A recent study reveals new clues on how changes to the mix of bacteria in the gut of young babies may offer a way to predict the future development of food allergy or asthma.
The finding is the work of researchers from the University of Alberta andUniversity of Manitoba in Canada and is published in the journalClinical & Experimental Allergy.
The team found that infants with less diverse gut bacteria at 3 months were more likely to show sensitivity to certain foods like egg, milk and peanut by the age of 12 months.
Two types of bacteria were of particular significance: Enterobacteriaceaeand Bacteroidaceae. The researchers found infants that developed food sensitization had different levels of these bacteria compared with those that did not.
The team used results of DNA analysis to classify bacteria in the stools of infants collected at 3 months and 12 months of age. From this, they could see which bacteria present early in life predicted the development of food sensitization at 1 year - as measured by a skin reaction test.
They suggest patterns of gut bacteria in infancy may serve as biomarkers of future disease.
"It is something that one can measure that indicates increased risk of food sensitization by 1 year of age," says Anita Kozyrskyj, professor in the Department of Pediatrics at the University of Alberta and senior author of the study.
Lead author Meghan Azad, assistant professor in the Department of Pediatrics and Child Health at the University of Manitoba, says they are continuing to study the process, and:
"Ultimately, we hope to develop new ways of preventing or treating allergies, possibly by modifying the gut microbiota."
Increase in gut bacteria richness at 3 months linked to reduced food sensitization at 1 year
Prof. Azad and colleagues analyzed data on 166 babies from the Canadian Healthy Infant Longitudinal Development (CHILD) Study, which is following more than 3,500 families and their newborn infants across Canada.
Twelve babies (7.2%) were found to be sensitized to one or more common foods at 1 year. The authors note that:
"Enterobacteriaceae were overrepresented and Bacteroidaceae were underrepresented in the gut microbiota of food-sensitized infants at 3 months and 1 year, whereas lower microbiota richness was evident only at 3 months."
The analysis revealed that increase in gut bacteria richness at 3 months was linked to a significant reduction in risk for food sensitization by 1 year.
Also, as the ratio of Enterobacteriaceae to Bacteroidaceae increased, so did the risk of food sensitization.
The researchers are keen to point out that their findings do not necessarily mean that food sensitive children will progress to having full-blown allergies later in life.
They plan to expand their sample size as data comes in from more participants in the CHILD study, and to keep following the children so they can do further analysis at ages 3 and 5 years. Prof. Kozyrskyj explains:
"At the end of the day, we want to know if infants who show changes to normal gut bacteria composition will go on to develop food or other allergies, or even asthma."