Destruction of Yeast in the Small and Large Intestines.

Different varieties of yeast were incubated with a mixture of human pancreatic juice and bile for 4 hours at 37.5°. From 50 to 99% of the yeast cells were killed. One variety of yeast showed a destruction of 50% in 16 hours and 81% at 48 hours, indicating that a part of the cells were more resistant than others or that the activity of the pancreatic juice decreased rapidly on standing. The pancreatic juice killed yeast least rapidly at about pH 7 and somewhat more rapidly in slightly acid solution (pH 6) than at pH 8.

Dogs were given 12 gm. of yeast with 100 cc. of water or 100 gm. of moist meat. The animals were killed at 2 or 4 hours after ingestion of yeast, different segments of the gastrointestinal tract tied off, and microscopical and plate counts of cells in each segment made. At 2 hours after taking yeast with water over 80% of the cells were found in the ileum. At 4 hours 70% were found in the cecum and colon and of these 40% were alive. When given with meat the recovery from cecum and colon at 4 hours was 40%, of which about 40% were living.

Destruction of yeast in different sections of the intestines of dogs was studied by injection of yeast into tied off segments in the living animal. No pronounced differences in rate of destruction in different parts of the intestine were noted nor any influence of reaction of injected material on such destruction. The per cent of yeast cells killed varied from 12 to 45%.

Yeast was fed in 12 gm. portions to normal men, 3 times a day with meals or with water before meals.