title: Consumption of dairy yogurt with the polysaccharide rhamnogalacturonan from the peel of the Korean citrus hallabong enhances immune function and attenuates the inflammatory response.
abstract: The aim of this study was to investigate the impact of consuming dairy yogurt supplemented with rhamnogalacturonan (RG), a polysaccharide from the peel of the Korean citrus hallabong, on natural killer (NK) cell activity and circulating cytokine levels. A randomized, double-blind, placebo-controlled study was conducted on 120 nondiabetic and nonobese subjects. Over an eight-week period, the test group consumed one pack (150 mL) of dairy yogurt containing 50 mg of probiotics and 100 mg of hallabong peel polysaccharide (60% RG) each day, whereas the placebo group consumed the same product without the hallabong peel supplement. NK cell activity (%) was measured based on the ratios of the effector cells (E; peripheral blood mononuclear cells, PBMCs) from each participant relative to the target cells (T; K562 cells) at E : T ratios of 10 : 1, 5 : 1, 2.5 : 1, or 1.25 : 1. NK cell activities under all assay conditions and interleukin (IL)-12 and interferon (IFN)-γ levels were significantly increased in the test group at eight weeks compared to the baseline values, whereas the placebo group showed a significant increase only in NK cell activity at E : T = 1.25 : 1. The test group had significantly greater increases in the changes in serum NK cell activity at the E : T ratios of 10 : 1, 5 : 1, and 2.5 : 1 and in the increases in IL-12 and IFN-γ levels than were observed in the placebo group, after adjusting for baseline values. After eight weeks of treatment, significant reductions were found in IL-6 and IL-1β levels in both the placebo and test groups. The daily consumption of dairy yogurt supplemented with RG, a polysaccharide from the peel of the Korean citrus hallabong, enhanced NK cell function and attenuated pro-inflammatory cytokine levels (ClinicalTrials.gov: NCT02535663).
authors.affiliation: National Leading Research Laboratory of Clinical Nutrigenetics/Nutrigenomics, Department of Food and Nutrition, College of Human Ecology, Yonsei University, Seoul, Republic of Korea. jhleeb@yonsei.ac.kr and Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul, Republic of Korea.
authors.forename: Mi-Hyang
authors.initials: MH
authors.lastname: Lee
authors.affiliation: Research Center for Silver Science, Institute of Symbiotic Life-TECH, Yonsei University, Seoul, Republic of Korea.
authors.forename: Minjoo
authors.initials: M
authors.lastname: Kim
authors.affiliation: National Leading Research Laboratory of Clinical Nutrigenetics/Nutrigenomics, Department of Food and Nutrition, College of Human Ecology, Yonsei University, Seoul, Republic of Korea. jhleeb@yonsei.ac.kr and Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul, Republic of Korea.
authors.forename: Minkyung
authors.initials: M
authors.lastname: Kim
authors.affiliation: Research Center for Silver Science, Institute of Symbiotic Life-TECH, Yonsei University, Seoul, Republic of Korea.
authors.forename: Jung Hyun
authors.initials: JH
authors.lastname: Kwak
authors.affiliation: Yonsei University Dairy R&D Center, Asan, Republic of Korea.
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Chang
authors.affiliation: Yonsei University Dairy R&D Center, Asan, Republic of Korea.
authors.forename: Won Kyu
authors.initials: WK
authors.lastname: Yu
authors.affiliation: Department of Family Practice, National Health Insurance Corporation, Ilsan Hospital, Goyang, Republic of Korea.
authors.forename: Sang-Hyun
authors.initials: SH
authors.lastname: Lee
authors.affiliation: National Leading Research Laboratory of Clinical Nutrigenetics/Nutrigenomics, Department of Food and Nutrition, College of Human Ecology, Yonsei University, Seoul, Republic of Korea. jhleeb@yonsei.ac.kr and Department of Food and Nutrition, Brain Korea 21 PLUS Project, College of Human Ecology, Yonsei University, Seoul, Republic of Korea and Research Center for Silver Science, Institute of Symbiotic Life-TECH, Yonsei University, Seoul, Republic of Korea.
authors.forename: Jong Ho
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D002957:Citrus / Q000737:chemistry*; D016207:Cytokines / Q000097:blood / Q000276:immunology; D004032:Diet; D004311:Double-Blind Method; D015444:Exercise; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000276:immunology; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010368:Pectins / Q000008:administration & dosage*; D019936:Probiotics / Q000008:administration & dosage; D014280:Triglycerides / Q000097:blood; D015014:Yogurt
chemical_list: D016207:Cytokines; D014280:Triglycerides; D010368:Pectins; D002784:Cholesterol