INFECTIONS OF THE DIGESTIVE TRACT 89 



types of microorganisms after a time disappear and the 

 plates show exclusively colonies of the colon bacillus 

 and B. lactis aerogenes in almost pure culture. On the 

 other hand, there is good evidence that the Gram-nega- 

 tive bacilli of the f seces may be temporarily replaced by 

 feeding Gram-positive acidophile bacteria. 



It appears probable that in considering the influence 

 of foods upon the flora of the intestinal tract one should 

 take into account .the factor of rapid digestion and 

 absorption in the upper part of the digestive tract. 

 For example, in cases where a patient takes daily a large 

 quantity of meat which is imperfectly masticated, there 

 is much more opportunity for the development of pu- 

 trefactive anaerobes in the lower part of the intestine 

 than if the same quantity of meat is thoroughly sub- 

 divided by mastication. I believe also that the influence 

 of diet must be largely modified by the character of the 

 dominant organisms in the intestinal tract and that this 

 influence may come to the front in a telling way in cases 

 of chronic infections of the large intestine. 



THE REDUCING ACTION OF MEAT 



In the study of the anaerobic conditions that prevail 

 in the digestive tract it is important to recognize every 

 factor that may enter into the production of anaerobic 

 conditions there. It seems extremely probable that 

 different articles of food have a different significance in 

 respect to their influence on the presence or absence of 

 oxygen in the digestive tract. It is known that fresh 

 tissues of animals exert a considerable degree of reduc- 



