Determinants of microbiome development and relation to allergy risk in childhood before and during the COVID-19 pandemic

The purpose is to study the effects of pandemic control measures and perinatal stressors on microbiome development and childhood allergy risk.

Specific aims are to: 1) Assess the impact of infection control measures and prenatal psychosocial distress on childhood allergy risk 2) Study if differences in microbiome development in children born before and during the COVID-19 pandemic impact immune maturation and allergy risk 3) Examine the association between prenatal psychosocial distress and allergy risk in the child 4) Validate our findings in aims 2 and 3.

The project is nested in NorthPop, a prospective population-based pre-birth cohort study in Sweden. It includes up to 5000 mother-infant dyads and spans over 4-years. Data on parental health, sociodemographics and pandemic infection control measures are collected perinatally. Stress and mental health are assessed in pregnancy by questionnaires.

Data on allergic morbidity in the child are collected until age 7-years. Immune status is analyzed pre- and postnatally, allergic sensitization at ages 18 months and 7-years.

The microbiome is analyzed in maternal vaginal, oral, fecal and breast milk samples and in child oral, fecal and skin samples by powerful sequencing methods. Validation will be done in the Dutch LucKi Gut cohort.

Our research will provide new knowledge on how to prevent or restore dysbiotic drift through lifestyle and behavioral interventions, with high significance for the health sector and public health.