Structure of the intestinal barrier

Dagmara Węgrzyn, Karolina Adamek, Beata Łoniewska


The intestinal barrier consist of several layers. It is made of gut microbiota, a protective layer of mucus, intestinal epithelial cells, and the blood, lymphatic, immune and nervous systems. Mucus, which prevents the adhesion and penetration of pathogens to the intestinal wall, is also a habitat for intestinal microbiota – one of the key and most dynamic elements of the intestinal barrier. Microbiota mainly consist of anaerobic bacteria, and also aerobic bacteria, yeast and viruses. The intestinal ecosystem is constantly changing during human life, but tends to keep a balance, which is a guarantee of health. The single layer of the intestinal epithelium is a part of the physical barrier, which is mainly formed by enterocytes, which in addition to the absorption of nutrients affect the development of immunity by mediating the release of cytokines and the expression of receptors involved in the immune response. Tight junctions are located at the apical ends of the lateral membranes of intestinal epithelial cells. They are the most important elements for maintaining intestinal permeability. Anchoring junctions and communicating junctions are also connections between epithelial cells. Under the layer of epithelial cells is the lamina propria, comprising intestinal lymphatic tissue, intestinal tract, and nervous system tissue. Continuous changes in the intestinal barrier influence the health and disease balance.


intestinal barrier; microbiota; tight junction; gut-associated lymphoid tissue

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Caricilli AM, Castoldi A, Câmara NO. Intestinal barrier: A gentlemen’s agreement between microbiota and immunity. World J Gastrointest Pathophysiol 2014;5(1):18 32. doi: 10.4291/wjgp.v5.i1.18.

Rescigno M. Dendritic cells in oral tolerance in the gut. Cell Microbiol 2011;13(9):1303-8. doi: 10.1111/j.1462 5822.2011.01626.x.

Konig MF, Abusleme L, Reinholdt J, Palmer RJ, Teles RP, Sampson K, et al. Aggregatibacter actinomycetemcomitans-induced hypercitrullination links periodontal infection to autoimmunity in rheumatoid arthritis. Sci Transl Med 2016;8:369. doi: 10.1126/scitranslmed.aaj1921.

Kawashima H. Roles of the gel-forming MUC2 mucin and its O-glycosylation in the protection against colitis and colorectal cancer. Biol Pharm Bull 2012;35(10):1637-41.

Nowak A, Libudzisz Z. Ability of probiotic Lactobacillus casei DN 114001 to bind or/an metabolise hetereocyclic aromatic amines in vitro. Eur J Nutr 2009;48(7):419-27. doi: 10.1007/s00394-009-0030-1.

Cammarota G, Ianiro G, Bibbo S, Gasbarrini A. Gut microbiota modulation: probiotics, antibiotics or fecal microbiota transplantation? Intern Emerg Med 2014;9(4):365-73. doi: 10.1007/s11739-014-1069-4.

Krakowiak O, Nowak R. Mikroflora przewodu pokarmowego człowieka – znaczenie, rozwój, modyfikacje. Post Fitoter 2015;3:193-200.

Tappenden KA, Deutsch AS. The physiological relevance of the intestinal microbiota – contributions to human health. J Am Coll Nutr 2007;26(6):679-83.

Purchiaroni F, Tortora A, Gabrielli M, Bertucci F, Gigante G, Ianiro G, et al. The role of intestinal microbiota and the immune system. Eur Rev Med Pharmacol Sci 2013;17(3):323-33.

Wu M, Wu Y, Deng B, Li J, Cao H, Qu Y, et al. Isoliquiritigenin decreases the incidence of colitis associated colorectal cancer by modulating the intestinal micro biota. Oncotarget 2016;7(51):85218-331. doi: 10.18632/oncotarget.13347.

Van Der Flier L, Clevers H. Stem cells, self-renewal, and differentiation in the intestinal epithelium. Annu Rev Physiol 2009;71:241-60. doi: 10.1146/annurev.physiol.010908.163145.

Pott J, Hornef M. Innate immune signalling at the intestinal epithelium in homeostasis and disease. EMBO Rep 2012;13(8):684-98. doi: 10.1038/embor.2012.96.

Lee SH. Intestinal permeability regulation by tight junction: implication on inflammatory bowel diseases. Intest Res 2015;13(1):11-8. doi: 10.5217/ir.2015.13.1.11.

Turner JR, Rill BK, Carlson SL, Carnes D, Kerner R, Mrsny RJ, et al. Physio¬logical regulation of epithelial tight junctions is associated with myosin light-chain phosphorylation. Am J Physiol 1997;273:1378-85.

Umeda K, Matsui T, Nakayama M, Furuse K, Sasaki H, Furuse M, et al. Establishment and characterization of cultured epithelial cells lacking expression of ZO-1. J Biol Chem 2004;279(43):44785-94. doi: 10.1074/jbc.M406563200.

Drago S, El Asmar R, Di Pierro M, Grazia Clemente M, Tripathi A, Sapone A, et al. Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac intestinal mucosa an intestinal cell lines. Scand J Gastroenterol 2006;41(4):408-19. doi: 10.1080/00365520500235334.

Zeissig S, Bürgel N, Günzel D, Richter J, Mankertz J, Wahnschaffe U, et al. Changes in expression and distribution of claudin 2, 5 and 8 lead to discontinuous tight junctions and barrier dysfunction in active Crohn’s disease. Gut 2007;56(1):61-72. DOI: 10.1136/gut.2006.094375.

Sander GR, Cummins AG, Henshall T, Powell BC. Rapid disruption of intestinal barrier function by gliadin involves altered expression of apical junctional proteins. FEBS Lett 2005;579(21):4851-5. doi: 10.1016/j.febslet.2005.07.066.

Al-Sadi R, Khatib K, Guo S, Ye D, Youssef M, Ma T. Occludin regulates macromolecule flux across the intestinal epithelial tight junction barrier. Am J Physiol Gastrointest Liver Physiol 2011;300(6):1054-64. doi: 10.1152/ajpgi.00055.2011.

Rao R. Occludin phosphorylation in regulation of epithelial tight junctions. Ann N Y Acad Sci 2009;1165:62-8. doi: 10.1111/j.1749-6632.2009.04054.x.

Martínez C, Lobo B, Pigrau M, Ramos L, González Castro AM, Alonso C, et al. Diarrhoea-predominant irritable bowel syndrome: an organic disorder with structural abnormalities in the jejunal epithelial barrier. Gut 2013;62(8):1160-8. doi: 10.1136/gutjnl-2012-302093.

Salvo-Romero E, Alonso-Cotoner C, Pardo-Camacho C, Casado-Bedmar M, Vicario M. The intestinal barrier function and its involvement in digestive disease. Rev Esp Enferm Dig 2015;107(11):686-96. doi: 10.17235/reed.2015.3846/2015.

Laukoetter MG, Nava P, Lee WY, Severson EA, Capaldo CT, Babbin BA, et al. JAM-A regulates permeability and inflammation in the intestine in vivo. J Exp Med 2007;204(13):3067-76. doi: 10.1084/jem.20071416.

Kojima T, Murata M, Go M, Spray DC, Sawada N. Connexins induce and maintain tight junctions in epithelial cells. J Membr Biol 2007;217(1-3):13-9. doi: 10.1007/s00232-007-9021-4.

Gill N, Wlodarska M, Finlay B. Roadblocks in the gut: barriers to enteric infection. Cell Microbiol 2011;13(5):660 9. doi: 10.1111/j.1462-5822.2011.01578.x.

Jónsdóttir I. Maturation of mucosal immune responses and influence of maternal antibodies. J Comp Pathol 2007;137:20-6. doi: 10.1016/j.jcpa.2007.04.007.

Woodland DL, Randall TD. Anatomical features of anti-viral immunity in the respiratory tract. Semin Immunol 2004;16(3):163-70. doi: 10.1016/j.smim.2004.02.003.

Fasano A. Leaky gut and autoimmune diseases. Clin Rev Allergy Immunol 2012;42(1):71-8. doi: 10.1007/s12016 011-8291-x.

Prasad S, Mingrino R, Kaukinen K, Hayes KL, Powell RM, MacDonald TT, et al. Inflammatory processes have differential effects on claudins 2, 3 and 4 in colonic epithelial cells. Lab Invest 2005;85(9):1139-62. doi: 10.1038/labinvest.3700316.

Nouri M, Bredberg A, Weström B, Lavasani S. Intestinal barrier dysfunction develops at the onset of experimental autoimmune encephalomyelitis, and can be induced by adoptive transfer of auto-reactive T cells. PLoS One 2014;9(9):106335. doi: 10.1371/journal.pone.0106335.

Zhang D, Zhang L, Yue F, Zheng Y, Russell R. Serum zonulin is elevated in women with polycystic ovary syndrome and correlates with insulin resistance and severity of anovulation. Eur J Endocrinol 2015;172(1):29-36. doi: 10.1530/EJE-14-0589.


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