Dissolved oxygen in the porcine gastrointestinal tract

Dissolved oxygen concentrations in gut contents in situ were measured in anaesthetized piglets by the electrode and membrane-inlet mass spectrometric methods. Very high concentrations of oxygen were observed throughout the gut. In the duodenum and jejunum, values approaching air-saturation were recorded. Taken together with previous findings on the distribution of anaerobes in the gut, it seems that the dissolved oxygen concentration may be an important factor determining the activity and composition of the pig gut microbial flora.