Evaluation of Probiotic Properties and Prebiotic Utilization Potential of Weissella paramesenteroides Isolated From Fruits.

Weissella paramesenteroides has gained a considerable attention as bacteriocin and exopolysaccharide producers. However, potential of W. paramesenteroides to utilize different prebiotics is unexplored area of research. Fruits being vectors of various probiotics, five W. paramesenteroides strains, namely, FX1, FX2, FX5, FX9, and FX12, were isolated from different fruits. They were screened and selected based on their ability to survive at pH 2.5 and in 1.0% sodium taurocholate, high cell surface hydrophobicity, mucin adhesion, bile-induced biofilm formation, antimicrobial activity (AMA) against selected enteropathogens, and prebiotic utilization ability, implicating the functional properties of these strains. In vitro safety evaluation showed that strains were susceptible to antibiotics except vancomycin and did not harbor any virulent traits such as biogenic amine production, hemolysis, and DNase production. Based on their functionality, two strains FX5 and FX9 were selected for prebiotic utilization studies by thin layer chromatography (TLC) and short-chain fatty acids (SCFAs) production by high performance liquid chromatography. TLC profile evinced the ability of these two strains to utilize low molecular weight galactooligosaccharides (GOS) and fructooligosaccharides (FOS), as only the upper low molecular weight fractions were disappeared from cell-free-supernatants (CFS). Enhanced ß-galactosidase activity correlated with galactose accumulation in residual CFS of GOS displayed GOS utilization ability. Both the strains exhibited AMA against E. coli and Staph. aureus and high SCFAs production in the presence of prebiotic, suggesting their synbiotic potential. Thus, W. paramesenteroides strains FX5 and FX9 exhibit potential probiotic properties with prebiotic utilization and can be taken forward to evaluate synergistic synbiotic potential in detail.

Antigenotoxic and Antimutagenic Activities of Probiotic Lactobacillus rhamnosus Vc against N-Methyl-N'-Nitro-N-Nitrosoguanidine.

The present study provides experimental evidence of in vivo reduction of genotoxic and mutagenic activities of potent carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) by the strain Lactobacillus rhamnosus Vc. In vitro studies revealed that coincubation of MNNG with viable cells of L. rhamnosus Vc resulted in the detoxification of the parent compound accompanied with reduction in genotoxicity (69%) and mutagenicity (61%) as evaluated by SOS-Chromotest and Ames test, respectively. Oral feeding of probiotic bacteria L. rhamnosus Vc (10(9) cfu) to Gallus gallus (chicks) for 30 days provided protection against MNNG-induced damage as evidenced from the significant decrease (P = 0.009) in glutathione S-transferase activity in the L. rhamnosus Vc+MNNG-treated chicks in comparison to the MNNG-treated chicks. Histopathology of colon and liver showed intact cells and mild inflammation in the L. rhamnosus Vc+MNNG-treated chicks, whereas heavy inflammation and degenerative changes were observed in MNNG-treated chicks. The results indicate that the probiotic L. rhamnosus Vc provided in vivo protection against MNNG-induced colon damage by detoxification of MNNG to less toxic metabolites.

Probiotic attributes of autochthonous Lactobacillus rhamnosus strains of human origin.

The study was aimed at evaluating the probiotic potential of indigenous autochthonous Lactobacillus rhamnosus strains isolated from infant feces and vaginal mucosa of healthy female. The survival of the selected strains and the two reference strains (L. rhamnosus GG and L. casei Actimel) was 67-81 % at pH 2 and 70-80 % after passage through the simulated gastrointestinal fluid. These strains are able to grow in the presence of 4 % bile salt, 10 % NaCl, and 0.6 % phenol. The cell surface of L. rhamnosus strains is hydrophilic in nature as revealed by bacterial adhesion to hydrocarbons (BATH) assay. Despite this, L. rhamnosus strains showed mucin adherence, autoaggregation and coaggregation properties that are strain-specific. In addition, they produce bile salt hydrolase (BSH) and ß-galactosidase activities. L. rhamnosus strains exhibit antimicrobial activity against food spoilage organisms and gastrointestinal pathogens, as well as Candida and Aspergillus spp. L. rhamnosus strains have similar antibiotic susceptibility pattern, and resistance to certain antibiotics is intrinsic or innate. The strains are neither haemolytic nor producer of biogenic amines such as histamine, putrescine, cadaverine and tyramine. Lyophilized cells of L. rhamnosus Fb exhibited probiotic properties demonstrating potential of the strain for technological suitability and in the preparation of diverse probiotic food formulations.