Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523, USA.
J Med Food. 2012 May;15(5):469-75. doi: 10.1089/jmf.2011.0213. Epub 2012 Jan 16.
Gut-associated lymphoid tissue maintains mucosal homeostasis by combating pathogens and inducing a state of hyporesponsiveness to food antigens and commensal bacteria. Dietary modulation of the intestinal immune environment represents a novel approach for enhancing protective responses against pathogens and inflammatory diseases. Dietary rice bran consists of bioactive components with disease-fighting properties. Therefore, we conducted a study to determine the effects of whole dietary rice bran intake on mucosal immune responses and beneficial gut microbes. Mice were fed a 10% rice bran diet for 28 days. Serum and fecal samples were collected throughout the study to assess total immunoglobulin A (IgA) concentrations. Tissue samples were collected for cellular immune phenotype analysis, and concentrations of native gut Lactobacillus spp. were enumerated in the fecal samples. We found that dietary rice bran induced an increase in total IgA locally and systemically. In addition, B lymphocytes in the Peyer's patches of mice fed rice bran displayed increased surface IgA expression compared with lymphocytes from control mice. Antigen-presenting cells were also influenced by rice bran, with a significant increase in myeloid dendritic cells residing in the lamina propria and mesenteric lymph nodes. Increased colonization of native Lactobacillus was observed in rice bran-fed mice compared with control mice. These findings suggest that rice bran-induced microbial changes may contribute to enhanced mucosal IgA responses, and we conclude that increased rice bran consumption represents a promising dietary intervention to modulate mucosal immunity for protection against enteric infections and induction of beneficial gut bacteria.
肠相关淋巴组织通过对抗病原体和诱导对食物抗原和共生细菌的低反应状态来维持黏膜稳态。调节肠道免疫环境代表了增强针对病原体和炎症性疾病的保护反应的一种新方法。全谷物米糠包含具有抗病特性的生物活性成分。因此，我们进行了一项研究，以确定全谷物米糠饮食摄入对黏膜免疫反应和有益肠道微生物的影响。将小鼠喂食 10%米糠饮食 28 天。在整个研究过程中收集血清和粪便样本，以评估总免疫球蛋白 A（IgA）浓度。收集组织样本进行细胞免疫表型分析，并在粪便样本中计数天然肠道乳杆菌属的浓度。我们发现，饮食米糠诱导局部和全身总 IgA 增加。此外，与对照组相比，喂食米糠的小鼠派尔集合淋巴结中的 B 淋巴细胞显示出表面 IgA 表达增加。抗原呈递细胞也受到米糠的影响，固有层和肠系膜淋巴结中的髓样树突状细胞数量显著增加。与对照组相比，喂食米糠的小鼠中观察到天然乳杆菌的定植增加。这些发现表明，米糠诱导的微生物变化可能有助于增强黏膜 IgA 反应，我们得出结论，增加米糠的摄入代表了一种有前途的饮食干预措施，可以调节黏膜免疫，以预防肠道感染和诱导有益的肠道细菌。
