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Pre-race nerves in the form of stomach butterflies are normal—most people experience them. But when unpleasant gut upset gets physical, it can signal a more urgent matter. The gastrointestinal tract is sensitive to emotion. Anger, anxiety, sadness, and happiness can trigger a reaction in the gut: You may lose your appetite or feel queasy when experiencing the unexpected. Likewise, if the gut is in turmoil, it can send warning signals to the brain, resulting in an array of symptoms such as diarrhea and vomiting.
This symbiotic connection is what’s known as the gut-brain axis. Dr. Sara Gottfried, author of The Hormone Reset Diet, The Hormone Cure, and Younger, explains, “The gut-brain axis refers to the communication between the gut (and its enteric nervous system) and the central nervous system, which links the gut with the emotional and cognitive centers of the brain.” The California-based, Harvard-educated gynecologist teaches natural hormone balancing in order to help patients lose weight and slow down aging. She often sees women with common complaints like gas, bloating, food sensitivities, and feelings of lethargy. What these people don’t realize is that the root cause of said issues may be an out-of-whack gut-brain axis.
New Zealand-based naturopath Katie Stone adds, “The microbiota in your gut help regulate various hormones involved with appetite, inflammation, and mood. When the microbiota are affected by an imbalance of bad bacteria, the messages being sent between the gut and the brain are affected.” Gottfried lists excessive stress, antibiotics, and an overload of sugar and inflammatory foods as major triggers for a dysfunctional gut-brain axis. Apart from physical manifestations, people may also complain of memory loss, anxiety, brain fog, and moodiness. “I think of inflammation as beginning in the gut and extending to the brain. Often brain inflammation doesn’t turn off unless you actively do something to cool it,” Gottfried says. Cortisol rise during exercise can exacerbate the problem and may result in conditions such as leaky gut syndrome (increased intestinal permeability).
“Taking vitamin C can reduce the rise in cortisol during exercise,” Gottfried continues. “Corticotropin, the releasing hormone for cortisol, can be the root cause of increased intestinal permeability, so vitamin C may act as a buffer.”
Gottfried also suggests prebiotic foods and probiotics in order to help improve performance and keep the gastrointestinal tract in good health. “Probiotics can seal leaky gut in athletes. They can also encourage a diversity in the gut that builds better immunity, metabolic function, and reduces inflammation after exercise,” she says.
The amino acid L-carnitine may also help protect and support gut flora. Gottfried points to a 2018 research article available via the National Center for Biotechnology Information that suggests L-carnitine prevents cellular damage, improves recovery, and helps cells break down fat and energy. Supplementing with branched-chain amino acids may also promote enhanced nutritional and intestinal health and function in the gut, as well as boosting energy levels and regulating metabolism.
When it comes to ensuring optimal nutritional intake, Stone advocates that athletes adhere to a wholesome diet rich in soluble fiber, alongside a quality probiotic supplement.
Ignoring persistent symptoms could lead to declining performance, longer recovery time, anxiety, depression, and even autoimmune conditions.
As a physician who practices personalized lifestyle medicine, Gottfried says “my wish is that athletes take a proactive approach to keeping the gut-brain axis in outstanding shape so that it can be the strong foundation for future performance.”