How Does Gut Health Affect Your Brain?

By Nadia Gonnermann

We often focus on sleep, stress, and study habits when trying to learn more effectively - and for good reason. These factors are known to shape how our brain performs. But what if part of that link lies in the gut?

It’s easy to assume that learning begins and ends in the brain, but scientists are discovering the importance of gut health and how it supports the way we think and learn.

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Your gut is home to trillions of bacteria and other microbes, known as the gut microbiota. These organisms don’t just help us digest food. They send chemical signals that can influence mood, attention, and even brain development.

Scientists studying the gut-brain link have found connections between gut bacteria and cognitive function. In this article, we’ll explore what the gut-brain connection is, what new research shows, and how improving gut health might boost learning and focus.

 how gut health affects brain

What is Gut Microbiota and the Gut-Brain Connection?

The gut microbiota contains a whole community of bacteria, fungi, viruses, and other microbes. Although this sounds quite intimidating, most of them are actually helpful. They break down your food, make vitamins, support the immune system, and defend against harmful bacteria and viruses. Think of them as the caretakers of your digestive system.

But their influence doesn’t stop in the stomach. Have you ever felt “butterflies” before a big exam, or an uneasy twist in your stomach when you’re stressed? That’s the gut and brain communicating with each other. Gut bacteria send messages to the brain through nerves, hormones, and chemical signals, and the brain sends messages back. This is a two-way system that scientists call the gut-brain connection.

When your gut microbiota is balanced, this communication runs smoothly. When it’s disrupted by stress, lack of sleep, or illness, it can affect both your gut and your brain. Scientists are still piecing together how this works, but it’s clear that your gut and brain are always in conversation.

How Do Gut Bacteria Affect Brain Function?

Research shows that gut health does more than aid digestion - it helps shape how the brain develops and learns. In one study of over 380 children, scientists compared the mix of bacteria in each child’s gut with brain scans and results from memory and reasoning tests. They found clear links between gut bacteria and how well the children performed in the tests.

Children who had more of certain “helpful” bacteria tended to do better on thinking and memory tasks. These bacteria can support the brain in many ways, such as making short-chain fatty acids (SCFAs) when they break down fibre from our diet.

SCFAs are small molecules that send signals through the blood and along nerves that connect the two systems. In the brain, they help strengthen its protective barrier, calm inflammation, and strengthen the connections between nerve cells that are important for learning and memory. They can even influence the brain chemicals that affect concentration and mood - two things that make a huge difference when you’re trying to learn new things.

Similar patterns have been seen in adults. People with more SCFA-producing bacteria often show better performance on memory or attention tasks.

These findings don’t mean gut bacteria control intelligence, but along with other studies, they do suggest that a healthy gut supports brain growth and function. Your brain and gut go through major changes during childhood and teenage years, making this a crucial time to build habits that benefit both.

How To Improve Gut Health

So, what should you take away from this? Here are three science-backed ways to support your gut and your mind:

1.  Eat more fibre.

Our daily diet strongly shapes what microbes thrive in our gut. Diets high in sugar and processed foods feed the less helpful bacteria, upsetting the balance. On the flip side, fibre feeds your beneficial gut bacteria.

As they digest it, they produce molecules like the SCFAs mentioned earlier that support both gut and brain health. Adding whole grains, vegetables, and legumes to your diet is a great place to start.

Source: Pexels, by Vanessa Loring

2.  Boost your gut with probiotics.

Probiotics add more “good bacteria” to your gut. These are found naturally in yoghurt, kefir, and fermented foods. Studies show that probiotics can improve mood, focus, and general well-being by helping to keep your gut microbiota balanced.

3.  Prioritise sleep.

Poor sleep can disrupt gut bacteria and the hormones that regulate digestion, appetite, and focus. It can also reduce the beneficial bacteria and allow the harmful ones to grow. Over time, this imbalance can affect learning and mood. A consistent bedtime benefits both your brain and gut.

Your gut and brain are in constant conversation. Supporting your gut health through good nutrition, sleep, and healthy habits may help you think, feel, and learn better. A healthy brain begins with a healthy gut, so start building those habits now.

References

(Key articles)

Bonham, K.S., Fahur Bottino, G., McCann, S.H., Beauchemin, J., Weisse, E., Barry, F., Cano Lorente, R., RESONANCE Consortium, Huttenhower, C., Bruchhage, M. and D’Sa, V., 2023. Gut-resident microorganisms and their genes are associated with cognition and neuroanatomy in children. Science advances, 9(51), p.eadi0497.

Meyer, K., Lulla, A., Debroy, K., Shikany, J.M., Yaffe, K., Meirelles, O. and Launer, L.J., 2022. Association of the gut microbiota with cognitive function in midlife. JAMA network open, 5(2), pp.e2143941-e2143941.

(Supporting articles)

Kim, C.S., Cha, J., Sim, M., Jung, S., Chun, W.Y., Baik, H.W. and Shin, D.M., 2021. Probiotic supplementation improves cognitive function and mood with changes in gut microbiota in community-dwelling older adults: a randomized, double-blind, placebo-controlled, multicenter trial. The Journals of Gerontology: Series A, 76(1), pp.32-40.

Kumar, A., Sivamaruthi, B.S., Dey, S., Kumar, Y., Malviya, R., Prajapati, B.G. and Chaiyasut, C., 2024. Probiotics as modulators of gut-brain axis for cognitive development. Frontiers in Pharmacology, 15, p.1348297.

Paton, S.E., Solano, J.L., Coulombe-Rozon, F., Lebel, M. and Menard, C., 2023. Barrier–environment interactions along the gut–brain axis and their influence on cognition and behaviour throughout the lifespan. Journal of Psychiatry and Neuroscience, 48(3), pp.E190-E208.

Scott, K.P., Duncan, S.H. and Flint, H.J., 2008. Dietary fibre and the gut microbiota. Nutrition bulletin, 33(3), pp.201-211.