CIDCA   05380
CENTRO DE INVESTIGACION Y DESARROLLO EN CRIOTECNOLOGIA DE ALIMENTOS
Unidad Ejecutora - UE
artículos
Título:
Administration of kefir-fermented milk protects mice against Giardia intestinalis infection.
Autor/es:
CORREA FRANCO, M.; GOLOWCZYC, M. A.; DE ANTONI, G. L.; PÉREZ, P. F.; HUMEN, M. A. AND SERRADELL, M. DE LOS A.
Revista:
JOURNAL OF MEDICAL MICROBIOLOGY
Editorial:
SOC GENERAL MICROBIOLOGY
Referencias:
Lugar: London; Año: 2013 vol. 62 p. 1815 - 1822
ISSN:
0022-2615
Resumen:
Giardiasis, caused by the protozoan Giardia intestinalis, is one of the most common intestinal
diseases worldwide and constitutes an important problem for the public health systems of various
countries. Kefir is a probiotic drink obtained by fermenting milk with ?kefir grains?, which consist
mainly of bacteria and yeasts that coexist in a complex symbiotic association. In this work, we
studied the ability of kefir to protect mice from G. intestinalis infection, and characterized the host
immune response to this probiotic in the context of the intestinal infection. Six- to 8-week-old
C75BL/6 mice were separated into four groups: controls, kefir mice (receiving 1 : 100 dilution of
kefir in drinking water for 14 days), Giardia mice (infected orally with 4107 trophozoites of G.
intestinalis at day 7) and Giardia?kefir mice (kefir-treated G. intestinalis-infected mice), and killed
at 2 or 7 days post-infection. Kefir administration was able to significantly reduce the intensity of
Giardia infection at 7 days post-infection. An increase in the percentage of CD4+ T cells at
2 days post-infection was observed in the Peyer?s patches (PP) of mice belonging to the Giardia
group compared with the control and kefir groups, while the percentage of CD4+ T cells in PP in
the Giardia?kefir group was similar to that of controls. At 2 days post-infection, a reduction in the
percentage of B220-positive major histocompatibility complex class II medium cells in PP was
observed in infected mice compared with the other groups. At 7 days post-infection, Giardiainfected
mice showed a reduction in RcFce-positive cells compared with the control group,
suggesting a downregulation of the inflammatory response. However, the percentages of RcFcepositive
cells did not differ from controls in the kefir and Giardia?kefir groups. An increase in IgApositive
cells was observed in the lamina propria of the kefir group compared with controls at
2 days post-infection. Interestingly, the diminished number of IgA-positive cells registered in the
Giardia group at 7 days post-infection was restored by kefir feeding, although the increase in IgApositive
cells was no longer observed in the kefir group at that time. No significant differences in
CXCL10 expression were registered between groups, in concordance with the absence of
inflammation in small-intestinal tissue. Interestingly, a slight reduction in CCL20 expression was
observed in the Giardia group, suggesting that G. intestinalis might downregulate its expression
as a way of evading the inflammatory immune response. On the other hand, a trend towards an
increase in TNF-a expression was observed in the kefir group, while the Giardia?kefir group
showed a significant increase in TNF-a expression. Moreover, kefir-receiving mice (kefir and
Giardia?kefir groups) showed an increase in the expression of IFN-c, the most relevant Th1
cytokine, at 2 days post-infection. Our results demonstrate that feeding mice with kefir reduces G.
intestinalis infection and promotes the activation of different mechanisms of humoral and cellular
immunity that are downregulated by parasitic infection, thus contributing to protection.