It is generally believed that the liver rids the portal blood of many bacteria. There is little doubt that the liver is fully capable of this sterilizing action1 when called upon in acute infections or ulcerative lesions of the gut. Nevertheless, there is considerable doubt that this action takes place in health and that bacteria are normally poured into the liver by way of the portal vein.
A few years ago an attempt was made by me to prove or disprove the thesis that the portal vein normally carries bacteria. The cultures of portal blood which were taken at that time were sterile. The means of obtaining these early cultures were laborious and time consuming. It was necessary to carry out bacteriological sterility which was considerably more complicated than the mere drawing of blood from the portal vein during the course of an operative procedure. Interest in the problem
TAYLOR FW. Blood-Culture Studies of the Portal Vein. AMA Arch Surg. 1956;72(6):889–892. doi:10.1001/archsurg.1956.01270240001001