Probiotics face a new frontier as sports supplements.
Sports supplements have traditionally involved high-protein formulations, but now, research indicates that probiotics may have a place in the world of sports nutrition. Beyond just maintaining gut health, probiotics may play an important role in accelerating fat loss, shortening recovery times, reducing subjective feelings of soreness, and combatting inflammation, studies show. Here are just some of the potential sports nutrition applications of probiotics-and the studies that validate them.
Anti-Inflammatory Probiotics Promote Muscle Recovery
Ralf JÃ¤ger, PhD, is the cofounder of Increnovo LLC (Milwaukee, WI), a scientific advisor to Ashland Inc. (Kearny, NJ) and the lead author of the upcoming International Society of Sports Nutrition (ISSN) position stand on probiotics that is slated for publication later in 2019. JÃ¤ger says probiotic ingredients can serve a valuable role in sports formulations thanks to their ability to promote muscle recovery and reduce inflammation.
“Muscle damage is caused either through oxidative stress or through inflammation,” JÃ¤ger says. “Bifidobacterium breve BR03 is the leading probiotic strain for combatting inflammation. We [Increnovo] conducted a double-blind, placebo-controlled crossover trial to study the effect of probiotic supplementation on athletic performance, muscle damage, and recovery following muscle-damaging exercise. Three weeks of probiotic supplementation reduced baseline inflammation and improved performance and range of motion.”
The trial1 that JÃ¤ger cites followed 15 healthy resistance-trained men between the ages of 21 and 29 who received a daily dose of a probiotic containing 5 billion units each of Bifidobacterium breve and Streptococcus thermophilus, or a matching placebo, for 21 days while performing muscle-damaging elbow exercises. A 21-day washout period separated the crossover conditions. The study authors measured participants’ performance on an elbow flexor task, as well as their interleukin-6 levels. The study found that probiotic supplementation reduced baseline and post-exercise inflammation, attenuated post-exercise decreases in performance, reduced interleukin-6 levels, and improved recovery.
John Quilter, vice president and general manager of GanedenBC30 for Kerry Functional Ingredients & Actives (Mayfield Heights, OH), says that the probiotic strain Bacillus coagulans has properties that make it ideal for post-exercise products that reduce muscle soreness and promote recovery.
“Generalizing about the benefits of probiotics is risky,” Quilter says, “because no two strains are the same-and in research, the results are always strain-specific. However, initial research found that [Kerry’s branded Bacillus coagulans GBI-30, 6086, ingredient] GanedenBC30 enhances the body’s ability to efficiently utilize protein, making this strain an excellent ingredient for use in sports nutrition products.”
Quilter points to the results of an additional study2 on GanedenBC30, funded by the company, that examined the effects of a combination of a probiotic supplement and 20 g of casein protein versus casein alone. This placebo-controlled repeated-measures trial followed 29 recreationally trained men in their early 20s and measured their athletic performance and level of muscle damage following exercise. Participants engaged in muscle-damaging single-leg exercises and were evaluated for perceived recovery, muscle soreness, creatine kinase levels, muscle thickness, and blood urea nitrogen levels at one, two, and three days after exercise.
The study found that combination protein-plus-probiotic supplementation increased perceived recovery, reduced muscle soreness, decreased muscle damage, and prevented an exercise-induced reduction in athletic performance relative to just protein supplementation alone. The probiotic-plus-protein group showed a lower post-exercise increase in serum creatine kinase relative to the protein group, indicating less muscle damage. The study authors concluded that the combination of the probiotic and the protein reduced muscle damage and significantly improved recovery.
Bacillus coagulans Boosts Amino Acid Absorption
JÃ¤ger, who coauthored the study that Quilter references, says that GanedenBC30 holds promise as a sports supplement in more ways than one. Bacillus coagulans has also been shown in studies to influence digestive enzymes in a manner that improves amino acid absorption from protein. Another of JÃ¤ger’s studies, a literature review3 on the effect of GanedenBC30 on protein utilization, found that GanedenBC30 produces active digestive enzymes like alkaline proteases that, when administered jointly with protein, boost blood amino acid concentrations.
JÃ¤ger says that probiotics are currently being studied for their value as sports supplements in 42 human clinical trials, but most of these studies are on the implications of probiotics for immune health in athletes. Very few studies, he says, are examining the potential benefits of incorporating probiotics in a resistance-training regimen. JÃ¤ger expects future research to examine probiotics’ other potential benefits.
“Probiotics have been linked to normalizing age-related drops in testosterone levels, reducing stress-induced cortisol levels, improving mood, and reducing age-related muscle loss,” JÃ¤ger says. “But more research, on athletes specifically, is needed in order to substantiate these potential benefits.”
Bacillus subtilis Improves Body Composition and Accelerates Recovery
While the functional properties of probiotics are highly strain-specific, research is showing that there’s more than one species of the Bacillus genus that holds promise for sports nutrition. John Deaton, PhD, vice president of science and technology for Deerland Probiotics & Enzymes (Kennesaw, GA), says that clinical trials are now demonstrating the efficacy of Bacillus subtilis in exercise formulations.
A randomized, placebo-controlled clinical trial4 funded by Deerland Probiotics & Enzymes followed 23 Division I female collegiate athletes during offseason training and assessed the efficacy of Bacillus subtilis as a sports supplement. Over the course of 10 weeks, participants performed three to four upper- and lower-body workout sessions per week and were randomized to receive either 5 billion CFUs per day of Deerland's Bacillus subtilis DE111 strain (n=11) or a matching placebo (n=12). All participants also received a protein and carbohydrate-enriched recovery drink after exercise. Participants were assessed on tests of strength, agility, body fat composition, and muscle thickness at baseline and again at the end of the 10-week offseason training period.
After 10 weeks, the recovery drink-plus-probiotic group saw a statistically significant increase in body fat loss relative to the recovery drink-plus-placebo group. Subjects in the experimental condition saw a 2% decrease in body fat, compared to a 0.2% decrease in the control group. The study authors concluded that probiotic supplementation may be an effective means of improving body composition in collegiate athletes, but caution that the exact mechanism of action remains unclear and requires further study. The study authors also hypothesize that probiotics’ immunomodulatory properties could promote the repair of musculoskeletal tissue after exercise.
Deaton says that in addition to body composition and recovery, probiotics are also desirable as sports supplements for athletes who experience digestive distress. High-protein diets and other sports nutrition trends can create digestive issues that probiotics are ideally suited to address.
“A large number of long-distance runners tend to experience digestive problems due to reduced blood flow to the intestines,” Deaton notes. “Athletes also have very high nutrient needs, which are better fulfilled when digestion is improved.”
Sports Probiotics Go Smart
Industry experts say they expect the sports probiotics niche to diversify, explore new delivery formats, and adopt a clean-label approach. Quilter says that sports probiotics brands will be working on building buyer confidence through robust research and strong branding.
“Sports nutrition consumers tend to be well-informed and curious about what they consume,” Quilter notes, “which means a strategy of using branded ingredients is likely to succeed in this space. Sports nutrition customers want a clear point of reference that helps them understand exactly what a product has been fortified with. It builds confidence in a product and helps keep active consumers loyal to a product that works for them.”
Deaton says that pill fatigue will lead to probiotics being included in more diverse formulations. Athletes tend to take more supplements than other supplement consumers, he says, which is why sports probiotics will diversify into functional foods and other formats.
“Athletes want superior nutrition and protection from nutraceutical-infused beverages, like healthy recovery drinks with probiotics,” Deaton says. “Don’t forget healthy treats, either; imagine a probiotic-enriched dark chocolate bar.”
JÃ¤ger expects probiotics to expand into multiple areas of sports health, such as hormone regulation and muscle maintenance, provided that further research substantiates these functional benefits. Until then, probiotics will remain a popular supplement for muscle repair and amino acid absorption.
As research continues to investigate the various roles that probiotics can play in sports nutrition, expect new opportunities for innovation. Success in the sports probiotics space will likely involve innovations in delivery systems, marketing, consumer education, and formulation.