Contrary to what Erin Andrews’ latest probiotic commercial would lead you to believe, there is nothing “cute” about your gut (i.e., your digestive system). Fortunately, the growing popularity of probiotic supplements (see STACK’s article on the Best Probiotic Supplements) has focused public and medical attention on the importance of maintaining a healthy gut. This is a step in the right direction, because everyone, especially athletes, needs a healthy gut for optimum health.

What often gets lost in the conversation is the true complexity of the gut. It contains healthy bacteria that aid in digestion and immune function. It’s not as cut and dry as we’re led to believe. Everything from exercise to supplements and nutrition can alter how your gut functions daily. Although many people seek to protect themselves with a probiotic supplement (containing healthy bacteria), supplements are often unnecessary for a healthy gut. Sometimes all we need is a simple adjustment to our diet and lifestyle to rid ourselves of a leaky gut and subsequent illness.

What is a leaky gut?

A leaky gut is damage to the intestinal lining that alters the body’s ability to protect its internal environment. Unhealthy bacteria and toxins, incompletely digested proteins and fats, and waste not normally processed may “leak” out of the intestines into the bloodstream.

How do I know if I have a leaky gut?

Symptoms include abdominal bloating, excessive gas and cramps, fatigue, food sensitivities, joint pain, skin rashes and autoimmunity. Physicians diagnose gut problems indirectly via a blood test. The blood contains markers that provide cues of gut leakiness, potentially indicating damage. Such markers include:

• Protein carbonyl (CO) groups: marker of oxidative stress
• TNF-alpha: mediator of the acute phase of inflammation
• IL-6: proinflammatory cytokine
• Zonolin: sign of impaired junctions in the gut (Fasano, 2011); simply put, the higher the zonolin, the leakier the gut!

What Causes Gut Leakiness?

• Intense exercise: Sorry all you exercise fanatics, but intense exercise increases intestinal permeability (Gareau 2010).
• Use of nonsteroidal anti-inflammatory drugs (NSAIDs) increases gut permeability (van Wijck 2012) (Read more about NSAIDs before training).
• Lack of bacterial exposure: Obsessive cleanliness can actually increase the incidence of certain diseases—like asthma, obesity, allergies and cancer. The condition can even in newborns, as the decreasing incidence of breast feeding and the increasing number of Cesarean sections are reducing infants’ exposure to healthy bacteria. Researchers have  found that infants delivered by Cesarean section lack a specific group of bacteria found in infants delivered vaginally, even if they were breastfed. Infants strictly formula-fed, compared with babies who are exclusively or partially breastfed, also had significant differences in their gut bacteria (Azad 2013). Their lack of bacterial exposure prevents them from having the healthy bacteria they need to maintain a healthy gut and fight against unhealthy bacteria that may enter their systems through the environment.

What Helps Gut Leakiness?

Many of those seeking the best probiotic supplement probably think they help a leaky gut. Unfortunately, money spent on expensive supplements is likely wasted, as Lamprech (2012) demonstrated. After 14 weeks of probiotic treatment, zonolin was reduced by only 30 percent. This suggests that probiotic supplements are not the solution for preventing the contributors to a leaky gut.

A safe bet is a combination of pro- and pre-biotics, which are luckily found in many foods:

• Fermented foods (sauerkraut and kimchi for example)
• Mushrooms
• Leeks
• Artichokes
• Milk and yogurt
• Onions
• Asparagus
• Bananas

References

Azad MB, Konya T, Maughan H, Guttman DS, Field CJ, Chari RS, Sears MR, Becker AB, Scott JA, Kozyrskyj AL. “Gut microbiota of healthy Canadian infants: profiles by mode of delivery and infant diet at 4 months.” CMAJ. 2013 Feb 11. [Epub ahead of print]

Fasano A. “Zonulin and its regulation of intestinal barrier function: the biological door to inflammation, autoimmunity, and cancer.” Physiol Rev 2011, 91:151-175.

Gareau M.G, Sherman P.M., Walker, W.A. “Probiotics and the gut microbiota in intestinal health and disease.” Nat. Rev. Gastroenterol. Hepatol. Sept 2010, 7:503-514. doi:10.1038/nrgastro.2010.117.

Lamprecht M, Bogner S, Schippinger G, Steinbauer K, Fankhauser F, Hallstroem S, Schuetz B, Greilberger JF. “Probiotic supplementation affects markers of intestinal barrier, oxidation, and inflammation in trained men; a randomized, double-blinded, placebo-controlled trial.” J Int Soc Sports Nutr. 2012 Sep 20;9(1):45.

Wroblewska M, Brzuzan L, Jaroslawska J, Zdunczyk Z. “Effect of buckwheat sprouts and groats on the antioxidant potential of blood and caecal parameters in rats.” Int J Vitam Nutr Res. 2011 Sep;81(5):286-94.

van Wijck K, Lenaerts K, Grootjans J, Wijnands KA, Poeze M, van Loon LJ, Dejong CH, Buurman WA. “Physiology and pathophysiology of splanchnic hypoperfusion and intestinal injury during exercise: strategies for evaluation and  prevention.” Am J Physiol Gastrointest Liver Physiol. 2012 Jul 15;303(2):G155-68. Epub 2012 Apr 19. Review.