Our intestinal tract is home to a microbiome of trillions bacteria from hundreds of different bacterial species. They work in synergy with our own physiology in a symbiotic relationship to help us keep our gut healthy, break down food, provide nutrients, regulate our immune response, and protect us from pathogenic bacteria.
How are probiotics and exercise linked? Research has shown that exercise can lead to a break down in the gut lining and this can trigger the inflammatory response which in turn adversely affects the health of the cells lining your gut.
Research data suggests that by controlling the immune response, probiotics can help prevent and treat gastrointestinal (GI) issues like diarrhea, constipation, and gas by decreasing inflammation caused by diet and stress, as well as exercise.
That sounds strange but yes, although exercise is a good thing it can lead to GI damage and GI related issues, particularly in athletes and those who do regular intense exercise and work out routines. However, one of the best ways to combat this is through the use of probiotics, as probiotics can help protect the gut and allow you to exercise without suffering from related GI problems.
The fact that exercise can also deplete our “good” gut bacteria and cause GI issues may surprise many. Yes, although exercise is good for you, high-performance athletes, especially endurance athletes, and those who have intense exercise and work out routines often suffer from a lot of GI complaints.
Exercise causes blood to be preferentially moved to the muscles and away from the GI tract. This raises our core temperature, and causes less blood to move towards our internal organs. The increased internal temperature can quickly disrupt the intestinal wall lining and initiate the inflammatory response. Therefore, high training loads, such as training hard for several hours a week, puts a chronic stress on your body which the body struggles to recover from. Before you know it, you have altered the balance between “good” and “bad” gut bacteria, and in doing so, have made yourself more prone to respiratory infection or some other illness (West N.P. et al).
Probiotics also reduce inflammation in the body which can cause our proteins to lose function and can damage the lipids in our cell membranes, creating free radicals. Too many free radicals results in an increased risk of illness and disease.
At the cellular level, under normal heathy conditions, gut cells are connected to each other by an impermeable barrier called a tight junction. Tight junctions are composed of more than 50 proteins and allow gut cells to closely control the passage of nutrients from the gut into circulation while retaining toxins and contaminants that are excreted. In an unhealthy gut lining, or a gut lining suffering from the effects of intense exercise, the tight junctions are compromised, which allows toxins and contaminants to leak into your circulatory system, where they can cause inflammation in the gut and in distant organs and tissues. Celiac disease is an example of what can happen when these junctions are compromised. Undigested gluten fragments seep into the underlying tissue, setting off an immune response.
Research by Lamprecht. M., et al, at the Medical University of Graz, Austria, concluded that intense exercise seems to affect the immune system by compromising the integrity of the intestinal tight junctions leading to increased permeability and “leaks." In the case of your GI, leaks mean that toxins and other undesirables make their way into your bloodstream.
In the Lamprecht. M., et al, study, the 14 weeks of probiotic supplementation modulated zonulin concentrations, a modulator of intestinal barrier function to a normal range. This demonstrates that probiotics worked to improve tight junction integrity and stop “leaks” by affecting the expression of the signaling pathway that increases intestinal resistance.
Two other studies have also illustrated the potential for probiotics for exercise. Chen, Y.M., et al at the National Taiwan Sport University, Taiwan, observed that when mice were given long-term supplementation of Lactobacillus plantarum (a common probiotic species), their muscle mass increased, energy harvesting was enhanced, and activity performance and anti-fatigue effects improved.
Gleeson, M. and Pyne, D.B. at the Australian Institute of Sport, Australia, observed that dietary supplementation with probiotics and other antioxidants can reduce the incidence or severity of upper respiratory illness in some athletes.
From these and other studies it is clear that for professional and amateur athletes as well as those who enjoy regular exercise and work out routines, the results point to a role for probiotics as an important and integral part of a daily routine.