Composition of Faecal Microbiota and Metabolism of Faecal Bacteria of Pig-Flora-Associated (PFA) mice

The composition of the faecal microbiota and concentrations of faecal short chain fatty acids (SCFAs) and putrefactive products were studied in pig-flora-associated (PFA) mice inoculated with faecal suspensions from pigs before and after weaning. Major faecal bacteria of pigs colonised the intestine of PFA mice, and the composition of microbiota of the PFA mouse faeces were similar to that of the pig faeces inoculum. Unexpectedly, pig faecal lactobacilli also colonised the intestines of PFA mouse groups at levels of 10 6 -10 9 /g faeces. However, faecal concentrations of putrefactive products in PFA mice did not simulate those in the inocula, although the concentrations of the major components of SCFAs of PFA mice were similar to those of the inocula. These findings indicate that PFA mice are a good model for studying the ecosystem of pig faecal microbiota and the control of SCFAs in the pig intestine, but not for studying putrefactive products generated in the pig intestine. Keywords: pig-flora-associated mice, faecal microbiota, putrefactive products, short chain fatty acids.