Effects of diet and trained immunity on responses to enteric helminth infection in mice

Mice were “preimmunized” with UV‑inactivated bacterial and viral pathogens, generating a trained immune response but compatible with SPF housing. Preimmunization increased memory T‑cell populations and strengthened baseline Th1‑associated cytokine responses. When combined with dietary interventions, this immune training altered susceptibility patterns to Trichuris muris (Tm) infection. In chow‑fed mice, preimmunization increased susceptibility to Tm, while in SSD‑fed mice, the diet‑associated resistance was largely preserved. Across both diets, preimmunization enhanced Th1‑skewed cytokine responses during infection, consistent with the Th1 dominance of early Tm immunity. These findings demonstrate that immune maturity modulates, but does not eliminate, diet‑associated differences in helminth susceptibility.