Probiotics help improve digestive health, immune function, weight loss, and more. They may even help with symptoms of depression.

Did you know that you have more bacteria than cells in your body, and most of it lies in the belly?

Your gut, aka your “second brain,” has its own little nervous system with millions of neurons. That’s why what’s in your gut can impact your brain. It can change your brain chemistry and improve your mood.

There are helpful and harmful bacteria out there. Taking a probiotic is a way to let in some good ones.

Probiotics have many health benefits, including helping to improve mood.

According to the Centers for Disease Control and Prevention (CDC), 1 out of every 6 adults will experience symptoms of depression in their lifetime. It affects people of all ages and ethnicities.

Depression is more than having a bad day or feeling low. If you’re living with depression, these feelings can last for weeks, interfering with your daily life and your relationships.

The common symptoms of depression are:

  • a persistent feeling of sadness or loneliness
  • irritability
  • feelings of hopelessness
  • lack of energy
  • difficulties sleeping (getting too much or not enough sleep)
  • changes in appetite (eating too much or too little)
  • loss of interest in activities you once enjoyed
  • feelings of worthlessness and guilt

Treatment for depression typically includes therapy, medication, or a combination of both. Adding probiotics to your treatment regimen may also be recommended.

The brain and gut work closely together. This connection is called the gut-brain axis (GBA) and links the central nervous system and the brain.

Your gut produces hundreds of neurochemicals, aka neurotransmitters, that the brain uses for mental processes, such as:

  • mood
  • memory
  • learning

Additionally, according to the American Psychological Association (APA), gut bacteria produces about 95% of the serotonin in the body — the neurotransmitter responsible for mood.

So, your gut health is connected to your mood and mental health.

Which probiotics are best for depression?

Probiotics for mental health are also known as psychobiotics, according to a 2020 review. Psychobiotics work by:

  • altering your response to stress
  • reducing your body’s inflammation
  • activating your immune response
  • boosting neurotransmitters such as serotonin

Psychobiotics can help restore your mental health and may be helpful when medications aren’t enough or cause unwanted side effects.

But not every probiotic is best for treating depression. A 2018 study found that the probiotic Lactobacillus plantarum P8 may be helpful for depression. It was shown to relieve stress and anxiety and improve memory and learning.

Bifidobacterium is another probiotic shown to improve mental health. A 2017 animal study found that it may prevent the onset of depression from stress in humans. Additionally, it may help lower the chances of recurrence.

But more research is needed to determine which probiotics would be the best for managing symptoms of depression.

Probiotics are live bacteria and yeast that naturally lives in your body. They aim to improve your gut health by getting rid of harmful bacteria.

Many factors might alter your gut microbes. These include:

You find microbes all over the body — for example, on your skin and inside your nose.

Probiotics contain a variety of microorganisms that help do things such as fight infection or digest food.

Experts aren’t exactly sure how probiotics work, but there are several health benefits, including:

  • Eases digestion: Probiotics reduce harmful bacteria in the gut and help relieve gastrointestinal discomfort.
  • Helps keep you regular: Healthy bowel movements keep your colon empty with less bloating.
  • Boosts your immune system: It improves your overall immunity to help fight infection.
  • Reduces inflammation. Probiotics have anti-inflammatory effects.
  • Helps manage pain: They may affect your pain receptors to lower discomfort.
  • Impacts your state of mind: Your emotions can be influenced by what’s in your gut.

A 2016 review hints that probiotics might lower your chance of depression and improve mood and stress when taken regularly.

Imbalances in the immune system and inflammation may lead to depression, according to a 2021 review. Probiotics in the intestines work to correct this imbalance.

A 2015 article points out that, like many antidepressant medications, probiotics can help reduce inflammation. It also highlighted several animal studies, each pointing to how microbes in the gut may help improve mood.

If you’re considering trying a probiotic, it’s recommended that you reach out to a healthcare or mental health professional before starting any new medication or supplement.

Specific strains of probiotics are better for certain conditions and needs. A doctor can work together with you to determine which probiotics may be helpful for you based on your symptoms, medical history, and any medications you’re taking.

Probiotics and probiotic blends may be available over the counter at your local grocery or pharmacy. You can also add probiotic foods to your diet, such as:

  • yogurt
  • kefir
  • tempeh
  • kombucha
  • miso
  • kimchi
  • sauerkraut

Dietary supplements and beauty products are also sources of probiotics. Each product will have directions on how to take them. A doctor may also recommend dosing.

Probiotics are generally considered safe to take, but they might cause unwanted symptoms when taken.

You may initially experience some digestive pain and diarrhea. But this usually subsides after a few days.

Some research points to possible and more serious concerns with probiotic therapy.


According to research from 2018, probiotic bacteria may trigger specific infections such as:

But these infections are also caused by other factors. For example, you may be more prone to infection if you’re undergoing chemotherapy.

Immune system effects

Some probiotics may affect your immune response. So, you might experience a fever or joint pain.

More research is needed to make any definitive conclusions.

Digestive system effects

Probiotics might cause a buildup of bile acids in your intestines, which may lead to diarrhea and intestinal lesions.

This effect may also increase your chance of gallbladder disease or colorectal cancer. But, again, more research is needed.

While much research exists about probiotics, more is needed to fully understand how they work and affect the body.

They may not be helpful or safe for many health conditions. Additionally, some types of probiotics are more helpful than others. Questions still exist about dosing, too.

In general, the Food and Drug Administration (FDA) deems probiotics overall safe despite their risks.

Probiotics improve your gut health and may even have an effect on your mental health.

Your gut is connected to your brain and produces hundreds of neurochemicals, including serotonin, that are responsible for mood, memory, and concentration.

Probiotics that help specifically target symptoms of anxiety and depression are called psychobiotics.

But taking probiotics alone isn’t a cure for depression but may be taken in conjunction with other treatments for depression such as therapy, medication, and self-care strategies.

Maintaining good gut health isn’t just about taking probiotics. Eating a well-balanced diet, exercising, and avoiding smoking and alcohol can help, too.

Speaking with a healthcare or mental health professional before trying a probiotic is a great way to manage any side effects. Together with a doctor, you can make a well-informed and shared decision about your mental health.

To learn more about depression and its treatment, you can check out Psych Central’s hub depression hub.