In Vitro Bile Salt Hydrolase (BSH) Activity Screening of Different Probiotic Microorganisms.

Bile salt hydrolase (BSH) activity in probiotic strains is usually correlated with the ability to lower serum cholesterol levels in hypercholesterolemic patients. The objective of this study was the evaluation of BSH in five probiotic strains of lactic acid bacteria (LAB) and a probiotic yeast. The activity was assessed using a qualitative direct plate test and a quantitative high-performance thin- layer chromatography assay. The six strains differed in their BSH substrate preference and activity. Lactobacillus plantarum DGIA1, a potentially probiotic strain isolated from a double cream cheese from Chiapas, Mexico, showed excellent deconjugation activities in the four tested bile acids (69, 100, 81, and 92% for sodium glycocholate, glycodeoxycholate, taurocholate, and taurodeoxycholate, respectively). In the case of the commercial probiotic yeast Saccharomyces boulardii, the deconjugation activities were good against sodium glycodeoxycholate, taurocholate, and taurodeoxycholate (100, 57, and 63%, respectively). These last two results are part of the novelty of the work. A weak deconjugative activity (5%) was observed in the case of sodium glycocholate. This is the first time that the BSH activity has been detected in this yeast.

Characterization of substrate specificity and inhibitory mechanism of bile salt hydrolase from Lactobacillus reuteri CRL 1098 using molecular docking analysis.

OBJECTIVES: To elucidate the molecular mechanisms involved in the substrate interaction of the bile salt hydrolase of Lactobacillus reuteri CRL 1098 (LrBSH) with bile acids (BAs) and to evaluate potential enzyme inhibitors based on computer and in vitro modeling assays. RESULTS: Asp19, Asn79, and Asn171 participated in the LrBSH interaction with all BAs tested while Leu56 and Glu 222 played an important role in the interaction with glyco- and tauro-conjugated BAs, respectively. A great percentage of hydrophobic and polar interactions were responsible for the binding of LrBSH with glyco- and tauro-conjugated BAs, respectively. Remarkably, the four binding pocket loops participated in the substrate binding site of LrBSH unlike most of the reported BSHs. Inhibition assays showed that ascorbic acid, citric acid, penicillin G, and ciprofloxacin decreased LrBSH activity by 47.1%, 40.14%, 28.8%, and 9%, respectively. Docking analysis revealed that tetracycline and caffeic acid phenethyl ester had the low binding energy (-7.32 and -7.19 kcal/mol, respectively) and resembled the interaction pattern of GDCA (-6.88 kcal/mol) while penicillin (-6.25 kcal/mol) and ascorbic acid (-5.98 kcal/mol) interacted at a longer distance. CONCLUSION: This study helps to delve into the molecular mechanisms involved in the recognition of substrates and potential inhibitors of LrBSH.

Impact of Acerola (Malpighia emarginata DC) Byproduct and Probiotic Strains on Technological and Sensory Features of Fermented Soy Beverages.

Ten probiotic cultures were screened for the ability to hydrolyze soy proteins and bile salt deconjugation (BSD) to select one lactobacilli and one bifidobacteria strain to produce fermented soy beverages (FSBs) containing acerola byproduct (ABP). Next, the effect of the strains and the ABP on the technological and sensory characteristics of these beverages was evaluated during refrigerated storage for up to 28 days. None of the tested strains presented any proteolytic activity against soy proteins. Among the probiotic strains, the best BSD activities were observed for Lactobacillus acidophilus LA-5 and Bifidobacterium longum BB-46, which were further employed, individually or combined, to produce FSB supplemented or not with ABP, using Streptococcus thermophilus TH-4 as a starter, and the effect of these strains and ABP on the technological and sensory acceptability of FSB was evaluated. The probiotic strains did not influence FBS texture parameters, but ABP increased firmness in the ready product. BB-46 increased acidity, therefore decreasing acceptance, whereas the presence of LA-5 and/or ABP increased acceptance, even though the appearance was negatively affected by ABP after 21 days of storage. Thus, the presence of LA-5 and ABP contributed for the sensory acceptance of the FSBs without affecting their technological features. PRACTICAL APPLICATION: Lactobacillus acidophilus LA-5, Bifidobacterium longum BB-46, and/or acerola byproduct (ABP) were applied in the production of fermented soy beverages (FSBs). Principal components analysis was used to evaluate the formulations of the 23 factorial design and the sensory attributes and the effect of storage independently and covariance was the matrix type used for mapping purposes. LA-5 and ABP contributed for the sensory acceptance of FSB, without affecting their technological features, and could be used by food processing companies after scaling up, also reducing the environmental impact by decreasing discarding byproducts, which are sources of bioactive compounds.

Studies on the interactions between bile salts and food emulsifiers under in vitro duodenal digestion conditions to evaluate their bile salt binding potential.

During the last decade a special interest has been focused on studying the relationship between the composition and structure of emulsions and the extent of lipolysis, driven by the necessity of modulate lipid digestion to decrease or delay fats absorption or increase healthy fat nutrients bioavailability. Because bile salts (BS) play a crucial role in lipids metabolism, understanding how typical food emulsifiers affect the structures of BS under duodenal conditions, can aid to further understand how to control lipids digestion. In the present work the BS-binding capacity of three emulsifiers (Lecithin, Tween 80 and ß-lactoglobulin) was studied under duodenal conditions. The combination of several techniques (DLS, TEM, ζ-potential and conductivity) allowed the characterization of molecular assemblies resulting from the interactions, as modulated by the relative amounts of BS and emulsifiers in solution.

Red drum Sciaenops ocellatus growth and expression of bile salt-dependent lipase in response to increasing dietary lipid supplementation.

Sciaenops ocellatus has a long history in aquaculture and many difficulties associated with its commercial culture have been addressed and successfully resolved; nevertheless, further research in lipid nutrition could address more comprehensive questions on the way these nutrients are utilized. The purpose of this study was to evaluate S. ocellatus growth and lipase gene expression in response to increasing dietary lipid supplementation. Four experimental diets were formulated to provide 3, 10, 16, or 23% lipid using menhaden fish oil. Twenty juveniles (mean initial weight 2.3 ± 0.1 g) were stocked per aquaria in a recirculating system; each diet was assigned to three aquaria and fed to fish for 6 weeks. At the end of the study, fish fed 3% of dietary lipid were significantly (P < 0.0001) smaller and showed significantly lower feed efficiency, condition factor, hepatosomatic index, and intraperitoneal fat than fish fed the other diets, but no differences were observed among fish fed 10, 16, or 23% lipid. A straight broken-line regression model for thermal growth coefficient provided an estimated value of 9.4% of dietary lipid as the optimal inclusion level. The bile salt-dependent lipase (BSDL) of red drum was 80.3 kDa. Relative gene expression of BSDL was significantly higher (P = 0.0007) in fish fed 10% lipid, with no differences among the other dietary treatments. Results provided could help monitor the metabolic status of farmed fish and contribute to optimize diet formulations based on maximum gene expression of BSDL for supplementation of dietary lipid.

Mechanisms responsible for the hypocholesterolaemic effect of regular consumption of probiotics.

CVD affect a large proportion of the world's population, with dyslipidaemia as the major risk factor. The regular consumption of both probiotic bacteria and yeast has been associated with improvement in the serum lipid profile. Thus, the present review aims to describe and discuss the potential mechanisms responsible for the hypocholesterolaemic effect of regular consumption of probiotic bacteria and yeast. Regarding the hypocholesterolaemic effect of probiotic bacteria, the potential mechanisms responsible include: deconjugation of bile salts; modulation of lipid metabolism; and decreased absorption of intestinal cholesterol through co-precipitation of intestinal cholesterol with the deconjugated bile salts, incorporation and assimilation of cholesterol in the cell membrane of the probiotics, intestinal conversion of cholesterol in coprostanol, and inhibition of the expression of the intestinal cholesterol transporter Niemann-Pick C1 like 1 (NPC1L1) in the enterocytes. The potential mechanisms responsible for the hypocholesterolaemic effect of probiotic yeasts include: deconjugation of bile salts; co-precipitation of intestinal cholesterol with the deconjugated bile salts; incorporation and assimilation of cholesterol in the cell membrane; and inhibition of hepatic cholesterol synthesis. The regular consumption of probiotic bacteria and yeast, as a non-pharmaceutical approach to help manage cardiovascular risk, holds promise, according to the beneficial hypocholesterolaemic effects described herein. However, the hypocholesterolaemic effects vary according to the strains used, the physiological state of the host, and the type of diet to which the probiotics are added. Further studies are necessary to fill the gaps with regard to the knowledge related to this topic.

Nuevas terapias para la colestasis / New therapies in cholestasis

The introduction of ursodeoxycholic acid (UDCA) in the treatment of patients with cholestasis enabled remarkable progress and improvements in hepatic inflammatory activity, progression to cirrhosis and quality of life. However, the benefits of UDCA are particularly evident in patients with primary biliary cirrhosis and also 30 percent of patients have sub optimal response. For this reason, in order to improve the number of people with complete responses to therapy, new pharmacological alternatives have been investigated to add to UDCA treatment. This review aims to show potential new therapies against cholestasis that have been investigated by systematizing them depending on the receptor or target on which they act. Finally, a special reference will be made in relation to the treatment of pruritus associated with cholestasis.

La introducción del ácido ursodeoxicólico (AUDC) en el tratamiento de los pacientes con colestasia permitió notables avances con mejoras en la actividad inflamatoria hepática, progresión hacia la cirrosis y calidad de vida. Sin embargo, los beneficios de AUDC se aprecian especialmente en pacientes con cirrosis biliar primaria y además, 30 por ciento de los pacientes tiene una respuesta sub óptima. Por esta razón, con la finalidad de mejorar el número de personas con respuestas completas a la terapia, se han investigado nuevas alternativas farmacológicas para adicionar al tratamiento con AUDC. La presente revisión pretende mostrar las nuevas posibles terapias contra la colestasia estudiadas sistematizándolas según el tipo de receptor o diana sobre el que actúan. Finalmente se hará referencia especial en relación al tratamiento del prurito asociado a la colestasia.

Selection of superior bifidobacteria in the presence of rotavirus

The main purpose of this study was to investigate bifidobacteria flora in fecal samples from children with rotavirus infection and determine the significance of their selected probiotic properties for improvement of health status. Enzyme-linked immunosorbent assay was used to identify rotavirus antigen in fecal samples from 94 patients with gastroenteritis and from 30 without gastroenteritis. Bifidobacteria were identified by selective media, gram reaction, colony morphology, fructose-6-phosphate phosphoketolase enzyme activity and classical identification tests. Exopolysaccharide (EPS) production was identified by phenol-sulphuric acid method. The modified method was then used to identify the quantity of taurocholic and glycocholic acid deconjugation and cholesterol elimination of the strains. Thirty-five of the 94 fecal samples were found positive for rotavirus antigen (37.23%). Bifidobacteria were identified in 59 of the samples. The EPS production ranges were 29.56-102.21 mg/L. The cholesterol elimination rates ranged between 8.36-39.22%. Furthermore, a positive and strong correlation was determined between EPS production and the presence of cholesterol (r=0.984, P<0.001). The deconjugation rates for the sodium glycocholate group was higher than the sodium taurocholate group. Rotavirus (+) bifidobacteria strains had higher EPS production, deconjugation rate and cholesterol elimination compared to bifidobacteria strains isolated from children in the rotavirus (-) sample and without gastroenteritis. Significant differences were observed among groups in all parameters (P<0.05). Given the increased number of rotavirus cases in Turkey and worldwide, it is very important to add superior bifidobacteria in the diets of infected children to improve the intestinal and vital functions.

Isolation, Identification and Partial Characterization of a Lactobacillus casei Strain with Bile Salt Hydrolase Activity from Pulque.

The aim of this study was to isolate, from pulque, Lactobacillus spp. capable of survival in simulated gastrointestinal stress conditions. Nine Gram-positive rods were isolated; however, only one strain (J57) shared identity with Lactobacillus and was registered as Lactobacillus casei J57 (GenBank accession: JN182264). The other strains were identified as Bacillus spp. The most significant observation during the test of tolerance to simulated gastrointestinal conditions (acidity, gastric juice and bile salts) was that L. casei J57 showed a rapid decrease (p ≤ 0.05) in the viable population at 0 h. Bile salts were the stress condition that most affected its survival, from which deoxycholic acid and the mix of bile salts (oxgall) were the most toxic. L. casei J57 showed bile salt hydrolase activity over primary and secondary bile salts as follows: 44.91, 671.72, 45.27 and 61.57 U/mg to glycocholate, taurocholate, glycodeoxycholate and taurodeoxycholate. In contrast, the control strain (L. casei Shirota) only showed activity over tauroconjugates. These results suggest that L. casei J57 shows potential for probiotic applications.

Expression and function of renal and hepatic organic anion transporters in extrahepatic cholestasis.

Obstructive jaundice occurs in patients suffering from cholelithiasis and from neoplasms affecting the pancreas and the common bile duct. The absorption, distribution and elimination of drugs are impaired during this pathology. Prolonged cholestasis may alter both liver and kidney function. Lactam antibiotics, diuretics, non-steroidal anti-inflammatory drugs, several antiviral drugs as well as endogenous compounds are classified as organic anions. The hepatic and renal organic anion transport pathways play a key role in the pharmacokinetics of these compounds. It has been demonstrated that acute extrahepatic cholestasis is associated with increased renal elimination of organic anions. The present work describes the molecular mechanisms involved in the regulation of the expression and function of the renal and hepatic organic anion transporters in extrahepatic cholestasis, such as multidrug resistance-associated protein 2, organic anion transporting polypeptide 1, organic anion transporter 3, bilitranslocase, bromosulfophthalein/bilirubin binding protein, organic anion transporter 1 and sodium dependent bile salt transporter. The modulation in the expression of renal organic anion transporters constitutes a compensatory mechanism to overcome the hepatic dysfunction in the elimination of organic anions.