Poster Topical Area: Nutritional Immunology
Location: Hall D
Poster Board Number: 829
Objective: The long chain n-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) in fish oil have immunomodulatory properties. B cells are a poorly studied target of EPA/DHA in humans. Therefore, in this pilot double-blind placebo controlled study, we tested how n-3 PUFAs influenced B cell responses of obese humans.
Methods: Obese men and women were assigned to consume four, 1 gram capsules per day of olive oil (OO, n=12), fish oil (FO, n=12) concentrate, or high DHA-FO concentrate (n=10) for 12 weeks in a parallel design. Next, ex vivo B cell cytokines were assayed after stimulation of Toll-like receptors (TLRs) and/or the B cell receptor (BCR) to determine if the effects of n-3 PUFAs were pathway-dependent. Finally, ex vivo antibody levels were assayed with a subset of subjects consuming FO (n=7) after TLR9+BCR stimulation.
Results: Fish oils had no effect on the frequency of circulating levels of monocytes, CD4+ and CD8+ T cells. B cell subset analyses revealed that relative to baseline, FO lowered the percentage of circulating memory and plasma B cells whereas the other supplements had no effect. There were no post-intervention differences between the three supplements. B cell IL-10 and TNF alpha secretion were respectively increased with high DHA-FO, relative to baseline, with respective TLR9 and TLR9+BCR stimulation. OO and FO had no influence on B cell cytokines compared to baseline and there were no differences in post-intervention cytokine levels between treatment groups. Compared to baseline, FO lowered IgM but not IgG levels accompanied by select modifications to the plasma lipidome.
Conclusions: Altogether, the results suggest n-3 PUFAs in fish oils differently modulate B cell activity in humans, which will require further testing in a larger cohort.
Gillings School of Global Public Health, University of North Carolina at Chapel Hill
Chapel Hill, North Carolina