More and more studies are focusing on the overall impact of gut bacteria on health including the immune system. The newest study on this topic originates from the University of Alberta and University of Manitoba in Canada and is published in the journal Clinical & Experimental Allergy and determined that infants with less diverse gut bacteria were more likely to develop food sensitives which could lead to food allergies.
The study consisted of collecting stools of infants at 3 and 12 months of age and performing DNA analysis to classify the bacteria. Data was analyzed on 166 babies from the Canadian Healthy Infant Longitudinal Development (CHILD) Study.
Two specific types of bacteria were of particular significance: Enterobacteriaceae and Bacteroidaceae. The researchers found infants that developed food sensitization had different levels of these bacteria compared with those that did not. Generally increase in gut bacteria diversity at 3 months was linked to reduced food sensitization at 1 year. Twelve babies (7.2%) were found to be sensitized to one or more common foods at the 1 year level.
The study found that Enterobacteriaceae were over represented and Bacteroidaceae were under represented in the gut microbiota of food-sensitized infants at 3 months and 1 year. There was a definite link between food sensitization and gut bacteria ratio. As the ratio of Enterobacteriaceae to Bacteroidaceae increased, so did the risk of food sensitization.
“Using DNA techniques to classify bacteria in the Scott and Guttman laboratories at the University of Toronto, we obtained information on the different types of ‘good’ bacteria present in infant stool collected at three months of age and then at one year of age,” said Anita Kozyrskyj, professor in the Department of Pediatrics at the University of Alberta and senior author of the study. “We were able to then see which bacteria present at three months predicted the development of food sensitization at one year, as measured by a skin reaction test to the food.”
Infant gut microbiota and food sensitization: associations in the first year of life, M. B. Azad, et al., Clin Exp Allergy., doi:10.1111/cea.12487, published online 25 February 2015, abstract.