The relationship between gut health and athletic performance is gaining increasing attention in the fields of sports nutrition and exercise science. In particular, physical exercise—especially at high intensity or duration—can significantly influence gut health and create a need for probiotic support. As research evolves, probiotics for athletes are being recognised for their potential to support immune function, enhance nutrient absorption, and reduce the impact of exercise-induced gastrointestinal distress. A recent sports nutrition position stand highlights the importance of probiotics for athletes and provides evidence-based recommendations for their use.
Together with our resident sports nutritionist, we've explored the current understanding of how probiotic supplementation may offer beneficial effects for both amateur and elite athletes, particularly those undergoing prolonged or strenuous exercise.
Introduction to Probiotics and Gut Health
Probiotics are live microorganisms that, when consumed in adequate amounts, deliver a health benefit to the host—a definition established by the Food and Agriculture Organization and the World Health Organization. These beneficial bacteria play a vital role in maintaining gut health, which is increasingly recognized as a cornerstone of overall wellbeing. For athletes, a balanced gut microbiome supports not only digestion but also immune function and recovery, both of which are essential for optimal performance. Probiotic supplementation has been associated with a range of health benefits, including the reduction of symptoms related to irritable bowel syndrome and inflammatory bowel disease. By supporting a healthy gut environment, probiotics can help athletes stay healthy, recover faster, and perform at their best.
Gut Health and Athletic Performance: A Research Perspective
Recent studies in sports science reveal that gut microbiota composition in physically active individuals tends to be more diverse than that of sedentary populations. This variation, often referred to as 'athletic gut microbiota', is believed to positively influence metabolic function, immune health, and even mental resilience, playing a significant role in athletic performance.
A landmark investigation involving endurance athletes training for a marathon race found a marked shift in gut bacteria composition following the event. Specifically, there was a measurable increase in bacteria associated with the breakdown of lactic acid, a by-product of intense exercise that often leads to muscle fatigue. The findings from this double-blinded placebo-controlled study highlight how certain microbial profiles may support faster recovery and greater exercise performance. Maximal oxygen uptake (VO2max), a key indicator of aerobic capacity, is also influenced by gut microbiota, further linking gut health to endurance outcomes.
Additionally, long-distance runners have been found to host gut microbes that aid in carbohydrate metabolism and fibre digestion—essential for fuelling endurance exercise. In contrast, short-burst athletes, like sprinters and rowers, did not show the same microbial traits. This suggests a potential link between gut health and the type of physical activity performed.
Mechanisms of Action
Probiotics exert their effects by introducing beneficial bacteria into the gastrointestinal tract, where they help maintain a balanced microbial ecosystem. This balance is crucial for efficient digestion, robust immune function, and the synthesis of important nutrients. One of the key ways probiotics support gut health is through the production of short chain fatty acids, which nourish the cells lining the colon and help preserve the integrity of the gut barrier. Additionally, probiotics can modulate the immune system, enhancing immune responses and reducing inflammation—factors that are particularly important for athletes exposed to physical and environmental stressors. While the mechanisms of action are complex and still being explored, ongoing research continues to uncover how these beneficial bacteria contribute to overall health and athletic performance.
Types of Probiotics for Athletes
Athletes have a variety of probiotic options to choose from, each offering unique benefits. Some of the most well-studied and effective strains for supporting gut health and immune function include Lactobacillus acidophilus, Bifidobacterium bifidum, and Streptococcus thermophilus. These beneficial bacteria have been shown to help maintain a healthy digestive system and may reduce the risk of gastrointestinal discomfort. Multi strain probiotics, which combine several different species, are often recommended for athletes because they provide a broader spectrum of support. By incorporating a diverse range of probiotic strains, athletes can maximize the potential benefits for both gut health and immune resilience.
Do Probiotics Help Build Muscle?
One of the most frequently asked questions in sports nutrition is: Do probiotics increase muscle growth?
Muscle development is primarily influenced by resistance training and adequate protein intake. However, emerging evidence indicates that probiotic supplementation can assist in protein absorption, allowing athletes to make more efficient use of their dietary intake. Improved digestion means amino acids reach the muscles more effectively, contributing to body composition improvements.
Further, probiotic use has been shown to support the body's ability to produce digestive enzymes, which help break down complex proteins—especially important for athletes consuming large quantities of protein from powders, shakes, or high-protein meals. This optimised digestion reduces the likelihood of gastrointestinal tract discomfort, which can otherwise hinder nutrient absorption. Additionally, probiotics may help reduce exercise induced muscle damage and support muscle repair, aiding recovery after intense physical activity.
Do Probiotics Help with Energy Levels?
Probiotics may also contribute to improved energy metabolism. Certain species of gut bacteria have been found to synthesise B vitamins, including B1, B2, B9, and B12, all of which are critical for red blood cell formation and cellular energy production.
While not all probiotics produce the same nutrients, some strains are particularly beneficial in maintaining energy levels, especially during periods of high physical exertion. The role of probiotics in supporting nutrient absorption further enhances their contribution to endurance performance.
Although probiotics are not a direct source of energy, their function in helping the body better utilise macronutrients and micronutrients supports athletic performance indirectly.
The effect of probiotics supplementation has been shown to positively influence energy metabolism and endurance performance.
Benefits for Endurance Athletes
Endurance athletes, such as marathon runners and cyclists, often face unique challenges related to prolonged physical activity, including exercise induced gastrointestinal distress and an increased risk of upper respiratory tract infections. Probiotic supplementation has been shown to help reduce symptoms like abdominal pain and diarrhea, which are common during intense or extended exercise sessions. In addition to supporting digestive comfort, probiotics can enhance immune function, helping to lower the incidence of upper respiratory tract infections that can disrupt training and competition. Some research also suggests that probiotics may improve endurance performance by boosting the production of short chain fatty acids, which serve as an additional energy source for working muscles during exercise.
Should Athletes Take Probiotics?
According to insights from our nutrition expert, probiotic for athletes can be especially useful for those engaged in high-volume training, including marathon running, cycling, or offseason resistance training. These forms of intense exercise are associated with a higher incidence of upper respiratory tract infections (URTI) (upper respiratory tract infection), digestive problems, and immune suppression.
Several randomized double-blinded placebo studies have found that probiotic supplementation reduces the risk of respiratory tract infection in healthy adults undergoing strenuous physical activity. This outcome has been attributed to enhanced mucosal immunity and more stable immune responses.
Furthermore, intense workouts can stress the intestinal barrier and increase intestinal permeability, leading to what's often referred to as “leaky gut.” This condition reduces the gut's ability to filter harmful substances and absorb nutrients efficiently. Research supports the idea that probiotics can help restore intestinal barrier function and modulate intestinal permeability, especially in those engaging in frequent, high-load training sessions.
The effect of probiotic supplementation in athletes includes reducing the incidence and severity of upper respiratory tract infections, improving gut health by modulating intestinal permeability, and supporting immune function.
Digestive Relief from Probiotics
Many endurance athletes experience exercise-induced gastrointestinal distress. Symptoms may include diarrhoea, bloating, or cramping—largely due to a reduction in blood flow to the digestive system during prolonged exercise.
In response, multi-strain probiotic supplementation has shown significant improvements in gut comfort by promoting a balanced gut microbiome and reducing inflammatory responses. These beneficial bacteria play a crucial role in maintaining gut integrity and supporting recovery from exercise-induced GI symptoms.
Mental Health and Gut-Brain Connection
Athletes are not immune to the mental challenges that come with competition, fatigue, and high performance expectations. Psychological stress can manifest as physical symptoms, such as nausea, appetite disturbances, and gastrointestinal dysfunction. A growing body of literature links these effects to the gut-brain axis.
Supporting gut health through probiotic supplementation may contribute to better stress management, mood regulation, and mental resilience, indirectly aiding in performance consistency and overall well-being.
Probiotics and Athletic Performance: A Review of the Literature
A growing body of evidence supports the role of probiotic supplementation in enhancing exercise performance and recovery. A recent systematic review and meta-analysis examined the effects of probiotics on athletic performance, gut health, and immune function, finding that regular use of probiotics can lead to improvements in endurance performance and a reduction in the risk of upper respiratory tract infections. The review also highlighted the positive impact of probiotics on symptoms of irritable bowel syndrome and inflammatory bowel disease, which can otherwise hinder training consistency. Both the Society of Sports Nutrition and the International Society of Sports Nutrition have issued position stands acknowledging the potential benefits of probiotics for athletes, while also calling for further research to determine optimal strains, dosages, and supplementation protocols. As the science continues to evolve, probiotics are becoming an increasingly important consideration in sports nutrition strategies.
Best Probiotic Strategy for Athletes
The International Society of Sports Nutrition recommends that athletes approach dietary supplements cautiously and choose products that are supported by placebo-controlled trials. Options such as a probiotic supplement or probiotic supplements are increasingly considered by athletes for their potential benefits. Since the benefits of probiotics are strain-specific, the most effective strategy is using a multi-strain probiotic with a well-chosen probiotic strain and considering probiotics supplementation formulated for general support of immune health, digestive function, and energy production.
Although further research is required, current evidence suggests that consistent use of probiotics can positively impact physical performance and reduce the risk of training interruptions due to illness or digestive issues. The effects of probiotics supplementation have been demonstrated in several studies, where probiotic supplementation elicits favourable outcomes on immune function, gut health, and exercise recovery.
A study published in a respected sports medicine journal investigated probiotic supplementation among elite rugby players over a 4-week period using a randomized double blind placebo and double blind placebo controlled design. Athletes who received probiotics showed fewer instances of respiratory or gastrointestinal infections compared to those in the placebo group, although the difference in symptom severity was not statistically significant, indicating no significant difference in that outcome. However, probiotic supplementation affects markers of immune function and demonstrates gut microbiota modulation as a mechanism of action. Some studies report significant differences in immune and performance markers, while others do not. The effects of probiotic and the effects of probiotics supplementation on performance and health outcomes continue to be explored in both blinded placebo controlled trial and placebo controlled trial settings. For example, research by Smith C et al. highlights the importance of rigorous study design in evaluating these interventions.
Conclusion: Probiotic Supplementation and Athletic Success
To answer the core question: Do probiotics help athletes?
Yes—by supporting the immune system, improving gut health, aiding nutrient absorption, and reducing exercise-induced oxidative stress, probiotics offer a practical way to support athletic performance and physical resilience.
While probiotics should not be seen as a replacement for good training and nutrition practices, they can be a valuable tool in the athlete's recovery and performance strategy.
Frequently Asked Questions
Q: Who should avoid probiotics?
People with weakened immune systems or those under immunosuppressive therapy should consult a healthcare provider before starting probiotics.
Q: Do probiotics improve muscle growth?
They support protein absorption and digestion, which helps facilitate muscle recovery and growth when combined with proper training.
Q: Are probiotics effective for gym-goers?
Yes, particularly for those experiencing bloating, gas, or digestive discomfort from high-protein diets or supplements.
Q: How do probiotics affect energy?
By aiding the synthesis of B vitamins and improving nutrient absorption, probiotics contribute to improved energy metabolism.
