The role of probiotics in children with autism spectrum disorders: A study protocol for a randomised controlled trial.

BACKGROUND: Autism spectrum disorder (ASD) is a neurological and developmental condition that begins in infancy or earlier and lasts through the individual's lifetime. The aetiology and mechanisms of ASD are not yet fully understood, and current treatment comprises mainly education and rehabilitation, without significant improvement in the core symptoms. Recent studies suggest that microbiota change in children with ASD after the ingestion of probiotics may improve the balance of microbiota and thus ASD symptoms. OBJECTIVE: The objectives of this study are to evaluate the efficacy of probiotics on the symptoms of children with ASD and the possible mechanisms involved. METHODS: This is a prospective controlled trial. A total of 160 children with ASD will be stratified and allocated to placebo and probiotics groups randomised according to the severity of their ASD symptoms. The probiotics group will be given probiotics supplements orally twice a day for 3 months and the control group will be given a placebo at the same amount, in addition to the baseline therapy of education and rehabilitation. All the children will be evaluated systematically by using different scales, questionnaires before, during, and after 3 months' treatment, as well as 3 months after discontinuation. The potential impact of probiotics on immunity and inflammation, metabolism, and metagenome will also be investigated. DISCUSSION: Our previous study showed that the abundance of intestinal flora was greatly different in children with ASD, and that Bifidobacterium was associated with the severity of ASD. In the present study, we will investigate the impact of probiotics supplementation on the symptoms of Children with ASD, with the purpose of evaluating the possible therapeutic effects of additives on ASD and of providing a reference for clinical treatment. The results will help to disclose as yet unknown relationship between probiotics and ASD. TRIAL REGISTRATION: This study has been registered with Chinese Clinical Trial Registry (ChiCTR-2000037941).

Probiotic Lactobacillus and Bifidobacterium Strains Counteract Adherent-Invasive Escherichia coli (AIEC) Virulence and Hamper IL-23/Th17 Axis in Ulcerative Colitis, but Not in Crohn's Disease.

Hypersecretion of proinflammatory cytokines and dysregulated activation of the IL-23/Th17 axis in response to intestinal microbiota dysbiosis are key factors in the pathogenesis of inflammatory bowel diseases (IBD). In this work, we studied how Lactobacillus and Bifidobacterium strains affect AIEC-LF82 virulence mechanisms and the consequent inflammatory response linked to the CCR6-CCL20 and IL-23/Th17 axes in Crohn's disease (CD) and ulcerative colitis (UC) patients. All Lactobacillus and Bifidobacterium strains significantly reduced the LF82 adhesion and persistence within HT29 intestinal epithelial cells, inhibiting IL-8 secretion while not affecting the CCR6-CCL20 axis. Moreover, they significantly reduced LF82 survival within macrophages and dendritic cells, reducing the secretion of polarizing cytokines related to the IL-23/Th17 axis, both in healthy donors (HD) and UC patients. In CD patients, however, only B. breve Bbr8 strain was able to slightly reduce the LF82 persistence within dendritic cells, thus hampering the IL-23/Th17 axis. In addition, probiotic strains were able to modulate the AIEC-induced inflammation in HD, reducing TNF-α and increasing IL-10 secretion by macrophages, but failed to do so in IBD patients. Interestingly, the probiotic strains studied in this work were all able to interfere with the IL-23/Th17 axis in UC patients, but not in CD patients. The different interaction mechanisms of probiotic strains with innate immune cells from UC and CD patients compared to HD suggest that testing on CD-derived immune cells may be pivotal for the identification of novel probiotic strains that could be effective also for CD patients.

Study of the gut Microbiome Profile in Children with Autism Spectrum Disorder: a Single Tertiary Hospital Experience.

The role of gut microbiome was recently raised in the pathogenesis of neurodevelopmental disorders including autism spectrum disorder (ASD). The aim of this study was to elucidate changes in gut microbiome in Egyptian autistic children and its possible correlation with the severity of autism and gastrointestinal (GI) symptoms. The gut bacterial microbiome of 41 ASD children, 45 siblings, and 45 healthy controls were analyzed using quantitative SYBR Green real-time PCR technique targeting 16S rRNA of selected bacteria. The gut microbiome of ASD children and their siblings contained a higher relative abundance of Bacteroides as well as Ruminococcus than controls. Prevotella/Bacteroides (P/B) ratio and Firmicutes/Bacteroidetes (F/B) were significantly lower in both ASD cases and their siblings. The only difference between the autistic cases and their siblings was the significantly higher level of Bifidobacterium in siblings, which appears to offer them a protective role. There was no correlation between the altered gut microbiome and the severity of autism or GI symptoms. The current study showed an evidence of changes in the gut microbiome of autistic children compared to the unrelated control. However, the microbiome profile of siblings was more like that of autistic children than that of unrelated controls indicating that gut microbiota is affected by dietary habits, living conditions together with host genetic factors.

[Effect of Bifidobacterium-induced changes in tumor tissue acoustic properties on efficacy of high-intensity focused ultrasound ablation].

OBJECTIVE: To investigate the effects of Bifidobacterium on the acoustic characteristics of tumor tissue and how such acoustic changes affect the efficacy of high-intensity focused ultrasound (HIFU) ablation in nude mice. METHODS: Forty mice bearing human breast cancer cell (MDA-MB-231) xenograft were randomized into experimental group (n=20) and control group (n=20) for intravenous injection of Bifidobacterium suspension (200 µL, 4 × 108 cfu/mL) and PBS (200 µL) for 3 consecutive days, respectively. Before and at 3 and 7 days after the first injection, shear wave elastography was used to evaluate the hardness of the tumor tissue. On day 7 after the first injection, 10 mice from each group were sacrificed and the sound velocity and sound attenuation of the tumor tissues were measured. The changes in the collagen fibers in the tumors were evaluated using Masson staining, and neovascularization in the tumor was assessed with immunohistochemistry for platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31). The remaining 10 tumor-bearing mice in each group were subjected to HIFU ablation, and the ablation efficiency was evaluated by assessing the changes in irradiation gray values, coagulative necrosis volume, energy efficiency factor (EEF) and irradiation area and by pathological examination with HE staining. RESULTS: In the experimental group, the collagen fibers in the tumor tissues were strong and densely aligned, and the tumors contained fewer new blood vessels showing strip-or spot-like morphologies. In the control group, the collagen fibers in the tumors were thin and loosely arranged, and the tumors showed abundant elongated or round new blood vessels. Bifidobacterium colonized in the tumor 7 days after the injection, and the tumor hardness was significantly greater in the experimental group than in the control group (P=0.01); the acoustic velocity (P=0.001) and the acoustic attenuation (P=0.000) of the tumor tissues were also greater in the experimental group. HIFU irradiation resulted in significantly greater changes in the gray scale of tumor (P=0.0006) and larger coagulative necrosis volume (P=0.0045) in the experimental group than in the control group, and the EEF was significantly smaller in the experimental group (P=0.0134). CONCLUSIONS: Bifidobacterium can cause changes in collagen fiber content, acoustic velocity and attenuation in the tumor tissue and reduce the EEF of HIFU irradiation, thereby improving the efficacy of HIFU irradiation.

Fecal Microbiota of Diarrhea-Predominant Irritable Bowel Syndrome Patients Causes Hepatic Inflammation of Germ-Free Rats and Berberine Reverses It Partially.

Effects of the microbiome associated with diarrhea-predominant irritable bowel syndrome (IBS-D) on the gut have been reported, but no study has reported the effects of the IBS-D gut microbiome on the liver. We transplanted the fecal microbiota from an IBS-D patient and from a healthy volunteer to GF rats. The hepatic inflammation, serum biochemical parameters and metabolome, fecal microbiota profile, fecal short-chain fatty acids (SCFAs), and correlations among them before and after berberine intervention were assessed. Compared with the healthy control fecal microbiome transplantation (FMT) rats, the fecal microbiota of IBS-D patients induces significant Kupffer cell hyperplasia, hepatic sinusoid hypertrophy, and elevated levels of hepatic tumor necrosis factor-α and interferon-γ and decreases the synthesis of ALB in GF rats. This is possibly related to Faecalibacterium and Bifidobacterium attributable to fecal formate, acetate, and propionate levels, which are associated with the host linoleic acid pathway. Berberine can partially reverse the Kupffer cell hyperplasia, Faecalibacterium, fecal formate, acetate, and propionate by modulating the gut microbiome composition. These results may imply that IBS-D not only is an intestinal functional disorder but can cause liver inflammation, thus providing some implications regarding the clinical cognition and treatment of IBS-D.

Autoimmunity-Associated Gut Commensals Modulate Gut Permeability and Immunity in Humanized Mice.

OBJECTIVE: Although the etiology of rheumatoid arthritis (RA) is unknown, recent studies have led to the concept that gut dysbiosis may be involved in onset. In this study, we aimed to determine if human gut commensals modulate the immune response and gut epithelial integrity in DQ8 mice. METHODS: DQ8 mice were orally gavaged with RA-associated (Eggerthella lenta or Collinsella aerofaciens) and non-associated (Prevotella histicola or Bifidobacterium sp.) on alternate days for 1 week in naïve mice. Some mice were immunized with type II collagen and oral gavage continued for 6 weeks and followed for arthritis. Epithelial integrity was done by FITC-Dextran assay. In addition, cytokines were measured in sera by ELISA and various immune cells were quantified using flow cytometry. RESULTS: Gut permeability was increased by the RA-associated bacteria and was sex and age-dependent. In vivo and in vitro observations showed that the RA-non-associated bacteria outgrow the RA-associated bacteria when gavaged or cultured together. Mice gavaged with the RA-non-associated bacteria produced lower levels of pro-inflammatory MCP-1 and MCP-3 and had lower numbers of Inflammatory monocytes CD11c+Ly6c+, when compared to controls. E. lenta treated naïve mice produce Th17 cytokines. CONCLUSIONS: Our studies suggest that gut commensals influence immune response in and away from the gut by changing the gut permeability and immunity. Dysbiosis helps the growth of RA-associated bacteria and reduces the beneficial bacteria.

Phase 1 Study To Assess the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Multiple Oral Doses of DS-2969b, a Novel GyrB Inhibitor, in Healthy Subjects.

DS-2969b is a novel GyrB inhibitor in development for the treatment of Clostridium difficile infection (CDI). The aim of this study was to assess the safety, tolerability, pharmacokinetics, and effects on the normal gastrointestinal microbiota of multiple daily oral ascending doses of DS-2969b in healthy subjects. The study enrolled three sequential ascending-dose cohorts (60 mg, 200 mg, and 400 mg). In each cohort, subjects received an oral dose of DS-2969b or placebo (six subjects received DS-2969b, and two received placebo) each morning for 14 days. DS-2969b was safe and well tolerated at all dose levels examined. All adverse events related to DS-2969b were mild and predominantly related to the gastrointestinal tract. DS-2969a (free form of DS-2969b) plasma concentrations increased with increasing doses; however, both the maximum concentration of drug in serum (Cmax) and the area under the concentration-time curve (AUC) increased less than dose proportionally. In all cohorts, sufficient fecal levels of DS-2969a were achieved within 24 h following the administration of the first dose and maintained for at least 17 days. Following treatment with DS-2969b, clear reductions in the populations of Clostridium coccoides and Bifidobacterium groups were observed. However, populations of three other bacterial groups examined (Bacteroides fragilis, Clostridium leptum, and Prevotella) were not affected. Data from this study support and encourage the further development of DS-2969b as a novel treatment for CDI.

Links of gut microbiota composition with alcohol dependence syndrome and alcoholic liver disease.

BACKGROUND: Alcohol abuse has deleterious effects on human health by disrupting the functions of many organs and systems. Gut microbiota has been implicated in the pathogenesis of alcohol-related liver diseases, with its composition manifesting expressed dysbiosis in patients suffering from alcoholic dependence. Due to its inherent plasticity, gut microbiota is an important target for prevention and treatment of these diseases. Identification of the impact of alcohol abuse with associated psychiatric symptoms on the gut community structure is confounded by the liver dysfunction. In order to differentiate the effects of these two factors, we conducted a comparative "shotgun" metagenomic survey of 99 patients with the alcohol dependence syndrome represented by two cohorts-with and without liver cirrhosis. The taxonomic and functional composition of the gut microbiota was subjected to a multifactor analysis including comparison with the external control group. RESULTS: Alcoholic dependence and liver cirrhosis were associated with profound shifts in gut community structures and metabolic potential across the patients. The specific effects on species-level community composition were remarkably different between cohorts with and without liver cirrhosis. In both cases, the commensal microbiota was found to be depleted. Alcoholic dependence was inversely associated with the levels of butyrate-producing species from the Clostridiales order, while the cirrhosis-with multiple members of the Bacteroidales order. The opportunist pathogens linked to alcoholic dependence included pro-inflammatory Enterobacteriaceae, while the hallmarks of cirrhosis included an increase of oral microbes in the gut and more frequent occurrence of abnormal community structures. Interestingly, each of the two factors was associated with the expressed enrichment in many Bifidobacterium and Lactobacillus-but the exact set of the species was different between alcoholic dependence and liver cirrhosis. At the level of functional potential, the patients showed different patterns of increase in functions related to alcohol metabolism and virulence factors, as well as pathways related to inflammation. CONCLUSIONS: Multiple shifts in the community structure and metabolic potential suggest strong negative influence of alcohol dependence and associated liver dysfunction on gut microbiota. The identified differences in patterns of impact between these two factors are important for planning of personalized treatment and prevention of these pathologies via microbiota modulation. Particularly, the expansion of Bifidobacterium and Lactobacillus suggests that probiotic interventions for patients with alcohol-related disorders using representatives of the same taxa should be considered with caution. Taxonomic and functional analysis shows an increased propensity of the gut microbiota to synthesis of the toxic acetaldehyde, suggesting higher risk of colorectal cancer and other pathologies in alcoholics.

Bifidobacterium Bacteremia: Clinical Characteristics and a Genomic Approach To Assess Pathogenicity.

Bifidobacteria are commensals that colonize the orogastrointestinal tract and rarely cause invasive human infections. However, an increasing number of bifidobacterial blood culture isolates has lately been observed in Norway. In order to investigate the pathogenicity of the Bifidobacterium species responsible for bacteremia, we studied Bifidobacterium isolates from 15 patients for whom cultures of blood obtained from 2013 to 2015 were positive. We collected clinical data and analyzed phenotypic and genotypic antibiotic susceptibility. All isolates (11 Bifidobacterium longum, 2 B. breve, and 2 B. animalis isolates) were subjected to whole-genome sequencing. The 15 patients were predominantly in the extreme lower or upper age spectrum, many were severely immunocompromised, and 11 of 15 had gastrointestinal tract-related conditions. In two elderly patients, the Bifidobacterium bacteremia caused a sepsis-like picture, interpreted as the cause of death. Most bifidobacterial isolates had low MICs (≤0.5 mg/liter) to beta-lactam antibiotics, vancomycin, and clindamycin and relatively high MICs to ciprofloxacin and metronidazole. We performed a pangenomic comparison of invasive and noninvasive B. longum isolates based on 65 sequences available from GenBank and the sequences of 11 blood culture isolates from this study. Functional annotation identified unique genes among both invasive and noninvasive isolates of Bifidobacterium Phylogenetic clusters of invasive isolates were identified for a subset of the B. longum subsp. longum isolates. However, there was no difference in the number of putative virulence genes between invasive and noninvasive isolates. In conclusion, Bifidobacterium has an invasive potential in the immunocompromised host and may cause a sepsis-like picture. Using comparative genomics, we could not delineate specific pathogenicity traits characterizing invasive isolates.

Comparative in vitro investigation of the cariogenic potential of bifidobacteria.

OBJECTIVE: This study aimed to assess the in vitro cariogenic potential of some Bifidobacterium species in comparison with caries-associated bacteria. DESIGN: Bifidobacterium lactis, Bifidobacterium longum, Bifidobacterium animalis, Bifidobacterium dentium, Lactobacillus acidophilus, Lactobacillus casei, Actinomyces israelii, Streptococcus sobrinus and Streptococcus mutans were tested for acidogenicity and aciduricity by measuring the pH of the cultures after growth in glucose and bacterial growth after exposure to acid solutions. Biofilm biomass was determined for each species either alone or associated with S. mutans or S. mutans/S. sobrinus. Enamel hardness was analyzed before and after 7-days biofilm formation using bacterial combinations. RESULTS: B. animalis and B. longum were the most acidogenic and aciduric strains, comparable to caries-associated bacteria, such as S. mutans and L. casei. All species had a significantly increased biofilm when combined either with S. mutans or with S. mutans/S. sobrinus. The greatest enamel surface loss was produced when B. longum or B. animalis were inoculated with S. mutans, similar to L. casei and S. sobrinus. All strains induced similar enamel demineralization when combined with S. mutans/S. sobrinus, except by B. lactis. CONCLUSION: The ability to produce acidic environments and to enhance biofilm formation leading to increased demineralization may mean that Bifidobacterium species, especially B. animalis and B. longum, are potentially cariogenic.

Incidence and outcomes of bloodstream infections among hematopoietic cell transplant recipients from species commonly reported to be in over-the-counter probiotic formulations.

BACKGROUND: Probiotic supplementation has been promoted for numerous health conditions; however, safety in immunosuppressed patients is unknown. We evaluated bloodstream infections (BSIs) caused by common probiotic organisms in hematopoietic cell transplant recipients. METHODS: All blood culture (BC) results from a cohort of hematopoietic cell transplant recipients transplanted at Fred Hutchinson Cancer Research Center in Seattle, Washington, between 2002 and 2011 were reviewed. Patients with at least 1 positive BC for common probiotic organisms (Lactobacillus species, Bifidobacterium species, Streptococcus thermophilus, and Saccharomyces species) within 1 year post hematopoietic cell transplantation (HCT) were considered cases. Data were collected from center databases, which contain archived laboratory data, patient demographics, and clinical summaries. RESULTS: A total of 19/3796 (0.5%) patients developed a BSI from one of these organisms within 1 year post HCT; no Bifidobacterium species or S. thermophilus were identified. Cases had a median age of 49 years (interquartile range [IQR]: 39-53), and the majority were allogeneic hematopoietic cell transplant recipients (14/19, 74%). Most positive BCs were Lactobacillus species (18/19) and occurred at a median of 84 days (IQR: 34-127) post transplant. The incidence rate of Lactobacillus bacteremia was 1.62 cases per 100,000 patient-days; the highest rate occurred within 100 days post transplant (3.3 per 100,000 patient-days). Eight patients (44%) were diagnosed with acute graft-versus-host disease of the gut prior to the development of bacteremia. No mortality was attributable to any of these infections. CONCLUSION: Organisms frequently incorporated in available over-the-counter probiotics are infrequent causes of bacteremia after HCT. Studies evaluating the use of probiotics among high-risk patients are needed.

[The complex evaluation of condition of intestinal and nasopharyngeal microbiocenosis in alumni of children's home].

The examination of nasopharyngeal and intestinal microbiocenoses was implemented in orphan children aged 1-3 years residing in children;s home of Cheremkhovo of the Irkutskaia oblast. All children had compromised anamnesis: prematurity, hypotrophy, chicken pox, frequent acute respiratory viral infections, intestinal infections, atopic dermatitis. The study was carried out to comprehensively evaluate conditions of intestinal and nasopharyngeal biotops in children residing in closed children's institution - children's home. The microbiological analysis of qualitative and quantitative composition of content of intestine and nasopharynx was implemented according standard techniques. The analysis established in 81.2±6.90% of examined children deficiency of Bifidobacterium flora, decreasing of level of population density of bifidobacteria up to 6.9±1.53% lg KOE/g, in 31.2±8.1% - deficiency of normal colibacillus, in 78.1±7.3% - increased level of opportunistic flora. The analysis also established high rate of isolation of Escherichia coli with decreased enzyme activity and in 28.1±7.9% - Escherichia coli with hemolytic activity. The enterococci were permanent participants of nasopharyngeal and intestinal biotop (58.6±8.7%). From opportunistic flora, in nasopharynx were registered pathogenic streptococci - S.pyogenes, S.pneumonia and also pathogenic fungi Candida andpoly-resistant strains S. aureus. The study results demonstrated characteristics of microbial ecology of intestinal and nasopharyngeal biotops of orphan children in conditions of children institution of closed type where the circulation of pathogenic and opportunistic microorganisms occurs intensively, including strains with high medicinal resistance. All this determines necessity to attribute alumni of children's homes to risk group of infectious pathology and requires constant micro-ecological monitoring for timely correction of microbiocenoses.

Formulation and in vivo evaluation of probiotics-encapsulated pellets with hydroxypropyl methylcellulose acetate succinate (HPMCAS).

The aim of this study was to formulate probiotics-encapsulated pellets with hydroxypropyl methylcellulose acetate succinate (HPMCAS) using a dry powder coating technique to improve the storage stability, acid resistance, and intestinal adherence of viable bacteria (Lactobacillus acidophilus and Bifidobacteria animalis ssp. Lactis). Dry coated pellet (DCP) loaded with probiotics was optimized with respect to the quantity of the HPMCAS, an enteric coating polymer (108 mg), and the kinds and amounts of plasticizer (triethyl citrate, 15.7 mg; acetylated monoglyceride, 6.8 mg), by evaluating the survival rate of the bacteria during preparation process and in an acidic medium. Dry coating process allows the whole survivals of living bacteria during preparation process. The DCP formulation exhibited markedly higher acid tolerability and storage stability compared to uncoated viable bacteria. In an in vivo mucosal adherence study in rats, a profound colonization of viable bacteria in the small and large intestine was observed in rats receiving DCP system (p<0.05) compared to rats receiving uncoated probiotics. Moreover, we found that the repeated DCP administration noticeably inhibited intestinal penetration of endotoxin, a potent inflammatory stimulant, from intestinal mucus. The novel DCP system may be an alternative approach for improving bacterial viability in the preparation process and in an acidic medium, and to promote mucosal colonization of probiotic bacteria in the human gut.

Bifidobacterium longum bacteremia in preterm infants receiving probiotics.

Administration of probiotics to premature newborns has been shown to prevent necrotizing enterocolitis and reduce all-cause mortality. In our hospital, we documented 2 cases of Bifidobacterium longum subspecies infantis bacteremia in newborns receiving probiotics. By comparative genomics, we confirmed that the strains isolated from each patient originated from the probiotics.

[Lactic acid bacteria and health: are probiotics safe for human?]. / Bakterie kwasu mlekowego i zdrowie: czy probiotyki sa bezpieczne dla czlowieka?

The effect of Lactobacillus and Bifidobacterium on human health has been examined for many years. Numerous in vivo and in vitro studies have confirmed the beneficial activity of some exogenous lactic acid bacteria in the treatment and prevention of rotaviral infection, antibiotic-associated diarrhea, inflammatory bowel disease and other gastrointestinal disorders. Probiotics support the action of the intestinal microflora and exhibit a favorable modulatory effect on the host's immune system. However, it should be remembered that relatively harmless lactobacilli can occasionally induce opportunistic infections. Due to reaching almost 20x10(12) probiotic doses per year which contain live cultures of bacteria, it is essential to monitor the safety aspect of their administration. In recent years, infections caused by Lactobacillus and Bifidobacterium made up 0.05% to 0.4% of cases of endocarditis and bacteremia. In most cases, the infections were caused by endogenous microflora of the host or bacterial strains colonizing the host's oral cavity. According to a review of cases of infections caused by bacteria of the genus Lactobacillus from 2005 (collected by J.P. Cannot'a), 1.7% of infections have been linked directly with intensive dairy probiotic consumption by patients. Additionally, due to the lack of a precise description of most individuals' eating habits, the possible effect of probiotics on infection development definitively should not be ruled out. The present paper describes cases of diseases caused by lactic acid bacteria, a potential mechanism for the adverse action of bacteria, and the possible hazard connected with probiotic supplementation for seriously ill and hospitalized patients.

Association of levels of antibodies from patients with inflammatory bowel disease with extracellular proteins of food and probiotic bacteria.

Inflammatory bowel disease (IBD) is an autoimmune disease characterized by a chronic inflammation of the gastrointestinal tract mucosa and is related to an abnormal immune response to commensal bacteria. Our aim of the present work has been to explore the levels of antibodies (IgG and IgA) raised against extracellular proteins produced by LAB and its association with IBD. We analyzed, by Western-blot and ELISA, the presence of serum antibodies (IgA and IgG) developed against extracellular protein fractions produced by different food bacteria from the genera Bifidobacterium and Lactobacillus. We used a sera collection consisting of healthy individuals (HC, n = 50), Crohn's disease patients (CD, n = 37), and ulcerative colitis patients (UC, n = 15). Levels of IgA antibodies developed against a cell-wall hydrolase from Lactobacillus casei subsp. rhamnosus GG (CWH) were significantly higher in the IBD group (P < 0.002; n = 52). The specificity of our measurements was confirmed by measuring IgA antibodies developed against the CWH peptide 365-VNTSNQTAAVSAS-377. IBD patients appeared to have different immune response to food bacteria. This paper sets the basis for developing systems for early detection of IBD, based on the association of high levels of antibodies developed against extracellular proteins from food and probiotic bacteria.

Faecalibacterium prausnitzii upregulates regulatory T cells and anti-inflammatory cytokines in treating TNBS-induced colitis.

BACKGROUND AND AIMS: Faecalibacterium prausnitzii (F. prausnitzii) is a common anaerobic bacteria colonized in the human gut and inflammatory bowel disease (IBD) patients are usually lack of F. prausnitzii. The aims of this study were to evaluate the anti-inflammatory and immunomodulatory capacity of F. prausnitzii by comparing it with Bifidobacterium longum (B. longum) in both cellular and animal experiments. METHODS: Human peripheral blood mononuclear cells (PBMCs) and 2, 4, 6-trinitrobenzenesulphonic acid (TNBS)-induced colitis rat models were treated with F. prausnitzii, B. longum, F. prausnitzii supernatant or F. prausnitzii medium, respectively. Interleukin (IL)-10, TGF-ß1 and IL-12p70 in human PBMCs culture supernatant and rat blood serum were detected. The frequency of CD25(+)Foxp3(+)Treg in human PBMCs, rat PBMCs and rat splenocytes were investigated. Besides, the T-bet, GATA-3, ROR-γt and Foxp3 mRNA in human PBMCs, histopathologic characteristics of the intestinal mucosal and weight loss in the rat models were examined. RESULTS: F. prausnitzii, B. longum and F. prausnitzii supernatant clearly facilitated the induction of IL-10 and TGF-ß1, while induced relatively mild production of IL-12p70 in both cellular and animal models. The F. prausnitzii, B. longum and supernatant differed in their capacity to induce T-bet, GATA-3 and ROR-γt mRNA expression in human PBMCs (both bacterial strains inhibited the expression of ROR-γt while supernatant inhibited the T-bet and GATA-3). However, all of them induced the Foxp3 and Treg production and ameliorated the TNBS-induced colitis. In addition, F. prausnitzii supernatant exhibited the supreme anti-inflammatory capacity. CONCLUSIONS: F. prausnitzii and its unidentified metabolites in the supernatant are promising candidates in treating IBD, and further research remains necessary to elucidate the safety, efficacy, optimum and mechanism of this bacterium in the clinical practice.

Antimicrobial activity of bifidobacterial bacteriocin-like substances.

Antagonistic activity of 13 bifidobacterial strains, isolated from humans, has been studied. It was shown that specific antagonistic activity in bifidobacteria is a strain characteristic and does not depend on species of these microorganisms. It was determined that bifidobacteria are able to produce bacteriocin-like substances against both gram-positive and gram-negative bacteria. Strains Bifidobacterium sp. 278 and B. bifidum 174 produced antimicrobial substances of wide spectrum of activity and manifested the highest antagonistic activity as compared to the rest of bifidobacterial strains studied. The maximal activity of bacteriocin production by strains B. bifidum 174 ma Bifidobacterium sp. 278 occurs between 8-16 hours of cultivation that is in the late logarithmic phase of growth. According to obtained characteristics the antimicrobial substances are complex peptides and belong to the 4th class of bacteriocins.

In vitro inhibition of expression of virulence genes responsible for colonization and systemic spread of enteric pathogens using Bifidobacterium bifidum secreted molecules.

Enteric pathogens such as Salmonella enterica serovar Typhimurium and Enterohaemorrhagic Escherichia coli require an initial indispensable step of attachment or invasion of enterocytes before they can produce systemic disease and translocate to their target organs. Prevention of either of these steps will result in an avirulent state and limit their pathogenicity. In vitro tests demonstrated that molecules secreted by Bifidobacterium bifidum interfere with both attachment and invasion. The main regulatory genes controlling the virulence factors essential for these pathogenicity steps were efficiently down-regulated when treated with chromatographically separated B. bifidum cell free fractions as measured by reporter constructs and confirmed by RT-PCR. Moreover, the ability of both pathogens to colonize eukaryotic cells was significantly reduced, and the capacity of Salmonella to survive and multiply within macrophages was also diminished upon treatment with these bioactive molecules. These results indicate that probiotic Bifidobacteria strains may represent an effective alternative approach to control food-borne enteric pathogens.