T-Cell Populations in Infancy After Maternal Probiotic Supplementation to Prevent Atopic Dermatitis

Area of Science:

• Immunology
• Microbiome research
• Pediatric allergy

Background:

• Maternal probiotic intake during pregnancy and breastfeeding previously showed a reduction in offspring atopic dermatitis (AD).
• A prior analysis suggested this protective effect might be linked to decreased T helper 22 (Th22) cell percentages at 3 months of age.

Purpose of the Study:

• To investigate the longitudinal impact of maternal probiotics on various T helper (Th) cell subsets and regulatory T cells (Treg) in offspring.
• To compare immune cell profiles at 10 days, 3 months, and 2 years of age.

Main Methods:

• A randomized controlled trial involved 415 pregnant women assigned to probiotic or placebo milk.
• Offspring blood samples were analyzed for Treg and Th subsets (Th1, Th2, Th17, Th22) via flow cytometry at 10 days (n=112) and 2 years (n=156).
• Data from 3-month-old infants (n=76) were included for longitudinal comparison using linear mixed models.

Main Results:

• No significant differences in T cell populations (Th1, Th2, Th17, Th22, Treg) were observed between the probiotic and placebo groups at 10 days and 2 years of age.
• The previously noted reduction in Th22 percentage at 3 months was not sustained at later time points.

Conclusions:

• The observed reduction in Th22 cells at 3 months following maternal probiotic intake may not be the primary mechanism behind the prevention of atopic dermatitis.
• The lack of sustained differences in T cell profiles suggests other factors may mediate the protective effects of probiotics against childhood allergies.