Probiotics responses

Probiotics, such as Lactobacillus acidophilus or Bifidobacterium, may offer possible benefit, based on the rationale that modification of the host flora may alter the inflammatory response. Some evidence exists for improvement in disease symptoms, but further well-controlled trials are needed.26... 

Probiotics Dietary supplements containing potentially beneficial bacteria that promote health by stimulating optimal mucosal immune responses. 

Undesirable responses of prevalent gut microflora has raised interest in modiflcation of that flora by probiotic regimes, evidence of benefit is still too limited to justify general usage. 

The mechanisms by which probiotics (and prebiotics) produce beneficial effects on the gut have not yet been fully elucidated. However, at least three mechanisms of action have been proposed (i) antibacterial agents produced by probiotic organisms may have an inhibitory effect on pathogenic microbes (ii) immune responses may be enhanced to suppress potential pathogens and (iii) competition in the gut epithelium may allow lactic acid bacteria and bifidobacteria to supplant pathogenic organisms. 

Modifying primary and secondary immunological response by Bifidobacterium and Lactobacillus probiotics is linked with their structures being recognized by TLR 9 present on monocytes and lymphocytes, as well as with TLR expression on dendritic cells. As a result, release of IL 12 and IFNy is increased. Also preferential recruitment of Thl lymphocytes has been observed. Saito made a hypothesis that individually selected TLR ligand doses might be administered as a medicine to infants at risk of allergy (Saito et al., 2003). 

He, E, Tuomoloa, E., Arvilommi, H., and Salminen, S. 2000. Modulation of humoral immune response through probiotic intake. FEMS Immunol Med Microbiol 29 47-52. 

Matsuzaki, T. and Chin, J. 2000. Modulating immune responses with probiotic bacteria. Immunol Cell Biol 78 67-73. 

Nagy, A., Jgdrychowski, L., Gelencser, E., Wroblewska, B., Szymkiewicz, A. 2005b. Induction of specific mucosal immune responses by viable or heat denatured probiotic bacteria of Lactobacillus strains. Acta Alimentaria 34 33-39. 

De Angelis, M., Rizello, C.G., Fasano, A., Clemente, M.G., De Simone, C., Silano, M., De Vincenzi, M., Losito, I., Gobbetti, M. 2006. VSL 3 probiotic preparation has the capacity to hydrolyze gliadin polypeptides responsible for celiac sprue. Biochim Biophys Acta 1765 80-93. 

Probiotic bacteria regulate mucosal immune responses through induction of anti-inflammatory cytokines such as IL-10 and TGF-p, while decreasing expression of proinflammatory cytokines, such as TNF and IFN-y (Corr et al., 2007a Di Giacinto et al., 2005 Silva et al., 2004). B. breve and Streptococcus thermophilus secrete metabolites which inhibit LPS-induced TNF-a secretion from peripheral blood mononuclear cell (PBMC) monolayers (Menard et al., 2004). We demonstrated a significant reduction in interleukin-8 (IL-8) and an increase in IL-10 cytokines secreted from epithelial cells following pretreatment with probiotics... 

These last factors also up-regulate hBD-2 secretion by the intestinal epithelial cell lineage Caco-2 stimulated with probiotic bacteria [176]. Although not yet demonstrated experimentally, mammalian cathelicidins may respond to inflammatory stimuli, since the 5 flanking sequences upstream of the peptide coding sequence have several potential consensus sequences for transcription factors involved in inflammatory response, sueh as NF-kB, NF-IL-6, acute-phase response factor and IFN-y response elements [147,170,177]. 

A critical criterion of selection is that the probiotic strain must be tolerated by the immune system and should not provoke the formation of antibodies against the probiotic. This latter property, in conjunction with the ability of some LAB to survive and colonize in the gut, has given rise to further applications, which involve their use as live vectors for oral immunization, i.e., introducing antigens targeting the GALT and aiming to induce a mucosal immune response (Marteau and Rambaud, 1993). 

One of the most interesting aspects of probiotic supplementation is directed toward immune responses. Orally administered probiotic strains of LAB exert a positive impact on nonspecific and specific host immune responses. Nonspecific immune responses constitute the first line of host defense. 

Water, saccharides, lipids, proteins, and minerals — the main components — form the structure of and are responsible for the sensory and nutritional properties of foods. Other constituents, present in lower quantities, especially colorants, flavor compounds, vitamins, probiotics, and additives, also contribute to different aspects of food quality. The catabolysis that takes place in raw materials postharvest, as well as chemical and biochemical changes and interactions of components during storage and processing, affect all aspects of food quality. These processes can be effectively controlled by the food processor who knows food chemistry. 

Whitehead, K.J., Versalovic, J., Roos, S., and Britton, R.A. 2008. Genomic and genetic characterization of the bile stress response of probiotic Lactobacillus reuteri ATCC 55730. Applied and Environmental Microbiology 74 1812-1819. 

In the first clinical demonstration of specific probiotic strains modifying the changes related to allergic inflammation (i.e. tertiary prevention), a randomised double-blind controlled trial was carried out in Finland. A small number of infants who manifested atopic eczema while exclusively breast-feeding were weaned to probiotic supplemented Bifidobacterium lactis or Lactobacillus) extensively hydrolysed whey formulas, or to the same formula without probiotics. A significant improvement in skin condition occurred in patients given probiotic-supplemented formulas. The concentration of soluble CD4 in serum and eosinophilic protein X in urine were reduced, indicating that probiotics may counteract inflammatory responses beyond the intestinal milieu [186(Ib)]. 

Prasad, J., Mcjarrow, P, and Gopal, P. Heat and osmotic stress responses of probiotic Lactobacillus rhamnosus HNOOl (DR20) in relation to viability after drying, Appl. Environ. Microbiol, 69, 917, 2003. 

An emerging concept is that a balance in the GI tract normally exists among the mucosal epithelium, the normal gut flora, and the immune response. Some data suggest that colonic bacteria may either initiate or perpetuate the inflammation of IBD, and specific bacterial antigens in the pathogenesis of Crohn s disease. Thus, certain bacterial strains may be either pro- (e.g., Bacteroides) or antiinflammatory (e.g., Lactobacillus), prompting attempts to manipulate the colonic flora in patients with IBD. Traditionally, antibiotics have been used to this end, most prominently in Crohn s disease. More recently, probiotics have been used to treat specific chnical situations in IBD. 

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