Perinatal Programming of Immune Tolerance and Allergy Risk in Nigerian Children: The Role of Helminth Infection, Microbiome, and Maternal Immune Transfer

The hygiene hypothesis proposes that reduced early-life microbial and helminth exposures contribute to rising allergic disease prevalence. In Nigeria, where helminth infection burden is high but allergic disease is increasingly reported in urban populations, the perinatal immune programming pathways linking helminth exposure, gut microbiome composition, and maternal immune transfer to offspring allergy risk represent an understudied but theoretically rich research domain. This prospective birth cohort study in Lagos State, South West Nigeria, recruits 450 pregnant women in their third trimester with known maternal helminth infection status and follows their infants from birth to three years. Maternal blood at delivery, cord blood, breast milk, and infant stool samples at one, six, twelve, and thirty-six months are characterised for cytokine profiles, regulatory T-cell populations, IgE and IgG4 levels, and gut microbiome composition by 16S rRNA sequencing. Offspring allergy outcomes at three years include eczema, wheeze, and skin prick test positivity to common aeroallergens. Preliminary analysis of the first 180 mother-infant pairs at 12 months indicates that maternal helminth-infected mothers transfer significantly higher levels of IL-10 and TGF-beta through breast milk, associated with enhanced infant regulatory T-cell (Treg) frequencies. Infants of helminth-infected mothers have lower IgE sensitisation rates at 12 months (8.4% versus 21.7%). Gut microbiome analysis reveals higher Faecalibacterium prausnitzii abundance in infants of helminth-infected mothers, a taxon associated with Treg induction. The study makes an original immunological contribution to the DOHaD and hygiene hypothesis literature from a Nigerian context. Keywords: perinatal immune programming, helminth, allergy, birth cohort, South West Nigeria.