Bile Salt Hydrolase-active Lactobacillus Research Articles

Effect of bile salt hydrolase-active Lactobacillus plantarum Y15 on high cholesterol diet induced hypercholesterolemic mice

ABSTRACT This study aimed to elucidate the underlying mechanisms for the protective effect of Lactobacillus on hypercholesterolemia. Firstly, twenty Lactobacillus strains were screened for potential probiotics with high bile salt hydrolase (BSH) activity using in vitro methods. Secondly, hypercholesterolemic mice induced by a cholesterol-enriched diet were administrated by the probiotic candidate strain L. plantarum Y15, identified from the screen. Results in vitro showed that L. plantarum Y15 possessed high BSH activity. In vivo, L. plantarum Y15 supplementation decreased total cholesterol and triglyceride in serum and liver, increased total cholesterol and total bile acid in feces, and alleviated histopathological changes in the liver. Furthermore, L. plantarum Y15 supplementation modulated the gut microbiota to the control group’s pattern, leading to increase BSH activity, which further influence FXR and SHP signaling pathway to upregulate the expression level of CYP7A1 to enhance the cholesterol catabolism.

Effect of bile salt hydrolase-active Lactobacillus plantarum KLDS 1.0344 on cholesterol metabolism in rats fed a high-cholesterol diet

• L. plantarum KLDS 1.0344 was assayed for BSH activity and hypocholesterolemic effect. • L. plantarum KLDS 1.0344 improved lipid profiles and metabolic pathway in rats. • L. plantarum KLDS 1.0344 regulated hepatic CYP7A1 and HMGCR expression in rats. • L. plantarum KLDS 1.0344 modulated intestinal NPC1L1, ABCG5/8 and ABCA1 expression. The present study aimed to evaluate bile salt hydrolase (BSH) activity and hypocholesterolemic effect of Lactobacillus plantarum KLDS 1.0344. BSH activity of the strain KLDS 1.0344 varied with different bile salts. High-cholesterol diet-induced male Sprague-Dawley rats were simultaneously administrated with strain KLDS 1.0344 for 4 weeks. The strain KLDS 1.0344 significantly improved lipid profiles in serum and liver, and increased fecal total cholesterol and total bile acids levels in high-cholesterol diet-fed rats ( P < 0.05), and superior to L. rhamnosus GG. Moreover, expressions of genes related to cholesterol metabolism were regulated by the strain KLDS 1.0344, including down-regulation of hepatic HMGCR and FXR and intestinal NPC1L1, and up-regulation of intestinal LXRα, ABCG5, ABCG8 and ABCA1 and hepatic CYP7A1 ( P < 0.05). The hypocholeseterolemic effect of L. plantarum KLDS 1.0344 was modulated most likely by pathway of cholesterol absorption, synthesis, and catabolism, which might be partly due to its BSH activity.

Microbiome and metabolome modifying effects of several cardiovascular disease interventions in apo-E\u2212/\u2212 mice

BackgroundThere is strong evidence indicating that gut microbiota have the potential to modify, or be modified by the drugs and nutritional interventions that we rely upon. This study aims to characterize the compositional and functional effects of several nutritional, neutraceutical, and pharmaceutical cardiovascular disease interventions on the gut microbiome, through metagenomic and metabolomic approaches. Apolipoprotein-E-deficient mice were fed for 24 weeks either high-fat/cholesterol diet alone (control, HFC) or high-fat/cholesterol in conjunction with one of three dietary interventions, as follows: plant sterol ester (PSE), oat β-glucan (OBG) and bile salt hydrolase-active Lactobacillus reuteri APC 2587 (BSH), or the drug atorvastatin (STAT). The gut microbiome composition was then investigated, in addition to the host fecal and serum metabolome.ResultsWe observed major shifts in the composition of the gut microbiome of PSE mice, while OBG and BSH mice displayed more modest fluctuations, and STAT showed relatively few alterations. Interestingly, these compositional effects imparted by PSE were coupled with an increase in acetate and reduction in isovalerate (p < 0.05), while OBG promoted n-butyrate synthesis (p < 0.01). In addition, PSE significantly dampened the microbial production of the proatherogenic precursor compound, trimethylamine (p < 0.05), attenuated cholesterol accumulation, and nearly abolished atherogenesis in the model (p < 0.05). However, PSE supplementation produced the heaviest mice with the greatest degree of adiposity (p < 0.05). Finally, PSE, OBG, and STAT all appeared to have considerable impact on the host serum metabolome, including alterations in several acylcarnitines previously associated with a state of metabolic dysfunction (p < 0.05).ConclusionsWe observed functional alterations in microbial and host-derived metabolites, which may have important implications for systemic metabolic health, suggesting that cardiovascular disease interventions may have a significant impact on the microbiome composition and functionality. This study indicates that the gut microbiome-modifying effects of novel therapeutics should be considered, in addition to the direct host effects.

A combination of Tween 80 with CaCl2 enhances the hypocholesterolemic activity of bile salt hydrolase-active Lactobacillus casei F0422 in rats fed a cholesterol-rich diet

The effects of a Tween 80 and CaCl2 mixture on the hypocholesterolemic activity of bile salt hydrolase (BSH)-active Lactobacillus casei F0422 were investigated in rats fed a cholesterol-rich diet for 3 weeks. This mixture significantly enhanced the hypocholesterolemic activity of strain F0422 in rats. The group administered drinking water supplemented with both strain F0422 and the Tween 80 and CaCl2 mixture had significantly lower levels of total serum cholesterol, low-density lipoprotein cholesterol and total liver cholesterol than did the group administered drinking water supplemented only with strain F0422 or the Tween 80 and CaCl2 mixture. The hypocholesterolemic activity of the combined strain F0422 and Tween 80 and CaCl2 mixture was attributed to the increase in fecal bile acid excretion through enhancement of bile salt tolerance and BSH catalytic activity of strain F0422 by Tween 80 and up-regulation of the adhesion of strain F0422 to intestinal epithelial cells by CaCl2.

Oral Supplementation With ProbioticL. reuteriNCIMB 30242 Increases Mean Circulating 25-Hydroxyvitamin D: A Post Hoc Analysis of a Randomized Controlled Trial

Low serum 25-hydroxyvitamin D is a risk factor for osteoporosis, cardiovascular disease, diabetes, and cancer. Disruption of noncholesterol sterol absorption due to cholesterol-lowering therapies may result in reduced fat-soluble vitamin absorption. We have previously reported on the cholesterol-lowering efficacy and reduced sterol absorption of probiotic bile salt hydrolase active Lactobacillus reuteri NCIMB 30242; however, the effects on fat-soluble vitamins was previously unknown and the objective of the present study. DESIGN, SETTINGS, PATIENTS, AND INTERVENTION: The study was double-blind, placebo-controlled, randomized, parallel-arm, multicenter lasting 13 weeks. A total of 127 otherwise healthy hypercholesterolemic adults with low-density lipoprotein-cholesterol >3.4 mmol/L, triglycerides <4.0 mmol/L, and body mass index of 22 to 32 kg/m² were included. Subjects were recruited from 6 private practices in Prague, Czech Republic, and randomized to consume L. reuteri NCIMB 30242 or placebo capsules over a 9-week intervention period. The primary outcome measure was the change in serum low-density lipoprotein-cholesterol over the 9-week intervention. Analysis of fat-soluble vitamins at weeks 0 and 9 were performed post hoc. There were no significant differences between L. reuteri NCIMB 30242 and placebo capsule groups in serum vitamin A, vitamin E, or β-carotene or dietary intake over the intervention period (P > .05). L. reuteri NCIMB 30242 increased serum 25-hydroxyvitamin D by 14.9 nmol/L, or 25.5%, over the intervention period, which was a significant mean change relative to placebo of 17.1 nmol/L, or 22.4%, respectively (P = .003). To our knowledge, this is the first report of increased circulating 25-hydroxyvitamin D in response to oral probiotic supplementation.

Cholesterol lowering and inhibition of sterol absorption by Lactobacillus reuteri NCIMB 30242: a randomized controlled trial

The percentage of hypercholesterolemic individuals not reaching their LDL-cholesterol (LDL-C) goal remains high and additional therapeutic strategies should be evaluated. The objective of this study was to evaluate the cholesterol-lowering efficacy and mechanism of action of bile salt hydrolase-active Lactobacillus reuteri NCIMB 30242 capsules in hypercholesterolemic adults. A total of 127 subjects completed a randomized, double-blind, placebo-controlled, parallel-arm, multicenter study. Subjects were randomized to consume L. reuteri NCIMB 30242 capsules or placebo capsules over a 9-week intervention period. The primary outcome was LDL-C relative to placebo at the study end point. L. reuteri NCIMB 30242 capsules reduced LDL-C by 11.64% (P<0.001), total cholesterol by 9.14%, (P<0.001), non-HDL-cholesterol (non-HDL-C) by 11.30% (P < 0.001) and apoB-100 by 8.41% (P = 0.002) relative to placebo. The ratios of LDL-C/HDL-cholesterol (HDL-C) and apoB-100/apoA-1 were reduced by 13.39% (P = 0.006) and 9.00% (P = 0.026), respectively, relative to placebo. Triglycerides and HDL-C were unchanged. High-sensitivity C-reactive protein and fibrinogen were reduced by 1.05 mg/l (P = 0.005) and 14.25% (P = 0.004) relative to placebo, respectively. Mean plasma deconjugated bile acids were increased by 1.00 nmol/l (P=0.025) relative to placebo, whereas plasma campesterol, sitosterol and stigmasterol were decreased by 41.5%, 34.2% and 40.7%, respectively. The present results suggest that the deconjugation of intraluminal bile acids results in reduced absorption of non-cholesterol sterols and indicate that L. reuteri NCIMB 30242 capsules may be useful as an adjunctive therapy for treating hypercholesterolemia.

Protective effect of the bile salt hydrolase-active Lactobacillus reuteri against bile salt cytotoxicity.

Bacterial bile salt hydrolysis is considered a risk factor for the development of colon cancer because of the risk of forming harmful secondary bile salts after an initial deconjugation step. In this study, the influence of enhanced bacterial bile salt transformation by the bile salt hydrolase-active Lactobacillus reuteri was studied in batch culture using the microbial suspension of the Simulator of the Human Intestinal Microbial Ecosystem; (SHIME), which was supplemented with oxgall at 5 g/l or 30 g/l. Changes in the fermentative capacity of the microbial ecosystem and the (geno)toxic properties of the SHIME supernatants were investigated. Increasing concentrations of oxgall inhibited the fermentation. Transient cell toxicity was observed for samples supplemented with 5 g oxgall/l, while samples with 30 g oxgall/l exhibited toxicity. The results of the haemolysis test suggest that the detrimental effects were probably due to the membrane-damaging effects of bile salts. In all cases, the adverse effects could be counteracted by the addition of 7.5 +/- 0.5 log10 CFU L. reuteri/ml. Plausible mechanisms for the protective properties of L. reuteri could involve a precipitation of the deconjugated bile salts and a physical binding of bile salts by the bacterium, thereby making the harmful bile salts less bioavailable.

Bile salt deconjugation by lactobacillus plantarum 80 and its implication for bacterial toxicity

The effects of bile salts on the survival of lactobacilli were investigated using glycocholic acid, cholic acid and deoxycholic acid as model compounds and the bile salt hydrolase active Lactobacillus plantarum 80 (BSH+) and its BSH negative mutant. The detrimental effects of cholic acid, i.e. growth inhibition and cytotoxicity at a concentration of 1 and 5 mmol l-1, respectively, were considered to be due to the hydrophobic protonated form of the molecule, which brings about membrane damage. The conversion of glycocholic acid to cholic acid by the BSH active L. plantarum 80 caused a growth inhibition which was comparable with the inhibition observed in the broth supplemented with 1 mmol l-1 cholic acid. Deoxycholic acid caused toxicity through membrane damage when the compound was in solution. Its toxicity disappeared in the culture broth as the molecule precipitated. In case of cholic acid, the toxicity could be removed by buffering the solution at pH 7.0. It was calculated that at this pH most of the cholic acid molecules were ionized. The results led to the formulation of an extended hypothesis about the ecological significance of bile salt transformations. Primary deconjugation is carried out to counteract intracellular acidification. Yet, the deconjugated molecule can be harmful at moderately acidic pH-values. In this case, the BSH+ strains could effectively profit from their activity in case they are associated with 7alpha-dehydroxylating bacteria which dehydroxylate the deconjugated bile salts. The dehydroxylated molecule has a low solubility and precipitates at moderately acidic pH.

Development of a differential medium for bile salt hydrolase-active Lactobacillus spp

An agar plate assay was developed to detect bile salt hydrolase activity in lactobacilli. On Lactobacillus-selective MRS or Rogosa SL medium supplemented with taurodeoxycholic, taurocholic, or taurochenodeoxycholic acids, bile salt hydrolysis was manifested at two intensities: (i) the formation of precipitate halos around colonies or (ii) the formation of opaque granular white colonies. Sixty-six lactobacilli were tested for bile salt hydrolase activity by both the plate assay and a sensitive radiochemical assay. No false-positive or false-negative results were detected by the plate assay. Based on results of experiments with Eubacterium lentum and Bacteroides species, the plate assay was dependent on two factors: (i) the presence of bile salt hydrolytic activity and (ii) the ability of the organism to sufficiently acidify the medium to protonate free bile acids. The availability of a differential medium for determination of bile salt hydrolase activity will provide a rapid method for determining shifts in a specific functional activity of intestinal Lactobacillus species and provide a rapid screening capability for identifying bile salt hydrolase-deficient mutants. The latter application should allow bile salt hydrolase activity to be used as a marker enzyme in genetic experiments.