“The well-authenticated detection of Haemophilus influenzae in an early medieval child promises that it will be detectable in more cases in history, and potentially prehistory,” he says.

"Normal flora" include Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, and anaerobes such as Bacteroides species, anaerobic gram-positive cocci, and Fusobacterium species.