South Korean scientists conducted a national cohort study and concluded that taking antibiotics during pregnancy and infancy does not increase the risk of developing autoimmune diseases later in life. The report on the work was published in the journal PLOS Medicine.
In recent decades, there has been an increase in the incidence of autoimmune diseases, particularly in children. This has been observed worldwide, but the extent of the increase varies depending on genetic predisposition, environmental factors, and health care approaches. It has been suggested that the widespread use of antibacterial drugs may play a significant role, as they can directly interfere with the composition of the microbiota and the formation of the immune system. Research on this topic has yielded mixed results, perhaps due to the difficulty of accounting for the effects of infections and heredity.
Ju-Young Shin of Sungkyunkwan University and colleagues analyzed data from the Korean National Health Insurance Service for 2008–2021 on children born between April 1, 2009, and December 31, 2020. The analysis included more than 1.5 million children exposed to antibiotics in utero and nearly 1.2 million who were not, as well as nearly 2 million who were exposed to these drugs in infancy and more than 1.4 million who were not. Antibiotic-exposed and unexposed groups were matched using the inverse probability weighting (IPTW) calculation, which minimizes the influence of confounding factors and biases associated with non-random treatment assignment in the absence of randomization. The authors also performed a separate analysis among siblings to minimize the influence of familial factors. The association of antibiotic use with the development of six common autoimmune diseases was assessed using Cox proportional hazards models.
Analysis of prenatal antibiotic exposure did not reveal a significant association with the development of type 1 diabetes mellitus (p = 0.132), juvenile idiopathic arthritis (p = 0.83), ulcerative colitis (p = 0.895), Crohn's disease (p = 0.076), systemic lupus erythematosus (p = 0.053), and Hashimoto's thyroiditis (p = 0.448). Analysis of antibiotic exposure in infancy also did not reveal a similar association (p = 0.594; 0.253; 0.776; 0.403; 0.087 and 0.104, respectively). Narrowing the analysis to siblings yielded similar results. Subgroup analyses showed that maternal antibiotic use in the first and second trimesters of pregnancy was associated with a small increased risk of Crohn's disease, and antibiotic use in male infants or during the first two months of life was associated with a small increased risk of Hashimoto's thyroiditis.
Thus, the large, long-term study as a whole does not support a link between antibiotic exposure in utero and infancy and the development of autoimmune diseases. Risks specific to certain subgroups of patients deserve further study, the authors conclude.
Previous studies have linked antibiotic use in the first years of life with an increased risk of asthma, allergic rhinitis, atopic dermatitis, celiac disease, obesity, and attention deficit hyperactivity disorder, and with growth retardation in boys in the first month of life.
