[Transfer of the fecal microbial flora from holoxenic piglets and adult pigs to axenic piglets and axenic adult mice : effect of the animal host and of the diet on the fecal microbial pattern of these animals (author's transl)].

The purpose of the present work was to determine whether the axenic mouse inoculated with pig fecal microflora represents a valuable tool for studying the gastro-intestinal flora of holoxenic pigs. The microbial pattern of the feces of the different animals has been described by means of quantitative differential techniques of analysis, the limits and validity of which are discussed. The gnotoxenic mouse associated with the flora of piglet is a better model as the gnotoxenic mouse associated with the flora of adult pig. The gnotoxenic mouse represents an adequate means for preserving all the pig strains, especially if the inoculation is made in anaerobiosis, but the bacterial equilibrium is markedly affected by the host. In the case where the same holoxenic piglet flora is inoculated simultaneously into a gnotoxenic mouse and a gnotoxenic piglet placed in the same isolator in absolutely identical dietary and environmental conditions, the results observed in the mouse can be extrapolated to the piglet. However, this is only the case for short-term experiments. If the association between the piglet flora and the host mouse is prolonged, the microbial pattern changes, but these modifications seen to be reversible when the flora is transferred into another axenic either piglet or mouse. The nature of the different feeds absorbed by the gnotoxenic animals does not deeply change the bacterial equilibriums, except when the milk contains an antiseptic substance.