Movement and Fixation of Intestinal Microbiota after Administration of Human Feces to Germfree Mice

Abstract

Human flora-associated (HFA) mice have been considered a tool for studying the ecology and metabolism of intestinal bacteria in humans, although they have some limitations as a model. Shifts in dominant species of microbiota in HFA mice after the administration of human intestinal microbiota was revealed by 16S rRNA gene sequence and terminal restriction fragment length polymorphism (T-RFLP) analyses. Characteristic terminal restriction fragments (T-RFs) were quantified as the proportion of total peak area of all T-RFs. Only the proportion of the T-RF peak at bp 366, identified as the Gammmaproteobacteria group and the family Coriobacteriaceae, was reduced in this study. Increased T-RFs over time at bp 56, 184, and 196 were affiliated with the Clostridium group. However, most of the isolated bacteria with unique population shifts were phylotypes. The vertical transmission of the intestinal microbiota of the mouse offspring was also investigated by dendrogram analysis derived from the similarity of T-RFLP patterns among samples. As a result, the intestinal microbiota of HFA mice and their offspring reflected the composition of individual human intestinal bacteria with some modifications. Moreover, we revealed that human-derived lactobacilli (HDL), which have been considered difficult to colonize in the HFA mouse intestine in previous studies based on culture methods, could be detected in the HFA mouse intestine by using a lactic acid bacterium-specific primer and HDL-specific primers. Our results indicate that the intestinal microbiota of HFA mice represents a limited sample of bacteria from the human source and are selected by unknown interactions between the host and bacteria.

The Human Microbiome Project

“…A number of groups have introduced a human fecal microbiota into GF animals (e.g., ref. 19). Since these studies were conducted before large-scale 16S rRNA-based enumeration studies were feasible, we do not have a clear view of what fraction of the human gut microbiota takes hold in the mouse gut.…”

Increase in Terminal Restriction Fragments of Bacteroidetes -Derived 16S rRNA Genes after Administration of Short-Chain Fructooligosaccharides

“…PCR products were purified with the MinElute PCR purification kit (QIAGEN, Valencia, CA) and then digested with MspI. Lengths of terminal restriction fragments (T-RFs) in digested PCR products were analyzed by the ABI PRISM 310 genetic analyzer (Applied Biosystems, Foster City, CA) in Genescan mode, with the GS-500 ROX and GS-1000 ROX internal standards as described previously (10). The obtained T-RFLP profiles were analyzed by BioNumerics software (Applied Maths, Ver 3.0, Austin, TX) as described previously (10).…”

“…Lengths of terminal restriction fragments (T-RFs) in digested PCR products were analyzed by the ABI PRISM 310 genetic analyzer (Applied Biosystems, Foster City, CA) in Genescan mode, with the GS-500 ROX and GS-1000 ROX internal standards as described previously (10). The obtained T-RFLP profiles were analyzed by BioNumerics software (Applied Maths, Ver 3.0, Austin, TX) as described previously (10). To remove background and small peaks, T-RFs whose relative areas were less than 3.0% of total area were deleted by setting the "Min.…”

Rodent models to study the relationships between mammals and their bacterial inhabitants

“…[69][70][71] Recent publications adopt a more critical perspective by concluding that the composition of microbial communities from human donors resembles that of their corresponding HFA rodents only at the predominant species level. 72,73 Difficulties in achieving an exact match in microbial profiles between feces from recipient animals and human donors are not unexpected: reciprocal inoculation experiments in related vertebrates show that the host environment plays an important role in determining the microbial makeup. 74 This was challenged, however, when scientists from the Gordon group published the results of a transplantation study of human intestinal communities into GF animals.…”