Gastrointestinal flora was investigated by means of puncture method of alimentary tract during laparotomy of patients with benign and malignant diseases, and also during autopsy of accidental and diseased cadavers. Bacterial study of anal region was also carriedout in healthy adults and patients with anal diseases by means of direct culture.
Most frequently detected microbes in the transverse colon and in the sigmoid colon were E. coli and Bacteroides, and anal flora of healthy adults was similar to those of the colon.
Bacterial flora of the colon were not influenced by gastric acidity or cancer of the stomach.
Aerobic microbes decreased their detection rate after three days successful oral administration of Neomycin or Kanamycin, and reincreased after five days use. However, anaerobic microbes increased their detection rate after three days oral administration of Neomycin and decreased after four to six days use.
Aerobic microbes such as E. coli, Proteus, Klebsiella and Pseudomonas which were detected from subjects after five days administration of such antibiotics showed high resistence to some kinds of drugs.
Therefore, preoperative oral administration of aminoglycoside antibiotics for three days limitted period was considered to be effective as an intestinal antisepsis against aerobic microbes, but was not so effective against anaerobic flora.