For years, scientists suspected that genetics shaped individual salivary microbiomes, but new research published in the journal mBio counters that theory. Adam Roberts and Andrew Smith, along with their research team, analyzed a unique sample set: DNA and saliva from an extended family of Ashkenazi Jews living in households spread across four cities on three continents, plus additional DNA and saliva from unrelated individuals. Smith, an immunologist at University College London, knew about the collected Ashkenazi data that had been used for other studies. Because the individuals are all ultra-orthodox Ashkenazi Jews, they share cultural diets and lifestyles that control for many confounding factors. As a result, the dataset offers an opportunity to investigate the effects of environment and genetics separately. The researchers sequenced the bacterial DNA signatures present in the saliva samples from family members as well as 27 unrelated Ashkenazi Jews. The greatest determinant by far was household environment. Residences turn out to be surprisingly full of spit residue, even if people in the homes are frequent hand washers. Smith said tooth brushing will transfer saliva from the brush to the hands and covering the mouth with hands during coughs, sneezes, and certain other moments can also lead to transfers of saliva.
Collecting ant spit
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It's time to Kiss and Tell! From firsts to worsts, we're talking swapping spit all Valentine's week long. In this installment, Alli Maloney explores the science of kissing. Kissing is the end to many stories we tell, a passionate moment when two meant-to-be people realize their love — an action driven by romance.
Talk about intimate communication. Researchers have found that ants pass along chemical signals with their nest mates by sharing saliva. The oral fluid of the Florida carpenter ant Camponotus floridanus contains chemicals that might help homogenize the scent of ants in the colony and even impact the growth of their larvae, researchers reported in a study published Nov. To answer that question, the researchers had to find a way to collect ant spit. This was no easy task. Instances of trophallaxis happen quickly and are impossible to predict, making a wait-and-see approach impossible, the researchers wrote in eLife.