High Bile Salt Concentrations Research Articles

Effects of bile salts on the lovastatin pharmacokinetics following oral administration to rats

This study aimed to examine the effects of bile salts on pharmacokinetics of lovastatin, which has low bioavailability. Lovastatin solid dispersions were prepared using sodium deoxycholate (NaDC) and sodium glycholate (NaGC) at ratios of 1:19, 1:49, and 1:69. The formulated solid dispersions and control (commercial tablet) were administered to rats and plasma concentrations were determined by a validated LC-MS/MS method. Statistically significant differences were found in Cmax, AUC0–10, and AUC0–∞ values among lovastatin formulations (p < 0.05). NaDC-containing formulations revealed higher bioavailabilities than NaGC-containing solid dispersions at ratios of 1:19 and 1:49. Especially, NaDC-containing formulation at a ratio of 1:19 (NaDC19) showed the highest bioavailability. The AUC (both AUC0–10 and AUC0–∞) of NaDC19 was statistically higher than control and NaDC69 (p < 0.05). The AUC values decreased as bile salt concentrations increased. Overall, formulations containing bile salts showed higher AUC values than control, even though all formulations did not show significantly higher AUC. In conclusion, the addition of bile salts to lovastatin could enhance drug bioavailabilities. However, too high concentrations of bile salts could decrease bioavailabilities of lovastatin.

Different stability regimes of oil-in-water emulsions in the presence of bile salts

In this work, we study the stability of emulsified olive oil-in-water emulsions at different bile salt (BS) concentrations. The effect of the interfacial properties of the emulsion is analyzed by using different emulsifiers (Epikuron 145V and Pluronic F68). Emulsion characteristics (electrophoretic mobility, average droplet size) are measured under the different conditions, and the stability of these systems is characterized by monitoring backscattering, using a Turbiscan. Adsorption of BSs at the emulsion interface would explain the higher stability at low bile salt concentrations as well as the more negative electrophoretic mobility when comparing with the emulsion in the absence of BS. The stability of the emulsion decreases above a critical BS concentration, which is higher when the emulsifier is Pluronic, and is much higher than the critical micelle concentration of the BS. Depletion flocculation induced by BS micelles is the destabilizing mechanism proposed at high BS concentrations.

Direct toxicity effects of sulfo-conjugated troglitazone on human hepatocytes

Troglitazone (TGZ), an orally active hypoglycemic agent, was found to be associated with severe drug-induced liver failure and was withdrawn from the market in 2000. Although the exact mechanism is not clear, it has been postulated that the formation of its major sulfo-conjugated metabolite (TGZS) plays an important role in its toxicity. TGZS inhibits bile salt export pump (BSEP) that causes accumulation of bile salts in liver. High concentration of bile salts causes cell death and mitochondrial dysfunction via detergent properties. One question arises whether TGZS has direct toxicity effect on human liver cells in addition to BSEP inhibition. In this study, both TGZ and chemically synthesized TGZS were incubated with normal human hepatocytes (THLE-2 cells) for measuring their cytotoxicity in vitro using the MTT assay. Glutathione (GSH) and protein carbonyl (PC) assays were further performed to measure the oxidative stress generated by these two compounds during incubation with THLE-2 cells. The results from this study indicated that TGZS (EC 50 = 21.74 ± 5.38 μM) was more toxic than TGZ (EC 50 = 41.12 ± 4.3 μM) in THLE-2 cells. The GSH and PC data further confirmed that TGZS produced greater oxidative stress in THLE-2 cells as compared to TGZ. In conclusion, our study demonstrated for the first time that TGZS has direct toxicity effect on human liver cells and may be partially responsible for the hepatotoxicity of TGZ.

English

This study is related to the isolation and identification of strains of local thermophilic lactic acid bacteria belonging to the species,&nbsp;Streptococcus thermophilus&nbsp;andLactobacillus&nbsp;bulgaricus. These bacteria can exist under extreme conditions of the digestive tract (acidity and high concentration of bile salts) and have a high capacity to degrade lactose. The aim is to produce yoguort with the bacteria that remain viable and active in the digestive tract, so as to enhance lactase activity at the intolerant lactose. The results also show considerable variations between genera, species and strains of the same species in the decomposition of lactose in pure and mixed cultures (Sc.t5&nbsp;and Sc.t3, respectively, with 48 and 42%) (YSLB2, YSLB4and YSLB1,&nbsp;respectively, with 90.44, 87.22 and 84.28%) of initial lactose after 6 h of incubation at 37&deg;C while keeping a level of viability higher than 107&nbsp;cells/ ml. In the presence of pH (2.5, 4.5 and 6.5), put with or without 0.3% of bile salts, the results are also unmatched. The best cultures will be used to manufacture fermented milks (yoghurts) in order to correct intolerance with lactose in man after having to test them, in a second part,&nbsp;in vivo. &nbsp; Key words:&nbsp;Lactic acid bacteria, extremophile, intolerance of lactose, digestive tract.

Probiotic Strain Lactobacillus Plantarum NBIMCC 2415 with Antioxidant Activity as a Starter Culture in the Production of Dried Fermented Meat Products

ABSTRACTLactobacillus plantarum NBIMCC 2415 resistant to low and high values of pH and pepsin, and to high concentrations of bile salts was selected. It was demonstrated that Lactobacillus plantarum NBIMCC 2415 inhibited the growth of pathogenic microorganisms such as Escherichia coli ATCC 25922, Escherichia coli ATCC 8739, Proteus vulgaris G, Salmonella sp., Salmonella abony NTCC 6017, Staphylococcus aureus ATCC 25093, Staphylococcus aureus ATCC 6538 P, Listeria monocytogenes and Listeria monocytogenes I at temperature 15–18°C in the meat products. The high antioxidant activity of this strain against peroxide radicals (ORAC results) was determined. Experimental series of raw-dried meat products were produced. Reduction of the microflora of the meat raw-dried sausages and high concentration of viable cells of L. plantarum NBIMCC 2415 were observed, which makes them functional foods.

Development of a symbiotic cottage cheese added with Lactobacillus delbrueckii UFV H2b20 and inulin

The aim of the study was to develop a symbiotic cottage cheese containing Lactobacillus delbrueckii UFV H2b20 and inulin, and to evaluate the survival of this bacterium when the cheese was exposed to conditions simulating those found in the gastro-intestinal tract. Throughout the entire whole shelf-life period of the cheese, the probiotic cell counts were higher than those recommended for probiotic products containing 5% of inulin. The probiotic bacterium exhibited satisfactory resistance to low pH values and to high concentrations of bile salts. The addition of probiotic cells and inulin generated no alterations in the physicochemical characteristics of cheese.

PRODUÇÃO DE QUEIJO TIPO COTTAGE SIMBIÓTICO E ESTUDO DE SOBREVIVÊNCIA DAS CÉLULAS PROBIÓTICAS QUANDO EXPOSTAS A DIFERENTES ESTRESSES

Probiotics are microorganisms which promote beneficial effects on the health of their host, when ingested with food in adequate amounts. Prebiotics, on the other hand, are no digestible ingredients, which selectively stimulate the growth or metabolic activity of beneficial bacteria in the colon. A product is called symbiotic when it contains probiotic cells and prebiotic substances. The objectives of this work were: 1) to develop cottage-like symbiotic cheese with the addition of Lactobacillus delbrueckii UFVH2b20 and inulin (BENEO Raftiline GR); 2) to follow the viability of the probiotic microorganism Lactobacillus delbrueckii UFVH2b20, during the shelf life of cottage-like cheese, stored at 5°C; 3) to evaluate the survival of Lactobacillus delbrueckii UFVH2b20 strain present in cottage-like cheese, when exposed to typical gastrointestinal tract conditions. Throughout the shelf life period, the cheese, which was stored at 5°C, maintained a microorganism count above the level recommended for food considered to be probiotic: 10 8 CUF.g -1 . The inulin content of the cheese amounted to 5.0%, amount also considered as sufficient for beneficial effects on individuals. High resistance of the microorganism to low pH and high concentrations of bile salts were observed, suggesting that the Lactobacillus delbrueckii UFVH2b20 strain would survive under normal digestive gastric tract conditions, when added to cottage-like symbiotic cheese. KEYWORDS: Cheese; probiotics; Lactobacillus ; inulin; gastrointestinal tract.

In Vitro Characterization of Probiotic Properties of Lactic Acid Bacteria from Bulgarian Rye Sourdoughs

ABSTRACTLactic acid bacteria play a key role in human health. These friendly bacteria as a part of the microflora of the gastrointestinal tract (GIT) have a beneficial influence on microbial balance. The probiotic cultures stimulate the growth of beneficial microorganisms, crowd out potentially harmful bacteria and reinforce the body's natural defense mechanisms. Recent data improve the positive effects of probiotics and stimulate research for discovering of new lactic acid bacteria strains with probiotic properties.In present work the probiotic potential of 23 strains lactic acid bacteria, isolated from Bulgarian rye sourdoughs from different geographical regions was studied in vitro. Their affiliation to the genus Lactobacillus and Pediococcus was determined by classical phenotyping methods. Screening of the strains at selecting factors high acidity and different concentrations of bile salts was first accomplished. In addition, susceptibility to antibiotics, production of hydrogen peroxide and spectrum of antimicrobial activity were determined. After primary selection, 8 strains were chosen and they were tested in a model system for in vitro simulation of the conditions into the human GIT.As a result, two strains with high probiotic potential were found.

Resistance of Microencapsulated Lactobacillus acidophilus LA1 to Processing Treatments and Simulated Gut Conditions

This investigation reports the effect of microencapsulation using sodium alginate and starch on the tolerance of probiotic Lactobacillus acidophilus LA1 to selected processing conditions and simulated gastrointestinal environments. The organism survived better in the protected form at high temperatures (72, 85, and 90 °C) and at high salt concentrations (1%, 1.5%, and 2%). The free cells were completely destroyed at 90 °C whereas the microencapsulated cells reduced by 4.14 log cycles. The log cycle reduction was 5.67 and 2.30, respectively, in free and protected cells when incubated for 3 h with 2% (w/v) NaCl. Homogenization did not affect the viability of the cells but led to the disruption of the protective encapsulating material around the cells. Microencapsulation provided better protection at simulated conditions of gastric pH (1.0, 1.5, and 2.0) and at high bile salt concentrations (1.0%, 1.5%, and 2.0%). The free and protected cells registered 5.47 and 2.16 log cycle reduction, respectively, after 3-h incubation at 2% bile salt (w/v). The release of the microencapsulated organisms in simulated colonic pH required 2.5 h. These studies demonstrated that microencapsulation of probiotic L. acidophilus LA1 in sodium alginate is an effective technique of protection against extreme processing conditions and under simulated gastrointestinal environment.

Effect on Cellular Membrane Fatty Acids in the Stressed Cells of Leuconostoc Mesenteroides: A Native Probiotic Lactic Acid Bacteria

Probiotics are microbial cell preparations or components of microbial cells that have a beneficial effect on the health and well being of the consumer. With increasing demand for such products, a lactic acid bacterium was isolated from whey and studied for its probiotic properties. This study deals with the importance of the role of cell membrane fatty acids in response to a pH reduction. An increase of unsaturated fatty acids such as palmitoleic acid (9.1%), oleic acid (5.8%), linoeic acid (5.4%) and linolenic acid (2.8%) was found at pH 3.0, which were 103.2, 2.7, 15.6 and 9.93 fold higher, respectively, compared with the same culture grown at pH 6.5. The work was done on a native isolated culture, which was identified as Leuconostoc mesenteroides (Accession number MTCC 5209). It has antimicrobial properties against 6 toxic food pathogens and resistance to common antibiotics so as to maintain normal intestinal microflora. It has high β-galactosidase activity (278.6 micro M/100 mg protein) and can hydrolyze 3% lactose. The ability to adhere hydrocarbon provides evidence that the culture can adhere and colonize the intestinal tract. The culture is able to tolerate low pH and a high bile salt concentration, which implies the ability to survive harsh conditions of the gastrointestinal tract when orally administered in any food formulations. All these properties make it a potential probiotic culture.

Molecular and biochemical characterizations of human oral lactobacilli as putative probiotic candidates

The objective of this study was to characterize the lactobacilli from the human oral cavity as a potential source of probiotic strains. Samples were collected from four different locations within the oral cavity: surface of healthy tooth, oral mucous membrane, surface of tooth decay and deep tooth decay. On the basis of morphological and biochemical properties eight categories were formed and 26 isolates were selected for further characterization. The isolates were determined as Lactobacillus sp. using primers specific for 16S rDNA. Sequencing of 16S rDNA genes and repetitive sequence-based polymerase chain reactions were used for determination to species and subspecies levels. Predominant species were Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus salivarius and Lactobacillus paracasei subsp. paracasei, while Lactobacillus acidophilus, Lactobacillus cellobiosus, Lactobacillus delbrueckii subsp. lactis and Lactobacillus gasseri were also present. The isolates Lactobacillus salivarius BGHO1, Lactobacillus fermentum BGHO36 and BGHO64, Lactobacillus gasseri BGHO89 and Lactobacillus delbrueckii subsp. lactis BGHO99 exhibited antagonistic action on the growth of Staphylococcus aureus, Enterococcus faecalis, Micrococcus flavus, Salmonella enteritidis, Streptococcus pneumoniae and Streptococcus mutans, but not on growth of Candida albicans. Moreover, the isolates L. salivarius BGHO1 and L. gasseri BGHO89 were tolerant to low pH and high concentration of bile salts. Taken together, these findings imply that L. salivarius BGHO1 and L. gasseri BGHO89 might be subjects for additional investigation as potential probiotic strains.

The Efect of the Immobilization of Probiotic Lactobacilli in Chitosan on their Tolerance to a Laboratory Model of Human Gut

ABSTRACTA successful immobilization in chitosan of the lactic acid bacteria Lactobacillus acidophilus A., Lactobacillus helveticus H., Lactobacillus casei subsp. casei C. and Lactobacillus plantarum 226–15 was accomplished and high viable cell counts (∼1010 cfu/g) in the gel beads were obtained. The resistance of the included in the gel matrix cells to model conditions of digestion was investigated. The high resistance of the immobilized cells to low and neutral pH values and the presence of pepsin and high concentrations of bile salts were demonstrated. The immobilized in chitosan cells of all of the studied strains showed a significantly higher resistance when compared to free growing cells. Thus, they can successfully be used for the production of probiotic preparations.

The G-protein coupled bile salt receptor TGR5 is expressed in liver sinusoidal endothelial cells

Sinusoidal endothelial cells (SEC) constitute a permeable barrier between hepatocytes and blood. SEC are exposed to high concentrations of bile salts from the enterohepatic circulation. Whether SEC are responsive to bile salts is unknown. TGR5, a G-protein-coupled bile acid receptor, which triggers cAMP formation, has been discovered recently in macrophages. In this study, rat TGR5 was cloned and antibodies directed against the C-terminus of rat TGR5 were developed, which detected TGR5 as a glycoprotein in transfected HepG2-cells. Apart from Kupffer cells, TGR5 was detected in SEC of rat liver. SEC expressed TGR5 over the entire acinus, whereas endothelial cells of the portal or central veins were not immunoreactive toward TGR5 antibodies. In isolated SEC, TGR5 mRNA and protein were detected by reverse transcription (RT) PCR, immunofluorescence microscopy, and Western blot analysis. Bile salts increased cAMP in isolated SEC and induced mRNA expression of endothelial NO synthase (eNOS), a known cAMP-dependent gene. In addition, bile acids activated eNOS by phosphorylation of eNOS at amino acid position 1177. In line with eNOS activation, bile acids induced NO production in liver slices. This is the first report on the expression of TGR5 in SEC. The data suggest that SEC are directly responsive toward specific bile salts. Regulation of eNOS in SEC by TGR5 connects bile salts with hepatic hemodynamics. This is of particular importance in cholestatic livers when bile salt concentrations are increased.

Screening of Locally Isolated Lactic Acid Bacteria for Use as Probiotics in Poultry in Iran

A total of 250 chicken intestinal specimens were screened for the presence of lactic acid bacteria (LAB) by routine cultural, morphological and biochemical reactions. Based on the results, 75 isolates were identified as LAB and were characterized for their probiotic potential. During preliminary investigations, the viability of the isolated LAB strains under different environmental and stress conditions was evaluated. Three of the strains which appeared resistant to acidic pH values and high bile salt concentrations were selected for further detailed studies. Based on the biochemical reactions these strains were identified as, Lactobacillus acidophilus RNL26, Lactobacillus fermentum RNL 44, and Lactobacillus salivarius RNL 49. All three strains demonstrated enhanced inhibitory activity against gram positive species including Clostridium perfringens, Staphylococcus aureus and Listeria monocytogene, while L. fermentum RNL 44 was also inhibitory towards gram negative bacteria; Salmonella enteritidis and S. typhimurium. The antibacterial effect exerted by L. acidophilus RNL26 and L. salivarius RNL 49 appeared to be due to bacteriocin or bacteriocin like substance, as the neutralized and catalase treated supernatant fluid of both the strains retained their antibacterial activity. All three strains were further characterized for their cholesterol removal, aggregation, co-aggregation, and cell surface hydrophobicity under in vitro conditions. According to our results L. fermentum RNL 44 appeared to be a superior probiotic candidate compared to the other two studied probiotic strains, Lactobacillus acidophilus RNL26 and Lactobacillus salivarius RNL 49.

O.398 Osseointegration and bone reconstruction in patients affected by ectodermal dysplasia

Diabetes has steadily increased in the past few decades and causes huge influences on human health care and socioeconomic development, and drugs with minimal or no side effects for diabetes are imminent. In the present study, probiotic combination containing five selected probiotics were used to treat diabetes, the high glucose consumption capability and sound probiotic characteristics in vitro showed that the probiotics could consume all glucose within 24 h, and could tolerate low potential of hydrogen (pH) (pH = 2) and high bile salt concentration (0.3%), and they also had sound oxidation resistance [2,2-diphenyl-1-picrylhydrazyl (DPPH),∙O2−, OH, Fe2+ chelation, and the reducing powers] and antibacterial activity, highly adhere to HT-29 cells and markedly reduced the chance for pathogens to adhere to HT-29 cell (p < 0.05) in vitro. Then, the in vivo results further confirmed that probiotic combination had obviously reduced blood glucose in STZ-induced diabetic mice and glucose water-induced diabetic mice, via directly consuming glucose in intestines, increasing the β cell number, the expression of pancreas duodenum homeobox factor-1 (PDX-1), and reduced the expression of glucose transporters of Sodium Glucose Cotransporter 1 (SGLT-1) and Glucose Transporter type2 (GLUT-2) (p < 0.05). Moreover, probiotics had obviously reduced the intestinal permeability via increasing the intestinal mucosal barrier and permeability proteins of Claudin 1 and zonula occludens-1 (ZO-1), reducing the pancreatic inflammation [Toll-like receptors 4 (TLR4), Nuclear transcription factor kBP65 (p65), Interleukin-1β (IL-1β), Tumor Necrosis Factor α (TNF-α), Interleukin-6 (IL-6)] and promoted the cell apoptosis [B-cell lymphoma-2 (Bcl-2)/Bcl-2 Associated X Protein (Bax)]. In conclusion, our group verifies the key role of glucose consumption effect of probiotics, besides its insulin promoting effect and α-glucosidase inhibiting effect.

The mechanism of ABCG5/ABCG8 in biliary cholesterol secretion in mice

The main player in biliary cholesterol secretion is the heterodimeric transporter complex, ABCG5/ABCG8, the function of which is necessary for the majority of sterols secreted into bile. It is not clear whether the primary step in this process is flopping of cholesterol from the inner to the outer leaflet of the canalicular membrane, with desorption by mixed micelles, or decreasing of the activation energy required for cholesterol desorption from the outer membrane leaflet. In this study, we investigated these mechanisms by infusing Abcg8(+/+), Abcg8(+/-), and Abcg8(-/-) mice with hydrophilic and hydrophobic bile salts. In Abcg8(-/-) mice, this failed to substantially stimulate biliary cholesterol secretion. Infusion of the hydrophobic bile salt taurodeoxycholate also resulted in cholestasis, which was induced in Abcg8(-/-) mice at a much lower infusion rate compared with Abc8(-/-) and Abcg8(+/-) mice, suggesting a reduced cholesterol content in the outer leaflet of the canalicular membrane. Indeed, isolation of canalicular membranes revealed a reduction of 45% in cholesterol content under these conditions in Abcg8(-/-) mice. Our data support the model that ABCG5/ABCG8 primarily play a role in flopping cholesterol (and sterols) from the inner leaflet to the outer leaflet of the canalicular membrane.

Evolution and function of the NR1I nuclear hormone receptor subfamily (VDR, PXR, and CAR) with respect to metabolism of xenobiotics and endogenous compounds.

The NR1I subfamily of nuclear hormone receptors includes the 1,25-(OH)(2)-vitamin D(3) receptor (VDR; NR1I1), pregnane X receptor (PXR; NR1I2), and constitutive androstane receptor (CAR; NR1I3). PXR and VDR are found in diverse vertebrates from fish to mammals while CAR is restricted to mammals. Current evidence suggests that the CAR gene arose from a duplication of an ancestral PXR gene, and that PXR and VDR arose from duplication of an ancestral gene, represented now by a single gene in the invertebrate Ciona intestinalis. Aside from the high-affinity effects of 1,25-(OH)(2)-vitamin D(3) on VDRs, the NR1I subfamily members are functionally united by the ability to bind potentially toxic endogenous compounds with low affinity and initiate changes in gene expression that lead to enhanced metabolism and elimination (e.g., induction of cytochrome P450 3A4 expression in humans). The detoxification role of VDR seems limited to sensing high concentrations of certain toxic bile salts, such as lithocholic acid, whereas PXR and CAR have the ability to recognize structurally diverse compounds. PXR and CAR show the highest degree of cross-species variation in the ligand-binding domain of the entire vertebrate nuclear hormone receptor superfamily, suggesting adaptation to species-specific ligands. This review examines the insights that phylogenetic and experimental studies provide into the function of VDR, PXR, and CAR, and how the functions of these receptors have expanded to evolutionary advantage in humans and other animals.

Synthesis of a Polymer Skeleton at the Inner Leaflet of Liposomal Membranes: Polymerization of Membrane-Adsorbed pH-Sensitive Monomers

We describe the synthesis of liposomes with an artificial membrane skeleton as a model of the native cellular cytoskeleton. Similar to natural conditions, a flat polymer network is coupled to the inner membrane leaflet like a suspended ceiling via membrane-inserted anchor monomers with a spacer. The polymer is composed of DMAPMA (N-(3-N,N-dimethylaminopropyl) methacrylamide) and TEGDM (tetraethylene glycol dimethacrylate) as a linker and is coupled to the membrane anchor DOGM (1,2-distearyl-3-octaethylene glycol glycerol ether methacrylate). In the first step of the synthesis, DMAPMA and TEGDM are encapsulated into liposomes composed of egg phosphatidylcholine (EPC), and free monomers are removed by gel chromatography. At pH 10, DMAPMA adsorbs to the inner membrane surface, as demonstrated in parallel studies with lipid monolayers using a Langmuir film balance. The polymerization by UV irradiation was initiated with DEAP (2,2-diethoxyacetophenone) as the initiator and was shown to be complete after 15 min. At pH 6, polymer was desorbed from the inner membrane surface to form a lamellar structure similar to that of the cellular cytoskeleton, as shown by electron microscopy. In comparison to NIPAM (N-isopropylacrylamide), which was used as a monomer in a recent study (Stauch, O.; Uhlmann, T.; Frohlich, M.; Thomann, R.; El-Badry, M.; Kim, Y.-K.; Schubert, R. Biomacromolecules 2002, 3, 324-32), DMAPMA shows much slower membrane permeation leading to an essential restriction of the formed polymer to the liposomal interior. The DMAPMA-based composite structure stabilizes the lipid membrane against sodium cholate by a factor of 2.5 as compared to plain EPC liposomes. This is discussed in the context of the situation in the liver, where the cytoskeleton probably plays a crucial role in the stabilization of the membrane against high bile salt concentration.

Method for direct selection of potentially probiotic Bifidobacterium strains from human feces based on their acid-adaptation ability

A method for direct selection of acid-resistant Bifidobacterium strains was developed by prolonged exposure of human feces to homologous lethal stress conditions. The recovered strains were intrinsically resistant to acidic gastric conditions (pH 2.0) and also showed good tolerance to high concentrations of bile salts and NaCl. Bifidobacterium breve and Bifidobacterium adolescentis were, respectively, the infant- and adult-type bifidobacterial species showing the highest ability to develop an acid-tolerant phenotype. Therefore, this procedure could be applicable to the direct selection of Bifidobacterium strains with improved stability in adverse environments and, probably, contribute to expand the spectra of probiotic species of human origin currently marketed.

Effect of alginate concentrations on survival of microencapsulated Lactobacillus casei NCDC-298

This study reports the tolerance of Lactobacillus casei NCDC-298 encapsulated in different alginate concentrations (2%, 3% or 4%), to low pH (1.5), high bile salt concentration (1% or 2%) and heat processing (55, 60 or 65 °C for 20 min). The release of encapsulated cells in simulated aqueous solution of colonic pH was also assessed. The survival of encapsulated L. casei was better at low pH, high bile salt concentration and during heat treatment as compared to free cells. The survival increased proportionately with increasing alginate concentrations without affecting the release of entrapped cells in solution of colonic pH.