Prebiotic and immunomodulatory activity of kefiran in a murine model

MEDRANO, M.; HAMET, M.F.; RACEDO, S.M.; ROLNY, I.S.; PEREZ, P.F.; ABRAHAM, A.G.

Mar del Plata

Congreso; LIV Reunión Científica de la Sociedad Argentina de Investigación Clínica. LVII Reunión Científica de la Sociedad Argentina de Inmunología.; 2009

Kefiran is a branched non-digestible glucogalactan able to modulate immune response on intestinal mucosa. The aim of this work was to study, in vivo, the effect of kefiran on intestinal microbiota and its possible correlation with the balance of relevant populations of immune cells.. Balb/C mice were treated ad libitum (0, 2 and 7 days) with kefiran 300 mg/L dissolved in water. DNA from fecal samples was extracted using a commercial kit and was amplified by PCR with primers 518r and GC-338f for Eubacteria, Bif164f and GC-Bif662 for Bifidobacterium sp. and Lac1 and Lac2 for Lactobacillus sp. The amplicons were analyzed by DGGE and cluster analysis was performed. Macrophages (F4/80+ cells) in Peyer`s patches (PP), mesenteric lymph nodes (MLN) and peritoneal cavity were analyzed by flow cytometry. IgA+ and F4/80+ cells in lamina propria (LP) were studied by immunofluorescence in samples of small intestine. Number of goblet cells were assessed by Alcian Blue staining. Kefiran is a branched non-digestible glucogalactan able to modulate immune response on intestinal mucosa. The aim of this work was to study, in vivo, the effect of kefiran on intestinal microbiota and its possible correlation with the balance of relevant populations of immune cells.. Balb/C mice were treated ad libitum (0, 2 and 7 days) with kefiran 300 mg/L dissolved in water. DNA from fecal samples was extracted using a commercial kit and was amplified by PCR with primers 518r and GC-338f for Eubacteria, Bif164f and GC-Bif662 for Bifidobacterium sp. and Lac1 and Lac2 for Lactobacillus sp. The amplicons were analyzed by DGGE and cluster analysis was performed. Macrophages (F4/80+ cells) in Peyer`s patches (PP), mesenteric lymph nodes (MLN) and peritoneal cavity were analyzed by flow cytometry. IgA+ and F4/80+ cells in lamina propria (LP) were studied by immunofluorescence in samples of small intestine. Number of goblet cells were assessed by Alcian Blue staining. DGGE analysis using universal primers for Eubacteria indicated that, in kefiran-treated animals, Intestinal microbiota was modified. Indeed, a higher number of bands were observed in kefiran-treated mice after 2 and 7 days of kefiran administration. Those bands correspond to Bifidobacterium and Lactobacillus genera. Number of IgA+ cells increased in LP at days 2 and 7  of treatment. Number of F4/80+ cells diminished in PP and increased in LP and peritoneal cavity after 7 days of treatment. Interestingly, ratio of goblet cells was higher at 2 and 7 days of treatment. Our results show that oral administration of kefiran in mice leads to changes in the intestinal microbiota. Since the balance of immune cells was modified in kefiran treated mice, It could be hypothesized that the immunomodulatory effect of kefiran is related to the modification of the intestinal microbiota. However, the effect of direct interaction of kefiran with relevant immune cells cannot be ruled out.