Lactobacillus johnsonii BFE6154 Ameliorates Diet-Induced Hypercholesterolemia.

The functional characteristics of Lactobacillus johnsonii BFE6154, first isolated from Maasai traditional fermented milk, were previously identified in vitro, but its cholesterol-lowering properties have not been verified yet. In this study, we investigated the effect of L. johnsonii BFE6154 on cholesterol regulation and the mode of action. Stimulation of Caco-2 intestinal epithelial cells with L. johnsonii BFE6154 downregulated the gene expression of Niemann-Pick C1-like 1 (NPC1L1) through the activation of liver X receptor (LXR). Also, stimulation of HepG2 cells with the metabolites produced by L. johnsonii BFE6154 revealed an increase in the gene expression of low-density lipoprotein receptor (LDLR). Oral administration of L. johnsonii BFE6154 in mice receiving a high-fat and high-cholesterol diet (HFHCD), reduced total cholesterol and low-density lipoprotein-cholesterol (LDL) and increased high-density lipoprotein-cholesterol (HDL) in the blood, compared to the control. Diet-induced hypercholesterolemic mice receiving L. johnsonii BFE6154 showed a suppression of cholesterol absorption under the control of NPC1L1 in the intestine. Furthermore, L. johnsonii BFE6154 consumption ameliorated the hepatic cholesterol level and LDLR expression, which was reduced by HFHCD. These molecular modulations led to the increase of cholesterol excretion and the decrease of cholesterol levels in the feces and liver, respectively. Taken together, these results suggest that L. johnsonii BFE6154 may protect against diet-induced hypercholesterolemia through the regulation of cholesterol metabolism in the intestine and liver.

Effect of Oral Intake of Lactiplantibacillus plantarum APsulloc 331261 (GTB1TM) on Diarrhea-Predominant Irritable Bowel Syndrome: A Randomized, Double-Blind, Placebo-Controlled Study.

Irritable bowel syndrome (IBS) causes intestinal discomfort, gut dysfunction, and poor quality of life. This randomized, double-blind placebo-controlled trial evaluated the efficacy of Lactiplantibacillus (Lp., formerly Lactobacillus) plantarum APsulloc 331261 (GTB1TM) from green tea leaves in participants with diarrhea-predominant irritable bowel syndrome (IBS-D). Twenty-seven participants meeting the Rome IV diagnostic criteria were randomized for GTB1 or placebo ingestion for four weeks and follow-up for two weeks. The efficacy endpoints included adequate global relief of symptoms, assessment of intestinal discomfort symptom severity and frequency, stool frequency, satisfaction, and fecal microbiome abundance. Of all participants, 94.4% and 62.5% reported global relief of symptoms in the GTB1 and placebo groups, respectively, with significant differences (p = 0.037). GTB1 significantly reduced the severity and frequency of abdominal pain, bloating, and feeling of incomplete evacuation. The frequencies of diarrhea were decreased -45.89% and -26.76% in the GTB1 and placebo groups, respectively (p = 0.045). Hence, GTB1 ingestion improved IBS-D patient quality of life. After four weeks treatment, the relative abundance of Lactobacillus was higher in the GTB1 than in the placebo group (p = 0.010). Our results showed that GTB1 enhanced intestinal discomfort symptoms, defecation consistency, quality of life, beneficial microbiota, and overall intestinal health.

Two putative probiotic strains improve diet-induced hypercholesterolemia through modulating intestinal cholesterol uptake and hepatic cholesterol efflux.

AIMS: Two putative probiotic strains, Lacticaseibacillus (Lc.) rhamnosus BFE5264 and Lactiplantibacillus (Lp.) plantarum NR74, have been shown to suppress cholesterol uptake and promote cholesterol efflux in Caco-2 cells. However, an in vivo beneficial effect of these strains on plasma cholesterol levels has not been verified yet; neither have the underlying mechanisms of regulating cholesterol metabolism clarified thus far. This study has focused on these two aspects. METHODS AND RESULTS: A murine model has been used, and the animals receiving a high-fat/high-cholesterol diet showed elevated plasma cholesterol levels. However, supplementation of Lc. rhamnosus BFE5264 and Lp. plantarum NR74 resulted in the down regulation of Niemann-Pick C1-like 1 (NPC1L1) in the intestine in addition to counteracting the diet-induced suppression of low-density lipoprotein receptor expression in the liver. ATP Binding Cassette Subfamily A Member 1 (ABCA1) was only significantly increased upon administration of Lc. rhamnosus BFE5264. CONCLUSIONS: The present findings demonstrate that supplementation with Lc. rhamnosus BFE5264 and Lp. plantarum NR74 may improve diet-induced hypercholesterolemia by suppression of cholesterol absorption in the small intestine and by supporting the regulation of cholesterol metabolism in the liver. SIGNIFICANCE AND IMPACT OF THE STUDY: This work contributes to understanding the beneficial effects of probiotics on host cholesterol metabolism and underlying mechanisms related to hypercholesterolemia.

Structural specificities of cell surface ß-glucan polysaccharides determine commensal yeast mediated immuno-modulatory activities.

Yeast is an integral part of mammalian microbiome, and like commensal bacteria, has the potential of being harnessed to influence immunity in clinical settings. However, functional specificities of yeast-derived immunoregulatory molecules remain elusive. Here we find that while under steady state, ß-1,3-glucan-containing polysaccharides potentiate pro-inflammatory properties, a relatively less abundant class of cell surface polysaccharides, dubbed mannan/ß-1,6-glucan-containing polysaccharides (MGCP), is capable of exerting potent anti-inflammatory effects to the immune system. MGCP, in contrast to previously identified microbial cell surface polysaccharides, through a Dectin1-Cox2 signaling axis in dendritic cells, facilitates regulatory T (Treg) cell induction from naïve T cells. Furthermore, through a TLR2-dependent mechanism, it restrains Th1 differentiation of effector T cells by suppressing IFN-γ expression. As a result, administration of MGCP display robust suppressive capacity towards experimental inflammatory disease models of colitis and experimental autoimmune encephalomyelitis (EAE) in mice, thereby highlighting its potential therapeutic utility against clinically relevant autoimmune diseases.

Anthocyanin Structure and pH Dependent Extraction Characteristics from Blueberries (Vaccinium corymbosum) and Chokeberries (Aronia melanocarpa) in Subcritical Water State.

This study determines the optimal extraction conditions for the subcritical-water extraction (SWE) of anthocyanin from blueberries and chokeberries and compares the performance using conventional extraction methods. SWE is carried out under different conditions of extraction temperature (110 °C, 130 °C, 150 °C, 170 °C, 190 °C, and 200 °C), extraction time (1, 3, 5, and 10 min), and solvent pH (water and 1% citric acid). The solubility and stability of anthocyanin from blueberries and chokeberries influences the optimal condition for SWE. The presence of more methoxy and hydroxyl functional groups in the basic skeleton of anthocyanin will result in a lower solubility at a high temperature. Water at a higher temperature exhibits a better dissociation reaction, and a solvent has a lower pH at a higher temperature. One percent citric acid is used to reduce the pH of the solvent, which increases the extraction efficiency of anthocyanin in a subcritical water state.

Bacteriocins From LAB and Other Alternative Approaches for the Control of Clostridium and Clostridiodes Related Gastrointestinal Colitis.

The gut microbiome is considered as a promising target for future non-conventional therapeutic treatment of inflammatory and infectious diseases. The search for appropriate safe and beneficial (lactic acid bacterial and other) putative probiotic strains and/or their antimicrobial metabolites represents a challenging approach for combating several problematic and emerging infections. The process of selecting suitable strains, especially of lactic acid bacteria (LAB) with superior properties, has been accelerated and intensified during the past two decades, also thanks to recent developments in lab techniques. Currently, special focus is on the potential of antimicrobial metabolites produced by some LAB strains and their application as active therapeutic agents. The vision is to develop a scientific basis for 'biotherapeutics' as alternative to conventional approaches in both human and veterinary medicine. Consequently, innovative and promising applications of LAB to the therapeutic practice are presently emerging. An overview of the existing literature indicates that some antimicrobial metabolites such as bacteriocins, widely produced by different bacterial species including LAB, are promising biotherapeutic agents for controlling infections caused by potential pathogens, such as Clostridium and Clostridiodes. Non-conventional, safe and well designed therapeutic treatments may contribute to the improvement of gut dysbiotic conditions. Thereby gut homeostasis can be restored and inflammatory conditions such as gastrointestinal colitis ameliorated. Combining the knowledge on the production, characterization and application of bacteriocins from probiotic LAB, together with their antibacterial properties, appears to be a promising and novel approach in biotherapy. In this overview, different scenarios for the control of Clostridium spp. by application of bacteriocins as therapeutic agents, also in synergistic combination with antibiotics, will be discussed.

Safety Evaluation and Whole-Genome Annotation of Lactobacillus plantarum Strains from Different Sources with Special Focus on Isolates from Green Tea.

Lactobacillus plantarum shows high intraspecies diversity species, and has one of the largest genome sizes among the lactobacilli. It is adapted to diverse environments and provides a promising potential for various applications. The aim of the study was to investigate the safety and probiotic properties of 18 L. plantarum strains isolated from fermented food products, green tea, and insects. For preliminary safety evaluation the L. plantarum strains were tested for their ability to produce hemolysin and biogenic amines and for their antibiotic resistance. Based on preliminary safety screening, four strains isolated from green tea showed antibiotic resistance below the cut-off MIC values suggested by EFSA, and were selected out of the 18 strains for more detailed studies. Initial selection of strains with putative probiotic potential was determined by their capacity to survive in the human GIT using an in vitro simulation model, and for their adhesion to human Caco-2/TC-7 cell line. Under simulated GIT conditions, all four L. plantarum strains isolated from green tea showed higher survival rates than the control (L. plantarum subsp. plantarum ATCC 14917). All studied strains were genetically identified by 16S rRNA gene sequencing and confirmed to be L. plantarum. In addition, whole-genome sequence analysis of L. plantarum strains APsulloc 331261 and APsulloc 331263 from green tea was performed, and the outcome was compared with the genome of L. plantarum strain WCFS1. The genome was also annotated, and genes related to virulence factors were searched for. The results suggest that L. plantarum strains APsulloc 331261 and APsulloc 331263 can be considered as potential beneficial strains for human and animal applications.

Cell surface polysaccharides of Bifidobacterium bifidum induce the generation of Foxp3+ regulatory T cells.

Dysregulation of intestinal microflora is linked to inflammatory disorders associated with compromised immunosuppressive functions of Foxp3+ T regulatory (Treg) cells. Although mucosa-associated commensal microbiota has been implicated in Treg generation, molecular identities of the "effector" components controlling this process remain largely unknown. Here, we have defined Bifidobacterium bifidum as a potent inducer of Foxp3+ Treg cells with diverse T cell receptor specificity to dietary antigens, commensal bacteria, and B. bifidum itself. Cell surface ß-glucan/galactan (CSGG) polysaccharides of B. bifidum were identified as key components responsible for Treg induction. CSGG efficiently recapitulated the activity of whole bacteria and acted via regulatory dendritic cells through a partially Toll-like receptor 2-mediated mechanism. Treg cells induced by B. bifidum or purified CSGG display stable and robust suppressive capacity toward experimental colitis. By identifying CSGG as a functional component of Treg-inducing bacteria, our studies highlight the immunomodulatory potential of CSGG and CSGG-producing microbes.

Anion induced structural transformation in silver-(3,6-dimethoxy-1,2,4,5-tetrazine) coordination polymers under mechanochemical conditions.

Mechanochemical reactions of 3,6-dimethoxy-s-tetrazine (dmotz) with AgCF3SO3 and AgClO4 afforded the 1D linear polymer [Ag(dmotz)(CF3SO3)]n (1) and the 2D grid polymer {[Ag(dmotz)2](ClO4)}n (2), respectively. Mechanochemical processes convert 1 to 2 in the presence of an equivalent of [ClO4](-) and dmotz; even on using excess [CF3SO3](-), conversion from 2 to 1 was not observed.

Probiotics as an Immune Modulator.

Probiotics are nonpathogenic live microorganism that can provide a diverse health benefits on the host when consumed in adequate amounts. Probiotics are consumed in diverse ways including dairy product, food supplements and functional foods with specific health claims. Recently, many reports suggest that certain probiotic strains or multi strain mixture have potent immunomodulatory activity in diverse disorders including allergic asthma, atopic dermatitis and rheumatoid arthritis. However, underlying mechanism of action is still unclear and efficacy of probiotic administration is quite different depending on the type of strains and the amounts of doses. We and others have suggested that live probiotics or their metabolites could interact with diverse immune cells (antigen presenting cells and T cells) and confer them to have immunoregulatory functions. Through this interaction, probiotics could contribute to maintaining immune homeostasis by balancing pro-inflammatory and anti-inflammatory immune responses. However, the effect of probiotics in prevention or modulation of ongoing disease is quite diverse even within a same species. Therefore, identification of functional probiotics with specific immune regulatory property is a certainly important issue. Herein, we briefly review selection methods for immunomodulatory probiotic strains and the mechanism of action of probiotics in immune modulation.

A tyrosine phosphorylation switch controls the interaction between the transmembrane modulator protein Wzd and the tyrosine kinase Wze of Lactobacillus rhamnosus.

BACKGROUND: One proposed mechanism for assembly of secreted heteropolysaccharides by many Gram positive bacteria relies on the coordinated action of a polymerization complex through reversible phosphorylation events. The role of the tyrosine protein kinase transmembrane modulator is, however, not well understood. RESULTS: The protein sequences deduced from the wzb, wzd and wze genes from Lactobacillus rhamnosus ATCC 9595 and RW-9595 M contain motifs also found in corresponding proteins CpsB, CpsC and CpsD from Streptococcus pneumoniae D39 (serotype 2). Use of an anti-phosphotyrosine antibody demonstrated that both Wzd and Wze can be found in tyrosine phosphorylated form. When tyrosine 266 was mutated to phenylalanine, WzdY266F showed slightly less phosphorylated protein than those produced by using eight other tyrosine mutated Wzd genes, when expressed along with Wze and Wzb in Lactococcus lactis subsp. cremoris MG1363. In order to demonstrate the importance of ATP for the interactions among these proteins, native and fusion Wzb, Wzd and Wze proteins were expressed and purified from Escherichia coli cultures. The modulator protein, Wzd, binds with the phosphotyrosine kinase Wze, irrespective of its phosphorylation status. However, Wze attained a higher phosphorylation level after interacting with phosphorylated Wzd in the presence of 10 mM ATP. This highly phosphorylated Wze did not remain in close association with phosphorylated Wzd. CONCLUSION: The Wze tyrosine kinase protein of Lactobacillus rhamnosus thus carries out tyrosine phosphorylation of Wzd in addition to auto- and trans- phosphorylation of the kinase itself.