TORONTO -- A new study suggests the way babies are born and fed in early life affects the bacteria they carry around in their gut.
And that in turn may influence their future health, including such things as whether they will develop asthma, allergies or other medical conditions.
The study, conducted by researchers at the University of Alberta, is published in this week's issue of the Canadian Medical Association Journal.
Senior author Anita Kozyrskyj said it is important medical teams and parents understand the choices made about mode of delivery and method of feeding have an impact.
She and colleagues studied the gut microbiomes of 24 infants; that's the term for the diverse collection of bacteria people carry in their intestinal tracts.
They found distinct differences in the numbers and types of bacteria present when they compared babies born by caesarean section to those born by vaginal birth, as well as babies breastfed and fed with formula.
"There are a lot of things we don't know about the impact of health-care interventions such as caesarean section delivery on the developing infant," said Kozyrskyj. "To date, most of the evidence informing physicians and I guess families too is focused on the mother," said Kozyrskyj, who is a research chair and associate professor in the department of pediatrics at the University of Alberta.
It's long been known people carry an enormous number of bacteria in and on their bodies, most of which are benign or even helpful. For instance, friendly bacteria in the gut help protect against invaders that are ingested with contaminated food and could cause illness.
It's said bacteria in the gut outnumber the cells in the respiratory tract by a ratio of 10 to one.
In recent years, though, it has become increasingly clear the wrong balance of bacteria can have negative health implications.
Kozyrskyj and colleagues used a DNA sequencing technique to identify the bacteria in 24 babies' guts by studying a stool sample from each. The samples were taken when the babies were four months old.
They found a greater variety of bacteria in the children born vaginally as compared to those that were born by planned C-section -- though babies born by emergency C-section had an even higher variety of bacteria than those born vaginally. Infants who were exclusively breastfed had a less varied collection of gut bacteria than those who were bottle fed. But in this case, more isn't necessarily better, Kozyrskyj said. Some of the bacteria found in the stools of bottle-fed babies were the types that could cause illness, such as Clostridium difficile, which can cause diarrhea.
-- The Canadian Press