Major Finding: Children who received at least one antibiotic during the first year of life were 2.6 times more likely to develop inflammatory bowel disease during childhood than were those who did not take an antibiotic during infancy.

Data Source: Case-control study of 393 children.

Disclosures: Mr. Shaw said he had no conflicts of interest. Dr. Bernstein disclosed relationships with Abbott Canada, Shire Pharmaceuticals, and UCB Pharma. Dr. Proctor disclosed relationships with Abbott Laboratories and Genentech.

NEW ORLEANS — Children who receive antibiotics during their first year of life may be at increased risk of developing inflammatory bowel disease before age 10, based on a case-control study presented at the meeting.

The investigators found that children with inflammatory bowel disease were almost three times more likely to have received at least one antibiotic prescription before reaching their first birthday, compared with children in a control group.

The findings are enough to give pediatricians a moment's pause before reaching for the prescription pad, said lead author Dr. Charles Bernstein, head of gastroenterology and director of the University of Manitoba IBD clinical and research center.

“This association may give us cause to think about the overuse of antibiotics in young children, especially in those who may be at risk for developing IBD,” he said in a prepared statement.

His protg, Manitoba University doctoral student Souradet Y. Shaw, presented the data at the meeting. The investigators conducted a case-control study that used information extracted from the University of Manitoba Inflammatory Bowel Disease Epidemiological Database, which contains information on every IBD patient diagnosed in the province since 1984.

The investigators found 36 cases of pediatric inflammatory bowel disease with full prescribing records. The controls were 360 children without IBD who were matched for age, sex, and region of residence.

Most of the pediatric IBD patients had Crohn's disease (79%); the rest had ulcerative colitis. The average age at diagnosis was 8 years.

Antibiotic use was significantly more common among the cases than the controls; 58% of the cases (21 children) had received at least one prescription during their first year of life, compared with 39% (139) of the controls. About half of those prescriptions were for otitis media.

A regression analysis indicated that cases were 2.6 times more likely than were controls to have taken antibiotics during infancy. When the investigators controlled for sex, however, the association remained significant only for boys.

“There does seem to be some link between getting an antibiotic in the first year of life and developing an inflammatory bowel disease in childhood,” Mr. Shaw said. “But this was a small sample size, and shows only an association—not a causative effect.” However, the findings are strong enough to warrant further investigation in larger groups, he said.

He speculated that early transformation of the gut biome could predispose a child to inflammatory bowel disease. “One possible mechanism is that early antibiotics might change the balance between the 'good' flora and the 'bad' flora,” he said. “There may also be some interference with proper immune system exposure to the bacteria in the gut.”

Dr. Mara T. Abreu commented in an interview, “Something is different about the environment in the developed world that leads to an increase in IBD. Therefore, it is reasonable to consider that changes in the gut microbiome may predispose to IBD.

“We also know that innate immune defects are associated with IBD, so it may be that these patients need antibiotics more often. Nevertheless, there are many good reasons to discourage needless antibiotic use in children,” said Dr. Abreu, professor of medicine and chief, division of gastroenterology, University of Miami.

Dr. Bernstein also cautioned against interpreting the findings as indicating a cause of IBD. “It's also possible that children who require antibiotics may, for other reasons, be predisposed to developing IBD,” he said. “However, if the use of antibiotics is associated with triggering IBD, it may be by [affecting] bowel flora at a vulnerable point in development.”

Dr. Deborah Proctor, who moderated the session, agreed. “A baby is born with a sterile GI tract and it gets populated with bacteria in the first 1–2 years of life. The use of antibiotics during this time could change the flora and therefore could change the ratio of bacteria. This is all speculation, since this study did not address a causal association, but if it holds up in review, physicians should think twice about prescribing antibiotics in infants,” said Dr. Proctor, medical director of the inflammatory bowel disease program at Yale University, New Haven, Conn.

Reporting from the AAP NCE 2010

Pediatric News reporters Sherry Boschert (left) and Alicia Ault will be onsite at NCE 2010. They'll be bringing you the specialty-specific news that has made Pediatric News the best-read publication in the field.

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Early Antibiotics May Predispose Children to IBD