Although much of your athletic performance originates in your muscles, other bodily systems also contribute. Interestingly, your gut may have a larger contribution to your overall performance than you may have thought.

Your gut microbiome plays a role in your immune health, inflammatory response, development of specific diseases and on your mental and emotional health. The health of your gut may also play a role in the development of anxiety and depression.

Antibiotics, herbicides, vaccines, pesticides and the tens of thousands of synthetic chemicals you may come in contact with all have an impact on the health of your microbiome.

The link between your gut and brain is well-recognized, but often overlooked in the diagnosis and treatment of health conditions. Recent research has now demonstrated a link between the inflammation in your muscles after significant exertion and specific probiotics.

Although your intestinal health begins at birth and continues to grow and mature as you age, it is never too late to address the health of your gut microbiome.

Adding probiotics to your daily routine is an easy way of improving your gut health and a step I highly encourage, whether you’re a performance athlete or want to achieve better health.

Research demonstrates athletes will experience a drop in performance after exercise induced muscle damage.2 This may occur after any type of exercise that stresses the muscle, such as weight lifting, plyometric jumps or a hard run.

A recent study demonstrates that using a probiotic may help reduce the muscle inflammation, and thus improve your performance in your next session.3 Scientists from the U.S., New Zealand and Italy collaborated in this study, which involved 15 healthy men who were given a 21-day supply of probiotics or a placebo.

After 21 days, the men performed a muscle strength test known to induce damage to the muscle. Results showed that an inflammatory marker in the blood was decreased in those who had taken the probiotics, but it was not statistically different from the placebo.4

The athletes who took probiotics also experienced better peak torque production within the first 72 hours post exercise, indicating to the researchers that probiotics improved performance. Another recent study using recreationally trained males, probiotics and protein supplementation delivered similar results.5

The participants used either a protein supplement, or a protein supplement along with probiotics. After two weeks, measurements were taken of athletic performance and muscle damage following an exercise known to cause muscle damage.

The athletes who took the supplement with probiotics had reduced muscle damage, better physical performance and better exercise recovery.6 In still another study, which used kefir to deliver probiotics to the athlete’s system, researchers discovered a reduction in the measurement of C-reactive protein (CRP).7

They theorized that while the group taking kefir experienced an improvement in their endurance, the more significant result was the reduction in CRP, potentially improving the risk profile for cardiovascular disease.

Improved Digestion and Increased Absorption Advances Performance

Probiotics also increase your absorption of nutrients, which will improve your athletic performance as your muscle cells have a better nutrient foundation.8

The nutrients improve your recovery time, and increase the consistency of your performance over time. Improving your nutrient absorption may also reduce your risk of illness and disease.

In order for the food you eat to be broken down and used by your body, your stomach and intestines must do the work of digestion. As you age, your digestion may become less efficient. This may create an environment in which a variety of digestive disorders are more prevalent.

Athletes with a strenuous schedule may experience a common number of issues, including gas, bloating, diarrhea, nausea and vomiting.9

The prevalence of gastrointestinal disorders ranges between 30 and 70 percent among endurance athletes, depending upon the study and participants.10 Probiotic supplementation improves healthy bacteria population within your intestinal tract and also improves digestion.

Large independent studies are limited, but two large reviews suggest that using probiotics may reduce diarrhea associated with antibiotic use when compared with a placebo,11 demonstrating that probiotic supplements can repopulate your gut microbiome and promote better digestion and absorption of nutrients.

A systematic review of the literature found little evidence that probiotics have a direct link to improved athletic performance.12 However, the results do demonstrate secondary health benefits that have an effect on athletic performance, including muscle fatigue recovery, immune system support and a healthy gastrointestinal tract.

Probiotics also have a unique and significant effect on your emotional and mental outlook.13 When athletes experience an improvement in mood,14 they may also enjoy a boost in performance.15

Physical Exertion May Have a Short-Term Negative Effect on Your Digestive and Immune System

While mild to moderate athletic endeavors have a positive long-term effect on your overall health, there is evidence that endurance events or short bursts of intense training may increase immunosuppression in the short term. Respiratory infections and minor illnesses are commonly observed after competition, which can reduce performance.16

This may be the result of physiological stress that taxes your immune system. Inadequate nutrition affects almost all aspects of your immune system, so including a single nutrient may not be an effective means of addressing this challenge.17 Although elite athletes are not immune-deficient, the combined effects of small changes to the immune system may compromise resistance.

This open window of altered immunity may last between three and 72 hours, depending upon the exertion of the athlete, previous athletic ability and overall health. Many studies have evaluated the impact of sleep, nutrition, stress and training sessions on the reduction in immune status after prolonged exertion.

Probiotics, and a strong gastrointestinal microbiome, are now known to play a key role in controlling and adapting your body to physical activity. Studies have demonstrated supplementation with probiotics reduces the frequency and severity of respiratory and gastrointestinal disorders in highly active athletes.18,19

The theorized mechanism of action includes a direct interaction between your gut microbiome and your immune system signals to your liver, brain and respiratory tract. While more studies are needed, researchers recommend athletes use plant polyphenols and probiotics to help colonize and support their gut microbiome.20

Better Immunity May Improve Performance

As probiotics help to modulate your gut microbiota, they also offer a practical way of diversifying bacterial species and enhancing your gut and immune function.21 These friendly bacteria help protect your body from infection, and are important for maintaining homeostasis.

Probiotics also have a capacity for modulating your immune function after exercise. This highlights a potential for use, as probiotics from food and many supplements are well tolerated. Without the obstacles of upper respiratory illness or gastrointestinal illness, athletes are able to continue training, thus improving their performance.

In a study evaluating the effectiveness of probiotic yogurt on endurance swimmers, those who consumed 400 milliliters (just under 1 3/4 cups) of probiotic yogurt exhibited a reduction in the number and duration of upper respiratory illnesses, compared to those who received yogurt devoid of probiotics.22 Without the hindrance of an infection, the swimmers also demonstrated an improvement in max VO2 (peak oxygen uptake).

Another study using highly trained rugby players found supplementation with probiotics resulted in a significant reduction in respiratory tract illnesses and gastrointestinal issues.23 Although the probiotics had an effect on the number of illnesses the players experienced, it did not affect the severity of the infections.

Using a popular Brazilian raw cheese high in Lactobacillus acidophilus and Bifidobacterium longum, researchers fed rats for two weeks and then exercised them to exhaustion on a treadmill.24 Two hours later material was collected to measure immune system responses in the animals. In the experimental and control animals there were changes to lymphocyte counts, but the changes were halved in the rats fed the cheese.

Monocyte counts did not change in the rats fed the cheese, but the control group experienced a significant decline. However, the most important result was that the animals fed the probiotic cheese experienced an increase in HDL cholesterol and a 50 percent decrease in triacyglycerols. They concluded that the probiotic cheese would be a healthy alternative to improve the immune function in elite athletes.25

Probiotics Improve Heat Tolerance

Yet another benefit to increasing probiotics in your diet as an athlete is your ability to train in the heat. Researchers focused one investigation on the effect of a multi-strain probiotic supplement using 10 male runners over a four-week period.26

The runners exercised to fatigue at 80 percent of their respiratory capacity in a very controlled environment, at 35 degrees C (86 degrees F) and 40 percent humidity. In order to evaluate the participants’ gastrointestinal permeability, the runners ingested lactulose and rhamnose before the exercise and urine was collected before, immediately at the conclusion of the exercise and one hour later.

Researchers found that probiotic supplementation increased the amount of time it took the runners to reach fatigue. Serum lipopolysaccharides increased post exercise in the control group, but the experimental group experienced a moderate to large reduction in pre and post exercise concentrations. The researchers felt that:27

“Four weeks of supplementation with a multi-strain probiotic increased running time to fatigue in the heat. Further studies are required to elucidate the exact mechanisms for this performance benefit.”

How to Optimize Your Gut Health

An estimated 80 percent of your immune system is located in your gut, which means that reseeding your gut with healthy bacteria may be one of the more important strategies you can use to prevent most diseases. It may even improve your athletic performance.

Radically reducing your sugar intake is an important step. You can take the best fermented foods and/or probiotic supplements, but if you fail to reduce your sugar intake you will sabotage your efforts to rebuild your gut flora. This would be similar to driving your car with one foot on the accelerator and one on the brake simultaneously. It’s simply not an effective strategy.

When you consume sugar at the level of the typical American, you are virtually guaranteed to have a preponderance of pathogenic bacteria, yeast and fungi, no matter what supplements you are taking.

Traditionally fermented, unpasteurized foods will provide you with a diverse array of beneficial bacteria. Some of the beneficial bacteria found in fermented foods are also excellent chelators of heavy metals and pesticides, which will also have a beneficial health effect by reducing your toxic load. Healthy choices include:

• Fermented vegetables
• Lassi (an Indian yogurt drink, traditionally enjoyed before dinner)
• Fermented milk, such as kefir
• Natto (fermented soy)

Fermented Veggies Are Easy to Make at Home

Fermented vegetables are an excellent way to reseed your gut with healthy bacteria. As an added bonus, they may also be a great source of vitamin K2 if you ferment your own using the proper starter culture.

We tested samples of high-quality fermented organic vegetables made with our specific starter culture, and a typical serving (about 2 to 3 ounces) contained not only 10 trillion beneficial bacteria, but also 500 micrograms (mcg) of vitamin K2, which we now know is a vital co-nutrient to both vitamin D and calcium.

Most high-quality probiotics supplements will supply you with only a fraction of the beneficial bacteria found in such homemade fermented veggies, so it’s your most economical route to optimal gut health as well.