* 
FERMENTED MILKS 11 
fruit jar and put away in a warm place. One of the vacuum- jacketed 
bottles will be found very convenient for this purpose, because the 
milk can be held at a nearly constant temperature favorable to the 
growth of the lactic-acid bacteria. On the following day the bottle 
is shaken thoroughly to break up the curd, and the product is put 
on ice to cool. The process is repeated, a teaspoonful of the freshly 
curdled milk being used to inoculate the heated and cooled milk. 
Butter makers in the Northwest make a very refreshing and nutri- 
tious drink by adding sugar and lemons to buttermilk. As the casein 
is already precipitated, the acid juice of the lemon has no effect. 
Slightly more sugar and lemon juice are necessary than in making 
ordinary lemonade, and the mixture should be well iced. 
ACIDOPHILUS MILK 
It has been shown elsewhere that the possibilities ascribed to 
fermented-milk therapy by Metchnikoff (61) lacked one important 
detail. He chose a bacterium foreign to the alimentary tract, and 
therefore one not adaptable to conditions existing in the intestines. 
It has been shown further that Lactobacillus acidophilus is a normal 
inhabitant of the intestines, and under the proper influence predomi- 
nates the bacterial flora of the feces to the exclusion of putrefactive 
and other undesirable bacteria. 
Rettger (73) has shown the following methods to be effective in 
bringing about the preponderance of L. acidophilus in the intestines: 
(1) The daily use by an adult person of from 100 to 300 grams of 
lactose; (2) the daily ingestion of relatively large amounts of fresh 
pure-broth cultures of the L. acidophilus, together with appreciable 
quantities of lactose or dextrin; and (3) the ingestion of a pure 
culture of the L. acidophilus in milk or acidophilus milk. 
Acidophilus milk is generally conceded to be the best method of 
implanting L. acidophilus in the intestines. Milk is a medium which 
is especially suitable for the growth of L. acidophilus, once the or- 
ganism has become acclimated. The organism remains viable in 
milk for a longer time than in any other medium. The product is 
palatable, has an agreeable mildly acid flavor, and is an easily 
digested food. It contains about 5 per cent of lactose, which has 
been shown by Rettger to be so valuable an agent in the transfor- 
mation of the intestinal flora. 
Acidophilus milk has been prescribed by physicians and has been 
reported to be efficacious in the treatment of constipation, diarrhea, 
and other intestinal disorders. According to Rettger (75) acid- 
ophilus milk, to be effective, must contain large numbers of viable 
L. acidophilus organisms of proved therapeutic value. The product 
therefore should be fresh and should be obtained from a reliable 
manufacturer. Kopeloff (51) has shown that about 90 per cent of 
the viable organisms are destroj^ed after three days at ice-box tem- 
perature and recommends keeping the product at room temperature. 
The dose is usually about 1 quart of acidophilus milk a day and 
may or may not be reinforced with from 50 to 300 grams of lactose. 
It is sometimes better to begin with a smaller dose and gradually 
increase the quantity. Sometimes a considerable amount of gas is 
produced in the intestines the first few days, but this soon disap- 
