Adults Ages 50+

Microbes and Your Memory: The Gut-Brain Connection

Microbes and Your Memory: The Gut-Brain Connection


the gut brain connection

Have you ever sauntered with purpose into a room only to forget why you’re there the second you walk through the door? Or maybe you’ve forgotten where you left your keys...for the tenth time that day. If so, you have experienced a normal—albeit inconvenient—memory lapse that affects everyone at some point in their lives.

Memory is a complex process the brain uses to encode, store, retain, and retrieve all of the information we encounter on a daily basis. Some memories flit in and out of our brains within seconds and others last a lifetime. Our memory enables us to learn, remember, interact with the world, and have relationships with others; without it we’d be lost, unable to retain any information about our lives or the world around us.

In fact, memory is so crucial to our well-being and happiness that experts have long recommended tactics for improving it. Physical exercise, brain games, nutritional supplements, special diets, and plenty of sleep can all enhance memory, but new research points to another memory-supporting powerhouse—the friendly gut bugs in your microbiome.

There’s a Brain in Your Gut

Our body is home to 100 trillion microbes (both good and bad) that make up our microbiome, an ecosystem of bacteria that work together with our human cells. Most of these microorganisms reside in our gut, where they produce vitamins, and support our immune system, digestion, and nutrient absorption.

Scientists are discovering that the bacteria in our gut may also have a large influence on our brain. You see, the gut—often called the “second brain”—is home to the enteric nervous system, a vast network of millions of neurons that send and receive messages and respond to emotions (think of a “gut feeling”).

Studies now indicate that probiotics (the good guys) in the gut—which help produce the majority of the body’s serotonin, along with other important brain chemicals—send messages and chemicals to the brain that may affect memory.

In one animal study, researchers discovered that probiotic supplementation fixed (and prevented) memory impairment in mice with bacterial overgrowth1. In another, unbalanced mice microbiomes were associated with altered levels of brain-derived neurotrophic factor (BDNF), a protein important for memory2.

Human studies show promising results as well. Male volunteers who took probiotics for four weeks followed by a placebo for four weeks (subjects didn’t know which they were taking) scored higher on memory tests and reported less stress and anxiety during the probiotic period than during the placebo period3.

It’s clear that the beneficial bacteria in our gut are talking to and influencing our brain, but how?

Cruising Along the Gut-Brain Highway

The vagus nerve is an information superhighway that extends from the brain stem all the way into the abdomen. Researchers are discovering that microbes in our gut can send messages and important brain chemicals via the vagus nerve to our brain, affecting how we think, feel, and remember.

To prove the point, researchers demonstrated that severing the vagus nerve renders the bacteria incapable of communicating with the brain. Mice given Lactobacillus rhamnosus showed increased GABA (a memory-related chemical in the brain) activity in the hippocampus, the part of the brain associated with memory—but only if the nerve was intact. Mice with severed vagus nerves given the same probiotic showed none of the brain changes4.

In addition to helping to influence and produce chemicals in the brain that affect memory, many strains of good microbes act as antioxidants, protecting brain cells from oxidative stress that can lead to memory problems, especially in older adults5.

So, how do you make sure you are maintaining your populations of beneficial bacteria for optimal brain support and memory function?

Remember to Take Your Probiotics

A balanced microbiome, crucial for vibrant health, is made up of about 85% of the good guy microbes and only 15% of the bad guys. Sounds pretty straightforward, right? Unfortunately, this delicate microbial balance is easily thrown off by factors like diet, stress, aging, antibiotics both in food and as medicine, overuse of antibacterial products, and hidden contaminants in food.

That’s why taking a daily multi-strain probiotic formula like GBX-Focus is such a wise first step to keeping the good guys in the majority. GBX-Focus utilizes BIO-tract®, a patented delivery method that delivers the probiotics alive right to the gut, where they can start working with your brain to support your memory, focus, and concentration.

Our memories shape who we have been, who we are, and who we are becoming every second of every day. Consuming plenty of high-quality probiotics can help keep your brain and gut working in tandem so your precious memories remain at the forefront of your life.

Did you find this article helpful and watnt to know even more? Then consider checking - The Microbiome and the Power of Time Released Probiotics.


1. Gareau, M. G., Wine, E., Rodrigues, D. M., Cho, J. H., Whary, M. T., Philpott, D. J., . . . Sherman, P. M. (2010). Bacterial infection causes stress-induced memory dysfunction in mice. Gut, 60(3), 307-317.
2. Bercik, P., Denou, E., Collins, J., Jackson, W., Lu, J., Jury, J., . . . Collins, S. M. (2011). The Intestinal Microbiota Affect Central Levels of Brain-Derived Neurotropic Factor and Behavior in Mice. Gastroenterology, 141(2).
3. Allen, A.P., Hutch, W., Borre, Y., Kennedy, P.J., Temko, A., Boylan, G., Kiely, B., Clarke, G., Cryan, J.F., Dinan, T.G. (2015, October). Towards psychobiotics for stress & cognition: Bifidobacterium Longum blocks stress-induced behavioural and physiology changes and modulates brain activity and neurocognitive performance in healthy human subjects. Paper presented at the meeting of the Society for Neuroscience, Chicago, Il.
4. Bravo, J. A., Forsythe, P., Chew, M. V., Escaravage, E., Savignac, H. M., Dinan, T. G., . . . Cryan, J. F. (2011). Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. Proceedings of the National Academy of Sciences, 108(38), 16050-16055.
5. Amaretti, A., Nunzio, M. D., Pompei, A., Raimondi, S., Rossi, M., & Bordoni, A. (2012). Antioxidant properties of potentially probiotic bacteria: In vitro and in vivo activities. Applied Microbiology and Biotechnology, 97(2), 809-817.


Emily Courtney is a Writer and Editor at Hyperbiotics and mom to two fun and active boys. Emily is passionate about natural wellness and helping others learn about the power of probiotics for vibrant health! For more ideas on how you can benefit from the power of probiotics and live healthier days, be sure to subscribe to our newsletter.