Probiotic bacteria are antagonistic to Salmonella enterica and Campylobacter jejuni and influence host lymphocyte responses in human microbiota‐associated immunodeficient and immunocompetent mice

Abstract

A defined human microbiota-associated (HMA) mouse model in BALB/c and immunodeficient Tgepsilon26 mice was used to assess the ability of probiotic lactobacilli and bifidobacteria to enhance colonization resistance to gastrointestinal (GI) tract pathogens. Probiotic bacteria (1x10(8) colony forming unit (CFU)/mL) successfully excluded Campylobacter jejuni from both strains of mice 7 days after challenge. The probiotic bacteria also reduced the number of Salmonella in the large intestines of both mouse strains. The nylon wool fractionated spleen lymphocyte populations were incubated with Salmonella or C. jejuni antigens. The probiotic treatments did not affect lymphocyte proliferation to C. jejuni antigens, but significantly increased proliferation of lymphocytes to Salmonella antigens by 68 and 55%, respectively, over untreated mice. Caspase 3/7 activation was significantly reduced 33 and 38% in the T and B lymphocyte fractions, respectively, of probiotic-treated, Salmonella-challenged HMA BALB/c mice, suggesting that lymphocyte rescue from apoptosis was occurring as a result of probiotic bacteria activity. These results revealed an immunosuppressive activity by Salmonella that was inhibited by the presence of probiotic bacteria. In summary, lactobacilli and bifidobacteria competitively excluded C. jejuni from immunocompetent and immunodeficient mice and antagonized an observable Salmonella-induced immunosuppression in immunocompetent mice.

Probiotic Colonization of the Adherent Mucus Layer of HT29MTXE12 Cells Attenuates Campylobacter jejuni Virulence Properties

“…Probiotics have been shown to attenuate the virulence of several enteropathogens in vitro (9,36). Preliminary data from coculture (7) and animal studies (29,41,45) point to the potential effectiveness of probiotics in inhibiting C. jejuni infection. In a recent paper, Wine et al (46) provide evidence for strain-and cell-type-specific reduction in C. jejuni invasiveness following coculture with probiotics.…”

Recent developments and perspectives in the investigation of probiotic effects

“…This effect may be responsible for the prevention of antibiotic-associated diarrhea by S. boulardii in humans (Barc et al, 2008). In both immunocompetent and immunodeficient HMA mice, the application of probiotic lactobacilli and bifidobacteria resulted in a complete exclusion of the pathogenic Campylobacter jejuni and reversed a Salmonellainduced immunosuppression in immunocompetent mice after experimental infection (Wagner et al, 2009). …”

Probiotics: An alternative strategy for combating salmonellosis

“…One alternative used to study the mechanisms exerted by probiotic in humans are the assays carried out in human microbiota associated (HMA) animals. Wagner et al observed that the application of probiotic lactobacilli and bifidobacteria reversed a Salmonella induced immune suppression in immune competent HMA mice after experimental infection (Wagner, Johnson, & Kurniasih Rubin, 2009). Nevertheless, only little number of clinical trials on healthy volunteers has been reported.…”