Weight gain variation is a great challenge in diet induced obesity studies since low gainer animals are of limited value. The inbred B6 mice are frequently used models due to their genetic homogeneity and susceptibility to diet induced obesity. The gut microbiota has previously been linked to weight development and may influence the number of low gainers in DIO studies.
100 male B6 mice were fed a high fat diet for fourteen weeks and divided into the study groups high gainer and low gainer based on their weight gain. Subsequently, fecal matter transplantation was done on germ-free B6 mice with GM from HG and LG donors.
LG and HG animals were identified by the weight gain from week 1 to week 12. The start weight of the LG and HG groups differed significantly. The difference in weight gain between the microbiota-transplanted HG and LG males was significant, as were the differences in serum leptin levels and epididymal fat pad weight. A LG specific GM composition could not be distinguished by 16S rRNA gene amplicon sequencing, but significantly more fighting was recorded in LG groups of both donor population and FMT population.
The HG and LG phenotypes could be transferred to germ-free mice and the increased fighting in the LG group in both studies suggests that fighting should be prevented in DIO studies to minimize the number of LG animals. Less...