I3O MILK BACTERIA AND HEALTH. 



out such treatment of the milk. Moreover, it is found that the 

 amount of intestinal sickness in children has been noticeably 

 reduced in communities where a general sterilizing or pas- 

 teurizing of milk has been adopted. This has been done 

 quite largely in European communities, and in some Amer- 

 ican communities, during the last fifteen years, and wherever 

 accurate statistics have been obtained it has appeared that the 

 introduction of such treatment of the milk is accompanied by 

 a reduction in the amount of intestinal sickness and in. the 

 number of deaths from such causes. These various facts 

 together have led to the conclusion that the bacteria in the 

 milk are associated with this class of troubles. 



Cause of Diarrheal Diseases. Probably this class of dis- 

 eases is not produced by any single bacterium. Indeed, the 

 troubles referred to do not form a distinct disease, like 

 typhoid or scarlet fever, but represent a general class of dis- 

 eases characterized by intestinal disturbances. This being 

 the case, it would not be expected that any single bacillus 

 would be found to be the cause of them all. At all events, 

 at the present time no distinct bacterium and no particular 

 group of bacteria can be mentioned as being positively the 

 cause of all such intestinal disturbances. 



Moreover, it is evident that milk bacteria may produce 

 trouble in either of several ways. They may produce toxic 

 products in the milk, either before it is swallowed or after it 

 is taken into the stomach. If the bacteria have a chance to 

 multiply in the milk before it is used as a food they 

 will produce their toxic secretions in the milk. These 

 might act as a direct poison upon the body of a person 

 drinking the milk, and in such a case the intestinal disturb- 

 ances would be due to the toxic products developed in 

 the milk before the milk is used as food. On the other 

 hand, it is possible that the bacteria may grow after 

 reaching the stomach and intestine and produce their 

 toxic products in the intestine. In such a case the diarrheal 



