The gut-muscle connection and its impact on exercise recovery

Post-workout muscle soreness – what is it?

When we exercise, we are often performing new exercises or increasing our intensity in order to improve our fitness and strength. During these exercises, our muscle tissue is damaged as it is unaccustomed to these movements. As our muscles are repaired, they become stronger and more well-adapted to these performances in the future.

While an essential part of getting stronger and fitter, muscle damage triggers inflammation and causes muscle soreness and swelling as well as short-term reductions in strength and range of motion. These physical changes can impair our capacity to exercise in the following days and reduce the intensity at which we can exercise, especially during intense periods of back-to-back training or competition (1).

Many people take non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen to help reduce their muscle inflammation and manage these symptoms. This approach is akin to trying to put out the fire after it’s gotten out of control. What’s more, the overuse of these medications come with unwanted side effects (2).

Inflammation, immune dysfunction & muscle repair

Inflammation is a necessary response which helps to kickstart muscle repair. When muscle tissue is damaged during exercise, the immune system responds by stimulating an inflammatory response. Immune cells arrive at the site of muscle damage and release chemical messengers which act to coordinate muscle cells, blood vessels and connective tissue towards rebuilding and repairing muscle. However, if the immune system stimulates excessive inflammation beyond what is needed to repair muscle tissue, it can exaggerate muscle soreness, delay recovery time and disrupt future exercise capacity for longer than necessary (1).

Underlying immune system dysfunction can contribute to excessive inflammation after exercise. Inflammation is the best tool that the immune system has to help keep us alive. It releases chemical messengers that increase inflammation in order to neutralise perceived threats such as infections and to repair tissue damage, such as that caused by exercise or physical injuries. A well-functioning immune system knows when to turn inflammation on, and when to turn it off. However, a number of different factors in our everyday life can disrupt this important function, such as high levels of psychological stress, poor dietary choices, chronic diseases, or gut microbiome dysbiosis (3).

People who perform regular exercise and are experiencing excessive muscle soreness or prolonged recovery times may benefit from improving their immune system function, especially those with risk factors for immune dysregulation and high levels of inflammation. By working to

improve the function of the immune system, it can help to lower inflammation in the body and prevent exaggeration of the inflammatory response following exercise. Ultimately, these changes may help to accelerate muscle recovery and support a quicker return to peak performance. As opposed to using non-steroidal anti-inflammatory medications which attempt to put out fires that have already started, this approach is akin to a fire prevention strategy.

The gut microbiota & immune-mediated inflammation

Because the vast majority of the body’s immune cells are found just below the lining of the gut, it is considered the gateway to immune regulation and improved inflammation control. On the other side of this lining is the gut microbiota, a community of living microorganisms found inside the gut. We now know that the community of microorganisms living in our gut, known as the gut microbiome, can impact our health and influence the function of many of our vital organs and body systems - including our immune system.

Signals from the gut microbiota play a vital role in the development and maturation of the immune system in our formative years. Many different microorganisms live within the gut, each playing an important role and working together to create the conditions for a healthy gut and body. These microorganisms are just as important for the maintenance of healthy immune cell function for the remainder of our lives as they were during childhood. A healthy gut microbiome enhances immune system function and keeps systemic inflammation under control by ensuring the correct balance of pro-inflammatory and anti-inflammatory chemical messengers are being produced by immune cells (3).

When the diversity and composition of the gut microbiota is disturbed, it can negatively impact our health. This is referred to as ‘gut dysbiosis’ and it can stimulate significant pro-inflammatory responses from the immune system lining the gut. These effects are transferred from immune cells in the gut to immune cells throughout the body as they travel through circulation and communicate with each other. Inflammatory responses in the gut therefore influence inflammation levels all around the body (3). Because of its effects on systemic inflammation, gut dysbiosis is believed to contribute to a number of different chronic diseases, such as obesity, asthma and osteoporosis (4), and other health concerns– such as post-exercise muscle recovery (5).

Because gut microorganisms can alter how immune cells function, researchers have begun to investigate the effect of specific probiotic strains on levels of muscle inflammation after exercise and if they may be able to aid post-exercise recovery (5).

Probiotic supplements for muscle recovery

Probiotics are beneficial bacteria which can help to restore balance to the gut microbiota and provide additional health benefits to the human body while they are present in the digestive tract. However, not all probiotics offer the same benefits and this depends entirely on the specific strains being used.

Just like beneficial microorganisms in the gut, select probiotic strains have the ability to positively interact with immune cells and can have an anti-inflammatory effect over time. As alluded to previously, these effects can be transferred from immune cells living in the gut to the immune cells that are entering muscle tissue. Therefore, probiotic supplements containing specific probiotic strains have the potential to influence muscle recovery by keeping the immune system’s inflammatory response under control (5).

Biome Recovery™ Probiotic

Biome Recovery™ Probiotic is Activated Probiotics’ latest condition-specific probiotic that contains a clinically-trialled combination of two probiotic strains shown to help reduce mild muscle inflammation and improve recovery time following exercise: Streptococcus thermophilus FP4 and Bifidobacterium breve BR03 (6).

A double-blind randomised placebo-controlled trial involving a group of healthy resistance-trained men found that after 21 days of supplementation, the combination of probiotic strains in Biome Recovery Probiotic™ helped to reduce mild muscle inflammation, improve muscle recovery time, and support back-to-back performance. Blood tests taken before and after supplementation for 21 days found that a key marker of inflammation, IL-6, had been reduced by 43% when compared to placebo. The effects of a muscle-damaging exercise, performed on day 21, found that these reductions in inflammation remained lower when compared to placebo for 48 hours after exercise, which was accompanied by improved muscle function (6).

Research such as this is highlighting how the health of the gut and its connection to muscle function may be an overlooked aspect of training and exercise recovery. By targeting the immune system and improving its function, specific probiotic strains may help to reduce the amount of inflammation created by immune cells in muscle tissue and, over time, help to keep it under control. The gut-muscle connection is an exciting area of research that for some, may hold the key for improved exercise recovery and a quicker return to peak performance.



1. Peake, J. M., Neubauer, O., della Gatta, P. A., & Nosaka, K. (2017). Muscle damage and inflammation during recovery from exercise. Journal of Applied Physiology, 122(3), 559–570.

2. Marcum, Z. A., & Hanlon, J. T. (2010). Recognizing the risks of chronic nonsteroidal anti-inflammatory drug use in older adults. Annals of Long-Term Care, 18(9), 24–27.

3. Gizard, F., Fernandez, A., & De Vadder, F. (2020). Interactions between gut microbiota and skeletal muscle. Nutrition and Metabolic Insights, 13, 117863882098049.

4. Anwar, H., Irfan, S., Hussain, G., Naeem Faisal, M., Muzaffar, H., Mustafa, I., Mukhtar, I., Malik, S., & Irfan Ullah, M. (2020). Gut Microbiome: A New Organ System in Body. In Parasitology and Microbiology Research (pp. 1–20). IntechOpen.

5. Giron, M., Thomas, M., Dardevet, D., Chassard, C., & Savary-Auzeloux, I. (2022). Gut microbes and muscle function: can probiotics make our muscles stronger? Journal of Cachexia, Sarcopenia and Muscle, 13(3), 1460–1476.

6. Jäger, R., Purpura, M., Stone, J. D., Turner, S. M., Anzalone, A. J., Eimerbrink, M. J., Pane, M., Amoruso, A., Rowlands, D. S., & Oliver, J. M. (2016). Probiotic Streptococcus thermophilus FP4 and Bifidobacterium breve BR03 supplementation attenuates performance and range-of-motion decrements following muscle damaging exercise. Nutrients, 8(10), 1–11.

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