Microbiologist Prof John Tagg's study aims to determine if newborns can receive, and establish, good bacteria that has 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."
Women would be checked to see if they naturally carried streptococcus salivarius K12, which occurs in 5% of the population.
Why some people had K12 was a mystery; it was random, but there were indications it ran in families.
"What we want is to take the randomness out of it."
If Prof Tagg's hunch is right, his method will establish the good bacteria, potentially with lifelong benefits.
"When she kisses baby, it should give the kiss of protection to her baby."
The study is based on the same principle as Blis K12 Throat Guard, which Prof Tagg developed.
Only two participants so far were signed up for the newborn trial, but Prof 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.
Prof Tagg said one of his jobs was educating people that not all bacteria were bad.
In fact, most were good and essential for the body's processes.
Prof Tagg suggested a fringe benefit for expectant mothers might be K12's ability to combat bad breath.
One of the features of late-stage pregnancy included bad breath because of hormonal changes, he said.
Dunedin mother-of-three Anna Wescombe, who is six and a-half months pregnant, was pleased to be taking part in the study.
Hopefully, her baby would benefit from the "good bacteria", Mrs Wescombe said.
