CHAPTER XL VI 

 BACTERIA OF THE INTESTINAL TRACT 



LEO F. RETTGER 



Yale University 



NUMBERS AND QUANTITY 



The large intestine of man and lower mammals is a veritable culture tube in which 

 definite bacterial types appear to be struggling constantly to gain supremacy, A hasty 

 microscopic examination of the contents from the colon or of the feces is sufficient to 

 indicate that bacteria constitute a large part of the fecal material. No very extensive 

 investigation is required, however, to show that only a very small proportion of the 

 total flora is made up of living micro-organisms. 



Strasburger,' by the use of his gravimetric method, arrived at the conclusion that 

 the average normal adult excretes about 8 gm. (dry weight) of bacteria daily, or 128 

 trillions. MacNeal, Latzer, and Kerr^ estimated the number of bacteria (living and 

 dead) excreted daily by a normal adult as 33X10", and that this number of bacterial 

 cells is equivalent to 5.34 gm. of dried bacteria or 0.585 gm. of bacterial nitrogen. 

 Matill and Hawk'' place the daily output at 8.27 gm. (dry weight), and Sato^ at 

 8.54 gm. 



Numerous attempts have been made to reduce or control the microbic flora of the 

 intestine by the administration of a sterile diet, but on the whole they were not suc- 

 cessful. Sucksdorfif^ claimed that the number of intestinal bacteria is reduced by the 

 use of sterile food. Somewhat similar results were obtained by Gilbert and Dominici*^ 

 and by Brotzu.'^ However, numerous investigators, including Escherich,^ Hammerl,' 

 and Belonowsky,'" were unable to confirm these claims. 



The possibility of regulating or completely suppressing bacterial growth and ac- 

 tivity in the intestine by the use of chemical antiseptic agents has also received much 

 consideration. Wassilieff," Baumann,'^ and others claimed that calomel lessened the 

 intestinal putrefactive processes, and according to the observations of Fiirbringer'^ 



■ Strasburger, J.: Zlschr.f. klin. Med., 46, 413. 1902. 



^MacNeal, W. J., Latzer, L. L., and Kerr, J. E.: J. Infect. Dis., 6, 123, 571. 1909. 



^Matill, H. A., and Hawk, P. B.: J. Exper. Med., 14,433. iQ"- 



'* Sato, T.: Zlschr.f. exper. Path. u. Therap., 7, 427. 1910. 



sSucksdorff, W.: Arch.f. Hyg., 4, 355. 1886. 



^Gilbert, A., and Dominici, S. A.: Compt. rend. Soc. de biol., 117, 277. 1894. 



'Brotzu, L.: Centralbl.f. Bakteriol., 17, 726. 1895. 



^Escherich, T.: Fortschr. d. Med., 3, 515. 1885. 



'Hammerl, H.: Ztschr.f. Biol., 35, 355. 1897. 



'" Belonowsky, J.: Ann. de I'lnst. Pasteur, 21, 991. 1907. 



" Wassilieff, N. P.: Ztschr.f. phys. Chemie, 6, 112. 1882. " Baumann, E.: ibid., 10, 123. 1886. 



'3 Fiirbringer, F.: Deutsche med . Wchnschr., 13, 209, 235. 1887. 



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