FERMENTED MILKS. 7 



Milk is usually looked upon as a nitrogenous food, but it should be 

 remembered that it contains about 5 per cent of lactose, a carbohydrate 

 which seems to be peculiarly adapted to bacterial fermentation. 



Aside from the possible therapeutic value of fermented milks, there 

 can be no question that they are nutritious and refreshing and that 

 their use should be encouraged for their food value. 



FOOD VALUE OF FERMENTED MILK. 



The high food value of milk is too generally recognized to need 

 discussion here ; fermented milks also have a high food value, except 

 that in some cases the fat is partially or entirely removed. Other- 

 wise the food value of the fermented milk differs little from that of 

 the fresh milk from which it is made. Any increased digestibility 

 of the fermented milk is due not so much to change in the chemical 

 nature as to the fact that the casein is furnished in a precipitated 

 and finely divided condition. In none of the fermented milks is there 

 any material cleavage of the casein resembling the digestion in the 

 stomach. The fat is practically unchanged, and a part only of the 

 sugar is converted into acid, alcohol, or gas. In certain gastric 

 troubles in which it is difficult to find any food that can be retained 

 by the patient, fermented milks are frequently used with good results. 

 Kefir and kumiss especially are used under such circumstances, as 

 the stimulating action of the carbon dioxid which they contain is 

 believed to aid in their digestion. To the physician the value of a 

 highly nutritious food which can be digested when other foods are 

 rejected is obvious. 



There are many questions that should be very carefully considered 

 before a fermented milk is introduced as an important part of the 

 diet. As Herter (41) has pointed out in the admirable paper already 

 cited, the addition of fermented milk to the diet may change very 

 materially the ratio of protein to other classes of food. If the milk is 

 taken in place of other food, the daily protein ration may be so re- 

 duced that intestinal putrefaction, which is dependent on the protein 

 part of the food, is diminished. On the other hand, if milk is added 

 to the usual food, the protein ratio may be increased rather than di- 

 minished. In many cases the condition of the mucous membranes 

 will not permit the presence of organic acid, and soured milk can not 

 be retained. It is also possible that symptoms of autointoxication are 

 not caused by unusual bacterial activity in the intestine, but by func- 

 tional failure of certain organs. This point could be determined only 

 by a physician. It would be very unsafe to consume large quantities 

 of milk, fermented or unfermented, under certain pathological con- 

 ditions. In any case an important change in the diet should be 

 mafic only upon the advice of a physician. 



