Psychobiotics: Probiotics and the Brain

As children head back to school and students head off to university, one question I am often asked is whether there are any natural supplements that people can use to support brain function and mental performance. This is especially true this year, after months of disrupted education, and many hours of lost classroom time. 

Traditional supplements to support cognitive function – such as B vitamins – are always a welcome recommendation. However, people are often surprised to learn that their microbiome – the world of bacteria which lives inside their gut – may also have an impact on brain function and performance. Scientists over the last few years have been studying the impact of probiotics (good bacteria) on our brain and have identified specific ‘brain probiotics’ – also known as ‘psychobiotics’. 

So which are the best probiotics for the brain? 

Your Second Brain 

Everyone is aware that their brain is housed in their head, protected by their skull. But not everyone realises that we all have a second brain housed in our gut! Stretched out in our gut are enough ‘brain’ cells to form the brain of a cat. These cells produce neurotransmitters (brain chemicals) – including: 

  • Serotonin – which is involved with mood and happiness
  • Dopamine – which helps with motivation and determination

The cells of your ‘gut brain’ are in direct communication with the brain, via the Vagus Nerve. What’s more, this communication goes both ways – the gut influences the brain, and the brain responds. The bacteria of your microbiome can influence how well this communication works and play an important role in the production of vital neurotransmitters like serotonin and dopamine. 

The Best Psychobiotic Strains

Scientists have been researching which probiotics have the most beneficial effect on our brain function and mental performance. 

This research suggests that, if we want to use probiotics for brain function, we should look out for the following strains: 

  • L. rhamnosus. L. rhamnosus has been shown to help improve the production of dopamine in some people who take it. Research has also indicated that supplementing with L. rhamnosus will help increase focus and motivation. (1) 
  • L. acidophilus, L. casei and B. bifidum. A research project found that taking these good bacteria together in one supplement could improve memory, learning and concentration. (2)
  • A different study also found that combining L. acidophilus, L. casei and B. bifidum could benefit our mental wellbeing, by helping to reduce anxiety. (3)

Therefore, if you are looking to use probiotics for mental performance, then the best probiotics to look out for would be a combination of L. acidophilus, L, casei, L. rhamnosus and B. bifidum. 

Taking Psychobiotics

As we become more aware of the many diverse roles of the microbiome in health and wellbeing, many people are choosing probiotics to help them work towards specific goals – such as supporting brain function. When using probiotics in this way, it can be beneficial to choose a specifically designed, targeted supplement to make sure you are taking the right strains for your aims. When looking to use probiotics to support a specific area of our health, such as brain function, it may be best to use a supplement, as this will ensure you are taking the right strains. 

Research has suggested that the ideal level of probiotics as a ‘psychobiotic’ is at least 10 billion bacteria cultures per day for a minimum of 4 weeks. (3) 

To support your goals, you can also think about combining probiotics with complementary nutrients. For example, alongside a ‘psychobiotic’ you may also choose nutrients that support mental function and the nervous system, to achieve the optimum result. 

Nutrients to Support Psychobiotics

The best nutrients to take in combination with your probiotics for the brain include: 

  • Vitamin B5. This member of the B vitamin family helps to reduce tiredness and fatigue, supports brain function and is required for the production of important neurotransmitters. As well as supporting the action of the psychobiotics, this B vitamin could also be helpful for ‘brain fog’.
  • Magnesium. Magnesium supports the function of the nervous system. Studies have also shown that people who are low in magnesium are more likely to struggle with anxiety, low mood and poor concentration. 

In conclusion

We have a second brain in our gut, which has a huge influence on the function and wellbeing of our ‘main brain’. Supporting this second brain with probiotics could help to improve mental performance and ease brain fog. There are specific strains that have this action, known as ‘psychobiotics’; these are L. acidophilus, L, casei, L. rhamnosus and B. bifidum. 

Written by Jenny Logan DNMed. (Jenny is a Nutritional Therapist who has worked with clients in health foods stores and private clinics for over 20 years, and is Product Development & Training Manager for Natures Aid).


  1. Sarkar, Amar et al. “Psychobiotics and the Manipulation of Bacteria-Gut-Brain Signals.” Trends in neurosciences vol. 39,11 (2016): 763-781. doi:10.1016/j.tins.2016.09.002
  2. Akbari Elmira et al; Effect of Probiotic Supplementation on Cognitive Function and Metabolic Status; Frontiers in Aging Neuroscience 2016; Vol 8; 256. 
  3. The effects of probiotics on depressive symptoms in humans: a systematic review; Caroline J Wallace; Ann Gen Psychiatry 2017

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