A recent study evaluated whether supplements with a fermented milk mixture would reduce the negative effects associated with high-intensity exercise.
The intestinal system helps to protect the body from dangerous pathogens. Exercise has been shown to compromise this function by affecting the intestinal barrier. Intense physical activity can alter a person’s natural gut microbiota and may compromise immune function. This increases an individual’s risk for infections in the gastrointestinal tract and upper respiratory tract.
The gut microbiota also has important roles in nutrient absorption and maintaining the intestinal barrier. The microbiota help prevent pathogenic bacteria from causing infection. However, during exhausting exercise, the body’s glucose stores become depleted. When the body’s glucose stores lower, the body begins to use glutamate from muscles for energy. When the body uses up a lot of the glutamate stores, this affects the intestine’s ability to absorb nutrients.
How glutamate affects the intestinal system
Glutamate, found in the muscles, also helps to maintain the function of the intestinal barrier. During intense exercise, glutamate stores may also lower. Lower amounts of glutamate reduce the ability of the intestines to absorb nutrients properly. Effective absorption of nutrients is necessary to fuel muscles.
How oxidative stress affects the intestinal system
Intense physical activity also leads to oxidative stress. Oxidative stress occurs when the body is unable to detoxify molecules that damage cells. These molecules, referred to as free radicals, are a result of the energy consumption in our cells. When our cells use energy, they release free radicals. When there are too many free radicals, they can damage the body’s tissues. Oxidative stress occurs when the body has trouble ridding itself of too many free radicals.
Oxidative stress and an altered intestinal barrier trigger an immune response. Researchers believe that fermented milk with whey protein, probiotics, and pomegranate juice may prevent the undesirable effects caused by intense physical activity.
Supplements that may improve the function of the intestinal system
- Whey protein: Whey protein provides the body with amino acids that are necessary for muscle maintenance. It can be used as an energy source during exercise, rather than glutamate. Whey protein supplementation may prevent glutamate deprivation and thereby improve intestinal integrity.
- Probiotics: Probiotic supplementation in athletes have previously been shown to reduce the severity, frequency and duration of gastrointestinal problems and respiratory illness by maintaining healthy gut microbiota.
- Pomegranates: Previous studies have reported the antioxidant and anti-inflammatory properties of pomegranates. Pomegranate supplementation may prevent some oxidative stress and inflammation that affects intestinal barrier function during exercise.
In a study published in the British Journal of Nutrition, Brazilian scientists were curious whether fermented milk supplemented with whey protein, probiotics, and pomegranate juice could re-establish intestinal microbiota and protect the body from undesirable effects of intense physical activity.
The scientists studied whether this supplementation would affect physical performance, intestinal microbiota, intestinal barrier integrity, and inflammation in rats undergoing high-intensity exercise.
Supplementation with fermented milk mixture improved gut microbiota
The scientists found that in rats, antioxidants from the pomegranate juice reduced oxidative stress. This further reduced the extent of an inflammatory response and prevented muscle damage during intense physical activity.
The scientists also found that intense exercise reduced healthy microbiota in rats. However, that supplementation with fermented milk containing whey protein, probiotics, and pomegranate juice favoured healthy gut microbiota. The gut microbiota is important to neutralize the effects of carcinogens and drugs on the body, modulate the activity of the immune system, and maintain the intestinal barrier.
Overall, the scientists found that fermented milk with whey protein, probiotics, and pomegranate juice reduced the negative effects experienced during and after intense physical activity in rats, compared to rats that underwent intense physical activity without supplementation. Supplementation protected the healthy gut microbiota, and therefore aided in the maintenance of intestinal barrier integrity.
Intact intestinal integrity is important to protect against pathogenic bacteria and prevent gastrointestinal and upper respiratory tract infections. The supplementation also reduced the immune response because of sufficient glutamate availability, a healthy gut microbiota, and an intact intestinal barrier. This study was performed in rats, although it is likely that humans would experience similar positive benefits of fermented milk supplementation before high-intensity exercise.
Written by Mallory Wiggans
Reference: Chaves, Fernanda M., et al. “High-intensity-exercise-induced intestinal damage is protected by fermented milk supplemented with whey protein, probiotic and pomegranate (Punica granatum L.).” British Journal of Nutrition 119.8 (2018): 896-909.