The use of antibiotics very early in life may alter the normal development of the gut bacteria, which may play a role in the development of inflammatory bowel disease (IBD), according to a new mouse study.

The study, titled “Early-life antibiotic treatment enhances the pathogenicity of CD4⁺ T cells during intestinal inflammation,” is published in the Journal of Leukocyte Biology.

The researchers believe their findings indicate that altering gut flora may be a feasible treatment approach for some inflammatory diseases like IBD.

“Our study demonstrates that gut bacteria in early life do affect disease development in adulthood, but this response can be changed,” Colby Zaph, Department of Biochemistry and Molecular Biology in the School of Biomedical Sciences at Monash University, Australia, said in a news release.

“This has important ramifications for the use of pre- and probiotics, the administration of antibiotics to neonates, and our understanding of how gut bacteria play a critical role in influencing the development of inflammatory diseases such as IBD.”

IBD has increasing incidence and prevalence in most countries and has become an emerging global disease. IBDs are thought to occur as a result of a complex interplay between host genetics and environmental factors, such as the composition of the intestinal microbiota, which in turn leads to a dysregulated intestinal immune response.

In the new study, Zaph and his team conducted experiments using two groups of mice with IBD. The first group included pregnant female mice that received a treatment with broad spectrum antibiotics during pregnancy and baby mice that received the same treatment for the first three weeks of their life. The second group of mice included pregnant female mice and pups that received no treatment.

At three weeks of age, the pups in the treated group were weaned and antibiotic treatment was discontinued. Pups in the antibiotic treatment group had reduced levels of gut bacteria and were allowed to age naturally.

Then the researchers examined immune cells (CD4 T-cells) from both the treated and untreated pups when they were 8 weeks old. The aim was to see the ability of the immune cells to induce the development of IBD in other mice.

The researchers found that immune cells from the group of mice that were treated with antibiotics led to IBD more rapidly and in a more severe form than the cells from mice that received no treatment.

“Our intestinal commensal bacteria are now understood to have a major role in shaping immune health and disease, but the details for this process remain poorly understood,” said John Wherry, PhD, deputy editor of the Journal of Leukocyte Biology. “These new studies provide an important clue as to how the early signals from our gut bacteria shape key immune cells and how these neonatal events can shape disease potential later in life.”