In fact , researchers found that the human salivary microbiome -- that is , the community of bacteria in saliva -- does not vary greatly between different geographic locations . Saliva has more bacteria than blood because of all of the oral bacteria . Most common type of bacteria in blood is bacteria , in a mostly harmless form . Saliva spreads molecules to the taste receptors on the tongue .
Saliva has more bacteria than blood because of all of the oral bacteria . Most common type of bacteria in blood is bacteria , in a mostly harmless form . Saliva spreads molecules to the taste receptors on the tongue .