An experimental study on bacterial colonization, nitrite and nitrosamine production in the operated stomach.

Intragastric bacterial growth and nitrite and nitrosamine formation were investigated in animal experiments after different surgical procedures of ulcer management with regard to carcinogenesis in the operated stomach. The operative procedures resulted in an alteration in the gastric flora with an increase and predominance of nitrate-reducing bacteria. There was an increase in the intragastric nitrite and nitrosamine concentration corresponding to the increase in nitrate-reducing bacteria. All three parameters showed the greatest increase after gastric resection, whereas there were no significant differences after vagotomy with pyloroplasty, compared with a control group. These findings in animal experiments are of etiopathological relevance to the known danger of cancer in the resected human stomach and should be taken into consideration when choosing a procedure for surgical ulcer therapy.