Probiotics are beneficial bacteria most of us associate with improved digestive health. These microbes are found in a variety of foods, and they’re available in supplement form. They work in your “gut,” or gastrointestinal tract, to help balance out the harmful microbes living there.
But evidence now suggests that a certain type of probiotics, known as psychobiotics, may work to help improve your mood, too.
Psychobiotics at a Glance
You don’t necessarily need to have a problem, however, to experience benefits from psychobiotics. If you’re stressed, have issues affecting your mood, or feel anxious, there’s a good chance that psychobiotics will be able to help you as well.2
The Connection Between the Gut and Brain
A growing body of research supports the idea of something known as “the gut-brain axis.” This means that your gut has a major impact on how you think and feel. And the relationship is a two-way street: The way you feel and think also has a direct effect on the overall health of your gut.3
While the connection between the brain and gut affects all of us, it is even more important for anyone dealing with mood and mental health issues to understand how the digestive system affects the way we think and behave.
So, how do the brain and gut communicate with each other? Extensive research has shown that we actually have two nervous systems. One is the central nervous system, made up of the brain and the spinal cord. The other is known as the “enteric” nervous system, which is located in the gut.4
But there are other factors that help your brain and gut “talk” to each other. The immune system and metabolic system play a major role, as do your hormonal and stress response systems.5
And the trillions of bacteria that live in your gut are major players. These bacteria are collectively known as your gut microbiota.6
They produce substances that directly affect your gut-brain axis.
They have, for example, been shown to reduce the amount of cortisol, the hormone responsible for stress.
Conversely, they increase the amount of oxytocin, also known as the “love hormone.” The microbes that make up your gut microbiota also produce neurotransmitters. These are chemicals that help to improve your mood and also help you relax.7
Gut bacteria also help protect gut health. They do so by breaking down fiber and producing butyrate, which is an important fatty acid. Butyrate keeps your intestines strong, and helps to keep your blood sugar at safe levels. In addition, it helps ensure that your nervous system and immune system continue to work properly.8
How Psychobiotics Help Your Brain
Psychobiotics are incredibly powerful probiotics that may help with symptoms of anxiety or depression. But how do they work? What makes these particular probiotics so mighty?
Psychobiotics produce neurotransmitters, such as serotonin, acetylcholine, gamma-aminobutyric acid (GABA), and others.9 These neurotransmitters trigger cells in the lining of your gut to release molecules. These molecules then send signals to your brain that control behavior.10
Research also indicates that psychobiotics affect your adrenal glands, which control how your body responds to stress. Continual stress disrupts the timing of cortisol production. Scientists believe this leads to not only cognition problems but mood disorders as well.11
Identifying the Best Strains of Psychobiotic Bacteria
There are thousands of different types of beneficial bacteria. Researchers have now identified specific strains that may help decrease stress, improve mood, and relieve some of the symptoms associated with mental health issues.
In one trial, researchers gave patients suffering from major mental health issues either a placebo or supplements containing three strains: Lactobacillus casei, Bifidobacterium bifidum, and Lactobacillus acidophilus. The patients participated in the study for two months.
Participants who received the psychobiotics showed substantial improvement in the severity of their symptoms. They also showed reduced resistance to insulin and saw a rise in their antioxidant levels.12
Another study tried to determine if psychobiotics could help reduce normal stress, depression, and anxiety in healthy people, as well as improve their coping strategies. A group of healthy volunteers with no chronic mental health issues participated for a month. They took probiotics containing strains of Lactobacillus helveticus and Bifidobacterium longum bacteria.
The study found that both strains of bacteria provided beneficial psychological effects.13
Lactobacillus casei also shows promise as an alternative for people who suffer from stress on a regular basis. Researchers studied the effect of the strain on a group of medical students. They gave them kefir, a type of fermented milk, which contained L. casei.
The results showed that the drink helped decrease problems such as abdominal pain that is typically associated with stress. The students also had lower incidents of cortisol spikes (another sign of stress) and higher levels of serotonin. The latter is a hormone that is linked to relaxation.14
Don’t Forget About Prebiotics
While the main focus when it comes to psychobiotics is on probiotic bacteria, there is also evidence that prebiotics could have beneficial mental effects as well.
Prebiotics serve as a food source for probiotics. They are fibers that the body can’t digest, but probiotic bacteria can. You can find prebiotics in many different types of food and in supplement form.
But it appears that prebiotics could play other roles when it comes to mental health. Researchers conducting a study found that one specific type of prebiotic, B-GOS (Bimuno-galactooligosaccharide), substantially reduced cortisol levels in participants versus others who took a placebo.15
Prebiotics could also help reduce symptoms of anxiety and other mental health issues that are often connected to digestive issues and gut health. One study involved participants with digestive problems who took the prebiotic galactooligosaccharide once a day for a month. At the end of the study, researchers found that the participants reported an improved quality of life, and they also exhibited reduced anxiety levels.16
The Bottom Line
There is solid evidence that certain strains of beneficial bacteria are not only good for your gut, they are also good for your mood and other aspects of your mental health. You can get psychobiotics through food and through supplements you can get online, or at your local pharmacy. However, you should never change your diet or take any sort of supplement without talking to your doctor first.