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The intestinal barrier

Between individual epithelial cells are narrow gaps. These gaps are sealed by tight junctions (TJ) that regulate transport of molecules between the cells and prevent harmful molecules or bacteria from passing through this paracellular space.1, 2, 3 TJ are made up of highly regulated and complex protein networks.4

However, TJ are dynamic and may not always perfectly seal the paracellular gaps. Compromised TJ increase the epithelial permeability to inflammatory molecules, such as endotoxins and may result in an influx into the body of such substances.5, 6 This condition may be referred to as a leaky gut.7

Barrier dysfunction may result in intestinal inflammation8 and has been associated with intestinal conditions such as celiac disease, Crohn’s disease, and irritable bowel syndrome.9 However, as inflammatory molecules may reach other organs via the blood, sustained intestinal hyperpermeability has been found as an underpinning physiological mechanism in a range of chronic inflammatory diseases including autoimmune, metabolic, and cardiovascular diseases,6, 10, 11, 12, 13 and has recently also been associated with psychological and psychiatric disorders.14, 15, 16, 17

Dietary and lifestyle factors influence TJ function and intestinal permeability. Thus, a diet rich in fats impairs the TJ structure, whereas dietary fibers which stimulate the production of beneficial molecules by the gut microbiota protects TJ.6, 13, 18 Chronic alcohol intake has been shown to increase intestinal permeability and circulating endotoxin levels.6, 19, 20 Stressful stimuli that activates the sympathetic nervous system and hypothalamic–pituitary–adrenal-axis may also lead to increased intestinal permeability.6, 21

Some probiotics may help support healthy TJ and make them less vulnerable to damage from lifestyle and other factors.22, 23

Numerous in vitro and pre-clinical studies have demonstrated effects of Lactobacillus rhamnosus, LGG® on the intestinal barrier through stabilization of TJ.24, 25, 26, 27, 28, 29, 30 LGG® has proven benefits across many health areas in different age groups. Human clinical studies have suggested that fortification of TJ and the intestinal barrier is involved in some of these clinical effects.31, 32, 33

LGG® is a registered trademark of Chr. Hansen A/S.

The article is provided for informational purposes regarding probiotics and is not meant to suggest that any substance referenced in the article is intended to diagnose, cure, mitigate, treat, or prevent any disease.


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References Open Close

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