A study out of New Zealand has found that mum's kiss could give newborn babies lifelong protection against sore throats and ear infections.
The University of Otago study aims to determine if newborns can receive, and establish, good bacteria that have been introduced to their mother's mouths.
Pregnant women will suck a probiotic lozenge each day of the last month of their pregnancy to colonise their mouths with the bacteria associated with preventing sore throats and ear infections.
"There has been no study like this before," the New Zealand Herald quoted John Tagg as saying.
Women would be checked to see if they naturally carried streptococcus salivarius K12, which occurs naturally in 5 per cent of the population.
Although, researchers were unaware why some people had K12, they knew that it was random.
In fact, there were indications that it ran in families.
"What we want is to take the randomness out of it," he said.
If his theory is proved, his method will establish the good bacteria, potentially with life-long benefits.
"When she kisses baby, it should give the kiss of protection to her baby," said Tagg.
The study is based on the same principle as Blis K12 Throat Guard, developed by Tagg.
Only two participants were signed up for the trial, but Tagg hoped about 50 women would take part over the next year.
Sterile when they were born, babies inherited bacteria from their main carer, usually their mother.
The person who got the most "spits in" passed on their bacteria to the baby.
Babies would be checked for K12 at one week, and then at six weeks, to see if the bacteria remained.
The babies would not be tracked as they grew up, but that could be the basis of future research, said Tagg.