It is frequently urged, as an argument against Behring's theory as to tuberculous infection taking place through the intestinal tract, that if this were true, then primary tuberculous lesions in the intestines of tuberculous children and adults would be a common finding at necropsy instead of a very rare one.
Koch's paper at the London Congress, in which he asserted that no case of tuberculosis can be considered of alimentary origin unless a primary tuberculous lesion is found in the intestinal tract, gave a new impetus to the controversy over this question as long ago as 1890. Dobroklonski, working under Cornil, had practically proved that tubercle bacilli can pass through an intact intestinal mucosa, for he demonstrated the presence of tubercle bacilli in the solitary follicles, the mesenteric lymph glands and liver of guinea-pigs, which had been fed on glycerin bouillon cultures of this bacillus, and whose intestinal mucosa proved
ABSORPTION OF TUBERCLE BACILLI FROM THE ALIMENTARY TRACT.. JAMA. 1904;XLII(7):468-469. doi:10.1001/jama.1904.02490520058005