DIGESTIBILITY OF WHEAT BRAN. 17 
In computing the digestibility of bran protein negative results 
were obtained in experiments Nos. 410 and 411; that is, the fecal 
protein was greater than that supplied by the bran. In three of the 
remaining tests (experiments Nos. 409, 436, and 439) the values were 
decidedly lower than in the remaining tests. Omitting these low 
values the average coefficients of digestibility for -bran becomes 38.8 
per cent instead of 28 per cent. 
The reports made by the subjects regarding their physical condi- 
tion vary from “normal except for occasional slight pains in the 
stomach after eating” to “extreme laxative effect.” 
No definite relation was apparent between such observations and 
the coefficients of digestibility. It is also interesting to note that the 
subjects were all of the opinion that no differences with respect to 
laxative effect were noted in the tests with finely ground and with 
coarse bran. 
GENERAL DISCUSSION. 
The results of numerous studies conducted both in this country 
and abroad to determine the digestibility of wheat flours containing 
little, if any, bran as compared with the digestibility of flours con- 
taining all the bran normally present in the grain show that the 
protein and carbohydrate of flours from which the bran has been 
largely removed is more completely utilized by the human body 
than the protein and carbohydrate of flours prepared from the whole 
grain. 
So far as can be learned, no studies have been made to determine 
the digestibility of wheat bran when eaten as a constituent of a 
diet which did not include the flour prepared from the remainder 
of the kernel. With the purpose of securing more data on the 
digestibility of wheat bran included in a diet from which all forms 
of wheat flour were excluded, two series of experiments were made, 
one with fine bran and one with coarse bran, the subjects and ex- 
perimental conditions being alike for both series. 
An average of 465 grams of fine bran bread, equivalent to 155 
grams bran, and of 395 grams of coarse bran bread, equivalent to 
132 grams bran, was eaten per man per day. The results of tests 
with fine bran indicate that the protein supplied by the bran was 
_ 44.7 per cent and the bran carbohydrate was 56.6 per cent digested, 
while the results of the tests with coarse bran indicate a digestibility 
of 28 per cent for the bran protein and 55.5 per cent for the bran 
carbohydrate. The result for the digestibility of fine bran protein 
is in agreement with the results of Pannwitz,' who found that the 
protein of fine rye bran was 43.68 per cent digested. 
1 Nihrwerth des Soldatenbrotes, Inaug. Diss., Berlin, 1898, p. 100. 
