The inner of the two Muc2 mucin-dependent mucus layers in colon is devoid of bacteria

We normally live in symbiosis with approximately 10(13) bacteria present in the colon. Among the several mechanisms maintaining the bacteria/host balance, there is limited understanding of the structure, function, and properties of intestinal mucus. We now demonstrate that the mouse colonic mucus consists of two layers extending 150 mum above the epithelial cells. Proteomics revealed that both of these layers have similar protein composition, with the large gel-forming mucin Muc2 as the major structural component. The inner layer is densely packed, firmly attached to the epithelium, and devoid of bacteria. In contrast, the outer layer is movable, has an expanded volume due to proteolytic cleavages of the Muc2…

• SC
  Swedish Cancer Foundation
• SF
  Stiftelsen för Strategisk Forskning
• V
  Vetenskapsrådet
• GU
  Göteborgs Universitet