A new study reveals children who develop asthma or allergies have an altered immune response to intestinal bacteria in the mucous membranes even as infants. According to a Medical Xpress news report, the results also suggest the mother’s immune defense plays a role in the development of allergies and asthma in children. The study, which investigated in detail the immune defense of the mucous membranes against different bacteria, analyzed stool samples from infants aged 1 month and then at 12 months.

The researchers identified the intestinal bacteria and determined whether they had IgA bound to them or not. “Children who subsequently developed allergies had a lower fraction of IgA antibodies bound to their intestinal bacteria when aged 12 months than children who did not. This difference may suggest that the barrier function of the mucous membranes is less effective in children who later develop allergies,” Maria Jenmalm, one of the authors of the study, explains. “The lack of IgA was particularly noticeable in children who developed asthma during the first seven years of life.”

According to Medical Xpress, the research team looked at the composition of the bacteria in the stools and used bioinformatic methods to study differences in IgA antibodies against intestinal bacteria between healthy and allergic children.

“There were clear differences in the types of bacteria that the immune defenses of the two groups of children reacted against. We were interested to note that these differences were clear in infants as young as one month. This surprised us, since the IgA antibodies in children so young come largely from the mother, through breast milk,” says Jenmalm. “So it seems that the immune response of the mother and the antibodies that the child receives in breast milk are connected with the development of allergies. This is something we want to look at in more detail.”

Jenmalm adds, “The results confirm our idea that the intestinal flora (also known as the ‘intestinal microbiota’) early in life plays a role during the development of allergy symptoms. We believe that diversity among the bacteria contributes to strengthening the immune defense in the mucous membranes. In our new study we saw differences in the immune response against intestinal bacteria in children who subsequently developed allergy symptoms.”

Photo Credit: Thor Balkhed, Linköping University

Source: Medical Xpress