The sialic acid and carbohydrate content and the synthesis of glycoprotein from radioactive precursors by tissues of the normal and diseases upper intestinal tract.

The sialic acid and total hexose content of perorally obtained mucosal biopsies have been determined. Gastric mucosa has a higher content of sialic acid/mg protein and a lower content of total hexoses/mg protein than does jejunal mucosa. There were no differences chemically between gastric biopsies from subjects with or without peptic ulcers. Neither were there any differences between normal jejunal mucosa and jejunal mucosa from patients with untreated or treated coeliac disease. The studies of the incorporation of radioactive glucose into glycoprotein using all these tissues indicate that bacteria make a major in vitro contribution. This method is not suitable for study of de novo synthesis in either gastric or jejunal mucosa. Results are presented which suggest that bacteria may normally be present within the mucous layer of the stomach.