A new study has claimed that consumption of antibiotics in early life can increase human body's long-term defense against specific diseases.

According to the research by New University of British Columbia, most bacteria living in the gut play a positive role in promoting a healthy immune system, but antibiotic treatments often do not discriminate between good and bad bacteria. The study helped scientists understand how different antibiotics affect good bacteria.

The researchers tested the impact of two antibiotics, vancomycin and streptomycin, on newborn mice. They found that streptomycin increased susceptibility to a disease known as hypersensitivity pneumonitis later in life, but vancomycin had no effect. The difference in each antibiotic's long-term effects can be attributed to how they changed the bacterial ecosystem in the gut. Hypersensitivity pneumonitis is an allergic disease found in people with occupations such as farming, sausage-making, and cleaning hot tubs.

The researchers stress that infants should be treated with antibiotics when needed, but they hope these results would help pinpoint which bacteria makes people less susceptible to disease. It could open up the possibility of boosting helpful bacteria through the use of probiotics.

The study is published in Journal of Allergy and Clinical Immunology.