Probiotics in the new millennium

Abstract

Beneficial effects on human health by specific probiotic microorganisms such as prevention of gastrointestinal tract infections immune stimulation, and balancing of the intestinal microflora have been established in numerous clinical trials. The successful probiotic strains which are mainly members of Lactobacillus and more recently Bifidobacterium naturally found in the human intestinal tract, have been traditionally incorporated into fermented milk products but have excellent potential for further inclusion in functional foods and health-related products. While the health claims are generally accepted by both scientists and consumers, often the molecular mechanisms underlying the probiotic properties remains controversial. Further progress concerning the molecular basis of probiotic traits will give vital reinforcement to the probiotic concept and is a prerequisite for rational development into further applications. In this review, current research on the genetics of properties of the intestinal lactobacilli that may contribute to the activity and effectiveness of probiotics is described. The potential of molecular biology for future probiotic applications is addressed and a probiotic strains developed by modern biotechnology with advantages for specific consumers is presented.

Adherence of Probiotic Bacteria to Human Intestinal Mucus in Healthy Infants and during Rotavirus Infection

“…Intestinal mucin has been shown to inhibit the replication of rotavirus in vitro (3,29,35). Calves infected with rotavirus have been shown to have substantially less mucin covering the epithelium of the small intestine and colon than do healthy controls (34), but, as shown here, human infants, at least well-nourished infants, sustain the level of mucin during rotavirus diarrhea.…”

“…Thus, in vitro evaluation of the adhesion to human intestinal mucus provides a suitable model for estimating the ability of probiotics to adhere to intestinal surfaces. It has been suggested that adhesion of lactobacilli to human intestinal mucus has a probiotic function in preventing the adhesion to and colonization of damaged tissue sites by invading pathogens (34). The induction of mucin gene expression is perhaps one of the mechanisms whereby probiotic strains minimize the interplay of other microbes with intestinal mucosal cells and thereby intestinal inflammation (17).…”

Selection of probiotic bifidobacteria for lambs

“…Other probiotic characteristics are inhibition of pathogens, modulation of metabolic activities and immunomodulation. Probably no probiotic strain has all these characteristics, but it is desirable that as many as possible should be present (Vaughan and Mollet, 1999;Gibson and Fuller, 2000;Mättö et al, 2006).…”

Effect of Starter Cultures on Lactobacillus Acidophilus Survival and Gene Expression in Yogurt

“…bulgaricus, L. plantarum and L. acidophilus, heat-shock chaperones were found to be consistently upregulated presumably due to the need to repair acid-induced damaged proteins and/or to facilitate the folding of nascent proteins (Vaughan and Mollet, 1999;Somkuti and Steinberg, 1999;Van de Guchte et al, 2002). Although Lorca et al (2002) hypothesized that DnaK, DnaJ, GrpE, GroES and GroEL are important heat shock proteins found in L. acidophilus, little experimental evidence of the HSPs mechanism in this microorganismis established.…”

“…Probiotics may also produce other substances (such as hydrogen peroxide and bacteriocins) that are inhibitory to potential enteric pathogens. Charteris et al 1998;Chandan, 2006;Vasiljevic and Shah, 2008 When the epithelial cells or normal microflora of the intestines become damaged or disturbed as a results of infection or irritation, altered gut permeability and inflammation may occur (Vaughan and Mollet, 1999). As mentioned above, probiotics have the potential to prevent and/or reduce infection associated with enteric pathogens.…”