Protecting colonic mucosa

Short-chain fatty acids (SCFAs) — produced in the colon by bacterial fermentation of dietary carbohydrates — have considerable cytoprotective properties, although the mechanisms behind this phenomenon remain unclear. In September Gastroenterology, Hongyu Ren and colleagues from The University of Chicago, Illinois, show that SCFAs induce intestinal epithelial heat shock protein 25 (hsp25) expression which protects colonic cells against oxidant injury.

Using Western blotting and immunohistochemistry Ren et al. determined the levels of hsp25, hsp72 and hsc73 protein expression in rat intestinal tissues and IEC-18 cells. They found that SCFAs cause a dose-dependent, selective increase in expression of hsp25 in surface colonocytes in vivo and increased cell protection against oxidant-induced stress. In addition, they demonstrated that hsp25 expression in the colonic mucosa could be increased by a supplementation of the fibre content in the diet (Gastroenterology 2001, 121:631-639).

On the basis of this mechanism, SCFAs or analogues...