Written by: Erin Noble, MS, RDN
Written by a Collegiate and Professional Sports Dietitians Association Registered Dietitian (RD). To learn more about sports nutrition and CPSDA, go to www.sportsrd.org.
The gut is a complex organ in our body that can be physiologically altered when put under high levels of stress, a state that can be achieved through intense physical activity. Have you ever had an athlete approach you with questions about gastrointestinal (GI) pains? Perhaps constipation, diarrhea, or discomfort around exercise?
Endurance sports and high-intensity activity can negatively affect gut health primarily due to the redistribution of blood flow away from the GI tract. This effect can cause discomfort during activity, and in the long-term, can lead to an altered GI microbiome.2-5 In these instances, the fermentable oligosaccharides, disaccharides, monosaccharides, and polyols diet (FODMAP diet), gut training and high-fat food consumption may all be nutrition-related considerations that come to mind. Prebiotics and probiotics may also come to mind, both of which can serve to benefit gut health and minimize GI discomfort that may be common in athletes. Let’s digest it.
Prebiotics:
Prebiotics are non-digestible food ingredients that enhance the growth of gut microbiota. For the host, this growth provides a healthy immune system, prevents disease, and provides a protective barrier to the GI tract lining.1,2 When seeking whole foods for prebiotic benefits, fructo-oligosaccharides (artichokes, asparagus, bananas, garlic, onions, leeks, and wheat), galacto-oligosaccharides (foods derived from lactose) and polyphenols all fall within the category of prebiotics.2 However, it is also understood that many fibers (a form of carbohydrate) in our diets can also provide prebiotic-like benefits to the gut microbiota.1 These fibers include resistant starches (beans, legumes, oats, cooked rice), beta-glucans (oats, barley, fungi, algae, yeast, cereals), polydextrose and pectin (oranges, lemons, grapefruit, passionfruit, limes).1-3 However, despite being beneficial in many ways, sometimes these prebiotic specific foods may irritate an athlete’s GI tract further.2 Due to this risk, further tracking of prebiotic food intake is warranted and often encouraged to discover which foods are more tolerable to an athlete’s gut.
Research has shown that prebiotics can have additional health impacts aside from altering GI health, particularly improving glycogen stores.1 In short, this is due to certain microbiota accessible carbohydrates (MACs).1 Certain carbohydrates can be resistant to metabolic digestion, making these specific carbohydrates more available to be metabolized by the gut microbiota as a prebiotic derivative.1 In turn, MACs can be metabolized into short-chain fatty acids (SCFA) which can improve glycogen storage in the host.1 Therefore, by consuming optimal nutrients in the diet and using prebiotic food sources, athletes can improve their glycogen stores over time for energy use as well as improve mental health cognition and bone health for optimal performance.1,2
Probiotics:
Probiotics are “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”.2 While many research studies have been completed on two main probiotic strains, Bifidobacterium spp and Lactobacilli, it is likely that a multistrand probiotic could be most beneficial in providing varied support toward achieving a balanced and healthy gut.2,4,5
To incorporate probiotics into the diet, a food-first approach may be considered first. When ingested regularly in a diet containing optimal energy, food-derived probiotics (yogurt, kefir, and sauerkraut) can have a multitude of benefits due to the diversity of probiotic strains consumed. This approach is also further supported by the fact that the impact of each strain of probiotics may provide outcomes unique to each individual (i.e., diversification of sources can increase the likelihood of consuming strains that are beneficial and meet unique needs).2 However, if the athlete is not meeting the necessary requirement of probiotics through food, supplementation may be necessary to bridge the gap. While probiotic supplementation can have many health benefits to athletes, it is important to note that probiotics will not outweigh a poor diet or unbalanced nutrient intake.
Benefits of an increase of probiotics in the body via food and supplementation may include reduced infection, inflammation, muscle soreness and GI distress.2,4,5 More research is needed on this topic.
Common Brands of Probiotic Supplements:
Take-Aways:
An athlete approaches you about their gut health. What should you recommend? Hopefully, one of the first thoughts that may come to your mind is to refer the athlete to your team dietitian. After reading this, hopefully prebiotics and probiotics, also come to mind. In a food-first approach, it is likely that prebiotic-rich foods (e.g., beans, legumes, onions, garlic, etc.) and probiotic-rich foods (e.g., yogurt, kefir, and sauerkraut) are already being incorporated into an athlete’s diet.
If the goal is to better diminish GI distress during exercise, the likely solution would be to incorporate more probiotics into the athlete’s diet through food. If there is no difference in symptoms, a probiotic supplement blend is recommended. It is encouraged that you check with your team’s medical staff and dietitian about recommending supplements to your athletes. Happy digesting!
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