Accumulation of Endogenous Protein in the Cecum of the Germfree Rat ∗

Abstract

Summary

Considerable amounts of protein and insoluble nitrogen containing compounds are found in the cecal contents of germfree rats after 8 days of ingesting 0 or 10% casein diets. This implied that the majority of the proteins found in the cecal contents was derived from the host and not from the diet. Additional experiments showed that conventional animals reabsorb from 80 to 90% of the nitrogen containing compounds found in the contents of the distal half of the small intestine whereas these compounds were not reabsorbed in the distal half of the germfree small intestine. Thus it appears that the germfree rat cannot efficiently degrade and reabsorb the endogenous proteins which are shed into his gastrointestinal tract. The significance of these findings for the germfree animal are discussed.