Effect of Lactobacillus johnsonii La1 on immune function and serum albumin in aged and malnourished aged mice.
OBJECTIVE
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Kaburagi
Tomoko
T
Division of Clinical Nutrition, Department of Food and Nutrition, Japan Women's University, Tokyo, Japan. kaburagi@fc.jwu.ac.jp
Yamano
Toshihiko
T
Fukushima
Yoichi
Y
Yoshino
Haruka
H
Mito
Natsuko
N
Sato
Kazuto
K
D000375:Aging / Q000097:blood / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D004044:Dietary Proteins / Q000008:administration & dosage; D005243:Feces; D018928:Immunity, Mucosal / Q000187:drug effects*; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007778:Lactobacillus / Q000254:growth & development / Q000276:immunology / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009752:Nutritional Status; D019936:Probiotics / Q000008:administration & dosage*; D011502:Protein-Energy Malnutrition / Q000097:blood / Q000276:immunology*; D011897:Random Allocation; D012709:Serum Albumin / Q000032:analysis*
D004044:Dietary Proteins; D007070:Immunoglobulin A; D012709:Serum Albumin