Newborns exposed to laxatives in utero, during infancy may develop allergies later in life

Laxative exposure early in life was associated with later allergic disease development, including rhinitis, atopic dermatitis and asthma, according to a cohort study published in Annals of Allergy, Asthma & Immunology.

“Colonization of the gut by a ‘healthy’ microbiota is essential for maturation and modulation of the immune system,” Teng-Li Lin, MD, of the department of dermatology at Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, in Chiayi, Taiwan, and colleagues wrote. “In contrast, perturbation of commensal microbiomes in the fetus or infant might cause stunting and dysregulation of immunity, resulting in greater susceptibility to immune-mediated disorders later in life, including allergic diseases.”

The researchers used Taiwan’s National Health Insurance Research Database to evaluate data of 291 children who received laxatives for at least 7 days during their first 6 months of life (L-cohort), and 1,164 reference children who did not receive laxatives (R-cohort), between 1997 to 2013. The researchers matched patients by gender, propensity score, number of hospital visits and maternal age at delivery, and followed them for at least 5 years.

Laxatives assessed in the study included bulk-forming laxatives, osmotic laxatives, stimulant laxatives, lubricants and stool softeners. The researchers also analyzed maternal medication exposure during the mother’s pregnancy, defined as exposure for at least 7 days during the 9 months prior to childbirth.

According to the results, early-life laxative exposure was independently associated with allergic disease development in nearly all subgroups of children (adjusted HR = 1.61; 95% CI, 1.32-1.97). The researchers found that among the L-cohort, the 5-year cumulative incidence of allergic diseases was 49.81%, compared with 41.68% for the R-cohort (P = .014).

The prevalence of allergic rhinitis (38.1% vs. 30.8%), atopic dermatitis (4.9% vs. 2.4%) and asthma (5.9% vs. 3.5%) was higher in the L-cohort, but only the difference for allergic rhinitis met statistical significance.

Multivariate analysis showed that in addition to laxative exposure, risk factors for development of allergic diseases included maternal allergic diseases (aHR = 2.05; 95% CI, 1.48-2.85), preterm birth (aHR = 1.64; 95% CI, 1.14-2.35) and male sex (aHR = 1.44; 95% CI, 1.22-1.69).

The researchers also identified maternal laxative use during pregnancy as an independent risk factor for offspring allergic diseases later in life, regardless of exposure in children (aHR = 1.29; 95% CI, 1.02-1.64).

Cesarean delivery (aHR = 1.02; 95% CI, 0.86-1.2), maternal antibiotic use during pregnancy (aHR = 0.89; 95% CI, 0.74-1.06) and infection within the first 6 months of life (aHR = 1.16; 95% CI, 0.95-1.43) were not significantly associated with allergic disease development.

The research supports previous findings that the use of laxatives also changes the composition and function of gut microbiota by creating disturbances in metabolic pathways and making changes in microbial taxonomy.

“The present study adds to the mounting evidence regarding the negative impact of intestinal dysbiosis during infancy including the development of atopy later in life,” Lin and colleagues wrote. “The causality and mechanism of action are worth further investigation.”