Hello everyone, I hope everyone had a good, cozy time with family over the holidays!
Today we are addressing the not so well-known connection between leaky gut, how it happens, what are the causal agents, and how it is the very start of many medical issues -- and effects everyone!
Gluten, a complex protein found in wheat, barley, kamut and rye, has been increasingly scrutinized for its potential to disrupt the integrity of the gut lining, particularly the tight junctions that regulate the passage of substances through the intestinal wall layer. The primary component of gluten that has been targeted in this process is gliadin. Gliadin interacts with the cells lining of the gut, particularly by causing the release of zonulin, a signaling protein that modulates the permeability of tight junctions. In other words, it opens and closes the gut lining in order for absorption of nutrients and for selective immune function. They act as selective gatekeepers, allowing the absorption of nutrients, water, and electrolytes while preventing the passage of harmful substances such as pathogens and toxins.
In nutrient absorption, tight junctions ensure that the transport of molecules through the intestinal epithelium is highly controlled. The gut primarily uses two pathways for nutrient absorption: transcellular transport (through the cells) and paracellular transport (between the cells). Tight junctions govern the paracellular pathway, which is responsible for the passage of small ions and water. By modulating the permeability of this pathway, tight junctions help maintain a balance between absorbing essential nutrients and preventing the leakage of potentially harmful substances.
However, the function of tight junctions is not limited to absorption. They also play a vital role in maintaining immune surveillance by regulating what substances are exposed to the immune cells beneath the epithelial lining. This dual role ensures that the gut maintains a delicate balance: it allows the passage of beneficial molecules while keeping out pathogens and other harmful entities that could trigger an immune response. Research has shown that the release of zonulin and the subsequent loosening of tight junctions is not limited to individuals with celiac disease or gluten sensitivity; it occurs universally, though the extent of the damage and the resulting health consequences may vary (Fasano, 2012). This process, while intended to allow controlled immune surveillance, becomes broken, staying open and letting any and all things in, leading to an increase in intestinal permeability, colloquially known as "leaky gut." Unresolved leaky gut causes cells to be attacked by foreign or damaging molecules getting into the blood stream from the jammed open tight gap junctions hat eventually cause cells to start leaking also.
When tight junctions lose their integrity, substances such as undigested food particles, toxins, and microbial fragments can pass through the gut lining into the bloodstream. This breach triggers an immune response, as the body perceives these molecules as foreign invaders. Chronic activation of the immune system can lead to systemic inflammation, contributing to a wide array of health problems, including autoimmune disorders, chronic fatigue, neurological issues, and skin conditions (Fasano, 2020). Although not everyone exposed to gluten will experience severe health effects, the universal disruption of gut permeability suggests a baseline impact that inevitably predisposes individuals to long-term complications.
Gluten alone, is not the only culprit when it comes to disfunction of the gut and the leaking of the tight gap junctions:
**Dairy, meat, sugar, and excessive salt intake can all contribute to gut dysfunction, including the development and exacerbation of leaky gut syndrome. While each of these dietary components affects the gut in distinct ways, they often share overlapping mechanisms, such as promoting inflammation, altering gut microbiota, and compromising the integrity of the intestinal lining.
Dairy is a common dietary irritant that negatively impacts gut health, particularly in individuals with lactose intolerance or sensitivity to dairy proteins like casein and whey, but will lead to the same gut disfunction and damage in varying amounts in everyone. No one is exempt unless they don't put this ingresient into their body. Casein has been shown to trigger inflammation in individuals, which can disrupt the tight junctions that maintain gut barrier integrity. Additionally, certain dairy products may increase mucus production in the gut, which, when overproduced or poorly regulated, can impair the protective mucus barrier and expose the intestinal lining to damage. For all but also individuals with preexisting gut sensitivities, dairy consumption can amplify gut permeability and inflammatory responses.
Meat, particularly processed and red meats, has been linked to gut dysfunction due to its high levels of saturated fats, advanced glycation end products (AGEs), and heme iron. Saturated fats can promote the growth of pathogenic bacteria and disrupt the balance of the gut microbiota, leading to dysbiosis—a state of microbial imbalance that can increase intestinal permeability. AGEs, formed during high-temperature cooking methods such as grilling or frying, can induce oxidative stress and inflammation in the gut. Heme iron, found in meat in general, has been shown to exacerbate oxidative damage to the gut lining, further weakening the tight junctions.
Sugar, especially refined sugar and high-fructose corn syrup, is a well-documented contributor to leaky gut. Excessive sugar intake fuels the growth of harmful bacteria and yeast, such as Candida albicans, which can compromise the gut barrier. The resulting dysbiosis disrupts the delicate ecosystem of beneficial bacteria that support gut health and tight junction integrity. Moreover, high sugar consumption promotes low-grade, chronic inflammation through pathways such as the activation of Toll-like receptors (TLRs), which can damage gut cells and contribute to gut permeability. Sugar-induced inflammation is further compounded by its effect on insulin resistance, creating a feedback loop of systemic and localized gut inflammation.
Excessive salt intake has more recently been shown in gut health disturbances. High sodium levels can directly disrupt the gut microbiota, reducing populations of beneficial bacteria like Lactobacillus. This shift in microbial balance can lead to inflammation and an increased risk of autoimmune conditions. Studies have shown that high salt intake can also increase the production of inflammatory cytokines and stress the endothelial lining of the gut. Over time, this can impair tight junctions and increase intestinal permeability, further contributing to leaky gut syndrome.
Overall: The collective impact of these dietary factors is significant, as they often work synergistically to damage the gut barrier. For instance, a diet high in gluten, meats, sugar, and salt not only promotes inflammation and dysbiosis but also diminishes the body's ability to repair and maintain the gut lining. So, if anyone is consuming meat, dairy, sugar --- or lots of salt -- which is easy to do eating out and or trying to eat healthfully with foods from the grocery store, most all products are overloaded with it -- damage is being done.
All of these ingredients cause gut lining problems that starts with the removal of the protective mucus layer in the gut as another significant consequence. The mucus layer serves as the first line of defense, protecting the epithelial cells from direct contact with harmful substances. Gliadin, casein and heme from meat and dairy, sugar, and too much salt has been shown to increase oxidative stress and inflammatory markers, which can degrade this mucus barrier. This degradation leaves the epithelial cells exposed, compounding the risk of tight junction damage and perpetuating the cycle of inflammation and permeability (Celiac Disease Foundation, 2020). Even in individuals without overt gluten sensitivity, repeated exposure gradually weakens this critical protective layer, heightening the risk of broader health impacts. Usually starting with constipation, gut dehydration, and lack of mucus protective layer, the mucus layer is completely depleted and damage can then occur. Those who leave their bodies in this state and continue to experience this are all ages, but usually develop intestinal, colon, or rectal cancer. More than ever, those in their beginning stages of a career, ages 20-30, are being admitted for unexplained bleeding in their gut, and later cancer, as the continual irritation of the gut, from what they eat, eventually leads to decline.
Very quickly, the consequences of this disruption can cascade into broader health issues. The heightened immune activity may provoke autoimmune diseases such as celiac disease, Hashimoto’s thyroiditis, and rheumatoid arthritis. Neurological disorders like migraines, brain fog, and even depression are highly linked to the systemic inflammation driven by gut permeability (Lebwohl et al., 2015). Skin conditions such as eczema, acne, and psoriasis may also flare as the immune system reacts to circulating toxins. Additionally, metabolic conditions like insulin resistance and nutrient malabsorption become more pronounced when the gut is unable to effectively regulate what enters the bloodstream.
Advocating for the avoidance of gluten, meat, dairy, sugar, and low salt for ALL is grounded in these findings. While gluten or these things may not affect every individual equally, the evidence supports that its consumption universally impacts gut permeability to some degree, with the potential for more severe consequences in predisposed individuals. Transitioning to a gluten-free diet can reduce inflammation, restore gut integrity, and mitigate the risk of related health problems. Emphasizing whole, unprocessed foods and alternative grains such as millet, buckwheat, and quinoa (for those who tolerate it) rolled oats (make sure gluten free), can provide the body with essential nutrients without the inflammatory burden of gluten. Awareness and proactive dietary changes remain key steps in safeguarding gut health and overall well-being.
References:
Celiac Disease Foundation. (2020). Gluten and gut health. Retrieved from https://celiac.org
Fasano, A. (2012). Leaky gut and autoimmune diseases. Clinical Reviews in Allergy & Immunology, 42(1), 71-78. https://doi.org/10.1007/s12016-011-8291-x
Fasano, A. (2020). Zonulin and its regulation of intestinal barrier function: The biological door to inflammation, autoimmunity, and cancer. Physiological Reviews, 91(1), 151-175. https://doi.org/10.1152/physrev.00003.2018
Lebwohl, B., Ludvigsson, J. F., & Green, P. H. (2015). Celiac disease and non-celiac gluten sensitivity. BMJ, 351, h4347. https://doi.org/10.1136/bmj.h4347
EatingWell. (n.d.). 5 inflammation myths you should stop believing, according to science. Retrieved from [https://www.eatingwell.com/inflammation-myths-to-stop-believing-8740999](https://www.eatingwell.com/inflammation-myths-to-stop-believing-8740999)
MDPI. (2020). Sugar and gut permeability: Implications for inflammation and metabolic health. International Journal of Molecular Sciences, 21(21), 8368. Retrieved from [https://www.mdpi.com/1422-0067/21/21/8368](https://www.mdpi.com/1422-0067/21/21/8368)
MDPI. (2021). The effect of high salt intake on gut microbiota and intestinal permeability. International Journal of Molecular Sciences, 22(14), 7613. Retrieved from [https://www.mdpi.com/1422-0067/22/14/7613](https://www.mdpi.com/1422-0067/22/14/7613)
The Times. (n.d.). What salt, sugar, red meat, and alcohol really do to your body. Retrieved from [https://www.thetimes.co.uk/article/what-unhealthy-food-doing-body-sugar-salt-alcohol-coffee-red-meat-fr5lwmz2m](https://www.thetimes.co.uk/article/what-unhealthy-food-doing-body-sugar-salt-alcohol-coffee-red-meat-fr5lwmz2m)
This explains everything related to my leaky gut. People use the term a lot but I never knew why we get it; where it comes from. Doctors don’t tell you. Wow, thank you so much <3