Are you looking to boost your exercise performance, accelerate post-training recovery, and enrich your overall wellbeing? Whether you’re an elite athlete, a weekend warrior, or starting your fitness journey, enhancing athletic performance, speeding up recovery from physical exertion, and achieving overall wellbeing are likely high on your priority list. Increasing evidence points to optimal gut health and a robust immune system as key drivers of peak performance (1).

Emerging research highlights probiotics—beneficial microorganisms—as instrumental in bolstering gut health, immune function, and recovery post-training, thereby boosting performance (1,2,3,4)

Exploring Probiotics

Defined by the World Health Organisation (WHO) and the International Olympic Committee (IOC) as live microorganisms that confer health benefits when taken in appropriate amounts, probiotics can increase beneficial bacteria in the gut. Originating from certain fermented foods and supplements, these bacteria were first noted by Nobel laureate Elie Metchnikoff in 1900 for their positive impact on gastrointestinal health through fermented milk. Today, probiotics are linked to various health benefits, crucial for athletes’ endurance and wellbeing (1,3,4).

Probiotics’ Role in Peak Athletic Performance

The position statement by the International Society of Sports Nutrition (ISSN) on probiotics and athletic performance shed light on how probiotics can significantly benefit athletes:

Enhancing Gastrointestinal Health and Performance

Endurance athletes often face gastrointestinal issues during prolonged activities, leading to discomforts like nausea and diarrhoea. Studies show that taking a combination of probiotic strains before competitions can reduce these symptoms, bolster immune and inflammatory responses, and even enhance exercise performance, VO2 max, and aerobic power (5).

The Mechanisms Behind the Benefits

By modulating metabolism, improving the availability and absorption of amino acids, vitamins and minerals

• Probiotics assist in the maintenance of appropriate gut pH and digestive function through enzyme activity and metabolism within the gut. This improves the availability of amino acids, vitamins, short chain fatty acids, micronutrients and minerals; these are then easily absorbed through from the gut to the circulation.
• Probiotics provide the favourable environment for the resident healthy microorganisms by maintaining appropriate PH, recycling nitrogen, detoxification and transformation of many substances and micronutrients (1).

By improving immune functions, reducing inflammation and infections

70% of the immune system (cells) is located in the gut and probiotic supplementation has been shown to promote a healthy immune response in people (1).

• A number of studies have demonstrated that certain strains of probiotics improve the structural integrity of the gut by influencing a protein called Zonulin. Thereby keeping the gut lining intact and preventing the leaking of partially digested macro (big) molecules in body’s circulation. This is very important to prevent ‘leaky gut’ and certain allergic reactions (1). It is important to note that the gut undergoes a lot of stressful events in high endurance athletes.
• Probiotics reduce the adhesion of pathogens (harmful microorganisms) to the mucosal lining of the gut, this helps in reducing the number of pathogens in the gut. Probiotics also produce antimicrobial substances, thus defending against invaders and maintaining a balance of good microflora in the gut. This is important to reduce the frequency of infections and abdominal discomfort.

Upper respiratory tract infections (URTIs) represent approximately 35-65% of the health issues addressed in sports medicine. Interestingly, the occurrence of URTIs among athlete’s mirrors that of non-athletes, with no significant difference in incidence rates.

Athletes suffering from these infections often see detrimental effects on their health and performance, a fact particularly noticeable among swimmers during intense training periods. Distance runners, for instance, tend to report a higher frequency of URTIs after competing. This highlights the role of probiotic supplementation as an effective nutritional approach to reduce an athlete’s vulnerability to such illnesses.

Supporting Post-Training Recovery

Fatigued and/or damaged muscles, systemic inflammation, and build-up of harmful and muscle damaging oxidative molecules (called oxidative stress) are common in athletes and these can impact post-training recovery and performance. The anti-inflammatory properties of certain probiotic strains such as lactobacillus Plantarum have been shown to aid in the recovery of fatigued muscles by mitigating inflammation and oxidative stress, crucial for healing and recovery (6).

Overtraining can also compromise the immune system. This is characterised by an imbalance between training and recovery resulting in symptoms such as prolonged fatigue, decreased performance, and increased vulnerability to infections.

Maintaining Optimal Hydration

Probiotics can help maintain the integrity of the gut lining, ensuring that water and electrolytes are more efficiently absorbed back into the body, which is essential for maintaining hydration and also helping to prevent GI upset during exercise.

Influencing Stress and Hormonal Balance

Early research suggests probiotics may modulate stress hormones, support hormonal functions related to body composition, and improve stress response, underscoring their potential in enhancing athletic performance. This research falls under the category of psychobiotics, a term that describes probiotics with potential mental health benefits through their action on the gut-brain axis.

Research has shown that the gut-brain axis, a complex communication network linking the gastrointestinal tract and the brain, plays a crucial role in modulating stress responses. Probiotics can influence this axis, potentially affecting the production and regulation of stress hormones, including cortisol (7).

International Travel

There is an increased risk of GI problems during international travel. Typically, good hygiene helps to prevent bacterial contamination and spread, but much of the time that is not enough. Therefore, probiotic supplementation for athletes traveling abroad can form part of a sports nutrition plan. One of the most widely research strains of bacteria related to traveller’s diarrhoea is  Lactobacillus rhamnosus GG (8).

This is particularly relevant when an athlete is overreaching. Functional overreaching is an increase in training load that leads to a temporary performance decline followed by improved performance after adequate recovery. It’s considered a positive and intentional aspect of training designed to enhance athletic performance however it can lead to temporary immunosuppression and may be even more of a consideration if it coincides with travelling overseas.

Probiotic Efficacy: Elite vs. Novice Athletes

While elite athletes might utilise probiotics for quicker recovery and overall wellbeing, novices may notice more pronounced performance improvements, underscoring probiotics’ broad applicability.

The Synergy of Nutrition and Probiotics

Optimal performance and probiotic benefits are maximised with a balanced diet rich in proteins, fibre, and fatty acids. Foods promoting probiotic functions, known as prebiotics, include bananas, onions, garlic, leek, barley, oats as well as potatoes and pasta that have been cooked then cooled, enhancing probiotics’ effectiveness.

Safety and Recommendations

Common probiotic species are deemed safe for general use, though individuals with specific health conditions should consult healthcare professionals. Athletes should choose reputable probiotic supplements to avoid contamination risks, especially concerning sport doping regulations.

Incorporating probiotics offers a promising avenue for athletes aiming to enhance performance, recovery, and wellbeing.

References

1. Jäger et al. International Society of Sports Nutrition Position Stand: Probiotics. Journal of the International Society of Sports Nutrition. 2019; 16:62.
2. Jäger et al. Probiotic Streptococcus thermophilus FP4 and Bifidobacterium breve BR03 supplementation attenuates performance and range-of-motion decrements following muscle damaging exercise. Nutrients. 2016;8.
3. Maughan et al. IOC consensus statement: Dietary supplements and the high-performance athlete. Br J Sports Med. 2018;52:439–55.
4. Wakeman M. (2013). A review of the role of probiotics in sport. ISSSMCconference abstract 031 2013.
5. Salarkia et al. Effects of probiotic yogurt on performance, respiratory and digestive systems of young adult female endurance swimmers: a randomized controlled trial. Med J Islam Repub Iran. 2013;27:141–6.
6. Huang, W. C., Wei, C. C., Huang, C. C., Chen, W. L., & Huang, H. Y. (2019). The Beneficial Effects of Lactobacillus plantarum PS128 on High-Intensity, Exercise-Induced Oxidative Stress, Inflammation, and Performance in Triathletes.Nutrients, 11(2), 353.
7. Clapp, M., Aurora, N., Herrera, L., Bhatia, M., Wilen, E., & Wakefield, S. (2017). Gut microbiota’s effect on mental health: The gut-brain axis. Clinics and practice, 7(4), 987.
8. Hempel, S., Newberry, S. J., Maher, A. R., Wang, Z., Miles, J. N., Shanman, R., Johnsen, B., & Shekelle, P. G. (2012). Probiotics for the prevention and treatment of antibiotic-associated diarrhea: a systematic review and meta-analysis.JAMA, 307(18), 1959–1969.