Abstract
Gas chromatographic analysis of volatile fatty acids (VFA) and determination of pH were performed on the gastrointestinal contents of normal and Shigella-infected monkeys (Macaca fascicularis). The results obtained are as follows. 1) In both normal and Shigella-infected monkeys, the total VFA concentration of the large intestine, especially of the cecum, was evidently higher than that of the stomach and of the lower small intestine. However, the total VFA concentration in the every part of the gastrointestinal tract of Shigella-infected monkeys decreased by about 50% as compared with that of the normal ones except for the stomach. 2) The most predominant VFA was acetic acid, followed by propionic and n-butyric acids in both normal and Shigella-infected monkeys. 3) With regard to pH, Shigella-infected monkeys showed higher values than the normal ones in all parts of the gastrointestinal tract except for the stomach. The largest difference was observed in the cecal contents. 4) There was a statistically significant reciprocal relationship between total VFA concentrations and pH in the contents of the large intestine of normal monkeys. These resiults of VFA and pH are discussed as possible predisposing factors for the establishment of Shigella infection.
