Intestinal Implantation of B. Acidophilus. 31 



Particular attention is being given to the preparation of 

 B. acidophilus milk which is uniform from day to day in its 

 physical and chemical properties. Experience thus far has shown 

 that such a product may be obtained easily when certain conditions 

 are carried out. In the first place, the stock strains, preferably 

 mixed strains, must be grown sufficiently long in milk to bring 

 about light curdling within a period of 24 hours. When such 

 strains are once developed they should remain viable for many 

 months at least. We are still employing the strains which were 

 first used for this purpose eight months ago, and are unable as yet 

 to detect any signs of deterioration. The character of the soft 

 curd is very much influenced by the quality of the milk at the 

 time of sterilization preliminary to inoculation. If the milk is 

 more or less acid, even though no curdling is observed, the final 

 product tends to be of uneven consistency, granules and lumps of 

 curd being quite apparent. As a rule overnight incubation suffices 

 to bring about the formation of the soft curd. At any rate, the 

 incubation should not be continued for more than 24 hours. 



Successfully prepared B. acidophilus milk should have the 

 following properties. It should be of a uniform creamy con- 

 sistency, except for some particles of thin film which is formed 

 during the process of sterilization of the milk, and should have 

 only a very thin layer of whey on the surface. The creamy char- 

 acter becomes more marked on vigorous shaking of the product. 

 The odor should be slightly aromatic with no suggestion of ordi- 

 nary bacterial decomposition. Both odor and taste should be 

 pleasant. On standing at ordinary or refrigerator temperature 

 without contamination, little change should be noted in the physical 

 and chemical characters. The acidity, which always remains well 

 below 1 per cent., increases but little after the initial incubation 

 period. Samples of the milk which have been held at room tem- 

 perature for two weeks were practically indistinguishable from 

 the freshly prepared product. 



Although a number of clinical cases have been included in 

 the 30 or more subjects which have been employed in the present 

 study of implantation of B. acidophilus, and with most promising 

 results, we do not wish to make any statements as to the thera- 

 peutic value of B. acidophilus feeding until a time when an abun- 

 dance of information on this phase may be at hand. 



