A new multi-university study reports that differences in bacterial colonization of the infant gut in formula-fed and breast-fed babies lead to changes in the expression of genes involved in the infant's immune system.

This image shows bacterial infection of host cells: Pathogens of the type Salmonella typhimurium (orange) establish contact to a human host cell (blue). The plague, bacterial dysentery, and cholera have one thing in common: These dangerous diseases are caused by bacteria which infect their host using a sophisticated injection apparatus. Through needle-like structures, they release molecular agents into their host cell, thereby evading the immune response. Researchers at the Max Planck Institute for Biophysical Chemistry in Göttingen in cooperation with colleagues at the Max Planck Institute for Infection Biology in Berlin and the University of Washington in Seattle (USA) have now elucidated the structure of such a needle at atomic resolution. Their findings might contribute to drug tailoring and the development of strategies which specifically prevent the infection process.