The study's lead author Adriana Pedroso, a post doctoral researcher at the University of Georgia College of Veterinary Medicine, said the finding could have important implications for the poultry industry and for food safety.

"Understanding the microbial ecology of the developing chicken is the first step toward producing healthy birds without antibiotics," said Pedroso.

Pedroso and her colleagues incubated more than 300 eggs and dipped them into a light bleach solution before extracting the embryos using sterile tools. DNA analysis revealed a diverse community of bacteria within the intestines of the developing embryos. The researchers hypothesize the bacteria penetrate the surface of the shell to the egg white, which is then ingested by the developing embryo.

The study, led by Professor John Maurer, was presented this week in Boston during a meeting of the American Society for Microbiology.