Much of the publicity on the benefits of probiotics has centered around how they improve gut health. There is little doubt that probiotics can improve the balance of beneficial bacteria in the gut, but there is more to probiotics than just improving digestion. Probiotics can positively impact both physical and mental health in surprising ways.
Research shows that certain strains of probiotics are neurologically active. They play roles in communication between the brain and the enteric nervous system in the gut. By consuming an adequate amount of particular neuroactive probiotics, you can potentially reduce symptoms associated with depression, anxiety, and unwanted effects of autism spectrum disorder (ASD).
The Gut-Brain Axis
The gut and the brain have a special relationship. They are connected via a system known as the "gut-brain axis," which is a direct line of communication between these two systems via the body's longest nerve: the vagus nerve. Not only do the brain and gut communicate, but the gut nourishes the brain. The gut also produces critical hormones called neurotransmitters that affect both mood and mental health. In order to fulfill this important responsibility, the gut needs to be functioning properly.
The human gut is filled with billions of microorganisms that make up the microbiome. The microbiome contains a combination of microorganisms like bacteria and yeasts, many of which are beneficial to human health. Keeping the right balance of good and bad microbes is important to wellness. Research over the past several years has found that taking probiotics has surprising effects on other aspects of health. One of the most compelling findings is the way that certain probiotics positively affect neurotransmitter production and mental health.
Take L. plantarum PS128 as an example. A 2021 animal study noted that mice who took PS128, the probiotic strain in Neuralli, synthesized and stored more serotonin in their intestinal cells. Serotonin is a neurotransmitter associated with positive mood and focus, and about 90% of it is produced by endocrine cells in the intestines. PS128 therefore positively affects neurotransmitter production, and preclinical and clinical studies suggest it supports mental health* both in mice and in humans.
Gut Health & Mental Health: The Science
The idea that your gut and your mental health are connected may not seem to make sense at first glance. But the gut plays a major role in producing serotonin, a neurotransmitter that affects mood. GABA and tyrosine (which forms dopamine) are also produced in the gut. If the gut can’t make a sufficient supply of neurotransmitters, there can be noticeable mood impacts.
The same microbiome imbalances that affect neurotransmitter production can affect digestion as well. In fact, for many years doctors have noted an overlap between mental health conditions and digestive conditions. It's not unusual to hear individuals mention stomach discomfort alongside feelings of anxiety or upset. People talk about feeling sick about bad news, or worrying that they might throw up from nerves in a tense situation. Doctors have also noted a correlation between people with clinical mental health symptoms and people with clinical digestive health symptoms.
There is certainly a connection between feelings generated from the brain and feelings generated from the gut. It isn't entirely clear if depression and anxiety disorders cause gastrointestinal (GI) tract problems, or if GI tract issues contribute to mood disorders but the connection is undeniable.
Researchers are beginning to explore whether treating the gut can change mental health. One study from 2016 showed that changing the gut microbiome of mice can produce depressive behavior. Researchers took the gut flora from people with major depression disorder and transferred them to mice. The mice with the "depression microbiota" started showing more anxiety and depression behaviors. The study authors concluded that the balance of the gut microbiome could affect mental health.
Other studies address the problem in reverse: Instead of trying to induce depression by changing gut bacteria, researchers try to improve mental health conditions by introducing better balance to the gut flora via probiotics. A recent review of the scientific literature points out benefits of probiotics for people with depression, anxiety, and autism.
How Can Probiotics Help Autistic People?
Autistic individuals often experience symptoms of anxiety, stress, and emotional overwhelm that make day-to-day life challenging. People may find that managing their emotions takes an undue amount of energy, leaving them exhausted and stressed. Constant mental unease may cause an increase in certain behaviors like stimming, meltdowns, or withdrawing from other people.
Some autistic people also have concurrent issues with digestion and gut health, experiencing episodes of uncomfortable constipation or diarrhea as well as stomach cramps and pain. Chronic discomfort and worry about needing to use the bathroom can further exacerbate anxiety and stress.
The effects of probiotics have the capacity to improve both mental and physical discomfort associated with gut problems. Relieving digestive discomfort alone can make a difference in mood and stress levels. Everyone feels better when they're not contending with an upset stomach! Adding probiotics to the diet can also reduce episodes of constipation or diarrhea.
There is also research emerging that particular strains of probiotics can ease some of the challenging emotional effects of autism. In one study from 2019, researchers gave boys with autism twice-daily doses of PS128. The boys' parents noted reductions in anxiety, repetitive behaviors, and oppositional behaviors.
Another study investigating the effects of PS128 showed that autistic children and adolescents taking the probiotic demonstrated increased attention, increased communication, and more independence compared to other probiotic strains.
Read more about probiotics for autistic people here.
Additional Probiotic Benefits
Beyond the direct effects on mental health, probiotics have the capacity to improve general well-being. Researchers have found benefits of probiotics including:
- Improved sleep: Research shows that certain strains of probiotics can increase tryptophan. Tryptophan is best known for causing the feeling of sleepy fullness after a Thanksgiving dinner due to its high levels in turkey. It's also a precursor to the neurotransmitter serotonin. Serotonin is important to healthy sleep. By increasing tryptophan, and therefore serotonin, your sleep quality may improve. Being better rested can improve mood.
- Increased immune function: Experts have found that probiotics can play a role in preventing illness and infections. For one thing, probiotics may be able to increase antibody production. This improves the immune response to illness. Research shows that taking Lactobacillus probiotics reduces the occurrence and intensity of respiratory infections in children. Being sick can exacerbate feelings of depression. If you're able to avoid or quickly recover from illnesses, it can help avoid low moods.
- Improved gut health: Many people with ASD or mood disorders also suffer from digestive problems. Their symptoms can cause persistent discomfort as well as anxiety about when symptoms might flare up. Many studies confirm that probiotics improve general gut health and some may also relieve IBS symptoms. The absence of stomach discomfort is almost guaranteed to make people feel better overall.
Does the Type of Probiotic Matter?
There are innumerable microorganisms living in and on the human body, and scientists are only beginning to understand them all. They do understand that each bacterium has its own role in the microbiome. Research has started revealing which specific bacteria have beneficial effects, including:
- All strains of the Bifidobacterium genus are able to produce acetate, which reduces inflammation in the gut
- Other strains of Bifidobacterium may play a role in managing immunity and regulating digestion
- Some Lactobacillus species produce lactic acid in the small intestine. This may reduce the number of harmful bacteria in the gut, which can strengthen the gut barrier and improve overall health
- Certain Lactobacillus strains may support healthy lactose digestion and help maintain healthy cholesterol levels
These benefits of Bifidobacterium and Lactobacillus species have made them common ingredients in probiotic products. However, they are not the only types of probiotics that have significant implications for better health.
Certain probiotics, called psychobiotics, are considered neurologically active. These probiotic strains appear to have an effect on neurotransmitter production, possibly influencing mind, mood and movement. One such strain, L. plantarum PS128, has been shown to positively affect mental health in depressed people. Researchers believe that PS128, the probiotic in Neuralli, may help by modulating levels of dopamine and serotonin.
Are Probiotics Safe?
Probiotics can be taken by people of all ages. As with any supplement, be sure to talk with your doctor first before adding them to your health care routine. If you are currently taking medication for a mental health condition – or any prescription medication, for that matter – a health care professional can alert you to any possible drug interactions or issues to look out for. In one small open-label trial studying the effects of PS128 on mental health, all but one patient with MDD had existing prescriptions, and they continued to safely take their usual medications alongside the probiotic intervention.
When taking probiotics, the effects may not be immediate. Most likely, you will notice changes over time. GI tract discomfort may be reduced, providing a welcome relief from upset stomach and related issues. If you're a parent or caregiver of someone taking probiotics for mental health support, you may also see positive changes such as better sleep, improved mood, greater independence and communication.
Keep in mind that certain medications, such as antibiotics or antifungals, may decrease the effectiveness of probiotics. Additionally, people with certain immune conditions should consult their doctor before taking any probiotics.
Some people notice temporary side effects when they first begin taking probiotics. You may experience bloating, or changes in your bowel movements. This is usually a sign that your body is adjusting to a change in your microbiome. The symptoms should decrease within a couple of weeks. If they do not, it might be a sign that the particular probiotic you're taking doesn't agree with you. In that case, you should discontinue use. Of course, do not discontinue any prescription medicine without first consulting with a health care professional.
If you are uncertain whether you or a family member should add probiotics to your routine, talk to your doctor.
Adding a Probiotic for Mental Health Support
When you are ready to begin taking probiotics to support your mental well-being, it's important to select one that contains strains that will address mental health conditions in particular. The probiotic L. plantarum PS128 has demonstrated results in addressing issues with mind, mood and movement. Other strains may help with additional symptoms such as digestive discomfort, but they may not be effective for mental health issues.
If you want to try probiotic support for mental health, consider Neuralli, the first gut-brain medical probiotic for neurological conditions and mental health. It contains L. plantarum PS128 which is backed by 12 clinical studies and counting, showing health benefits related to dopamine and serotonin. Order your first bottle here.