Effect of Microorganisms upon Zinc Metabolism Using Germfree and Conventional Rats

This study was designed to elucidate the effect of gastrointestinal microorganisms upon zinc metabolism. Rats free of microorganisms (germfree) served as the principal experimental model. Measurements for assessing zinc metabolism included weight gain, degree of alopecia and dermatitis, and plasma and tissue zinc concentration. When germfree and conventional controls were fed the same zinc-deficient diet the above parameters of zinc metabolism indicated that the germfree animals had a lower dietary zinc requirement. In addition, Streptococcus sp. and/or Staphylococcus epidermidis organisms were identified as affecting zinc metabolism. The data suggest that the presence of certain microorganisms results in an increased dietary zinc requirement. Thus, where the total body burden of microorganisms is altered the dietary zinc requirement may be affected.