Amling Lara, Rink Lothar, Bennstein Sabrina B
Institute of Immunology, Medical Faculty, RWTH Aachen University, Aachen, Germany.
J Transl Med. 2025 Mar 14;23(1):333. doi: 10.1186/s12967-025-06259-y.
Zinc is an essential trace element with high importance for immune function. Previous research has shown that vegetarians and vegans are at increased risk of zinc deficiency, due to low zinc bioavailability in plant-based food. However, its effects on immune parameters in healthy adults following these diets remain largely unexplored. Therefore, this study investigated the effects of dietary patterns, serum zinc levels, and short-term oral zinc supplementation on Natural Killer (NK) cells, circulating Innate Lymphoid Cells (cILCs), and NK cell functionality in omnivores, vegetarians, and vegans.
A total of 54 study participants, including 21 omnivores, 18 vegetarians, and 15 vegans were enrolled in our study. NK cell and cILC counts and frequencies were analyzed by flow cytometry and NK cell cytotoxicity assay was performed and compared between the three dietary cohorts as well as between zinc adequate (ZA) and zinc deficient (ZD) individuals. Based on serum zinc concentrations and/or Food Frequency Questionnaire (FFQ) scores, study participants classified as ZD were supplemented with 10 mg zinc daily for 14 days. After this period, the same experiments were performed.
Our results show that neither dietary patterns nor baseline zinc levels significantly affect cILC or NK cell counts, frequencies, or NK cell cytotoxicity. However, short-term oral zinc supplementation significantly reduced cILC counts and frequencies, while enhancing NK cell functionality. Here, NK cell cytotoxicity is significantly positively correlated, whereas cILC counts are negatively correlated with serum zinc concentrations. Remarkably, 72% of all study participants, including 48% of omnivores, were classified as ZD.
Since proper NK cell functionality is required for early defense against infected or malignant cells, and cILCs act as progenitors to replenish tissue resident ILCs, which are crucial for tissue homeostasis and barrier integrity, our results suggest that routine zinc supplementation might be a simple yet effective strategy to enhance immune defense and potentially prevent diseases across different dietary groups.
The study was approved and registered by the Institutional Ethics Committee of the Medical Faculty of RWTH Aachen University on the 19th of July 2023 (study numbers: EK 23-148 and EK 23-234, CTC number: 23-163).
锌是一种对免疫功能至关重要的必需微量元素。先前的研究表明，素食者和纯素食者因植物性食物中锌的生物利用度低，患锌缺乏症的风险增加。然而，这些饮食方式对健康成年人免疫参数的影响在很大程度上仍未得到探索。因此，本研究调查了饮食模式、血清锌水平和短期口服锌补充剂对杂食者、素食者和纯素食者的自然杀伤（NK）细胞、循环固有淋巴细胞（cILC）以及NK细胞功能的影响。
本研究共纳入54名研究参与者，包括21名杂食者、18名素食者和15名纯素食者。通过流式细胞术分析NK细胞和cILC的数量及频率，并进行NK细胞细胞毒性测定，比较三个饮食队列以及锌充足（ZA）和锌缺乏（ZD）个体之间的差异。根据血清锌浓度和/或食物频率问卷（FFQ）评分，将被归类为ZD的研究参与者每天补充10毫克锌，持续14天。在此期间后，进行相同的实验。
我们的结果表明，饮食模式和基线锌水平均未显著影响cILC或NK细胞的数量、频率或NK细胞细胞毒性。然而，短期口服锌补充剂显著降低了cILC的数量和频率，同时增强了NK细胞功能。在此，NK细胞细胞毒性呈显著正相关，而cILC数量与血清锌浓度呈负相关。值得注意的是，所有研究参与者中有72%，包括48%的杂食者，被归类为ZD。
由于针对感染或恶性细胞的早期防御需要适当的NK细胞功能，且cILC作为祖细胞可补充组织驻留ILC，而ILC对组织稳态和屏障完整性至关重要，我们的结果表明，常规锌补充可能是一种简单而有效的策略，可增强不同饮食群体的免疫防御并潜在预防疾病。
该研究于2023年7月19日获得亚琛工业大学医学院机构伦理委员会的批准和注册（研究编号：EK 23 - 148和EK 23 - 234，临床试验编号：23 - 163）。
