Updated: April 21, 2021 22:41 IST
Ottawa [Canada], April 21 (ANI): Researchers at the University of Alberta’s Faculty of Medicine and Dentistry have found a causal link between caesarean birth, low intestinal microbiota and peanut sensitivity in infants, and report that the effect is more pronounced in children of Asian descent. than others.
The findings were published in the journal of the American Society of Gastroenterology.
“It’s important to know what predicts or increases the risk of food sensitivity because they predict which babies will go on to develop asthma and other types of allergies,” said Anita Kozyrskyj, professor of pediatrics in the Faculty University of Alberta Medicine and Dentistry and supplement. professor at the School of Public Health.
The intestinal bacteria research team analyzed 1,422 babies in the CHILDREN Cohort Study, by examining faecal samples collected at three or four months of age and again one year old. They identified four typical trajectories for bacterial development, including one where infants had persistently low levels of Bacteroids, a type of bacteria known to be critical to the development of the immune system. This profile was most common in babies born by Caesarean section.
Babies were given skin injection tests at one and three years of age to assess their response to a variety of allergens, including egg, milk and peanuts. Babies with low Bacteroides levels were found to have a threefold increase in their risk of developing peanut sensitivity by the age of three – and babies born to mothers of Asian descent were eight times higher.
The team performed further statistical analysis to look for what is known as “mediation” or causal effects between exposure and outcome. “In this case, we observed an association between Asian ethnicity and peanut sensitivity, and then the mediation analysis provided additional evidence for the causal link to the Caesarean section,” Kozyrskyj explained, noting that this was the first study to note this link.
The researchers also noticed that babies with low Bacteroids have lower levels of sphingolipids, proteins that are key to cell development and signaling in many parts of the body, including the immune system. Gut microbiota is the main source of these proteins. Children who have this defect in their immune cells may be more likely to develop food allergies, Kozyrskyj said.
“As the gut microbiota develops, so does the gut immune system, training the gut to respond to pathogens and to be tolerant of the food we need,” he explained.
Half a million Canadian children have a food allergy, while a peanut allergy affects about two in 100 and can lead to severe anaphylaxis. Babies with food allergies are at increased risk of developing asthma, wheezing, eczema and allergic rhinitis later in life, the study’s authors reported.
The overall rate of allergies is rising in western countries and is likely to be linked to environmental factors, said Kozyrskyj, a principal laboratory researcher at SyMBIOTA (Synergy in Microbiota), which studies the effect of maternal and infant antibiotic use, mode of birth and breastfeeding. on the composition of the intestinal microbiota in infants.
“In China food allergies are rare, but those who immigrate to Canada are at higher risk and a more serious form of allergic disease,” he said. “It’s probably related to a change in diet and the environment.”
The next step for the research is for the results to be replicated in other studies around the world, Kozyrskyj said.
Previous research by Kozyrskyj and others has shown that babies born by caesarean section do not get the same beneficial transmission of microbiota from mother to child as babies born by vaginal delivery.
Studies that try to mitigate this by giving C-section infant probiotics or even swabbing them with their mother’s vaginal bacteria have not been as successful as hoped, Kozyrskyj said.
The best route is to avoid a Caesarean birth unless it is medically necessary. “With this evidence in hand, the parent and obstetrician may choose a different birth method,” he said. (ANI)