Antibiotics can be a double-edged sword, especially for very young kids. Recent research has found evidence that frequent antibiotic use can raise children’s risk of childhood asthma and allergies.
Scientists at Rutgers University led the research, published this month in the Journal of Infectious Diseases. The study found that children given antibiotics before the age of two were noticeably more likely to be diagnosed with asthma and allergies later on, particularly the more antibiotics they took. The findings are the latest to suggest that antibiotics should be carefully managed in their use, the researchers say.
Antibiotics are our best weapon against bacterial infections. But scientists have known for decades that they don’t come without risks. Bacteria have steadily learned how to resist these drugs, for instance, and antibiotic resistance is now one of the most pressing public health issues of our time.
Another risk concerns the microbiome, the neighborhood of usually harmless and often helpful bacteria that live in or on our bodies. Many antibiotics are broad-spectrum, meaning they can kill a wide variety of bacteria, including these friendly bacteria. The splash damage caused by antibiotics might then disturb the microbiome in ways that could increase our risk of other health problems.
Some research has suggested that antibiotic-triggered disruptions of the microbiome are even more harmful to children, with studies linking their use to chronic conditions like asthma. But according to the Rutgers researchers, past studies had limitations—such as small sample sizes and numerous variables to account for—issues they tried to minimize in their new study.
The researchers analyzed the medical records of over one million children born in the UK. They also conducted a separate analysis of children and their siblings, allowing them to compare children with similar environmental and genetic backgrounds.
Overall, the researchers found that antibiotic use before age two was positively linked to a higher risk of asthma, food allergy, and allergic rhinitis (hay fever). They also found a possible association between antibiotic use and intellectual disability in general. On the positive side, they failed to find any connection between antibiotics and most other conditions they looked for, including autism spectrum disorder, celiac disease, type 1 diabetes, or anxiety.
This sort of research can’t prove that antibiotics are triggering asthma in some young children, it can only suggest a correlation. But the researchers did see a higher risk of asthma in children who took more antibiotics than others, which is evidence of a dose-response effect. The same pattern was also seen when the researchers only compared children to their siblings, further strengthening a causative link.
Other studies have shown that antibiotics are frequently prescribed when they shouldn’t be, such as for infections likely not caused by bacteria—a problem in children as well. A study in 2020, for instance, found that one of every four children given antibiotics in hospitals likely didn’t need them.
So while further research might be warranted to confirm these links between antibiotics and certain chronic childhood conditions like asthma, the take-home message should remain the same: We need to rein in our use of these vital, but not risk-free, medications, perhaps even more so in kids.
“Antibiotics are important and sometimes life-saving medicines, but not all infections in young kids need to be treated with antibiotics,” said lead author Daniel Horton, an associate professor of pediatrics and epidemiology at Rutgers Robert Wood Johnson Medical School and Rutgers School of Public Health, in a statement from the university. “Parents should continue to consult with their children’s doctors on the best course of care.”