Influence of intestinal microbes on heat production in germ-free, gnotobiotic and conventional mice.

To observe the influence of intestinal microbes on energy metabolism, male ICR strain germ-free (GF) mice, gnotobiotic (GB) mice, produced from GF mice monocontaminated with Staphylococcus epidermidis (Staph.) at three weeks of age, and conventional (CV) mice were used. Metabolizable energy, heat production and net energy (gain) per mouse were measured for three weeks when the mice were given 5 Mrad 60Co irradiated purified whole-egg protein diet from 5 to 8 weeks of age. With respect to metabolizable energy and heat production per mouse or per kg of metabolic body size for three weeks, CV mice gave the highest values, followed by GB and GF mice. GV mice showed the highest net energy (gain) followed by GF mice, with GB mice having the lowest value.