44 TRANSFORMATION OF THE INTESTINAL FLORA 



CHART 20 



Graph indicating average percentages of B. acidoph- 

 ilus appearing in the different parts of the intes- 

 tine of rats fed on a diet containing dextrin 

 and B. acidophilus 



60 



Dteti. 



/n qrarns 



'-^ 



Bread /o 



J3. acidotJ7i/vs J C C 



Parts of alimentary canal 



8 





05 



of the standard suspension for the first two weeks, followed by one 

 cubic centimeter of the same suspension during the remainder of the 

 experiment. 



The results obtained with the different rats during the first fourteen 

 days were very consistent and essentially the same as in previous ex- 

 periments with the special flora-simplifying diets, B. acidophilus becom- 

 ing the dominant organism and remaining so to the end of the fourteen 

 days' period. At the close of this period one cubic centimeter was sub- 

 stituted for the two cubic centimeters of B. acidophilus suspension ad- 

 ministered to the third set of rats, and this plan followed for the remain- 

 ing sixteen days of the experiment. The diet of the other rats remained 

 unchanged. 



The daily administration of one cubic centimeter of B. acidophilus 

 tended to preserve the simple character of the intestinal population for 

 six to eight days, after which a somewhat sudden reversion to the usual 

 mixed flora took place. (See Chart 23.) On the other hand, the flora 

 of the other six rats remained simplified and completely dominated by B. 

 acidophilus. These results lead to the conclusion that in the white rat 



