Immunity in Athletes: Benefits of Probiotics

Endurance athletes have a unique set of health concerns, probiotics can help.

You would think that athletes that run or bike or swim for miles are already healthy. But they too have health concerns unique to their lifestyle and physical stresses.

Competitive athletes undergo what is termed ‘training stress’ due to the regular, high intensity physical training they complete up to 6 days a week 4-6 hours per day.  And many of these athletes undergo the stress without adequate recovery.

New research seems to indicate that probiotics can help an athlete recover and stay healthier during and following training or performance events.

This stress works on many systems of the body, each differently.  The gut is often the focus of current research looking into immunosuppression and recovery rates for endurance athletes.

The Effect of Endurance Training on the Body

Endurance athletes have long been known to suffer from an increased incidence of upper respiratory tract infections (URTI) and gastrointestinal (GI) tract disturbances [1,2,3,4].  This is attributable to decreased immune function and an increased susceptibility to infection.

Diet can influence immunity and can be implicated in decreased immune function to some extent.  In fact, the diet of many high performance athletes often eliminates fiber to increase GI tract emptying and decrease the possibility of GI disturbances [1,4].  A low fiber diet is known to decrease the gut microbiota diversity and may have larger consequences for the long term health of the athlete.

Additionally, training and performance stress can increase systemic inflammation in the body as well as increased intestinal permeability associated with irritable bowel disease, celiac, food allergy and other metabolic illnesses [3].

Generally, moderate exercise increases gut microbiota diversity.  There is a reasonable body of evidence that this is beneficial in a number of ways, including improved immunity and decreases in systemic inflammation.  But for athletes there are compounding factors, such as diet and stress, that may work against gut microbial diversity.

Research is in the early state regarding elite and performance athletes. Less than 100 total scientific articles regarding the microbiome+exercise or probiotic+athlete could be found for a recent review [3].  It is important not to jump to conclusions but preliminary data indicate that probiotics could benefit these individuals.

Evidence that Probiotics Stimulate Immune Function in Elite Athletes

There is evidence that probiotics stimulate immune function in the gut [2].  Some experts estimate that up to 70% of our immune function is housed in our gut.   In fact, much research has been focused on the ability of probiotics to improve gut complaints like diarrhea of various causes or to improve constipation.

But other research is pointing in the direction of systemic immunity being stimulated by the use of probiotics.  One study found that the ingestion of a Lactobacillus strain stimulated cellular level immunity changes in the gut mucosa [2]. In one 14-week study a probiotic significantly decreased incidence of URTI and severity of upper respiratory infections when they occurred in endurance runners [2].

Probiotics have also been found to minimize GI distress in marathon runners who took a Lactobacillus rhamnosis supplement for only 2 weeks [3]. This compounding evidence suggests that probiotics may be a good strategy for endurance athletes and their long term health [3].

It is important to note, the mechanisms of improved immunity are still unclear, but results suggest that it may have something to do with T-lymphocyte cells and decreases in cytokines [2,3].  Other studies have found decreased markers for gut permeability following the use of a probiotic, though the research is far from definitive [3].

Are there guidelines for probiotic use?

There are no nutritional or probiotic guidelines as of yet for athletes and gut health.  And strain specific effects have not yet been fully determined.  Science does not yet know if the gut microbiota works on a strain by strain basis or if it is the sum of the parts that is important.

It is increasingly likely that probiotics and a well managed diet have the potential to improve athlete immunity and reduce GI distress, helping with long term health of the athlete.

Future research is sure to investigate how the gut microbiota may improve or influence performance as well.  In the meantime, results of these studies have been found with as few as 2 billion Colony Forming Units (CFU) per day.  H2PRO™ has 7 billion.  In addition, our strains include Lactobacillus sp. and Bifidobacterium sp., well researched and high quality strains that can be beneficial for athletes.

H2PRO™ helps you hydrate, and may help your body recover from training stress.




1- Bishop et al. (1999) Nutritional Aspects of Immunosuppression in Athletes. Sports Medicine Sep; 28 (3): 151-176.

2- Cox et. al. (2010) Oral administration of the probiotic Lactobacillus fermentum VRI-003 and mucosal immunity in endurance athletes. British Journal of Sports Medicine 44:222–226.

3-  Macha, Núria and Dolors Fuster-Botellaa (2016 in press) Endurance exercise and gut microbiota: A review. Journal of Sport and Health Science. Available online 10 May 2016. Accessed June 1, 2017:

4- Clark, Allison and Nuria Mach. (2016) Exercise-induced stress behavior, gut-microbiota-brain axis and diet: a systematic review for athletes. Journal of the International Society of Sports Nutrition (2016) 13:43 Accessed June 1, 2017 at BioMedCentral.

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