Preconception helminth infection alters offspring microbiota and immune subsets in a mouse modelOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This mouse study asked whether a helminth infection cleared before pregnancy leaves lasting effects on the mother's microbiota and her offspring. Female BALB/c mice were infected with the roundworm Nippostrongylus brasiliensis, treated with ivermectin, then mated three weeks later. The team profiled bacteria in maternal stool during pregnancy, in breastmilk, and in pup colons using 16S rRNA sequencing of the V6 region. They also measured pup splenic immune cells by flow cytometry, and ran litter-swap experiments to separate prenatal from nursing effects.
Who was studied?
The subjects were laboratory BALB/c mice kept under specific pathogen-free conditions. Mothers previously infected with N. brasiliensis (NbM) were compared with naive, ivermectin-exposed controls (NvM). Ten female mice were used per experiment for mating. Litters were culled to four or five pups per mother, and pups were analyzed at 14 days of age, before they began eating stool. Maternal stool was collected on gestation days 15 to 19. Breastmilk was sampled from pup stomachs. Experiments were repeated with separate litters.
What were the most important findings?
Preconception infection reshaped maternal and offspring bacteria despite the worm being cleared. Pregnant NbM mothers had distinct gut communities (R2 = 0.242, p = 0.001) with more Enterococcaceae than controls. Breastmilk microbiota also differed significantly by prior infection, though alpha diversity was unchanged. NbM pups had higher gut diversity (p = 0.005) and distinct communities (R2 = 0.18, p = 0.004), with more Coriobacteriaceae and Micrococcaceae. Litter swaps showed changes begin before birth and continue during nursing. NbM pups also had more activated CD4 T cells (CD4+CD44hi), B cells, and regulatory T cells in the spleen.
What are the greatest implications of this study?
The findings suggest a mother's infection history can influence her offspring's microbiota and early immune development, even after the parasite is gone. This matters for infant health in regions where intestinal worms are common. The results imply that both the prenatal period and breastfeeding shape the infant gut. Litter swaps showed nursing contributes, but there was no direct transfer of microbes from milk to pup gut. Because this is a mouse model, the authors do not claim the same effects occur in humans, and breastmilk sampling from pup stomachs warrants caution.