title: Consuming Lentinula edodes (Shiitake) Mushrooms Daily Improves Human Immunity: A Randomized Dietary Intervention in Healthy Young Adults.
abstract: BACKGROUND
  Mushrooms are widely cited for their medicinal qualities, yet very few human intervention studies have been done using contemporary guidelines.
  
  
  OBJECTIVE
  The aim of this study was to determine whether consumption of whole, dried Lentinula edodes (shiitake) mushrooms could improve human immune function. Primary objectives were to ascertain whether L. edodes consumption would improve γδ-T cell proliferation and activation responses, quantify a dose response, and elicit cytokine secretion patterns. Secondary objectives included determining changes in natural killer T (NK-T) cell proliferation and activation, secretory immunoglobulin A (sIgA) in saliva, and C-reactive protein (CRP) in serum.
  
  
  METHODS
  Fifty-two healthy males and females, aged 21-41 years, participated in a 4-week parallel group study, consuming either 5 or 10 g of mushrooms daily. Each subject had blood drawn before and after 4 weeks of daily L. edodes consumption. Saliva and serum were also collected. Peripheral blood mononuclear cells were cultured in autologous serum for 24 hours or 6 days, stained, and examined by flow cytometry.
  
  
  RESULTS
  Eating L. edodes for 4 weeks resulted in increased ex vivo proliferation of γδ-T (60% more, p < 0.0001) and NK-T (2-fold more, p < 0.0001) cells. Both cell types also demonstrated a greater ability to express activation receptors, suggesting that consuming mushrooms improved cell effector function. The increase in sIgA implied improved gut immunity. The reduction in CRP suggested lower inflammation. The pattern of cytokines secreted before and after mushroom consumption was significantly different; consumption resulted in increased interleukin (IL)-4, IL-10, tumor necrosis factor (TNF)-α, and IL-1α levels, a decreased macrophage inflammatory protein-1α/chemokine C-C ligand 3 (MIP-1α/CCL3) level, and no change to IL-6, IL-1β, MIP-1β, IL-17 and interferon (IFN)-γ levels.
  
  
  CONCLUSIONS
  Regular L. edodes consumption resulted in improved immunity, as seen by improved cell proliferation and activation and increased sIgA production. The changes observed in cytokine and serum CRP levels suggest that these improvements occurred under conditions that were less inflammatory than those that existed before consumption.
authors: a Department of Food Science and Human Nutrition , University of Florida , Gainesville , Florida.
authors: Xiaoshuang
authors: X
authors: Dai
authors: a Department of Food Science and Human Nutrition , University of Florida , Gainesville , Florida.
authors: Joy M
authors: JM
authors: Stanilka
authors: a Department of Food Science and Human Nutrition , University of Florida , Gainesville , Florida.
authors: Cheryl A
authors: CA
authors: Rowe
authors: b Department of Nutrition , Federal University of Jequitinhonha and Mucuri Valleys , Diamantina , MG , BRAZIL.
authors: Elizabethe A
authors: EA
authors: Esteves
authors: a Department of Food Science and Human Nutrition , University of Florida , Gainesville , Florida.
authors: Carmelo
authors: C
authors: Nieves
authors: a Department of Food Science and Human Nutrition , University of Florida , Gainesville , Florida.
authors: Samuel J
authors: SJ
authors: Spaiser
authors: c MCC Statistical Consulting , Gainesville , Florida.
authors: Mary C
authors: MC
authors: Christman
authors: a Department of Food Science and Human Nutrition , University of Florida , Gainesville , Florida.
authors: Bobbi
authors: B
authors: Langkamp-Henken
authors: a Department of Food Science and Human Nutrition , University of Florida , Gainesville , Florida.
authors: Susan S
authors: SS
authors: Percival
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D002478:Cells, Cultured; D016207:Cytokines / Q000097:blood / Q000378:metabolism; D004032:Diet; D005260:Female; D006801:Humans; D007109:Immunity / Q000502:physiology*; D007071:Immunoglobulin A, Secretory / Q000032:analysis / Q000097:blood; D007249:Inflammation / Q000517:prevention & control; D007422:Intestines / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008213:Lymphocyte Activation / Q000502:physiology; D008297:Male; D012463:Saliva / Q000276:immunology; D020942:Shiitake Mushrooms; D013601:T-Lymphocytes / Q000276:immunology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D016207:Cytokines; D007071:Immunoglobulin A, Secretory; D002097:C-Reactive Protein
keywords: mushroom, immunity, γδ-T cell, NK-T cell, cytokine