Bacteria, nitrosamines and cancer of the stomach.

Until recently the public water supply to Worksop contained high concentrations of nitrate. An epidemiological study has revealed that, compared with low nitrate control towns, Worksop has an increased death rate from gastric cancer. The possible role of the bacterial production of nitrosamines in the aetiology of these stomach cancer deaths is discussed.

The effect of a chemically defined diet on the faecal flora and faecal steroid concentration.

The consumption of a chemically defined diet altered both the faecal flora and faecal steroids. Enterobacteria increased while enterococci and other lactic acid bacteria decreased in number. No other obvious change occurred.

Bacteria and the N-nitrosation of secondary amines.

The ability of bacteria to catalyse the nitrosation of secondary amines has been investigated. It has been shown that this may be of importance in people with urinary tract infections living in areas where the concentration of nitrate in the drinking water is high.