Immune Response of Bifidobacterium-Monoassociated Mice

Abstract

Various investigators have discussed floral microorganisms influence on a host's immune system (4, 6, 9). Most of these statements come from investigations comparing responses of germfree animals and flora-bearing ones. The present authors attempted to analyze the effect of an indigenous floral organisms on the host under a more simplified condition. Bifidobacterium longum (BL) was given per os to germfree mice (GF) of BALB/c background and various aspects of immune responses to the associated organism were investigated first; antibody (mainly IgA) and cell-mediated immune (CMI) responses to BL, translocations of BL into the internal organs, and shift of lymphocyte subsets in the lymphoid organs were found following per os administration of BL. Some activities of BL on in vitro cultured lymphocytes were also found. Additionally, it was shown that the BL-monoassociated mouse (GB) exhibits beneficial effects in respect to specific immune response and non-specific antibacterial defence reactions to unrelated antigenic substances. These non-specific effects were seen on lethal activity of Escherichia coliendotoxin, IgA production to cholera toxin (CT), and induction of oral tolerance to unrelated antigens. IMMUNOLOGICAL AND MICROBIAL CHANGES AFTER MONOASSOCIATION WITH BL

Effect of Indigestible Saccharides on B Lymphocyte Response of Intestinal Mucosa and Cecal Fermentation in Rats.

“…Bifidobacterium is reported to enhance immunopotentiation by increasing IgA antibody production in vitro as well as in vivo by oral administration to germ-free mice (22)(23)(24)(25), and Rao (26) assumed that changes in intestinal microflora by dietary fibers affect the immunological functions .…”

Inhibition of Bacterial Translocation from the Gastrointestinal Tract of Mice by Oral Administration of a Culture Condensate of Bifidobacterium longum.

“…There are many reports on the effects of lactic acid bacteria concerning non-specific stimulation of the defense mechanism after oral administration [24]. Yamazaki et al [27] also reported that B. longum monoassociated mice exhibited beneficial effects with respect to specific and non-specific immunological defense reactions. However, Yamazaki et al [26] reported that antibacterial activity against E. coli administered into the stomach at a high dose was not observed in germ-free mice fed heat-killed B. longum.…”

“…It has also been reported that treatment with Bifidobacterium stimulates the nonspecific immune function [23,27], and Fujisawa et al [11] have reported that an administration of a culture condensate of Bifidobacterium longum (MB) increased the enzyme activity of intestinal epithelial cells and controlled the intestinal flora in rats.…”

Safety and Regulation of Probiotic Foods and Supplements

“…Conversely, if the possibility of causing sepsis or infection is high after probiotic translocation occurs, the probiotics should not be used even if it has low translocation ability. Yamazaki et al (1985Yamazaki et al ( , 1991 reported interesting investigations using germfree mice. When the pathogen E. coli O-111 was administered orally to germfree mice, most mice died within a few weeks because E. coli O-111 was translocated and produced enterotoxin in organs.…”