Short-Chain Fatty Acids in the Small-Bowel Bacterial Overgrowth Syndrome

The short-chain fatty acids (SCFAs) have been measured by gas chromatography in fasting jejunal secretions, saliva, and feces from 8 patients with the small-bowel bacterial overgrowth syndrome (BO) and 9 control patients; in jejunal secretions and saliva from 6 healthy subjects; and in feces from 20 healthy subjects. The concentrations of SCFAs (median (range), mUmol/l) in jejunal secretions of BO patients were as follows: total, 990 (210-12,370); acetic acid, 650 (170-6770); propionic acid, 110 (16-3070); isobutyric acid, 26 (1-310); n-butyric acid, 90 (12-1340); isovaleric acid, 35 (2-680); n-valeric acid, 7 (3-200). In BO patients the total concentration of SCFAs in jejunal secretions was approximately four times higher than in control patients (p < 0.01) and in healthy subjects (p < 0.025). The relative distribution of the acids resembled the distribution found in feces more than that of saliva or the normal jejunal secretions. These findings indicate that patients with BO have a colonlike flora in th...