FactⅢl 05 C-section compared with vaginal delivery, may be related with a reduced natural barrier 03 Mutans streptococci(变形链球菌)were detected more frequently and at a younger age in children delivered by c-section than in those delivered vaginallyFact III • C-section, compared with vaginal delivery, may be related with a reduced natural barrier. Mutans streptococci(变形链球菌) were detected more frequently and at a younger age in children delivered by C-section than in those delivered vaginally. 03 05