I could never really wrap my mind around leaky gut--I knew it had to do with permeability and junctions. Grace set me straight on these terms and showed my how to refine my searches.
It turns out, leaky gut is real--despite what your doctor may tell you. They all know it, they just don't know how to apply it.
It isn't as simple as it sounds--it's not junctions that are leaking--it's Tight Junctions. There is no such thing as a leaky junction, but there are malfunctioning Tight Junctions--huge difference!
'Tight Junctions' are a part of the GI Tract just like colonocytes, mucus, and the lumen. Tight Junctions are a component of the the junctional complex, which consist of the TJ, gap junctions, adherens junctions, and desmosomes. 'Leakiness' is a real thing in this system.
Intestinal epithelial cells are where nutrients are absorbed. These are known as enterocytes, but also include enteroendocrine, goblet, and Paneth cells. These epithelial cells are tightly bound together by the junctional complexes and are crucial for the integrity of the epithelial barrier.
When these junctional complexes, and Tight Junctions cease to be a barrier, we see chronic inflammatory diseases of the intestine, such as inflammatory bowel disease and celiac disease, type I diabetes, and autoimmune disease. A malfunctioning intestinal barrier is also implicated in immune reactions that target organs outside the digestive tract, leading to diseases such as fatty liver disease and multiple sclerosis in the brain. Furthermore, entry of unwanted antigens can lead to systemic inflammatory response syndrome, characterized by a whole body inflammatory state, and multiple organ failure. You can't make this stuff up!
So, what effects the 'tightness' of tight junctions? Gut microbes and food.
Commensal bacteria and probiotics have been shown to promote intestinal barrier integrity. Probiotic treatment also reduces epithelial barrier dysfunction following psychological stress. L. plantarum was shown to regulate human epithelial TJ proteins in vivo and to confer protective effects against chemically induced disruption of the epithelial barrier. Some probiotics and commensals have also been shown to prevent, and even reverse, the adverse effects of pathogens on intestinal barrier function. Live probiotic bacteria and their dead probiotics differ in their ability to protect against pathogen-induced changes to barrier function. This may be attributed to the fact that live probiotic bacteria are able to compete with pathogens for nutrients for growth and adhesion, whereas dead probiotic bacteria may strengthen intestinal TJ via a cell signaling pathway.
So what about food? Without boring you to death, the worst offenders to Tight Junction functionality are wheat, unsaturated fats (vegetable oil), and chemical food additives--especially surfactants which are used widely in food processing! What foods help to maintain Tight Junctions? Resistant starches, cellulose, pectins, and some oligosaccharides. Have you heard that somewhere before?
There. Now you are all smarter than your doctor. How to seal a gut: Plenty of probiotics and good food! Heard that before?
Here's a link to click if you want to see where this was all plagiarized from: Regulation of Tight Junction Permeability by Intestinal Bacteria and Dietary Components
Just in case you think I made it all up--lol