Paper summary generated by OpenAI: This study investigates the role of complement proteins in breast milk and their influence on the gut microbiota of offspring. Using a combination of microbiome sequencing and functional assays, the researchers demonstrate that specific complement components can shape microbial diversity and composition in the gut. The findings reveal that breast milk-derived complement not only supports the establishment of a healthy gut microbiome but also has implications for the development of immune responses in infants. These insights underscore the importance of maternal nutrition and its long-term effects on offspring health.