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Did you know probiotics may help your mood?

Did you know probiotics may help your mood?

The benefits of probiotics for gut health are something many of us are familiar with, but did you know that research shows they can also affect our moods and brain health? Read on to find out more about the gut-brain axis, probiotics, and their effect on mood and brain health.

Lifestyle insight
Reading time: 3 minutes

What is the gut-brain axis?

The brain and gut are intricately connected by a pathway known as the gut-brain axis. What affects the gut also affects the brain, and when something affects the brain, it also affects the gut.

You may have experienced this connection when you have been through a stressful event. When the body experiences stress the fight-or-flight response is initiated and the brain sends warning signals to the gut. This is why stressful events can often cause digestive problems like stomach cramps, nausea or increasing your need to go the bathroom. Similarly, digestive complaints like irritable bowel syndrome (IBS), or chronic constipation have been known to have a direct effect on mood.1

The gut-brain axis is an important two-way communication system between the central nervous system in the brain, and the enteric nervous system located in the gut.2

The bacteria in the gut, or the gut microbiota, play a key role in the ability of the gut to ‘talk’ to the brain and vice-versa. The brain and gut can also signal each other through chemicals called neurotransmitters, and via the nerves – in particular the vagus nerve.2

How does the gut-brain axis affect your mood?

The gut is often referred to as the ‘second brain’, because it produces many of the same neurotransmitters – or chemical messengers, as the brain does.

Neurotransmitters like serotonin, dopamine, and gamma-aminobutyric acid (or GABA for short) are made in both the brain and the gut and play key roles in regulating our moods and emotions.1

It is estimated that as much as 90% of the serotonin in our bodies – also known as the ‘feel good’ neurotransmitter, is made and stored in the cells lining the gastrointestinal system.3

Studies undertaken on animals have found that changing the balance of bacteria in the gut can alter brain chemistry and, in some cases, cause the animal to become more anxious. The brain can also exert a powerful influence on gut bacteria, with studies showing that even mild stress can alter the microbial balance in the digestive system.4

Probiotics, mood and mental health

Research has found that there are some probiotics that may help support mood and cognitive function, and also have positive effects on stress and mild anxiety.1

These probiotics are referred to as ‘psychobiotics’ and are defined as ‘probiotics that have mental health benefits to the host when ingested in a particular quantity’.5

While the exact way that these psychobitoics work is not completely understood experts believe some of the ways they work are through:

  • Producing and expressing neurotransmitters and neurohormones that affect appetite, mood, or sleep habits
  • Reducing inflammation in the body
  • Affecting immune responses5
  • Affecting cognitive function and your response to stress6

Which probiotics can support mood & brain health?

When it comes to probiotics for boosting your mood – not all probiotics are created equal.

In clinical trials, Lactobacillus and Bifidobacterium bacteria have been seen to be the most helpful for mood support.6

Lactobacillus helveticus Roselle-52 and Bifidobacterium longum Roselle-175 have been the subject of several trials and found to support healthy mood balance, relieve symptoms of stress and mild anxiety.7

Another Lactobacillus strain - Lactobacillus plantarum DR7 has been seen to reduce symptoms of stress and mild anxiety as well as showing positive results on brain health and memory in moderately stressed adults.8

It may also be beneficial to speak to your health professional. Probiotics are well tolerated, but it’s generally a good idea to get their advice before trying any new supplement or medication.


Learn more about the gut-brain axis here: What is the gut-brain axis?



  1. Harvard Health. Probiotics may help boost mood and cognitive function. 2019. https://www.health.harvard.edu/mind-and-mood/probiotics-may-help-boost-mood-and-cognitive-function - accessed 2-May-2022
  2. Carabotti M, et al. The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. Annals of Gastroenterology. 2015; 28: 203-209.
  3. Cleveland Clinic. Serotonin. 2022. https://my.clevelandclinic.org/health/articles/22572-serotonin - accessed 3-May-2022.
  4. Carpenter S. That gut feeling. Monitor on Psychology (APA). 2012; 43: 8. https://www.apa.org/monitor/2012/09/gut-feeling - accessed 3-May-2022.
  5. Del Toro-Barbosa M, et al. Psychobiotics: Mechanisms of Action, Evaluation Methods and Effectiveness in Applications with Food Products. Nutrients. 2020; 12: 3896.
  6. Raypole C. Can Probiotics Help with Depression? 2019. https://www.healthline.com/health/probiotics-depression - accessed 2-May-2022
  7. Messaoudi M, et al. Beneficial psychological effects of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in healthy human volunteers. Gut Microbes. 2011; 2: 4, 256-261.
  8. Chong HX, et al. Lactobacillus plantarum DR7 alleviates stress and anxiety in adults: a randomised, double-blind, placebo-controlled study. Benef Microbes. 2019; 10(4): 355-373.

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