Immunomodulatory effects of Lactobacillus plantarum colonizing the intestine of gnotobiotic rats

• Published in: Clinical and experimental immunology Vol. 116; no. 2; pp. 283 - 290
• Main Authors: HERIAS, M. V, HESSLE, C, TELEMO, E, MIDTVEDT, T, HANSON, L. A, WOLD, A. E
• Format: Journal Article
• Language: English
• Published: Oxford BSL Blackwell Science Ltd 01-05-1999; Blackwell; Oxford University Press; Blackwell Science Inc
• Subjects: analysis; Analysis of the immune response. Humoral and cellular immunity; Animals; Antibodies; Antibodies, Bacterial - blood; Antigens; Antigens, CD - analysis; Bacterial; Bacterial Adhesion; Bacterial Translocation; Biological and medical sciences; blood; Escherichia coli; Female; Fimbriae; Fimbriae, Bacterial; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Germ-Free Life; Immunobiology; Immunohistochemistry; Immunologi inom det medicinska området; Immunology in the medical area; immunomodulation; intestinal colonization; Intestines; Intestines - microbiology; Lactobacillus; Lactobacillus - physiology; Lactobacillus plantarum; Lymphocyte Activation; Male; Medicin och hälsovetenskap; microbiology; Microbiology in the medical area; Mikrobiologi inom det medicinska området; Miscellaneous; Original; physiology; Rats; Regulatory factors and their cellular receptors; Probiotic; Gnotobiotic animal; Lactobacillus plantarum; Rat; Escherichia coli; Rodentia; Gut; Immune regulation; Vertebrata; Local immunity; Mammalia; Immunological investigation; Animal; Bacteria; Lactobacillaceae; Colonization; Humoral immunity; Enterobacteriaceae
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1046/j.1365-2249.1999.00891.x

We have studied the effect of the probiotic strain Lactobacillus plantarum 299v on the immune functions of gnotobiotic rats. One group of germ‐free rats was colonized with the type 1‐fimbriated Escherichia coli O6:K13:H1 and another group with the same E. coli strain together with L. plantarum 299v. One and 5 weeks after colonization, bacterial numbers were determined in the contents of the small intestine, caecum and mesenteric lymph nodes. Small intestinal sections were examined for CD8+, CD4+, CD25+ (IL‐2R α‐chain), IgA+ and MHC class II+ cells and mitogen‐induced spleen cell proliferation was determined. Immunoglobulin levels and E. coli‐specific antibodies were measured in serum. Rats given L. plantarum in addition to E. coli showed lower counts of E. coli in the small intestine and caecum 1 week after colonization compared with the group colonized with E. coli alone, but similar levels after 5 weeks. Rats colonized with L. plantarum+ E. coli had significantly higher total serum IgA levels and marginally higher IgM and IgA antibody levels against E. coli than those colonized with E. coli alone. They also showed a significantly increased density of CD25+ cells in the lamina propria and displayed a decreased proliferative spleen cell response after stimulation with concanavalin A or E. coli 1 week after colonization. The results indicate that L. plantarum colonization competes with E. coli for intestinal colonization and can influence intestinal and systemic immunity.