Watch the video

To view this content, consent for functional cookies needs to be given. Click this text to open the consent form.

The intestinal barrier

The intestinal barrier stops unwanted molecules or bacteria entering the body

The whole of the intestine is lined by a single layer of cells called the intestinal epithelium. However, there are narrow gaps between neighboring cells in the epithelium. These gaps are normally sealed by complex protein networks called ‘tight junctions’ that help maintaining a barrier between the contents of the intestines and the rest of the body.1-4

However, the tight junctions may not always perfectly seal the gaps between epithelial cells. In this case, unwanted molecules, or bacteria that cause inflammation could pass through the gaps, therefore escaping from the gut and entering the rest of your body.5,6 This may be referred to as a ‘leaky gut’.7

Sometimes the intestinal barrier does not function as it should

If the intestinal barrier is not functioning properly, the result may be intestinal inflammation.8 This has been associated with conditions such as celiac disease, Crohn’s disease, and irritable bowel syndrome.9 However, because inflammatory molecules may reach other organs via the blood, long-term dysfunction of the intestinal barrier can play a role in other conditions around the body including autoimmune, metabolic, and cardiovascular diseases,6,10-13 and has recently also been associated with psychological and psychiatric disorders.14-17

What role do dietary and lifestyle factors play?

Dietary and lifestyle factors influence the function of tight junctions and how easily molecules can pass through. For example, the following can affect how well the tight junctions work:

  • A diet rich in fats impairs the tight junction structure6,13,18
  • A diet rich in fiber can protect the tight junctions by stimulating the production of beneficial molecules by the healthy bacteria in the gut6,13,18
  • Chronic alcohol intake can increase the passage of inflammatory molecules through the intestinal barrier and into the bloodstream6,19,20
  • Certain stressful stimuli may also lead to the tight junctions not working properly6,21
  • Some probiotics may help support healthy tight junctions and make them less vulnerable to damage from lifestyle and other factors22,23
Numerous laboratory studies have shown how the probiotic Lactobacillus rhamnosus, LGG® has positive effects on the intestinal barrier through stabilization of tight junctions.24-30 LGG® has been shown to provide benefits across many health areas in different age groups and the positive effects on tight junctions and the intestinal barrier may be a reason for some of these clinical effects.31-33

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.
 

Learn about the mode of action

Microbiome dysbiosis logo

Microbiome dysbiosis

Surviving stomach icon

Surviving the stomach

mucus layer logo

Mucus Layer

Immune system logo

Immune system

Intestinal barrier logo

Intestinal barrier

Reference list

  1. Anderson JM, Van Itallie CM. Physiology and function of the tight junction. Cold Spring Harb Perspect Biol. 2009; 1(2):a002584. (PubMed)
  2. Zihni C, et al. Tight junctions: From simple barriers to multifunctional molecular gates. Nat Rev Mol Cell Biol. 2016;17(9):564–580. (PubMed)
  3. Capaldo CT, et al. Layered defense: how mucus and tight junctions seal the intestinal barrier. J Mol Med. 2017;95(9):927–934. (PubMed)
  4. Rowart P, et al. Implications of AMPK in the formation of epithelial tight junctions. Int J Mol Sci. 2018; 19(7):2040. (PubMed)
  5. Ding LA, Li JS. Gut in diseases: Physiological elements and their clinical significance. World J Gastroenterol. 2003; 9(11):2385-2389. (PubMed)
  6. De Punder K, Pruimboom L. Stress induces endotoxemia and low-grade inflammation by increasing barrier permeability. Front Immunol. 2015;6:223. (PubMed)
  7. Hollander D. Intestinal permeability, leaky gut, and intestinal disorders. Curr Gastroenterol Rep. 1999;1(5):410–416. (PubMed)
  8. Zuo L, et al. Tight Junctions as Targets and Effectors of Mucosal Immune Homeostasis. Cell Mol Gastroenterol Hepatol. 2020;10(2):327-340. (PubMed)
  9. Camilleri M. The Leaky Gut: Mechanisms, Measurement and Clinical Implications in Humans. Gut. 2019;68(8):1516–1526. (PubMed)
  10. Fasano A. All disease begins in the (leaky) gut: role of zonulin-mediated gut permeability in the pathogenesis of some chronic inflammatory diseases. F1000Research. 2020;9:69. (PubMed)
  11. Fukui H. Increased Intestinal Permeability and Decreased Barrier Function: Does It Really Influence the Risk of Inflammation? Inflamm Intest Dis. 2016;1(3):135–145. (PubMed)
  12. Allam-Ndoul B, et al. Gut microbiota and intestinal trans-epithelial permeability. Int J Mol Sci. 2020;21(17):6402. (PubMed)
  13. Suzuki T. Regulation of the intestinal barrier by nutrients: The role of tight junctions. Anim Sci J. 2020;91(1):e13357. (PubMed)
  14. Yarandi SS, et al. Modulatory effects of gut microbiota on the central nervous system: How gut could play a role in neuropsychiatric health and diseases. J Neurogastroenterol Motil. 2016;22(2):201–212. (PubMed)
  15. Slyepchenko A, et al. Gut Microbiota, Bacterial Translocation, and Interactions with Diet: Pathophysiological Links between Major Depressive Disorder and Non-Communicable Medical Comorbidities. Psychother Psychosom. 2016;86(1):31–46. (PubMed)
  16. Simkin DR. Microbiome and Mental Health, Specifically as It Relates to Adolescents. Curr Psychiatry Rep. 2019;21(9):93. (PubMed)
  17. Van Ijzendoorn SCD, Derkinderen P. The Intestinal Barrier in Parkinson’s Disease: Current State of Knowledge. J Parkinsons Dis. 2019;9(s2):S323-S329. (PubMed)
  18. Rohr MW, et al. Negative Effects of a High-Fat Diet on Intestinal Permeability: A Review. Adv Nutr. 2020;11(1):77–91. (PubMed)
  19. Moreira APB, et al. Influence of a high-fat diet on gut microbiota, intestinal permeability and metabolic endotoxaemia. Br J Nutr. 2012;108(5):801–809. (PubMed)
  20. Mirmonsef P, et al. Circadian rhythms, alcohol and gut interactions. Alcohol. 2015;49(4):389–398. (PubMed)
  21. Ilchmann-Diounou H, Menard S. Psychological Stress, Intestinal Barrier Dysfunctions, and Autoimmune Disorders: An Overview. Front Immunol. 2020;11:1823. (PubMed)
  22. Ohland CL, Macnaughton WK. Probiotic bacteria and intestinal epithelial barrier function. Am J Physiol Gastrointest Liver Physiol. 2010;298(6):G807–819. (PubMed)
  23. Morris G, et al. Leaky brain in neurological and psychiatric disorders: Drivers and consequences. Aust N Z J Psychiatry. 2018;52(10):924–948. (PubMed)
  24. Han SK, Kim DH. Lactobacillus mucosae and Bifidobacterium longum Synergistically Alleviate Immobilization Stress-Induced Anxiety/Depression in Mice by Suppressing Gut Dysbiosis. J Microbiol Biotechnol. 2019;29(9):1369–1374. (PubMed)
  25. Gao J, et al. A novel postbiotic from Lactobacillus rhamnosus GG with a beneficial effect on intestinal barrier function. Front Microbiol. 2019;10:477. (PubMed)
  26. Cui Y, et al. Lactobacillus reuteri ZJ617 maintains intestinal integrity via regulating tight junction, autophagy and apoptosis in mice challenged with lipopolysaccharide. Oncotarget. 2017;8(44):77489–77499. (PubMed)
  27. Yan F, et al. Neonatal Colonization of Mice with LGG Promotes Intestinal Development and Decreases Susceptibility to Colitis in Adulthood. Mucosal Immunol. 2017;10(1):117–127. (PubMed)
  28. Ritze Y, et al. Lactobacillus rhamnosus GG Protects against non-alcoholic fatty liver disease in mice. PLoS One. 2014; 9(1):e80169. (PubMed)
  29. Donato KA, et al. Lactobacillus rhamnosus GG attenuates interferon-gamma and tumour necrosis factor-alpha-induced barrier dysfunction and pro-inflammatory signalling. Microbiology. 2010;156(11):3288–3297. (PubMed)
  30. Orlando A, et al. Lactobacillus GG restoration of the gliadin induced epithelial barrier disruption: the role of cellular polyamines. BMC Microbiol. 2014;14:19. (PubMed)
  31. Gotteland M, et al. Effect of Lactobacillus ingestion on the gastrointestinal mucosal barrier alterations induced by indometacin in humans. Aliment Pharmacol Ther. 2001;15(1):11–17. (PubMed)
  32. Francavilla R, et al. A Randomized Controlled Trial of Lactobacillus GG in Children With Functional Abdominal Pain. Pediatrics. 2010;126(6):e1445–1452. (PubMed)
  33. Sindhu KNC, et al. Immune response and intestinal permeability in children with acute gastroenteritis treated with Lactobacillus rhamnosus GG: A randomized, double-blind, placebo-controlled trial. Clin Infect Dis. 2014;58(8):1107–1115. (PubMed)