"Our results support the idea that probiotics and prebiotics may enhance immune maturation and protect infants against respiratory pathogens," Dr. Kaarina Kukkonen of Helsinki University Central Hospital in Finland and colleagues conclude in a report in the medical journal Pediatrics.
Probiotics are beneficial bacteria that may help preserve a healthy bacterial environment in the body, in the process possibly boosting immunity, Kukkonen's team explains. Prebiotics are nutrients that aren't digestible to humans but that do help "good bacteria" thrive in the gut.
A combination of probiotics and prebiotics, known as symbiotic treatment, is increasingly being used to help infants with autoimmune disorders and allergies, but the safety of the therapy has not been established, the researchers note.
To investigate, they randomly assigned pregnant mothers to receive a mix of four different probiotics or inactive placebo four weeks before delivery. The infants received the same bacterial mix, along with prebiotics known as galactooligosaccharides (GOSs) also found in breast milk, or placebo only, every day for six months.
The researchers followed the infants up to age two.
During their first six months of life, 28 percent of the infants on placebo were prescribed antibiotics, compared to 23 percent of the infants given synbiotic treatment, the researchers found. The infants in the treatment group averaged 3,7 respiratory infections by two years of age, compared to 4,2 for the placebo group.
There was no difference in growth, colic or serious adverse events between the two groups.
The researchers conclude that synbiotic treatment "carries no risks," and may help babies to fight off infection.