Levilactobacillus brevis MZ384011 and Levilactobacillus brevis MW362779 can mitigate lead induced hepato-renal damage by regulating visceral dispersion and fecal excretion.

Heavy metal pollution is a global issue. Current study provides evidence on Pb toxicity ameliorative potential and safe nature of Levilactobacillus brevis MZ384011 (S1) and Levilactobacillus brevis MW362779 (S2), isolated from carnivore gut and human milk, respectively. In a 60-days experiment, the rats were distributed into six groups. G-I, G-V and G-VI were kept on normal diet, while GII-IV were fed on lead nitrate (500 mg/kg) supplemented food, throughout experiment. After confirmation of Pb toxicity in GII-IV at 15th day, S1 was orally administered to G-III and G-V while S2 was given to G-IV and G-VI at a dose of 1 × 109 CFU/animal/day. On day 60 of experiment, positive control (G-II) displayed significant reduction in body weight, total protein, albumin, globulin, mineral profile, erythrocyte count, hemoglobin, hematocrit and hematological indices and elevation in leukocyte count, alanine aminotransferase, aspartate aminotransferase, bilirubin, uric acid and creatinine along with alterations in hepato-renal architecture. With reference to G-II, the G-III and G-IV displayed significant improvement in all aforementioned parameters, 40-60% reduction in tissue Pb levels (blood, liver, kidney and adipose tissue) and elevation in fecal Pb contents (p = 0.000). The groups V and VI did not show any sign of toxicity. The findings confirm that strains are safe for biological application and can reverse Pb toxicity by facilitating fecal Pb excretion and reducing its systemic dispersal. To best of our information this is the first report on Pb toxicity ameliorative role of Levilactobacillus brevis from human milk, the safest source.

Genetic diversity, cholesterol reduction, and presence of conserved bile salt hydrolase gene in probiotic strains from human milk.

Probiotics are known to possess strain- and species-specific functional properties, of which hypocholesteremia is of major interest. Bile salt hydrolase (BSH) activity is one of the key mechanisms involved in the hypocholesterolemic effect. The study was designed to genetically characterize probiotics obtained from human milk on the basis of simple sequence repeat (SSR), isolate potent hypocholesterolemic strains, and detect BSH activity, deconjugation of bile salts, and bsh polymorphism. This study, for the first time, linked genetic diversity with cholesterol reduction potential and proved the presence of conserved bsh of Levilactobacillus brevis in genetically diverse species. The strains displayed 2.78%-42.23% cholesterol reduction, which was not influenced by prebiotics. In this study, data obtained from SSR markers indicated 93.3% diversity, and based on cluster analysis, they were distributed into XI clades; out of five potent cholesterol-reducing strains, three belonged to clade I. The strains could deconjugate both sodium glycocholate and sodium taurocholate, but we preferred using sodium glycocholate. The variation in cholesterol reduction potential and BSH activity pointed toward the presence of more than one bsh in the strains. Weissella confusa MW051433 displayed highest cholesterol reduction (42.23%) and specific BSH activity (2.64 U ml -1). Search for other bsh and in vivo assessments of cholesterol reduction by W. confusa MW051433 have been proposed.

Lead biosorption efficiency of Levilactobacillus brevis MZ384011 and Levilactobacillus brevis MW362779: A response surface based approach.

Lead (Pb) is a substantial contaminant in the environment and a potent toxin for living organisms. Current study describes probiotic characteristics of Pb-biosorbing lactic acid bacteria (LAB), and response surface methodology (RSM) based optimization of physical conditions for maximum Pb biosorption. A total of 18 LAB, isolated from carnivore feces (n = 8) and human breast milk (n = 9), along with one reference strain Lactobacillus acidophilus ATCC4356 were included in the study. Pb biosorption was strain specific. Eight strains, demonstrating ≥ 70 % lead biosorption, were selected for further testing. The lactobacillus-Pb complex was found to be stable and strains had a negative surface charge. The strains displayed good probiotic properties with the survival rate of 71-90 % in simulated gastric environment, 36-69 % in intestinal condition (1.8 % bile salts) and 55-72 % hydrophobicity. On the basis of excellent probiotic ability, Levilactobacillus brevis MZ384011 and Levilactobacillus brevis MW362779 were selected for optimization of physical conditions of Pb biosorption through RSM. Maximum biosorption was observed at pH 6 in 60 min at a cell density of 1 g/L. L. brevis MZ384011 and L. brevis MW362779 are recommended for experimentation on Pb toxicity amelioration and safety evaluation in in-vivo setting.

Levilactobacillus brevis from carnivores can ameliorate hypercholesterolemia: In vitro and in vivo mechanistic evidence.

AIMS: The aim was to explore the probiotic and hypocholesterolaemic potential of two Levilactobacillus brevis strains of carnivore origin along with selected underlying mechanisms. METHODS AND RESULTS: Levilactobacillus brevis MT950194 and L. brevis MW365351 were analysed in vitro for oro-gastro-intestinal stress tolerance, cholesterol reduction, cholesterol adsorption (through scanning electron microscopy) and bile salt hydrolase (BSH) activity. Strains could survive (>80%) in oro-gastro-intestinal conditions and reduce high amount of cholesterol (35% and 54%) from media containing bile salts (0.3%) as compared with Lactobacillus acidophilus ATCC 4356 and presented the least pathogenicity towards mammalian cells. Exopolysaccharide production, cell surface cholesterol adherence and BSH activity were witnessed as possible cholesterol-lowering mechanisms. In in vivo experiment, the treatments of hypercholesterolaemic rats with L. brevis MT950194, L. brevis MW365351 and their mixture led to significant (p < 0.05) reduction in serum and hepatic cholesterol, low-density lipids, cholesterol ratio, liver steatosis and size of adipocytes. It further ameliorated diet-induced changes in hepatic enzymes. CONCLUSIONS: Levilactobacillus brevis MT950194 and L. brevis MW365351 from carnivores have probiotic pharmacological potential and can reduce serum cholesterol through surface adherence and BSH production. SIGNIFICANCE AND IMPACT OF THE STUDY: These strains may be utilized in treating hypercholesterolaemia and production of low-fat functional foods.