The most accurate method of estimating the total amount of bacteria in the feces is that devised by Strasburger,1 which determines the actual dried weight of all the bacteria whether living or dead.
Attempts to form an idea of the proportion of bacteria in the feces by plating a given quantity and then counting the colonies is inaccurate for several reasons— principally because a large proportion of the intestinal flora die in their passage through the colon and only a relatively small number of micro-organisms can be cultivated from the stool. Moreover, the different portions of a stool are far from homogeneous, and what is true of one portion will not be true of another.
It must be remembered that results obtained by Strasburger's method are entirely quantitative. No distinction is made between the putrefactive and fermentative bacteria, but the whole bulk of the intestinal flora, living and dead,
STEELE JD. THE METHOD OF DETERMINING THE TOTAL AMOUNT OF THE FECAL BACTERIA BY WEIGHT AND ITS CLINICAL SIGNIFICANCE.. JAMA. 1907;XLIX(8):647-649. doi:10.1001/jama.1907.25320080015001d