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

A defined human microbiota‐associated (HMA) mouse model in BALB/c and immunodeficient Tgε26 mice was used to assess the ability of probiotic lactobacilli and bifidobacteria to enhance colonization resistance to gastrointestinal (GI) tract pathogens. Probiotic bacteria (1×10⁸ 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.     

Polyphenols,carotenoids, and ascorbic acid in underutilized medicinal vegetables

The polyphenols, carotenoids, ascorbic acid, and protein were determined in 24 underutilized medicinal vegetables from Indonesia. Anacardium occidentale, Sauropus androgynus (L.) Merr., and Moringa pterygosperma Gaertn. leaves were rich sources of flavonoids, with 118–144 mg/100 g fresh weight. Quercetin, kaempferol, and chlorogenic acid were the predominant polyphenols among those measured in vegetables. Polyscias pinnata leaves and Solanum torvum Swartz fruits had the most phenolic acids, with 53 and 36 mg/100 g, respectively. Moringa pterygosperma had the most carotenoids among vegetables, with 14 mg β-carotene equivalents (βCE)/100 g. Ascorbic acid content of fresh vegetables was 12.03–494.43 mg/100 g. A. occidentale, S. androgynus, Ocimum americanum L., Cosmos caudatus H.B.K., and Carica papaya L. (papaya) leaves had more than 100 mg ascorbic acid/100 g. Thus, a number of underutilized vegetables from Indonesia may be rich sources of functional components including polyphenols and ascorbic acid.