12 INFECTIONS OF THE DIGESTIVE TRACT 



such feeding would be practicable in man on a scale suffi- 

 ciently great to secure definite results in the suppression 

 of harmful types, such as the putrefactive anaerobes, 

 can only be determined by experiment. At the present 

 time it is known that the acidophiles are represented in 

 all parts of the tract, especially in the large intestine, 

 but we cannot yet say with confidence what is their 

 physiological role or what would be their influence on 

 the organism if their numbers should be greatly in- 

 creased through feeding. 



The various facts that have now been advanced render 

 it certain that microorganisms of the B. coli type are 

 able under some conditions to check the growth of patho- 

 genic microorganisms which are often found among the 

 intestinal flora. The conditions that obtain in the colon 

 differ, however, with respect especially to the nutrient 

 pabulum and the digestive secretions, from any attain- 

 able experimental conditions, however cleverly these may 

 be designed to imitate what occurs in nature. We have 

 therefore to exercise some caution in transferring these 

 results, without due consideration, to the human digestive 

 tract. Nevertheless the evidence now available suggests 

 that in health the colon bacillus, both in man and the 

 higher mammals, exerts an important function in com- 

 bating the development of the injurious saprophytes 

 with which even in ordinary health the human intesti- 

 nal tract almost necessarily abounds. A long, largely 

 anaerobic intestinal tract, permitting gradual resorption 

 of the contents, is a physiological necessity in order that 

 a loss of water and its detrimental consequences may 



