70 TRANSFORMATION OF THE INTESTINAL FLORA 



CARBOHYDRATE FEEDING 



In all of the carbohydrate ingestion experiments on man either lac- 

 tose or dextrin was employed. These substances were administered 

 three times daily in 1 00 gram quantities, except when the total amount 

 per day was only 150 grams, in which case they were consumed in one 

 dose. The lactose was taken in the form of a heavy aqueous suspension, 

 while the dextrin was used in 50 per cent solution prepared by boiling 

 the dextrin in water. Owing to its unpleasant taste the dextrin was 

 flavored with a little orange juice. These carbohydrates were taken be- 

 tween meals. 



TRANSFORMING INFLUENCE OF LACTOSE 



This sugar was administered to six persons, and the results were 

 fairly uniform. The ingestion of 300 grams of lactose, in addition to 

 the ordinary daily diet, by subjects A, C, D and L effected a radical 

 transformation of the fecal flora within four to eight days, from the 

 usual mixed type to one dominated almost entirely by B. acidophilus. 

 The essentially aciduric flora persisted as long as the use of lactose was 

 continued. (See Tables 29 to 32, and Chart 31.) It will be seen, 

 however (Table 33 and Chart 31), that the flora of subject B, a sturdy 

 individual weighing almost 200 pounds, failed to respond to the influ- 

 ence of 300 grams of lactose taken daily for ten days, whereas the inges- 

 tion of 400 grams of the sugar brought about a complete simplification 

 of the intestinal flora within four days. 



The use of 150 grams of lactose daily by subject I (Table 34 and 

 Chart 32) resulted in an appreciable multiplication of B. acidophilus, 

 but there was no radical suppression of the other types of intestinal 

 bacteria. 



The simplification of the intestinal flora was characterized by an 

 enormous relative and actual increase in the numbers of B. acidophilus 

 appearing in the stools, and the almost complete suppression and elim- 

 ination of the other bacterial types ordinarily present. After the 

 expiration of the first four days following the initial administration 

 of the carbohydrate, the characteristic colonies of B. acidophilus were 

 found to dominate in the whey agar plates and at times were practically 

 the only colonies present. The Veillon tubes very strikingly indicated 

 a gradual diminution in the numbers of gas-producing organisms. 

 These observations were further confirmed by the increase in the rela- 

 tive numbers of Gram-positive rods in the Gram-stained slides. 



TRANSFORMING INFLUENCE OF DEXTRIN 



The ingestion of 300 grams of dextrin exerted a marked transform- 

 ing action on the intestinal flora, stimulating the proliferation of B. 



