Abstract
BackgroundLeukocyte activation (LA) testing identifies food items that induce a patient specific cellular response in the immune system, and has recently been shown in a randomized double blinded prospective study to reduce symptoms in patients with irritable bowel syndrome (IBS). We hypothesized that test reactivity to particular food items, and the systemic immune response initiated by these food items, is due to the release of cellular DNA from blood immune cells.MethodsWe tested this by quantifying total DNA concentration in the cellular supernatant of immune cells exposed to positive and negative foods from 20 healthy volunteers. To establish if the DNA release by positive samples is a specific phenomenon, we quantified myeloperoxidase (MPO) in cellular supernatants. We further assessed if a particular immune cell population (neutrophils, eosinophils, and basophils) was activated by the positive food items by flow cytometry analysis. To identify the signaling pathways that are required for DNA release we tested if specific inhibitors of key signaling pathways could block DNA release.ResultsFoods with a positive LA test result gave a higher supernatant DNA content when compared to foods with a negative result. This was specific as MPO levels were not increased by foods with a positive LA test. Protein kinase C (PKC) inhibitors resulted in inhibition of positive food stimulated DNA release. Positive foods resulted in CD63 levels greater than negative foods in eosinophils in 76.5% of tests.ConclusionLA test identifies food items that result in release of DNA and activation of peripheral blood innate immune cells in a PKC dependent manner, suggesting that this LA test identifies food items that result in release of inflammatory markers and activation of innate immune cells. This may be the basis for the improvement in symptoms in IBS patients who followed an LA test guided diet.
Highlights
Leukocyte activation (LA) testing identifies food items that induce a patient specific cellular response in the immune system, and has recently been shown in a randomized double blinded prospective study to reduce symptoms in patients with irritable bowel syndrome (IBS)
Of relevance to this study Protein kinase C (PKC) activation has been previously shown to be required for the release of DNA Nets by neutrophils, and our study provides supporting data for a role of PKC in DNA release by eosinophils [30]
Since long-term compliance with low calorie diets is very difficult, it would be of great interest to test if removal of specific foods which may be triggering release of DNA into the circulation can improve Nonalcoholic steatohepatitis (NASH). This is the first demonstration that specific foods can result in release of DNA by peripheral blood leucocytes, and further that these items can be identified by a peripheral blood LA test
Summary
Leukocyte activation (LA) testing identifies food items that induce a patient specific cellular response in the immune system, and has recently been shown in a randomized double blinded prospective study to reduce symptoms in patients with irritable bowel syndrome (IBS). Among the more widely utilized food sensitivity assays are leukocyte activation (LA) tests used to guide dietary advice used in complementary and alternative medicine practices [3, 4]. LA tests assess changes in blood leukocyte populations in response to incubation with a large panel of standardized food antigens and are analyzed using a quantitative algorithm that assesses changes in number, cell volume, and conductance [12] after exposure to individual foods. More commonly utilized conventional food allergy tests examine the humoral, or antibody response (typically IgE), but do not provide information of the response on Garcia-Martinez et al Nutrition & Metabolism (2018) 15:26 immune cells [13].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
