2021 Volume 35 Issue 4 Pages 231-239
We collected fecal samples from laboratory mice kept at 13 universities in Japan, and analyzed the DNA samples extracted from these fecal samples using quantitative PCR (qPCR), which has been reported elsewhere to be able to analyze the phylum-level analysis of mouse fecal microbiota almost as precisely as next-generation sequencers do. In addition, we conducted qPCR assays targeting the family to species level, which has been used by many researchers as a useful molecular tool, to evaluate the effects of food ingredients on the gut microbiota of mice. These qPCR results were subjected to multivariate analysis, which showed that different phylogenetic clusters had formed at the phylum and family/genus levels of the taxonomic hierarchy at each breeding facility. The chi-square test was used to determine whether the formation of these strain clusters was correlated with internal factors such as mouse strain, sex, and age, or external factors such as water supply, bedding, and feed. The results show a significant correlation between differences in feed. These results indicate that the fecal microbiota of laboratory mice in Japan is affected by exogenous factors, as has been reported in other countries, and indicate the need for standardization of the mouse bacterial microbiota, or the consideration of alternative methods that do not rely on laboratory animals for accurately evaluating the functionality of orally consumed foods.
