should avoid taking probiotics. A meta-analysis from 2017 indicated that some adults and children with these conditions suffered bacterial or fungal infections as a result of taking probiotics. (13) Always check with your doctor before starting any new supplement.

Follow Your Gut

Taking care of our mental health should be a priority for each of us. Recognizing that our minds are not separate from our bodies is one way that we can chip away at the stigma of mental illness. Along with better understanding the mind-body connection, science is also discovering a gut-brain connection that might encourage us to follow our gut in more ways than one.

While we definitely aren’t suggesting people toss their anti-anxiety pills out the window and just have a cup of yogurt instead, there is growing evidence that probiotic bacteria offers many health benefits, including a potential method to treat anxiety.

Just remember that not all probiotics are created equal. Whether you’re taking probiotics, natural nootropics, or any other supplements, make sure you only buy them from reputable sources that have been verified.