EXPERIMENTS WITH HUMAN SUBJECTS 107 



tribution, tests were made for the presence of reducing substances, the 

 technique being the same as that employed in the experiments with white 

 rats (page 58), with the exception that three grams of the human feces 

 were employed and added to fifty cubic centimeters of dilution water. 

 The results are shown in the following table (69). In this table are 

 included also the results obtained with two control subjects, that is 

 persons who were not receiving the special carbohydrate. The stools 

 from the subjects taking lactose gave an unmistakable reduction with 

 Benedict's solution, and harbored a flora almost completely dominated 

 by B. acidophilus, while those of the controls possessed no reducing 

 properties and contained the usual mixed flora. The conclusion is 

 drawn, therefore, that in man, as well as in rats, the lactose, when in- 

 gested in sufficient amounts to transform the flora, is not completely 

 absorbed before it reaches the large intestine, and that it serves as 

 particularly utilizable pabulum for the development of B. acidophilus 

 in the large intestine, where the activities of intestinal organisms are 

 greatest. Hence, an optimum environment is created in the lower 

 intestine for B. acidophilus. This correlation between the simplifying 

 property of lactose and its incomplete absorption from the enteric tube 

 must be viewed as of considerable significance. 



TABLE 69 



The Relation of Diet to Reducing Carbohydrates and to the Bacterial Flora in 

 Fecal Specimens from Human Subjects 



Reduction of Per Cent of 



Subject Diet Period of Feeding Benedict's Solution B. Acidophilus 



Control 

 F >. 10 days - 1 



.s ^ .Si 



I %^^ 10 days - 2 



A -3* i 10 days + 97 



*3 bo 



C ^*.§ 10 days + 91 



D 1^1 10 days + 99 



L O ^ 10 days + 87 



cd be 



^•.a^ 10 days + 89 



