Youāve probably heard the term āleaky gutā tossed around in wellness circles, but you want more than buzzwords. You want facts and science. So here it is: leaky gut, or increased intestinal permeability, is when the tight junctions in your intestinal lining lose their integrity, allowing unwanted substancesālike bacteria, toxins, and food particlesāto slip into the bloodstream (where they donāt belong).
š§ What Causes Leaky Gut?
Letās start with the science-backed culprits:
Processed food additives like carboxymethylcellulose, polysorbate 80, and carrageenan, artificial colours and flavours, emulsifiers.. the list goes on
Chronic stress (hello cortisol) from life and exercise
Overuse of NSAIDs and antibiotics like ibuprofen ā yikes!
Dysbiosis (imbalance in gut microbiota)
Alcohol (even in those post-race āearned itā glasses of wine)
Nutrient deficiencies, especially zinc and vitamin D
Strenuous or excessive endurance exercise (yep, more on that below)
šŖ Leaky Gut Meets Exercise
Hereās where it gets personal. As someone who trains, teaches, or coaches others through movement, your gut barrier literally supports your performance.
ā¢ Heat + high intensity = barrier stress: Prolonged, intense exercise (especially in heat) can reduce blood flow to the gut and increase gut permeability.
ā¢ GI distress: runners poops, bloating, nausea ā hello my endurance athletes and multi-game tournament players!
ā¢ Malabsorption of nutrients: If your gut lining is compromised, you're not fully absorbing the micronutrients that fuel recovery and mitochondrial health.
š Hormones + The Gut Connection
Leaky gut = inflammation = hormone disruption. Chronic low-grade inflammation can interfere with HPA axis function, which directly impacts cortisol from the adrenal glands, thyroid hormones, and reproductive hormones.
Estrogen metabolism depends on a healthy microbiome (hello estrobolome). Gut dysfunction can lead to estrogen dominance symptoms, PMS, irregular cycles, or perimenopausal chaos.
š§āāļø What You Can Do
ā¢ Prioritize gut-friendly whole foods and reduce ultra-processed intake. Read labels of protein powders and all supplements too.
ā¢ Limit emulsifiers and artificial sweeteners in your daily protein shakes and snacks.
ā¢ Support the microbiome with fiber diversity, fermented foods, and targeted probiotics.
ā¢ Be strategic with training load and support recoveryāyour gut lining regenerates during rest.
Bottom line: Your gut isn't just digesting your kale saladāit's shaping your recovery, energy, and hormonal rhythm. Keep the barrier strong, and the rest follows.
And know youāre not alone! Get the right science-based knowledge, get your blood tested for deficiencies and speak to a naturopathic doctor about what nutrition and supplements are right for you. Donāt make this a guessing game! You deserve more from your performance in sport and life!
References
Dr. Andrea Proulx, ND ā helping female athletes crush fatigue, fix their hormones, and finally perform like the athlete they know they are. Read full bio