Dietary yeast β‐glucan does not improve the response to influenza vaccination in neonatal piglets

Abstract

Purified yeast (1,3/1,6)‐β‐D‐glucan (βG) has been shown to enhance immune responsiveness. Herein, the hypothesis that βG would modulate the lung immune development and improve influenza vaccination response was tested. Piglets (n=5–6/group) were fed formula containing 0 (control), 1.8, 18 or 90 mg βG/kg body weight. Half of the piglets in each treatment were vaccinated (FV) by i.m. injection against influenza (Fluzone) on d7 and received a booster on d14. Piglets were euthanized on d7 and d21. Weight gain and formula intake were unaffected by diet or vaccination. Fluzone‐specific serum IgG was measured by ELISA. FV piglets had higher (p<0.001) IgG titer at d14 and 21 than non‐V piglets. This was unaffected by βG. Cytokine (IL −2, −4, −10, −12 and −17) mRNA in lung was unaffected by age or dietary βG. Lung TGFβ‐1 mRNA was greater (p<0.05) in d21 than d7 piglets, and lung TGFβ‐2 mRNA was lower (p<0.001) in all âG diets compared to control. T‐cell phenotypes were examined in mediastinal lymph nodes (MSLN) by flow cytometry. In MSLN, CD4+ T‐cells decreased, while CD8+ T‐cells increased between d7 and d21 (p<0.001), but these developmental patterns were unaffected by dietary βG. Thus, with the exception of reducing TGFâ‐2 mRNA in lung, dietary βG did not affect cytokine expression, T‐cell phenotypes or vaccination response in piglets. (Funded by Abbott Nutrition)