Kaburagi Tomoko, Yamano Toshihiko, Fukushima Yoichi, Yoshino Haruka, Mito Natsuko, Sato Kazuto
Division of Clinical Nutrition, Department of Food and Nutrition, Japan Women's University, Tokyo, Japan.
Nutrition. 2007 Apr;23(4):342-50. doi: 10.1016/j.nut.2007.02.001. Epub 2007 Mar 23.
Protein-energy malnutrition (PEM) is a serious nutritional problem that causes immune dysfunction in elderly people. Probiotic lactic acid bacteria may potentially modify immunity; however, there is little evidence to elucidate the influence of these bacteria on PEM in the elderly.
The immune modulation effects of lactic acid bacterium Lactobacillus johnsonii La1 (La1) were examined in aged mice and aged mice with PEM. Twenty-month-old male 57BL6/n mice (n = 28) were divided into four groups and received the following diet for 14 d: a complete diet (20% protein) without Lal (control) or with Lal or a low-protein diet (5% protein) to induce PEM, with or without La1. All mice were immunized with diphtheria toxin (DT) with alfacalciferol at 7 d and sacrificed 14 d after starting the experimental diets.
Serum albumin concentrations and body weight, both of which were reduced by the low-protein diet, were ameliorated by La1 intake and were the same as in mice receiving the control diet. Anti-DT immunoglobulin (Ig) A in fecal extract was increased by La1 intake in mice receiving the complete and low-protein diets. Serum anti-DT IgA, IgG, splenocyte proliferation, and CD8(+) T cells were reduced by the low-protein diet and restored by La1 intake.
La1 enhances intestinal IgA production and helps recover nutritional status and systemic immune responses in aged mice with PEM. It is possible that La1 may contribute to immune system recovery in immunocompromised hosts such as elderly humans with PEM.
蛋白质 - 能量营养不良（PEM）是一个严重的营养问题，可导致老年人免疫功能障碍。益生菌乳酸菌可能会调节免疫力；然而，几乎没有证据阐明这些细菌对老年人PEM的影响。
在老年小鼠和患有PEM的老年小鼠中检测了约翰逊乳杆菌La1（La1）的免疫调节作用。将20月龄雄性C57BL6/n小鼠（n = 28）分为四组，并给予以下饮食14天：不含La1的完全饮食（20%蛋白质）（对照）或含La1的完全饮食，或低蛋白饮食（5%蛋白质）以诱导PEM，有无La1。所有小鼠在第7天用白喉毒素（DT）和阿法骨化醇免疫，并在开始实验饮食14天后处死。
低蛋白饮食降低的血清白蛋白浓度和体重，通过摄入La1得到改善，与接受对照饮食的小鼠相同。在接受完全饮食和低蛋白饮食的小鼠中，摄入La1可增加粪便提取物中的抗DT免疫球蛋白（Ig）A。低蛋白饮食降低了血清抗DT IgA、IgG、脾细胞增殖和CD8(+) T细胞，而摄入La1可使其恢复。
La1增强肠道IgA产生，并有助于恢复患有PEM的老年小鼠的营养状况和全身免疫反应。La1可能有助于免疫受损宿主（如患有PEM的老年人）的免疫系统恢复。
