4 DEPARTMENT BULLETIN 319, TJ. S. DEPT. OF AGRICULTURE 
tinal tract by the ingestion of pure cultures of L. bulgaricus have 
given inconsistent results. 
Coliendy (14, 15, 16, 17), a confrere of Metchnikoff, in a series of 
papers, claims to have recovered considerable numbers of L. Irnlg ami- 
cus from the feces of patients who had been given daily 250 cubic 
centimeters of a 24-hour milk culture of L. bulgaricus. He reports 
implantation to have been established by the third to the fifth day 
and to have persisted at least 12 days after treatment was stopped. 
It was found that the volume and weight of the feces increased. The 
feces were slightly acid or neutral in reaction. 
Belonovsky (4) fed milk cultures of L. bulgarkus to rats and 
claims to have recovered the organism from the droppings 15 days 
after the last feeding. He states that the bacteria in the droppings, 
especially the gas-forming bacteria, were very much reduced as a 
result of feeding L. bulgaricus but were not affected when sterile 
milk or milk curdled with lactic acid was added to the basic diet. 
AYejnert (90) conducted an investigation in which he employed 10 
subjects who received sour milk administered rectally, 8 subjects who 
received sour milk by mouth, and 8 subjects who received an ordinary 
diet and L. bulgaricus milk. Bacteriological examinations of the 
feces from the patients receiving sour milk showed a reduction in 
bacterial count, which returned to normal in three or four days. 
Examination of the feces from patients receiving L. bulgaricus milk, 
however, showed a much greater reduction in bacterial count, which 
returned to normal much more slowly than when sour milk was 
given. 
Other investigations tend to disprove the implantability of Lacto- 
bacillus bulgaricus. Luerssen and Kiihn (58) found only a few 
organisms in feces three to five clays after discontinuing treatment. 
They had ingested one-third of a liter of L. bulgaiicus milk per day 
for about two weeks. They repeated the experiment with the same 
results and concluded that implantation of L. bulgaricus was impos- 
sible. 
Distaso and Schiller (22) fed white rats L. bulgaricus cultures 
with lactose, and L. bulgaricus milk cultures. They came to the con- 
clusion that foreign bacteria can not become acclimatized to the in- 
testinal tract, Herter and Kendall (45) found that in the digestive 
tract of a monkey killed after being fed L. bulgaricus milk for two 
weeks, the organism was abundant in the upper part of the small 
intestine only. In the lower part of the small intestine and in the 
large intestine L. bulgaricus was found in only moderate numbers as 
compared with other bacteria. Herter and Kendall (46) concluded, 
after prolonged administration of L. bulgaricus milk, that L. bul- 
garicus can not be implanted in the human intestinal tract. 
Rahe (72) made a critical investigation of the implantation of 
L. bulgaricus. His work tends to show that although L. bulgaricus 
may be found in the feces during the period in which L. bulgaricus 
milk is ingested, it disappears very soon after ingestion has stopped. 
This investigator also points out a very significant fact — that the 
difference between L. bulgaricus and certain acid-forming bacteria 
which are known to occur normally in the intestines is so slight that 
they can be distinguished only with difficulty. He suggests that the 
belief on the part of some investigators that L. bulgaricus becomes 
LT2 
