Microencapsulated Genetically Engineered Lactobacillus plantarum 80 (pCBH1) for Bile Acid Deconjugation and Its Implication in Lowering Cholesterol

Interplay between gut microbiome, host genetic and epigenetic modifications in MASLD and MASLD-related hepatocellular carcinoma

Metabolic dysfunction-associated steatotic liver disease (MASLD) encompasses a wide spectrum of liver injuries, ranging from hepatic steatosis, metabolic dysfunction-associated steatohepatitis (MASH), fibrosis, cirrhosis to MASLD-associated hepatocellular carcinoma (MASLD-HCC). Recent studies have highlighted the bidirectional impacts between host genetics/epigenetics and the gut microbial community. Host genetics influence the composition of gut microbiome, while the gut microbiota and their derived metabolites can induce host epigenetic modifications to affect the development of MASLD. The exploration of the intricate relationship between the gut microbiome and the genetic/epigenetic makeup of the host is anticipated to yield promising avenues for therapeutic interventions targeting MASLD and its associated conditions. In this review, we summarise the effects of gut microbiome, host genetics and epigenetic alterations in MASLD and MASLD-HCC. We further discuss research findings demonstrating the bidirectional impacts between gut microbiome and host genetics/epigenetics, emphasising the significance of this interconnection in MASLD prevention and treatment.

Bile acid-activated receptors in innate and adaptive immunity: targeted drugs and biological agents

Bile acid-activated receptors (BARs) such as a G-protein bile acid receptor 1 and the farnesol X receptor are activated by bile acids (BAs) and have been implicated in the regulation of microbiota-host immunity in the intestine. The mechanistic roles of these receptors in immune signaling suggest that they may also influence the development of metabolic disorders. In this perspective, we provide a summary of recent literature describing the main regulatory pathways and mechanisms of BARs and how they affect both innate and adaptive immune system, cell proliferation, and signaling in the context of inflammatory diseases. We also discuss new approaches for therapy and summarize clinical projects on BAs for the treatment of diseases. In parallel, some drugs that are classically used for other therapeutic purposes and BAR activity have recently been proposed as regulators of immune cells phenotype. Another strategy consists of using specific strains of gut bacteria to regulate BA production in the intestine.

Targeting the human gut microbiome with small-molecule inhibitors

The human gut microbiome is a complex microbial community that is strongly linked to both host health and disease. However, the detailed molecular mechanisms underlying the effects of these microorganisms on host biology remain largely uncharacterized. The development of non-lethal, small-molecule inhibitors that target specific gut microbial activities enables a powerful but underutilized approach to studying the gut microbiome and a promising therapeutic strategy. In this Review, we will discuss the challenges of studying this microbial community, the historic use of small-molecule inhibitors in microbial ecology, and recent applications of this strategy. We also discuss the evidence suggesting that host-targeted drugs can affect the growth and metabolism of gut microbes. Finally, we address the issues of developing and implementing microbiome-targeted small-molecule inhibitors and define important future directions for this research.

Synergistic Hypolipidemic and Immunomodulatory Activity of Lactobacillus and Spirulina platensis

Hyperlipidemia is a significant risk factor for atherosclerosis and coronary heart disease (CHD). The aim of this study was to investigate hypolipidemic effects of Lactobacillus, Spirulina and their combination on Swiss albino mice fed a regular or high-cholesterol diet. Rosuvastatin was used as a reference drug The highest body weight, total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol LDL-C and the lowest high-density lipoprotein cholesterol were recorded in a positive control group (G5). Treatment with Lactobacillus or Spirulina or by their combination resulted in a significant decrease in body weight, TC, TG, LDL-C and significant increase in HDL-C (p < 0.05) in both mice fed a regular diet or high-cholesterol diet. The treatments induced a significant increase in Hb, MCHC and HCT levels in mice fed a regular diet (p < 0.05). They did not induce a significant effect on these parameters in mice fed a high-cholesterol diet, while treatment with standard rosuvastatin induced a significant decrease in these parameters (p < 0.05). The treatments induced a significant increase in the platelet count and WBC number in mice fed a regular diet p < 0.05), while they induced significant decrease in these parameters in mice fed a high-cholesterol diet p < 0.05. They also stimulated the innate immunity represented by both monocyte and neutrophil cells in mice fed a regular diet, while this immunity was reduced in mice fed a high-cholesterol diet. It also caused a marked reduction in inflammation and an improvement in the congestion of cardiac tissues, the aorta, and the spleen. The treatment of hyperlipidemic mice with combination of Lactobacillus and Spirulina gave similar results to those obtained with treatment by rosuvastatin.

Safety assessment and probiotic characteristics of Enterococcus lactis JDM1

OBJECTIVE

The aims of this study were to evaluate the safety and probiotic characteristics of the newly isolated Enterococcus lactis strain JDM1.

METHODS

Safety assessment of E. lactis JDM1 was accomplished by the combination of whole genome sequence information analysis and phenotypic assays, including antimicrobial susceptibility test, haemolysis assay, biogenic amine production assay, cytotoxicity assay. The bacteriostatic experiment and gastrointestinal tolerance experiment were also conducted to evaluate its applicability.

RESULTS

E. lactis JDM1 possesses good gastrointestinal tolerance and can inhibit the growth of the pathogenic bacteria Clostridioides difficile and Listeria monocytogenes. The chromosome size of JDM1 was 2,570,998 bp with a GC content of 38.46%, which contained a plasmid. One intact prophage, 13 genomic islands and 19 IS elements were predicted in the JDM1 chromosome. Five resistance-related genes and seven virulence-related genes were predicted in the genome. Most resistance genes were conserved, and virulence factors were not related to functional pathogenicity. Antimicrobial susceptibility tests showed that JDM1 was sensitive to tedizolid, ciprofloxacin, levofloxacin, penicillin, ampicillin, vancomycin, linezolid, tetracycline, high-level gentamicin and high-level streptomycin. Genes encoding putative enzymes responsible for adverse metabolites were not found and JDM1 was unable to produce the six main biogenic amines. Cytotoxicity test showed that the JDM1 supernatant had no toxic effect.

CONCLUSION

E. lactis JDM1 is expected to be developed as a probiotic, and its probiotic properties are worthy of further exploration.

Gastrointestinal transit tolerance, cell surface hydrophobicity, and functional attributes of Lactobacillus Acidophilus strains isolated from Indigenous Dahi

Strains of Lactobacillus acidophilus WFA1 (KU877440), WFA2 (KU877441), and WFA3 (KU877442) were isolated from indigenous Dahi (yogurt), screened, and selected based on acid and bile tolerance along with the antimicrobial activity. These selected strains were further assessed for their probiotic and functional attributes. Results for simulated gastric and intestinal tolerance/ resistance revealed that all three strains can resist and survive under the following mentioned conditions. To access cell surface hydrophobicity, bacterial adhesion to hydrocarbons (BATH), cellular auto-aggregation, and salt aggregation were performed. In BATH, adhesion of strains against three hydrocarbons namely xylene, dichloromethane, and hexadecane was conducted. The results show that strains showed the least adhesion to xylene (54.25%) as compared to dichloromethane (55.25%) and hexadecane (56.65%). WFA1 showed maximum adherence percentage (55.48%) followed WFA2 (55.48%) and WFA3 (51.38%). Cellular auto-aggregation varied from 21.72% to 30.73% for WFA3 and WFA1, respectively. In the salt aggregation test (SAT), WFA1, WFA2, and WFA3 aggregated at 0.6, 1.0, and 2.0 molar concentrations of ammonium sulfate, respectively. PCR amplification of bile salt hydrolase gene (bsh) was performed and sequences were submitted to the public database of NCBI and Gene bank under accession numbers, KY689139, KY689140, and KY689141. Additionally, a cholesterol-lowering assay was conducted and up to 26% reduction in cholesterol was observed by the strains. Regarding functional properties, exopolysaccharide (EPS) production, and antioxidant potential, strain WFA1 showed promising results EPS (1.027mg/ml), DPPH (80.66%), ABTS (81.97%), and reducing power (1.787). It can be concluded from the present study that the mentioned strains of L. acidophilus (WFA1, WFA2, and WFA3) are strongly hydrophobic; thus having an ability to survive and colonize under the gastrointestinal tract which confirms their probiotic nature. Regarding their functional properties, L. acidophilus WFA1 (KU877440) showed excellent properties of antioxidants and EPS production.

Programming gene expression in multicellular organisms for physiology modulation through engineered bacteria

A central goal of synthetic biology is to predictably and efficiently reprogram living systems to perform computations and carry out specific biological tasks. Although there have been many advances in the bio-computational design of living systems, these advances have mainly been applied to microorganisms or cell lines; programming animal physiology remains challenging for synthetic biology because of the system complexity. Here, we present a bacteria-animal symbiont system in which engineered bacteria recognize external signals and modulate animal gene expression, twitching phenotype, and fat metabolism through RNA interference toward gfp, sbp-1, and unc-22 gene in C. elegans. By using genetic circuits in bacteria to control these RNA expressions, we are able to program the physiology of the model animal Caenorhabditis elegans with logic gates. We anticipate that engineered bacteria can be used more extensively to program animal physiology for agricultural, therapeutic, and basic science applications.

The influence of probiotics on bile acids in diseases and aging

Recent evidence indicates the use of probiotics in the prevention and treatment of diseases. Probiotics are capable of changing the gut microbiota composition and bile acid synthesis to elicit health benefits such as cholesterol-lowering, weight reduction, and improving insulin sensitivity. The aging population is prone to develop diseases because of their decreased physiological and biological systems. Probiotics are one of the promising supplements that may potentially counteract these detrimental effects. This review will discuss the influence of probiotics on bile acids in different populations-the elderly, obese individuals, and those with hypercholesterolemia, type 2 diabetes, hypertension, and non-alcoholic fatty liver disease.

Asparagine 79 is an important amino acid for catalytic activity and substrate specificity of bile salt hydrolase (BSH)

Microbial bile salt hydrolases (BSHs), a member of cholylglycine hydrolase (CGH) family, catalyze the hydrolysis of glycine and taurine-linked bile salts in the small intestine of human. BSH is evolutionarily related to penicillin V acylase (PVA) which hydrolyses a penicillin V and is also a member of CGH family. Although, five of the six amino acids, C2, R16, D19, N170, N79 and R223, supposed to be responsible for catalytic activity of BSH enzyme, are strictly conserved in all CGH family members, N79 is partially conserved in this family. In this study, in order to analyze the correlation between N79 and catalytic activity or substrate specificity of BSH, the polar and acidic N79 was substituted for the aliphatic and hydrophobic V79 by PCR-based site directed mutagenesis and mutant recombinant BSH was expressed in E. coli BLR(DE3). While the effects of the mutation on catalytic activity and substrate specificity of BSH were detected by ninhydrin assay. The effect of this mutation on the stability of the BSH was observed by SDS-PAGE analysis. Although V79 mutation resulted in stable BSH, it reduced the catalytic activity and altered substrate specificity of BSH. The results suggested that N79 might be important for substrate binding and catalytic turnover of BSH.

Investigation of the Protective Effect of Kefir against Isoproterenol Induced Myocardial Infarction in Rats

This study aims to investigate the protective effects of kefir against myocardial infarction induced by isoproterenol (ISO). The rats were randomly divided into 4 groups, each group consisting of 8 rats. The control group, the kefir group (5 mL/kg/d kefir administered to rats as intra-gastric gavage for 60 d), the ISO group (100 mg/kg ISO was administered to rats, s.c. on 61. and 62. d), and kefir+ISO group (5 mL/kg/d kefir was administered to rats intra gastric gavage for 60 days prior to ISO, 100 mg/kg in two doses on day 61 and 62). 12 h after the last ISO dose, all rats were decapitated and their blood samples were collected. Cardiac tissue was reserved for histopathological examination. creatine kinase (CK), alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), triglycerides, total cholesterol,very low density lipoprotein (VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL) and glucose were measured by autoanalyzer, whole blood malondialdehyde (MDA), glutathione (GSH) and plasma advanced oxidation protein products (AOPP) levels were measured spectrophotometrically. It was determined that in the group of kefir+ISO, the levels of AST (p<0.001), CK (p<0.001), LDH (p<0.001), MDA (p<0.001) and AOPP (p<0.001) were decreased, while the GSH (p<0.05) increased, compared to ISO group. There were no significant changes in lipid profile and glucose levels between these two groups. In conclusion, by examining cardiac enzymes and histopathological changes in cardiac tissue, it can be concluded that the administration of kefir in myocardial infarction induced by ISO can protect the heart with its antioxidant characteristic and minimize the toxic damage created by ISO.

Efficacy of Lactobacillus plantarum in prevention of inflammatory bowel disease

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L. plantarum have effects on inflammation for the prevention and management IBD.

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The mechanisms of action of L. plantarum on IBD are complex.

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Further clinical studies are needed to validate its potential use in IBD in humans.

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L. plantarum are considered safe overall for use as feed additives and humans.

The incidence of inflammatory bowel disease (IBD) is increasing globally. Altered gut bacteria and bacterial metabolic pathways are two important factors in the initiation and progression of IBD. Lactobacillus plantarum is distributed in a variety of ecological niches, has a proven ability to survive gastric transit, and can colonize the intestinal tract of human and other mammals. Several studies have described the effects of L. plantarum consumption on human physiology. This review summarizes the safety and the effects of L. plantarum in vitro and in animal models for the prevention and management of IBD. L. plantarum modulates the ratio of Th1 and Th2 cells by stimulating the production of different inflammatory cytokines such as tumor necrosis factor-alpha, interleukin (IL)-1β, IL-6, IL-10, IL-12, and interferon-gamma. The blocking of cyclooxygenase-2 in Th1 also is an apoptotic inhibition mechanism. This overview of the molecular studies addresses the activity of L. plantarum in the human gut environment and its’ potential for remission of IBD.

Bile acid-microbiota crosstalk in gastrointestinal inflammation and carcinogenesis

Emerging evidence points to a strong association between the gut microbiota and the risk, development and progression of gastrointestinal cancers such as colorectal cancer (CRC) and hepatocellular carcinoma (HCC). Bile acids, produced in the liver, are metabolized by enzymes derived from intestinal bacteria and are critically important for maintaining a healthy gut microbiota, balanced lipid and carbohydrate metabolism, insulin sensitivity and innate immunity. Given the complexity of bile acid signalling and the direct biochemical interactions between the gut microbiota and the host, a systems biology perspective is required to understand the liver-bile acid-microbiota axis and its role in gastrointestinal carcinogenesis to reverse the microbiota-mediated alterations in bile acid metabolism that occur in disease states. An examination of recent research progress in this area is urgently needed. In this Review, we discuss the mechanistic links between bile acids and gastrointestinal carcinogenesis in CRC and HCC, which involve two major bile acid-sensing receptors, farnesoid X receptor (FXR) and G protein-coupled bile acid receptor 1 (TGR5). We also highlight the strategies and cutting-edge technologies to target gut-microbiota-dependent alterations in bile acid metabolism in the context of cancer therapy.

An in vivo assessment of the cholesterol-lowering efficacy of Lactobacillus plantarum ECGC 13110402 in normal to mildly hypercholesterolaemic adults

Coronary heart disease (CHD) is one of the major causes of death and disability in industrialised countries, with elevated blood cholesterol an established risk factor. Total plasma cholesterol reduction in populations suffering from primary hypercholesterolemia may lower CHD incidence. This study investigated the cholesterol reducing capacity of Lactobacillus plantarum ECGC 13110402, a strain selected for its high bile salt hydrolase activity, in 49 normal to mildly hypercholesterolaemic adults. Primary efficacy outcomes included effect on blood lipids (total cholesterol (TC), low density lipoproteins (LDL-C), high density lipoproteins (HDL-C) and triacylgycerides (TAG), inflammatory biomarkers and occurrence/severity of gastrointestinal side effects to establish safety and tolerance of the intervention. Secondary outcomes included blood pressure, immune biomarkers, gut microbiota characterisation and metabonome changes. The study was run in a parallel, double blind, placebo controlled, randomised design in which the active group ingested 2x10⁹ CFU encapsulated Lactobacillus plantarum ECGC 13110402 twice daily. Daily ingestion of the active treatment resulted in a statistically significant reduction in LDL-C in volunteers with baseline TC<5mM during the 0–12 week period (13.9%, P = 0.030), a significant reduction in TC in volunteers with baseline TC≥6mM in the 0–6 week period (37.6%, P = 0.045), a significant decrease in TAG (53.9% P = 0.030) and an increase in HDL-C (14.7%, P = 0.007) in the over 60 years population in the 6–12 week period. A statistically significant reduction in systolic blood pressure was also observed across the active study group in the 6-12-week period (6.6%, P = 0.003). No impact on gastrointestinal function and side effects was observed during the study. Similar to blood and urine metabonomic analyses, faecal metagenomics did not reveal significant changes upon active or placebo intake. The results of this study suggest that Lactobacillus plantarum ECGC 13110402 is a well-tolerated, natural probiotic, that may be used as an alternative or supplement to existing treatments to reduce cardiovascular risk.

Trial registration: Clinical trials.gov NCT03263104

Gut microbiota as a potential target of metabolic syndrome: the role of probiotics and prebiotics

Metabolic syndrome (MS) comprises central obesity, increased plasma glucose levels, hyperlipidemia and hypertension, and its incidence is increasing due to changes in lifestyle and dietary structure in recent years. MS has been proven to be associated with an increased incidence of cardiovascular diseases and type 2 diabetes mellitus, leading to morbidity and mortality. In this manuscript, we review recent studies concerning the role of the gut microbiota in MS modulation. Manipulation of the gut microbiota through the administration of prebiotics or probiotics may assist in weight loss and reduce plasma glucose and serum lipid levels, decreasing the incidence of cardiovascular diseases and type 2 diabetes mellitus. To the best of our knowledge, short-chain fatty acids (SCFAs), bile salt hydrolase (BSH), metabolic endotoxemia and the endocannabinoid (eCB) system are essential in regulating the initiation and progression of MS through the normalization of adipogenesis and the regulation of insulin secretion, fat accumulation, energy homeostasis, and plasma cholesterol levels. Therefore, the gut microbiota may serve as a potential therapeutic target for MS. However, further studies are needed to enhance our understanding of manipulating the gut microbiota and the role of the gut microbiota in MS prevention and treatment.

Characterization of Bile Salt Hydrolase from Lactobacillus gasseri FR4 and Demonstration of Its Substrate Specificity and Inhibitory Mechanism Using Molecular Docking Analysis

Probiotic bacteria are beneficial to the health of poultry animals, thus are used as alternative candidates for antibiotics used as growth promoters (AGPs). However, they also reduce the body weight gain due to innate bile salt hydrolase (BSH) activity. Hence, the addition of a suitable BSH inhibitor along with the probiotic feed can decrease the BSH activity. In this study, a BSH gene (981 bp) encoding 326-amino acids was identified from the genome of Lactobacillus gasseri FR4 (LgBSH). The LgBSH-encoding gene was cloned and purified using an Escherichia coli BL21 (DE3) expression system, and its molecular weight (37 kDa) was confirmed by SDS-PAGE and a Western blot analysis. LgBSH exhibited greater hydrolysis toward glyco-conjugated bile salts compared to tauro-conjugated bile salts. LgBSH displayed optimal activity at 52°C at a pH of 5.5, and activity was further increased by several reducing agents (DTT), surfactants (Triton X-100 and Tween 80), and organic solvents (isopropanol, butanol, and acetone). Riboflavin and penicillin V, respectively, inhibited LgBSH activity by 98.31 and 97.84%. A homology model of LgBSH was predicted using EfBSH (4WL3) as a template. Molecular docking analysis revealed that the glycocholic acid had lowest binding energy of -8.46 kcal/mol; on the other hand, inhibitors, i.e., riboflavin and penicillin V, had relatively higher binding energies of -6.25 and -7.38 kcal/mol, respectively. Our results suggest that L. gasseri FR4 along with riboflavin might be a potential alternative to AGPs for poultry animals.

Probiotics and Prebiotics: Present Status and Future Perspectives on Metabolic Disorders

Metabolic disorders, including type 2 diabetes (T2DM) and cardiovascular disease (CVD), present an increasing public health concern and can significantly undermine an individual's quality of life. The relative risk of CVD, the primary cause of death in T2DM patients, is two to four times higher in people with T2DM compared with those who are non-diabetic. The prevalence of metabolic disorders has been associated with dynamic changes in dietary macronutrient intake and lifestyle changes over recent decades. Recently, the scientific community has considered alteration in gut microbiota composition to constitute one of the most probable factors in the development of metabolic disorders. The altered gut microbiota composition is strongly conducive to increased adiposity, β-cell dysfunction, metabolic endotoxemia, systemic inflammation, and oxidative stress. Probiotics and prebiotics can ameliorate T2DM and CVD through improvement of gut microbiota, which in turn leads to insulin-signaling stimulation and cholesterol-lowering effects. We analyze the currently available data to ascertain further potential benefits and limitations of probiotics and prebiotics in the treatment of metabolic disorders, including T2DM, CVD, and other disease (obesity). The current paper explores the relevant contemporary scientific literature to assist in the derivation of a general perspective of this broad area.

Monoculture parameters successfully predict coculture growth kinetics of Bacteroides thetaiotaomicron and two Bifidobacterium strains

Microorganisms rarely live in isolation but are most often found in a consortium. This provides the potential for cross-feeding and nutrient competition among the microbial species, which make it challenging to predict the growth kinetics in coculture. In this paper we developed a mathematical model to describe substrate consumption and subsequent microbial growth and metabolite production for bacteria grown in monoculture. The model characterized substrate utilization kinetics of 18 Bifidobacterium strains. Some bifidobacterial strains demonstrated preferential degradation of oligofructose in that sugars with low degree of polymerization (DP) (DP≤3 or 4) were metabolized before sugars of higher DP, or vice versa. Thus, we expanded the model to describe the preferential degradation of oligofructose. In addition, we adapted the model to describe the competition between human colonic bacteria Bacteroides thetaiotaomicron LMG 11262 and Bifidobacterium longum LMG 11047 or Bifidobacterium breve Yakult for inulin as well as cross-feeding of breakdown products from the extracellular hydrolysis of inulin by B. thetaiotaomicron LMG 11262. We found that the coculture growth kinetics could be predicted based on the respective monoculture growth kinetics. Using growth kinetics from monoculture experiments to predict coculture dynamics will reduce the number of in vitro experiments required to parameterize multi-culture models.

Inflammatory bowel disease: clinical aspects and treatments

Inflammatory bowel disease (IBD) is defined as a chronic intestinal inflammation that results from host-microbial interactions in a genetically susceptible individual. IBDs are a group of autoimmune diseases that are characterized by inflammation of both the small and large intestine, in which elements of the digestive system are attacked by the body’s own immune system. This inflammatory condition encompasses two major forms, known as Crohn’s disease and ulcerative colitis. Patients affected by these diseases experience abdominal symptoms, including diarrhea, abdominal pain, bloody stools, and vomiting. Moreover, defects in intestinal epithelial barrier function have been observed in a number of patients affected by IBD. In this review, we first describe the types and symptoms of IBD and investigate the role that the epithelial barrier plays in the pathophysiology of IBD as well as the major cytokines involved. We then discuss steps used to diagnose this disease and the treatment options available, and finally provide an overview of the recent research that aims to develop new therapies for such chronic disorders.

Construction of a novel inducible expression vector for Lactococcus lactis M4 and Lactobacillus plantarum Pa21

A vector that drives the expression of the reporter gusA gene in both Lactobacillus plantarum and Lactococcus lactis was constructed in this study. This vector contained a newly characterized heat shock promoter (Phsp), amplified from an Enterococcus faecium plasmid, pAR6. Functionality and characterization of this promoter was initially performed by cloning Phsp into pNZ8008, a commercial lactococcal plasmid used for screening of putative promoters which utilizes gusA as a reporter. It was observed that Phsp was induced under heat, salinity and alkaline stresses or a combination of all three stresses. The newly characterized Phsp promoter was then used to construct a novel Lactobacillus vector, pAR1801 and its ability to express the gusA under stress-induced conditions was reproducible in both Lb. plantarum Pa21 and L. lactis M4 hosts.

Isolation of potential probiotic Lactobacillus oris HMI68 from mother's milk with cholesterol-reducing property

The objective of this study was to evaluate the probiotic properties of Lactobacillus strains isolated from mother's milk and their effects on cholesterol assimilation. In this study 120 isolates from mother's milk were phenotypically and genotypically characterized. Among these, only 6 predominant strains were identified as Lactobacillus spp. The following parameters were selected as important test variables in model stomach passage survival trials: acid and bile tolerance, antimicrobial activity, antibiotic susceptibility and cholesterol reduction. Results showed that the considerable variation existed among six strains. Moreover, the strain HMI68 is the most acid-tolerant and the HMI28 and HMI74 is the most acid-sensitive of all strains tested. HMI118 did not grow at 0.5% and 1% bile concentration after 5 h but the HMI68 and HMI43 showed some tolerance to such bile concentration. The differences found in the growth rate were not significant (P > 0.05). HMI68 showed resistance to most of the antibiotics as well as antagonistic activity against the tested pathogens. The amount of cholesterol reduction is increased when the media supplemented with bile salts. HMI68 assimilate 61.05 ± 0.05 μg/ml cholesterol with the presence of 0.3% bile salt this could be significantly decreased by 25.41 ± 1.09 μg/ml without bile salt. HMI68 was identified to be Lactobacillus oris HMI68 and 16S rRNA sequence was deposited in the National Center for Biotechnological Information (GenBank). For the first time the cholesterol-reducing property of L. oris isolated from mother's milk were investigated in this study. Therefore the effective L. oris HMI68 strain was regarded as a candidate probiotic.

Effects of Probiotics, Prebiotics, and Synbiotics on Hypercholesterolemia: A Review

Cholesterol plays a major role in human health. High cholesterol is a leading risk factor for human cardiovascular disease such as atherosclerosis, coronary heart disease, and stroke. Excess cholesterol in the bloodstream can form plaque in the artery walls. Hypercholesterolemia is a major risk factor for the development of atherosclerosis. A number of pharmacological and non-pharmacological (including dietary) approaches being employed to reduce the cholesterol level. Numerous drugs that lower serum cholesterol have been developed to treat hypercholesterolemic patients, the best example being the statins drugs (Atorvastatin, Simvastatin, Rosuvastatin, and Lovastatin). However, the undesirable side effects of these compounds were observed and have caused concern about their long term therapeutic use. Several studies have been reported that the consumption of fermented dairy products decreases serum cholesterol. Probiotics are live microorganisms that promote health benefits upon consumption, while prebiotics are nondigestible food ingredients that selectively stimulate the growth of beneficial microorganisms in the gastrointestinal tract. Probiotics and prebiotics have been suggested to reduce cholesterol via various mechanisms without any deleterious effect to the human health. This paper may throw some light to prove the ability of these synbiotics as a novel alternative or adjuvant to chemical drugs to help fight the hypercholesterolemic problem.

The human microbiome is a source of therapeutic drug targets

It was appreciated early in drug discovery that the microbiota play an important role in the efficacy of therapeutic compounds. Indeed, the first antibiotic sulfa drugs were shown in the 1940s to be transformed by the bacteria that encode what we now call the intestinal microbiome. Here we briefly review the roles symbiotic bacteria play in the chemistry of human health, and we focus on the emerging appreciation that specific enzyme targets expressed by microbial symbiotes can be selectively disrupted to achieve clinical outcomes. We conclude that components of the microbiome should be considered 'druggable targets,' and we suggest that our rapidly evolving understanding of the chemical biology of mammalian-microbial symbiosis will translate into improved human health.

Microencapsulation for the Therapeutic Delivery of Drugs, Live Mammalian and Bacterial Cells, and Other Biopharmaceutics: Current Status and Future Directions

Microencapsulation is a technology that has shown significant promise in biotherapeutics, and other applications. It has been proven useful in the immobilization of drugs, live mammalian and bacterial cells and other cells, and other biopharmaceutics molecules, as it can provide material structuration, protection of the enclosed product, and controlled release of the encapsulated contents, all of which can ensure efficient and safe therapeutic effects. This paper is a comprehensive review of microencapsulation and its latest developments in the field. It provides a comprehensive overview of the technology and primary goals of microencapsulation and discusses various processes and techniques involved in microencapsulation including physical, chemical, physicochemical, and other methods involved. It also summarizes the state-of-the-art successes of microencapsulation, specifically with regard to the encapsulation of microorganisms, mammalian cells, drugs, and other biopharmaceutics in various diseases. The limitations and future directions of microencapsulation technologies are also discussed.

Selection of potential probiotic lactobacilli for cholesterol-lowering properties and their effect on cholesterol metabolism in rats fed a high-lipid diet

The objectives of this study were to screen probiotic characteristics of lactobacilli isolated from traditionally homemade koumiss products in Xinjiang and Inner Mongolia of China, and to determine and compare the effect of the Lactobacillus strains in vivo on lipid metabolism in rats fed with a high-lipid diet. Three out of 68 strains of Lactobacillus isolated from the koumiss were screened for bile-salt resistance, acid tolerance, and different hypocholesterolemic properties. The cholesterol-lowering effects of the 3 screened strains were estimated in rats fed a high-lipid diet by determination of serum lipids, liver, and fecal cholesterol, fecal total bile acids, and short-chain fatty acids. After a 4-wk feeding period, in comparison with the control group, the groups LIP-1 and MG9-2 had a significant reduction in serum total cholesterol, triglyceride and low-density lipoprotein cholesterol, and significantly increased high-density lipoprotein, the group E7301 had similar effects on serum lipids, but the change was not significant. The groups LIP-1, MG9-2 and E7301 had a significant reduction in liver cholesterol content and an increase in fecal cholesterol content compared with the control group. Total bile acid excretion was significantly higher in rats fed MG9-2 than the other groups. Rats fed diets containing lactic acid bacteria strains had significantly higher propionic acid and butyric acid concentrations in the feces compared with the control. Results indicated that the 3 screened Lactobacillus strains were able to lower cholesterol in vitro, and reduce cholesterol effectively in vivo. The mechanisms behind the hypocholesterolemic effect of 3 strains are likely to be diverse and will need further investigation.

Safety assessment of Bifidobacterium longum JDM301 based on complete genome sequences

AIM

To assess the safety of Bifidobacterium longum (B. longum) JDM301 based on complete genome sequences.

METHODS

The complete genome sequences of JDM301 were determined using the GS 20 system. Putative virulence factors, putative antibiotic resistance genes and genes encoding enzymes responsible for harmful metabolites were identified by blast with virulence factors database, antibiotic resistance genes database and genes associated with harmful metabolites in previous reports. Minimum inhibitory concentration of 16 common antimicrobial agents was evaluated by E-test.

RESULTS

JDM301 was shown to contain 36 genes associated with antibiotic resistance, 5 enzymes related to harmful metabolites and 162 nonspecific virulence factors mainly associated with transcriptional regulation, adhesion, sugar and amino acid transport. B. longum JDM301 was intrinsically resistant to ciprofloxacin, amikacin, gentamicin and streptomycin and susceptible to vancomycin, amoxicillin, cephalothin, chloramphenicol, erythromycin, ampicillin, cefotaxime, rifampicin, imipenem and trimethoprim-sulphamethoxazol. JDM301 was moderately resistant to bacitracin, while an earlier study showed that bifidobacteria were susceptible to this antibiotic. A tetracycline resistance gene with the risk of transfer was found in JDM301, which needs to be experimentally validated.

CONCLUSION

The safety assessment of JDM301 using information derived from complete bacterial genome will contribute to a wider and deeper insight into the safety of probiotic bacteria.

Cholesterol-lowering probiotics as potential biotherapeutics for metabolic diseases

Cardiovascular diseases are one of the major causes of deaths in adults in the western world. Elevated levels of certain blood lipids have been reported to be the principal cause of cardiovascular disease and other disabilities in developed countries. Several animal and clinical trials have shown a positive association between cholesterol levels and the risks of coronary heart disease. Current dietary strategies for the prevention of cardiovascular disease advocate adherence to low-fat/low-saturated-fat diets. Although there is no doubt that, in experimental conditions, low-fat diets offer an effective means of reducing blood cholesterol concentrations on a population basis, these appear to be less effective, largely due to poor compliance, attributed to low palatability and acceptability of these diets to the consumers. Due to the low consumer compliance, attempts have been made to identify other dietary components that can reduce blood cholesterol levels. Supplementation of diet with fermented dairy products or lactic acid bacteria containing dairy products has shown the potential to reduce serum cholesterol levels. Various approaches have been used to alleviate this issue, including the use of probiotics, especially Bifidobacterium spp. and Lactobacillus spp.. Probiotics, the living microorganisms that confer health benefits on the host when administered in adequate amounts, have received much attention on their proclaimed health benefits which include improvement in lactose intolerance, increase in natural resistance to infectious disease in gastrointestinal tract, suppression of cancer, antidiabetic, reduction in serum cholesterol level, and improved digestion. In addition, there are numerous reports on cholesterol removal ability of probiotics and their hypocholesterolemic effects. Several possible mechanisms for cholesterol removal by probiotics are assimilation of cholesterol by growing cells, binding of cholesterol to cellular surface, incorporation of cholesterol into the cellular membrane, deconjugation of bile via bile salt hydrolase, coprecipitation of cholesterol with deconjugated bile, binding action of bile by fibre, and production of short-chain fatty acids by oligosaccharides. The present paper reviews the mechanisms of action of anti-cholesterolemic potential of probiotic microorganisms and probiotic food products, with the aim of lowering the risks of cardiovascular and coronary heart diseases.

Cholesterol-lowering efficacy of a microencapsulated bile salt hydrolase-active Lactobacillus reuteri NCIMB 30242 yoghurt formulation in hypercholesterolaemic adults

Several studies have reported limited or no reduction in serum cholesterol in response to probiotic formulations. Recently, probiotics have shown promise in treating metabolic disease due to improved strain selection and delivery technologies. The aim of the present study was to evaluate the cholesterol-lowering efficacy of a yoghurt formulation containing microencapsulated bile salt hydrolase (BSH)-active Lactobacillus reuteri NCIMB 30242, taken twice per d over 6 weeks, in hypercholesterolaemic adults. A total of 114 subjects completed this double-blind, placebo-controlled, randomised, parallel-arm, multi-centre study. This interventional study included a 2-week washout, 2-week run-in and 6-week treatment period. Subjects were randomised to consume either yoghurts containing microencapsulated L. reuteri NCIMB 30242 or placebo yoghurts. Over the intervention period, subjects consuming yoghurts containing microencapsulated L. reuteri NCIMB 30242 attained significant reductions in LDL-cholesterol (LDL-C) of 8·92 % (P = 0·016), total cholesterol (TC) of 4·81 % (P = 0·031) and non-HDL-cholesterol (HDL-C) of 6·01 % (P = 0·029) over placebo, and a significant absolute change in apoB-100 of - 0·19 mmol/l (P = 0·049). Serum concentrations of TAG and HDL-C were unchanged over the course of the study. Present results show that consumption of microencapsulated BSH-active L. reuteri NCIMB 30242 yoghurt is efficacious and safe for lowering LDL-C, TC, apoB-100 and non-HDL-C in hypercholesterolaemic subjects. The efficacy of microencapsulated BSH-active L. reuteri NCIMB 30242 yoghurts appears to be superior to traditional probiotic therapy and akin to that of other cholesterol-lowering ingredients.

Efflux of bile acids in Lactobacillus reuteri is mediated by ATP

PURPOSE OF WORK

To study whether an active bile acid (BA) efflux occurs in Lactobacillus reuteri CRL 1098 as well as the nature (ATP or proton motive force [PMF] mediated primary transport) of the BA extrusion mechanism. BAs are powerful detergents which disorganize the lipid bilayer structure of cellular membranes. Specific bile resistance mechanisms (bile efflux, bile salt hydrolysis, and intrinsic architecture and composition of cell membrane the most prevalent) have been described in intestinal bacteria. L. reuteri, showed a significant degree of resistance to the toxic action of BA and the presence of an active efflux ATP-dependent of conjugated (taurocholic [TCA]) and free (cholic [CA]) BA in the CRL 1098 strain is now reported. However, due the high pKa (5.5) of cholic acid (CA) compared with the conjugated species, a significant fraction (between 35 and 50% at pH 6.5 and 5.2, respectively) of free BA also diffused passively, even in the absence of ATP. To our knowledge, our results represent the first evidence of ATP as the energy source involved in the BA extrusion in L. reuteri.

Bacterial biofilms associated with food particles in the human large bowel

Bacteria within the gastro-intestinal tract affect host function via production of short-chain fatty acids and synthesis of vitamins. Additionally, the commensal enteric bacteria modulate the immune system and provide protection from potentially pathogenic bacteria. Only recently heterogeneous bacterial biofilms were found to be associated with food particles within the intestinal tract. There are a number of studies investigating the formation and function of pathogenic and single-species biofilms, though few studies have investigated the dynamics of multispecies biofilms, especially with regard to food/microbial/host interactions. The scope of this review is to discuss the current knowledge of bacterial biofilms associated with food particles in the human large bowel, examine the established mathematical models depicting bacterial attachment, and elucidate key areas for further research.

Hypocholesterolaemic effect of dietary inclusion of two putative probiotic bile salt hydrolase-producing Lactobacillus plantarum strains in Sprague-Dawley rats

The purpose of the present study was to evaluate the anti-hypercholesterolaemic effects of two putative probiotic bile salt hydrolase (Bsh)-producing Lactobacillus plantarum strains, i.e. Lp91 and Lp21, in rats. L. plantarum Lp91 exhibited excellent tolerance to low pH and high bile salt concentrations as well as showed potential Bsh activity, cholesterol assimilation and cholesterol co-precipitation ability along with L. plantarum Lp21 and NCDO82 strains. Furthermore, the potential effect of L. plantarum Lp91 on plasma cholesterol level was evaluated in Sprague-Dawley rats. Five treatment groups of rats (n 6) were fed experimental diets: normal diet, hypercholesterolaemic diet (HD), HD plus L. plantarum Lp91 (HD91) at ≥ 1·0 × 108 colony-forming units (cfu)/g, HD plus microencapsulated L. plantarum Lp91 (HDCap91) at ≥ 1·0 × 108 cfu/g and HD plus L. plantarum Lp21 (HD21) at ≥ 1·0 × 108 cfu/g for 3 weeks. Feed intake and feed efficiency differed significantly among the five groups. After 21 d of dietary treatment, comparative analysis revealed 23·26, 15·71 and 15·01 % reduction in total cholesterol, 21·09, 18·77 and 18·17 % reduction in TAG, 38·13, 23·22 and 21·42 % reduction in LDL-cholesterol, and the corresponding HDL-cholesterol values increased at the rate of 18·94, 10·30 and 7·78 % in treated groups HD91, HDCap91 and HD21, respectively. Faecal excretion of cholic acid and faecal lactobacilli counts were significantly higher in the probiotic treatment groups than in the control groups. In conclusion, these results suggest that the indigenous L. plantarum Lp91 strain has the potential to be explored as a probiotic in the management of hypercholesterolaemia.

Oral microencapsulated live Saccharomyces cerevisiae cells for use in renal failure uremia: preparation and in vivo analysis

Orally administrable alginate-poly-L-lysine-alginate (APA) microcapsules containing live yeast cells was investigated for use in renal failure. At all times, yeast cells remain inside the microcapsules, which are then excreted in the stool. During their gastrointestinal passage, small molecules, like urea, diffuse into the yeast microcapsules where they are hydrolyzed. Orally administrating these microcapsules to uremic rats was found to decrease urea concentrations from 7.29 ± 0.89 mmol/L to 6.12 ± 0.90 mmol/L over a treatment period of eight weeks. After stopping the treatment, the urea concentrations increased back to uremic levels of 7.64 ± 0.77 mmol/L. The analysis of creatinine concentrations averaged 39.19 ± 4.33 μmol/L, 50.83 ± 5.55 μmol/L, and 50.28 ± 7.10 μmol/L for the normal-control, uremic-control and uremic-treatment groups, respectively. While creatinine concentrations for both uremic-control and uremic-treatment groups did not differ among each other (P > .05), they were, however, significantly higher than those of the normal control group (P < .05). Uric acid concentrations averaged 80.08 ± 26.49 μmol/L, 99.92 ± 26.55 μmol/L, and 86.49 ± 28.42 μmol/L for the normal-control, uremic-control and uremic-treatment groups, respectively. There were no significant differences in both calcium and phosphate concentrations among all three groups (P > .05). The microbial populations of five tested types of bacteria were not substantially altered by the presence of the yeast APA encapsulated yeast (P > .05).

Cholesterol-lowering effects of probiotics and prebiotics: a review of in vivo and in vitro findings

Probiotics are live microorganisms that promote health benefits upon consumption, while prebiotics are nondigestible food ingredients that selectively stimulate the growth of beneficial microorganisms in the gastrointestinal tract. Probiotics and/or prebiotics could be used as alternative supplements to exert health benefits, including cholesterol-lowering effects on humans. Past in vivo studies showed that the administration of probiotics and/or prebiotics are effective in improving lipid profiles, including the reduction of serum/plasma total cholesterol, LDL-cholesterol and triglycerides or increment of HDL-cholesterol. However, other past studies have also shown that probiotics and prebiotics had insignificant effects on lipid profiles, disputing the hypocholesterolemic claim. Additionally, little information is available on the effective dosage of probiotics and prebiotics needed to exert hypocholesterolemic effects. Probiotics and prebiotics have been suggested to reduce cholesterol via various mechanisms. However, more clinical evidence is needed to strengthen these proposals. Safety issues regarding probiotics and/or prebiotics have also been raised despite their long history of safe use. Although probiotic-mediated infections are rare, several cases of systemic infections caused by probiotics have been reported and the issue of antibiotic resistance has sparked much debate. Prebiotics, classified as food ingredients, are generally considered safe, but overconsumption could cause intestinal discomfort. Conscientious prescription of probiotics and/or prebiotics is crucial, especially when administering to specific high risk groups such as infants, the elderly and the immuno-compromised.

Investigation of Genipin Cross-Linked Microcapsule for Oral Delivery of Live Bacterial Cells and Other Biotherapeutics: Preparation and In Vitro Analysis in Simulated Human Gastrointestinal Model

Oral therapy utilizing engineered microorganisms has shown promise in the treatment of many diseases. By microencapsulation, viable cells can overcome the harsh gastrointestinal (GI) environment and secrete needed therapeutics into the gut. These engineered cells should be encased without escaping into the GI tract for safety concerns, thus robust microcapsule membrane is requisite. This paper examined the GI performance of a novel microcapsule membrane using a dynamic simulated human GI model. Results showed that the genipin cross-linked alginate-chitosan (GCAC) microcapsules possessed strong resistance to structural disintegration in the simulated GI environment. Leakage of encapsulated high molecular weight dextran, a model material to be protected during the simulated GI transit, was negligible over 72 h of exposure, in contrast to considerable leakage of dextran from the non-cross-linked counterparts. These microcapsules did not alter the microflora and enzymatic activities in the simulated human colonic media. This study suggested the potential of the GCAC microcapsules for oral delivery of live microorganisms and other biotherapeutics.

Orally delivered microencapsulated live probiotic formulation lowers serum lipids in hypercholesterolemic hamsters

Elevated serum cholesterol is a major risk factor for coronary artery disease. Nutritional therapies such as probiotics have been suggested to manage elevated cholesterol. This study investigates the cholesterol and triglyceride lowering potential of a microencapsulated feruloyl esterase-producing Lactobacillus fermentum 11976 (LF11976) probiotic formulation. Male Bio F(1)B hamsters were assigned to two groups to receive either the microcapsule probiotic formulation (containing LF11976 cells at 12.51 log colony-forming units/mL) or placebo formulation (empty) microcapsules, twice daily, by oral gavage for 18 weeks. For the duration of the study, animals were fed a hypercholesterolemic diet. Serum total cholesterol, low-density lipoprotein (LDL) cholesterol, and the atherogenic index were 21.36%, 31.43%, and 32.59% lower in the group gavaged with the microencapsulated probiotic formulation than in the placebo control group after 18 weeks (P < .05). Histology studies showed reduced progression of atherosclerotic lesions in animals treated with microencapsulated LF11976 as compared to control animals. Treatment with microencapsulated LF11976 formulation produces significant reductions in serum total cholesterol, LDL cholesterol, and serum triglyceride levels in diet-induced hypercholesterolemic hamsters. Findings suggest the potential of the oral microencapsulated probiotic cell formulation as a functional nutritional alternative for managing excessive serum cholesterol and triglyceride levels.

Microencapsulated bile salt hydrolase producing Lactobacillus reuteri for oral targeted delivery in the gastrointestinal tract

This is the first study of its kind to screen probiotic lactic acid bacteria for the purpose of microencapsulating a highly bile salt hydrolase (BSH)-active strain. A Lactobacillus reuteri strain and a Bifidobacterium longum strain were isolated as the highest BSH producers among the candidates. Microcapsules were prepared with a diameter of 619 +/- 31 mum and a cell load of 5 x 10(9) cfu/ml. Post de Man, Rogosa, and Sharpe broth-acid challenge, L. reuteri microcapsules metabolized glyco- and tauro-conjugated bile salts at rates of 10.16 +/- 0.46 and 1.85 +/- 0.33 micromol/g microcapsule per hour, respectively, over the first 2 h. Microencapsulated B. longum had minimal BSH activity and were significantly (P < 0.05) more susceptible to acid challenge. Further testing of L. reuteri microcapsules in a simulated human gastrointestinal (GI) model showed an improved rate, with 49.4 +/- 6.21% of glyco-conjugates depleted after 60 min and complete deconjugation after 4 h. Microcapsules protected the encased cells in the simulated stomach maintaining L. reuteri viability above 10(9), 10(8), and 10(6) cfu/ml after 2 h at pH 3.0, 2.5, and 2.0, respectively. Results show excellent potential for this highly BSH-active microencapsulation system in vitro, highlighted by improved viability and substrate utilization in simulated GI transit.

Feeding our immune system: impact on metabolism

Endogenous intestinal microflora and environmental factors, such as diet, play a central role in immune homeostasis and reactivity. In addition, microflora and diet both influence body weight and insulin-resistance, notably through an action on adipose cells. Moreover, it is known since a long time that any disturbance in metabolism, like obesity, is associated with immune alteration, for example, inflammation. The purpose of this review is to provide an update on how nutrients-derived factors (mostly focusing on fatty acids and glucose) impact the innate and acquired immune systems, including the gut immune system and its associated bacterial flora. We will try to show the reader how the highly energy-demanding immune cells use glucose as a main source of fuel in a way similar to that of insulin-responsive adipose tissue and how Toll-like receptors (TLRs) of the innate immune system, which are found on immune cells, intestinal cells, and adipocytes, are presently viewed as essential actors in the complex balance ensuring bodily immune and metabolic health. Understanding more about these links will surely help to study and understand in a more fundamental way the common observation that eating healthy will keep you and your immune system healthy.

Characterization of lactobacilli isolated from caper berry fermentations

AIMS

To determine the metabolic and functional properties of lactobacilli isolated from caper fermentation.

METHODS AND RESULTS

A collection of 58 lactobacilli from fermentation of caper berries (including species of Lactobacillus plantarum, Lactobacillus paraplantarum, Lactobacillus pentosus, Lactobacillus brevis and Lactobacillus fermentum) was studied. Strains were classified in different clusters according to sugar fermentation patterns. Most strains of L. plantarum (the predominant species in the fermentation) clustered in a single group. Analysis of enzymatic activities revealed a high incidence of leucine aminopeptidase, acid phosphatase, beta-galactosidase and beta-glucosidase among the different strains of lactobacilli. A high number of strains were able to degrade raffinose and stachyose. Phytase activity and bile salt hydrolase activity were only detected in certain strains of L. plantarum.

CONCLUSIONS

Lactobacilli from caper fermentation are metabolically diverse, and some strains display functional properties of interest.

SIGNIFICANCE AND IMPACT OF THE STUDY

Strains of lactobacilli with selected functional properties could be good candidates for future development of commercial starters for industrial caper fermentation.

Investigation of microencapsulated BSH active lactobacillus in the simulated human GI tract

This study investigated the use of microencapsulated bile salt hydrolase (BSH) overproducing Lactobacillus plantarum 80 cells for oral delivery applications using a dynamic computer-controlled model simulating the human gastrointestinal (GI) tract. Bile salt deconjugation rates for microencapsulated BSH overproducing cells were 4.87 +/- 0.28 mumol/g microcapsule/h towards glycoconjugates and 0.79 +/- 0.15 mumol/g microcapsule/h towards tauroconjugates in the simulated intestine, a significant (P< .05) increase over microencapsulated wild-type cells. Microcapsules protected the encased cells in the simulated stomach prior to intestinal release, maintaining cell viability above 109 cfu/mL at pH 2.5 and 3.0 and above 106 cfu/mL at pH 2.0 after 2-hour residence times. In the simulated intestine, encased cell viability was maintained above 1010 cfu/mL after 3, 6, and 12-hour residence times in bile concentrations up to 1.0%. Results show that microencapsulation has potential in the oral delivery of live BSH active bacterial cells. However, in vivo testing is required.