10 TRANSFORMATION OF THE INTESTINAL FLORA 



dextrose. Distaso and Schiller (1914) reported that, of the various 

 carbohydrates used by them, lactose and dextrin alone exercised a 

 profound influence on the intestinal flora, bringing about a pre- 

 dominance of B. bifidus. No mention is made of B. acidophilus. 

 Wollstein (1912) studied the eff'ect upon infants of high carbohydrate 

 and protein diets, and found that the former encourage the development 

 of cocci, B. coli, B. acidophilus and B. bifidus, whereas the high protein 

 diets favored B. mesentericus, and brought about a very great reduc- 

 tion in the numbers of B. acidophilus and B. bifidus. 



Torrey (1915) found that 250 to 300 grams of lactose were re- 

 quired to transform the fecal flora of typhoid patients from the usual 

 mixed type to one dominated by B. acidophilus. B. bifidus was occa- 

 sionally seen, but it was never present in sufficient numbers to be of very 

 much significance. In his very recent investigation on dogs Torrey 

 (1919) demonstrated that fifty grams of lactose or dextrin, when added 

 to a meat and rice diet, completely transformed the ordinary flora to 

 one strongly dominated by B. acidophilus. He showed further that 

 the feeding of a bread and milk diet favored the development of a flora 

 consisting almost enirely of B. acidophilus. Saccharose, maltose and 

 glucose exercised only a comparatively moderate, if indeed any, trans- 

 forming influence. Starchy foods in the form of white bread, potatoes 

 and beans tended to bring B. acidophilus into prominence, while rice 

 was less effective. Torrey claimed that while animal proteins en- 

 couraged a strongly proteolytic flora, vegetable proteins were without 

 this effect. 



