[Search for propionic acid bacteria in the human intestine].

The possibility of detecting propionic acid-producing bacteria in the intestine of healthy humans with a view to obtaining a strain which is physiologically most suitable for therapeutic purposes has been studied. The selective conditions for the isolation of propionic acid-producing bacteria from the large intestine have been experimentally established. Analysis of 70 puncture biopsy specimens of parietal mucus and luminal contents from different sections of the intestine has not shown the presence of the representatives of propionic acid-producing bacteria. The strains isolated under the conditions selective for such bacteria have been found to belong to the family Enterobacteriaceae. These strains have proved capable of synthesizing vitamin B12, but the synthesis of propionic acid has not been observed.