Gastric or rectal instillation of short-chain fatty acids stimulates epithelial cell proliferation of small and large intestine in rats

Short-chain fatty acids stimulate gut epithelial cell proliferation in vivo, although the difference between oral and rectal routes is unknown. Accordingly, we examined the effect of oral or rectal administration of these acids. We instilled a mixture of acetic acid, propionic acid, and n-butyric acid (150, 60, and 60 mmol/liter, respectively; pH 6.5) or saline (270 mM, pH 6.5) into the stomach (2 ml) or rectum (1 ml) three times daily for five days in rats fed an elemental diet. We measured crypt cell production rate of the jejunum, ileum, and distal colon of these rats. The crypt cell production rate of these segments was higher in rats with gastric or rectal instillation of short-chain fatty acids than in saline controls. The rectal route was slightly more effective than the gastric route. The above results indicated that the instillation of short-chain fatty acids orally or rectally stimulated gut epithelial cell proliferation.