Production of bioactive substances by intestinal bacteria as a basis for explaining probiotic mechanisms: Bacteriocins and conjugated linoleic acid

Microbiota regulate intestinal epithelial gene expression by suppressing the transcription factor Hepatocyte nuclear factor 4 alpha

“…Fatty acids are an attractive class of putative regulators of HNF4A, since the microbiota are known to regulate FA absorption in zebrafish IECs (Semova et al 2012). Further, specific bacterial taxa are known to modify the structure of polyunsaturated FAs (PUFAs), and these native and modified PUFAs have distinct impacts on animal health (O'Shea et al 2012) and may serve as therapeutics for IBD (Mbodji et al 2013).…”

Lactic Acid Bacteria as Source of Functional Ingredients

“…The probiotic bacteria compete with pathogenic bacteria for epithelial binding sites, inhibiting the colonization of strains like Salmonella and E. coli [28,29]. Probiotic bacteria interact with the epithelial cells of the gut, either directly (via cell compounds like DNA, lipoteichoic acids and cell-surface polysaccharides) or indirectly (through production of bioactive metabolites) [30]. The enhancement of mucosal barrier function may be an important mechanism by which probiotics benefit the host in various diseases such as Type 1 diabetes [31,32].…”

“…Additionally, bacteriocin production can contribute to the probiotic functionality of intestinal LAB, while in certain cases may be directly responsible for it, with respect to either beneficially modulating the gut microbiota or inhibiting some gastrointestinal pathogenic bacteria [30].…”

Produção de bacteriocina por Bifidobacterium lactis a partir de soro de leite

“…There are also a number of nutritional and biological factors that influence antimicrobial production by bifidobacteria including, as mentioned above, nutrient shortage as well as the presence of a competing microbiota (O'Shea et al, 2012). Touré et al (2003) reported that a co-culture of L. monocytogenes and Bifidobacterium spp.…”

“…Producing organisms are immune to their own bacteriocin(s), a property that is mediated by specific immunity proteins (Cotter et al, 2005b). Bacteriocin production takes place most frequently during the late exponential or early stationary phases of growth, is often influenced by quorum sensing and stress signaling (Klaenhammer, 1988;Kotelnikova and Gelfand, 2002;Riley and Chavan, 2007;Tagg et al, 1976), and is regarded as a probiotic trait (Dobson et al, 2012;O'Shea et al, 2012) contributing to the suppression of intestinal pathogens. In addition, the rise in demand for natural foods that do not contain chemical preservatives has increased the interest in their application as preservatives to ensure food quality and safety.…”