Bifidobacterium breve attenuates murine dextran sodium sulfate-induced colitis and increases regulatory T cell responses

The Role of Intestinal Microbiota in Celiac Disease and Further Therapeutic Perspectives

Celiac disease (CD) is an immune-mediated enteropathy caused by exposure to gluten and related prolamins in genetically susceptible individuals. It is a complex genetic disorder with multiple contributing genes. Linkage studies have identified several genomic regions that probably contain CD susceptibility genes. The most important genetic factors are HLA-DQ2 and DQ8. Several known environmental triggers promote the onset of CD at any age after gluten introduction in individuals with a genetic background, such as viral infections and intestinal dysbiosis. Recent publications have described the interference of the intestinal microbiome in gluten metabolism, modulation of local immune reactions, and in maintaining normal gut permeability. These results have promoted further lines of research on the benefit of probiotic administration to prevent disease onset or alleviate clinical symptoms along with a gluten-free diet (GFD). The relationship between gut microbiome changes and the onset of CD is incompletely understood, still being the subject of current research. This narrative review analyzes the interplay between environmental factors, intestinal microbiome alterations, and the course of CD. Furthermore, this review sets out to discuss if modulation of intestinal microflora with pre- and probiotics along with a GFD could represent a reliable therapeutic target for celiac patients.

Bifidobacterium breve CBT BR3 is effective at relieving intestinal inflammation by augmenting goblet cell regeneration

BACKGROUND AND AIM

Bifidobacterium breve was the first bacteria isolated in the feces of healthy infants and is a dominant species in the guts of breast-fed infants. Some strains of B. breve have been shown to be effective at relieving intestinal inflammation, but the modes of action have yet to be elucidated. In this study, we investigated the mechanisms of action of B. breve CBT BR3 isolated from South Korean infant feces in relieving colitis in vitro and in vivo.

METHODS

Colitis was induced in mice with dextran sodium sulfate (DSS) and dinitrobenzene sulfonic acid (DNBS). Quantitative reverse-transcription polymerase chain reaction, in vitro FITC-dextran flux permeability assay, and aryl hydrocarbon receptor (AhR) luciferase assay are performed using Caco-2 cells and HT29-Lucia™ AhR cells.

RESULTS

B. breve CBT BR3 was orally administered. B. breve CBT BR3 improved colitis symptoms in both DSS- and DNBS-induced colitis models. B. breve CBT BR3 increased the number of goblet cells per crypt. B. breve increased the mRNA expressions of Notch, Spdef, Muc5, and Il22. The mRNA expressions of Occludin, which encodes a membrane tight-junction protein, and Foxo3, which encodes a protein related to butyrate metabolism, were also increased in the DSS- and DNBS-induced colitis models. B. breve CBT BR3 protected inflammation-induced epithelial cell permeability and improved goblet cell function by inducing aryl hydrocarbon receptor in vitro.

CONCLUSIONS

These results indicate that B. breve CBT BR3 is effective at relieving intestinal inflammation by augmenting goblet cell regeneration.

Protective Effect of Novel Lactobacillus plantarum KC3 Isolated from Fermented Kimchi on Gut and Respiratory Disorders

Probiotics have been shown to possess anti-inflammatory effects in the gut by directly reducing the production of pro-inflammatory cytokines and by secreting anti-inflammatory molecules. However, their systemic anti-inflammatory effects have not been thoroughly investigated. In this study, we aimed to develop probiotics that have efficacy in both intestinal and lung inflammation. Lactobacillus plantarum KC3 (KC3), which was isolated from kimchi, was selected as a pre-candidate based on its inhibitory effects on the production of pro-inflammatory cytokines in vitro. To further validate the effectiveness of KC3, we used ear edema, DSS-induced colitis, and ambient particulate-matter-induced lung inflammation models. First, KC3 exhibited direct anti-inflammatory effects on intestinal cells with the inhibition of IL-1β and TNF-α production. Additionally, KC3 treatment alleviated ear edema and DSS-induced colic inflammation, improving colon length and increasing the number of regulatory T cells. Beyond its local intestinal anti-inflammatory activity, KC3 inhibited pro-inflammatory cytokines in the bronchoalveolar fluid and prevented neutrophil infiltration in the lungs. These results suggest that KC3 could be a potential functional ingredient with respiratory protective effects against air-pollutant-derived inflammation, as well as for the treatment of local gut disorders.

Oral Macrocystis pyrifera Fucoidan Administration Exhibits Anti-Inflammatory and Antioxidant Properties and Improves DSS-Induced Colitis in C57BL/6J Mice

Inflammatory bowel disease (IBD) is a complex and multifactorial disorder characterised by relapsing and remitting inflammation of the intestinal tract. Oxidative stress (OS) is the result of an imbalance between production and accumulation of reactive oxygen species (ROS), which has been associated with inflammatory responses and implicated in the exacerbation of IBD. Fucoidan, a sulfated polysaccharide from brown seaweed, is a well-known anti-inflammatory agent and emerging evidence indicates that fucoidan extracts from Macrocystis pyrifera (MPF and DP-MPF) may also modulate oxidative stress. This study investigated the impact of fucoidan extracts, MPF and DP-MPF in a dextran sodium sulphate (DSS)-induced mouse model of acute colitis. 3% DSS was administered in C57BL/6J male mice over a period of 7 days, and MPF and DP-MPF were co-administered orally at a dose of 400 mg/kg body weight. Our results indicated that MPF and DP-MPF significantly prevented body weight loss, improved the disease activity index (DAI), restored colon lengths, reduced the wet colon weight, reduced spleen enlargement, and improved the overall histopathological score. Consistent with the reported anti-inflammatory functions, fucoidan extracts, MPF and DP-MPF significantly reduced the colonic levels of myeloperoxidase (MPO), nitric oxide (NO), malondialdehyde (MDA) and increased the levels of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT). In addition, MPF and DP-MPF significantly inhibited levels of pro-inflammatory cytokines in colon-derived tissues. Collectively, our results indicate that MPF and DP-MPF exhibited anti-inflammatory and antioxidant effects representing a promising therapeutic strategy for the cure of IBD.

Probiotics, prebiotics, and synbiotics to prevent or combat air pollution consequences: The gut-lung axis

Air pollution exposure is a public health emergency, which attributes globally to an estimated seven million deaths on a yearly basis We are all exposed to air pollutants, varying from ambient air pollution hanging over cities to dust inside the home. It is a mixture of airborne particulate matter and gases that can be subdivided into three categories based on particle diameter. The smallest category called PM_0.1 is the most abundant. A fraction of the particles included in this category might enter the blood stream spreading to other parts of the body. As air pollutants can enter the body via the lungs and gut, growing evidence links its exposure to gastrointestinal and respiratory impairments and diseases, like asthma, rhinitis, respiratory tract infections, Crohn's disease, ulcerative colitis, and abdominal pain. It has become evident that there exists a crosstalk between the respiratory and gastrointestinal tracts, commonly referred to as the gut-lung axis. Via microbial secretions, metabolites, immune mediators and lipid profiles, these two separate organ systems can influence each other. Well-known immunomodulators and gut health stimulators are probiotics, prebiotics, together called synbiotics. They might combat air pollution-induced systemic inflammation and oxidative stress by optimizing the microbiota composition and microbial metabolites, thereby stimulating anti-inflammatory pathways and strengthening mucosal and epithelial barriers. Although clinical studies investigating the role of probiotics, prebiotics, and synbiotics in an air pollution setting are lacking, these interventions show promising health promoting effects by affecting the gastrointestinal- and respiratory tract. This review summarizes the current data on how air pollution can affect the gut-lung axis and might impact gut and lung health. It will further elaborate on the potential role of probiotics, prebiotics and synbiotics on the gut-lung axis, and gut and lung health.

Mitigation of DSS-Induced Colitis Potentially via Th1/Th2 Cytokine and Immunological Function Balance Induced by Phenolic-Enriched Buckwheat (Fagopyrum esculentum Moench) Bee Pollen Extract

Colitis is an inflammatory disease that results from the overactivation of effector immune cells, producing a high quantity of pro-inflammatory cytokines. Our study aimed to explore whether buckwheat (F. esculentum) bee pollen extract (FBPE) could inhibit the progression of dextran sulfate sodium (DSS)-induced colitis via regulating immune function. We isolated and identified six main phenolic compounds of FBPE such as luteolin (9.46 mg/g) by column chromatography, HPLC-DAD, ESI-MS and NMR spectroscopy, then assessed their effects on colonic mucosal injury by clinical symptoms, histomorphology and immunohistochemistry examinations. The results showed that FBPE at 25.2 g/kg body weight (g/kg BW) changed the clinical symptoms of colitis, the ICAM-1 expression in colon, the activity of related inflammatory mediators in colon tissue and helped restore the immune system. Compared with the model group (40.28%), the CD4 positivity was significantly reduced in the HD (High-dose group: 25.2 g FBPE/kg BW/day) group (20.45%). Administration of 25.2 g/kg BW of FBPE decreased the IFN-γ, TNF-α and IL-4 levels, while enhancing the IL-10 level, and significantly inhibited the abnormally decreased IgG (Model: 13.25 mg/mL, HD: 14.06 mg/mL), showing a reversal effect on the Th1/Th2 levels in colitis. These findings suggested that FBPE at 25.2 g/kg BW had the effects of alleviating colitis and immunomodulation, which can help in the development of safe and effective immune therapy.

The Panda-Derived Lactobacillus plantarum G201683 Alleviates the Inflammatory Response in DSS-Induced Panda Microbiota-Associated Mice

Intestinal diseases are one of the main causes of captive giant panda death. Their special dietary habits and gastrointestinal tract structure often lead to intestinal epithelium damage and secondary intestinal infection. The captive giant panda is predisposed to suffer from microbiota dysbiosis due to long-term artificial feeding and antibiotic misuse. However, there are few reported probiotics to treat giant panda enteritis and the associated dysbiosis. This study aims to elucidate the mechanism by which Lactobacillus plantarum G201683 (L. plantarum G83), a promising panda-derived probiotic, exerts a protective effect on intestinal inflammation in the dextran sulfate sodium- (DSS) induced panda microbiota-associated (DPMA) mouse model. The DPMA mouse was generated by antibiotic treatment and 5% DSS drinking water administration to assess the effect of L. plantarum G83 on intestinal inflammation and microbiota in vivo. Our results demonstrated the successful generation of a DPMA mouse model with Enterobacteriaceae enrichment, consistent with the giant panda intestinal microbiota. L. plantarum G83 decreased clinical and histological severity of intestinal inflammation, enhanced intestinal tight junction protein expression (ZO-1, Occludin) and alleviated inflammatory cytokine production (TNF-) in the colon of DPMA mice. The administration of L. plantarum G83 altered the microbiota composition by decreasing pathogen associated taxa such as E. coli and increasing abundance of beneficial bacteria including Bifidobacterium spp. These changes in microbiota composition were associated with an increased concentration of short chain fatty acids (SCFA), reduced NF-κB signaling, and an altered balance of T helper cell subsets. Our findings support L. plantarum G83 as a promising probiotic to treat intestinal inflammation in the giant panda.

The role of probiotics in the immune response and intestinal microbiota of children with celiac disease: a systematic review

OBJECTIVE

To evaluate changes in peripheral immunological response (decrease in blood proinflammatory cytokines) and fecal microbiota (especially Bacteroidetes and Firmicutes) after administration of probiotics in children with celiac disease on a gluten-free diet.

DATA SOURCE

The databases MEDLINE, LILACS, Springer and SciELO were used for this review, with the descriptors "celiac disease AND probiotics". At the end of the search, 168 articles were retrieved, four of which were included in the final qualitative synthesis, having as inclusion criteria randomized clinical trials and pediatric population (1-19 years) and, as exclusion criteria, interventions other than probiotics, studies with patients with other diseases associated with celiac disease, or patients who did not meet the diagnostic criteria. All elected studies were published until September 2020, without language restriction, with patients receiving strains of Bifidobacterium breve or B. longum and on a gluten-free diet.

DATA SYNTHESIS

The studies show that the administration of probiotics along with a gluten-free diet, can approximate the fecal microbiota of celiac patients to typical conditions of healthy individuals, by restoring the abundance of some microbial communities that characterize the typical physiological condition. In addition, the administration of probiotics can reduce serum proinflammatory cytokines (mainly TNF-alpha).

CONCLUSIONS

Despite the positive correlation between probiotics and fecal microbiota/serological markers in pediatric patients with celiac disease, we emphasize the need for future multicentric studies that should include a larger number of patients and a longer follow up period.

The Defect in Regulatory T Cells in Psoriasis and Therapeutic Approaches

Psoriasis is a chronic inflammatory skin disease characterized by accelerated tumor necrosis factor-α/interleukin (IL)-23/IL-17 axis. Patients with psoriasis manifest functional defects in CD4⁺CD25⁺ forkhead box protein 3 (Foxp3)⁺ regulatory T cells (Tregs), which suppress the excess immune response and mediate homeostasis. Defects in Tregs contribute to the pathogenesis of psoriasis and may attribute to enhanced inhibition and/or impaired stimulation of Tregs. IL-23 induces the conversion of Tregs into type 17 helper T (Th17) cells. IL-17A reduces transforming growth factor (TGF)-β1 production, Foxp3 expression, and suppresses Treg activity. Short-chain fatty acids (SCFAs), butyrate, propionate, and acetate are microbiota-derived fermentation products that promote Treg development and function by inducing Foxp3 expression or inducing dendritic cells or intestinal epithelial cells to produce retinoic acids or TGF-β1, respectively. The gut microbiome of patients with psoriasis revealed reduced SCFA-producing bacteria, Bacteroidetes, and Faecallibacterium, which may contribute to the defect in Tregs. Therapeutic agents currently used, viz., anti-IL-23p19 or anti-IL-17A antibodies, retinoids, vitamin D3, dimethyl fumarate, narrow-band ultraviolet B, or those under development for psoriasis, viz., signal transducer and activator of transcription 3 inhibitors, butyrate, histone deacetylase inhibitors, and probiotics/prebiotics restore the defected Tregs. Thus, restoration of Tregs is a promising therapeutic target for psoriasis.

The biological activities of postbiotics in gastrointestinal disorders

According to outcomes from clinical studies, an intricate relationship occurs between the beneficial microbiota, gut homeostasis, and the host's health status. Numerous studies have confirmed the health-promoting effects of probiotics, particularly in gastrointestinal diseases. On the other hand, the safety issues regarding the consumption of some probiotics are still a matter of debate, thus to overcome the problems related to the application of live probiotic cells in terms of clinical, technological, and economic aspects, microbial-derived biomolecules (postbiotics) were introducing as a potential alternative agent. Presently scientific literature confirms that the postbiotic components can be used as promising tools for both prevention and treatment strategies in gastrointestinal disorders with less undesirable side-effects, particularly in infants and children. Future head-to-head trials are required to distinguish appropriate strains of parent cells, optimal dosages of postbiotics, and assessment of the cost-effectiveness of postbiotics compared to alternative drugs. This review provides an overview of the concept and safety issues regarding postbiotics, with emphasis on their biological role in the treatment of some important gastrointestinal disorders.

Effects of Pretreatment with Bifidobacterium bifidum Using 16S Ribosomal RNA Gene Sequencing in a Mouse Model of Acute Colitis Induced by Dextran Sulfate Sodium

Background

Bifidobacterium is a potentially effective and safe treatment for patients with inflammatory bowel disease (IBD), including ulcerative colitis and Crohn’s disease. However, information on the influence of B. bifidum on gut microbial diversity of treated and pretreated IBD patients is limited.

Material/Methods

Our study investigated therapeutic and preventive effects of B. bifidum ATCC 29521 on C57BL/6 mice with dextran sulfate sodium (DSS)-induced acute colitis via 16S ribosomal ribonucleic acid (rRNA) gene sequencing.

Results

Treatment and pretreatment of mice with B. bifidum ATCC 29521 significantly alleviated the severity of acute colitis on the basis of clinical and pathologic indicators. 16S rRNA gene sequencing showed that administration of B. bifidum shifted composition of the gut microbiome in mice with DSS-induced colitis in both treated and pretreated groups. Mice pretreated with B. bifidum ATCC 29521 for 21 days exhibited a significant increase in diversity of the gut microbiome. Principal coordinate analysis showed that gut microbiota structure was shaped by different treatments and time points. On the basis of linear discriminant analysis of effect size, the abundance of the genus Escherichia-Shigella, belonging to the family Enterobacteriaceae, was reduced in the B. bifidum-treated group, indicating that pathogens were inhibited by the B. bifidum treatment. Furthermore, the genera Intestinimonas and Bacteroides were significantly associated with the B. bifidum-pretreated group.

Conclusions

16S rRNA gene sequencing showed that pretreatment with B. bifidum ATCC 29521 reduced intestinal inflammation and altered the gut microbiota to favor the genera Intestinimonas and Bacteroides.

Microbiota Modulation of the Gut-Lung Axis in COVID-19

COVID-19 is an infectious disease caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), and according to the World Health Organization (WHO), to date, SARS-CoV-2 has already infected more than 91.8 million people worldwide with 1,986,871 deaths. This virus affects mainly the respiratory system, but the gastrointestinal tract (GIT) is also a target, meanwhile SARS-CoV-2 was already detected in oesophagus, stomach, duodenum, rectum, and in fecal samples from COVID-19 patients. Prolonged GIT manifestations in COVID-19, mainly the diarrhea, were correlated with decreased richness and diversity of the gut microbiota, immune deregulation and delayed SARS-CoV-2 clearance. So, the bidirectional interactions between the respiratory mucosa and the gut microbiota, known as gut-lung axis, are supposed to be involved in the healthy or pathologic immune responses to SARS-CoV-2. In accordance, the intestinal dysbiosis is associated with increased mortality in other respiratory infections, due to an exacerbated inflammation and decreased regulatory or anti-inflammatory mechanisms in the lungs and in the gut, pointing to this important relationship between both mucosal compartments. Therefore, since the mucous membranes from the respiratory and gastrointestinal tracts are affected, in addition to dysbiosis and inflammation, it is plausible to assume that adjunctive therapies based on the modulation of the gut microbiota and re-establishment of eubiosis conditions could be an important therapeutic approach for constraining the harmful consequences of COVID-19. Then, in this review, we summarized studies showing the persistence of SARS-CoV-2 in the gastrointestinal system and the related digestive COVID-19 manifestations, in addition to the literature demonstrating nasopharyngeal, pulmonary and intestinal dysbiosis in COVID-19 patients. Lastly, we showed the potential beneficial role of probiotic administration in other respiratory infections, and discuss the possible role of probiotics as an adjunctive therapy in SARS-CoV-2 infection.

Effects of therapeutic probiotics on modulation of microRNAs

Probiotics are beneficial bacteria that exist within the human gut, and which are also present in different food products and supplements. They have been investigated for some decades, due to their potential beneficial impact on human health. Probiotics compete with pathogenic microorganisms for adhesion sites within the gut, to antagonize them or to regulate the host immune response resulting in preventive and therapeutic effects. Therefore, dysbiosis, defined as an impairment in the gut microbiota, could play a role in various pathological conditions, such as lactose intolerance, gastrointestinal and urogenital infections, various cancers, cystic fibrosis, allergies, inflammatory bowel disease, and can also be caused by antibiotic side effects. MicroRNAs (miRNAs) are short non-coding RNAs that can regulate gene expression in a post-transcriptional manner. miRNAs are biochemical biomarkers that play an important role in almost all cellular signaling pathways in many healthy and disease states. For the first time, the present review summarizes current evidence suggesting that the beneficial properties of probiotics could be explained based on the pivotal role of miRNAs.

Intestinal Dysbiosis in, and Enteral Bacterial Therapies for, Systemic Autoimmune Diseases

Recent studies have shown that a number of common autoimmune diseases have perturbations of their intestinal microbiome (dysbiosis). These include: Celiac Disease (CeD), Multiple Sclerosis (MS), Rheumatoid Arthritis (RA), Sjogren’s Syndrome (SS), and Type 1 diabetes (T1D). All of these have intestinal microbiomes that are different from healthy controls. There have been numerous studies using animal models of single probiotics (monoclonal) or mixtures of probiotics (polyclonal) and even complete microbiota transfer (fecal microbial transfer-FMT) to inhibit or delay the onset of autoimmune diseases such as the aforementioned common ones. However, proportionally, fewer clinical trials have utilized monoclonal therapies or FMT than polyclonal therapies for treating autoimmune diseases, even though bacterial mono-therapies do inhibit the development of autoimmune diseases and/or delay the onset of autoimmune diseases in rodent models of those autoimmune diseases. In this review then, we review the previously completed and currently ongoing clinical trials that are testing bacterial therapies (FMT, monoclonal, and polyclonal) to treat common autoimmune dseases and discuss the successes in using bacterial monotherapies to treat rodent models of these common autoimmune diseases.

Bifidobacterium breve UCC2003 Induces a Distinct Global Transcriptomic Program in Neonatal Murine Intestinal Epithelial Cells

The underlying health-driving mechanisms of Bifidobacterium during early life are not well understood, particularly how this microbiota member may modulate the intestinal barrier via programming of intestinal epithelial cells (IECs). We investigated the impact of Bifidobacterium breve UCC2003 on the transcriptome of neonatal murine IECs. Small IECs from two-week-old neonatal mice administered B. breve UCC2003 or PBS (control) were subjected to global RNA sequencing, and differentially expressed genes, pathways, and affected cell types were determined. We observed extensive regulation of the IEC transcriptome with ∼4,000 genes significantly up-regulated, including key genes linked with epithelial barrier function. Enrichment of cell differentiation pathways was observed, along with an overrepresentation of stem cell marker genes, indicating an increase in the regenerative potential of the epithelial layer. In conclusion, B. breve UCC2003 plays a central role in driving intestinal epithelium homeostatic development during early life and suggests future avenues for next-stage clinical studies.

Discovery of a Novel Multi-Strains Probiotic Formulation with Improved Efficacy toward Intestinal Inflammation

Dysbiosis is commonly detected in patients with inflammatory bowel disease (IBD), supporting the concept that a dysregulated immune reaction to bacterial antigens has a pathogenic role in the development of intestinal inflammation. In the present study, we have investigated the beneficial effects of a novel probiotic formulation assembled by combining four probiotics (Streptococcus thermophilus, Lactobacillus casei, Bifidobacterium breve, Bifidobacterium animalis subsp. Lactis) with Bacillus subtilis, a Gram-positive bacterium, with extensive bio-applications. Mice rendered colitic by administration of TNBS or DSS were administered with Bacillus subtilis alone, Vivomixx® or the novel Five strains formulation. Vivomixx® attenuated the severity of inflammation and reduced the development of signs and symptoms of colitis in both models. Adding Bacillus subtilis to Vivomixx® improved the beneficial effects of the bacterial therapy. The novel Five strains formulation was as effective as Vivomixx® in reducing the development of signs and symptoms of colitis and reduced the expression of pro-inflammatory mediators including Il-6 and Tnf-α while increased the expression of Il-10 mRNA and the number of Treg. In summary, we have shown that a novel Five strains probiotics formulation exerts beneficial effects on two chemical models of colitis, establishing Bacillus subtilis as a probiotic in rodent models of inflammation.

Gut Microbiota in Celiac Disease: Is There Any Role for Probiotics?

Celiac disease (CD) is an immune-mediated disorder initiated by the ingestion of gluten in genetically predisposed individuals. Recent data shows that changes in the gut microbiome composition and function are linked with chronic inflammatory diseases; this might also be the case for CD. The main aim of this manuscript is to discuss our present knowledge of the relationships between gut microbiota alterations and CD and to understand if there is any role for probiotics in CD therapy. PubMed was used to search for all of the studies published from November 2009 to November 2019 using key words such as “Celiac Disease” and “Microbiota” (306 articles), “Celiac Disease” and “Gastrointestinal Microbiome” (139), and “Probiotics” and “Celiac Disease” (97 articles). The search was limited to articles published in English that provided evidence-based data. Literature analysis showed that the gut microbiota has a well-established role in gluten metabolism, in modulating the immune response and in regulating the permeability of the intestinal barrier. Promising studies suggest a possible role of probiotics in treating and/or preventing CD. Nevertheless, human trials on the subject are still scarce and lack homogeneity. A possible role was documented for probiotics in improving CD-related symptoms, modulating the peripheral immune response and altering the fecal microbiota, although the results were not consistent in all of the studies. No evidence was found that probiotic administration might prevent CD onset. Knowledge of the role of intestinal bacteria in the development of CD opens new possibilities for its treatment through probiotic administration, even though further studies are needed to better clarify whether probiotics can help treat or prevent the disease and to define which probiotics to use, at what dose and for how long.

Bifidobacterium infantis Induces Protective Colonic PD-L1 and Foxp3 Regulatory T Cells in an Acute Murine Experimental Model of Inflammatory Bowel Disease

Background/Aims

The current study aims to investigate the protective effects of Bifidobacterium infantis on the abnormal immune response to inflammatory bowel disease (IBD) in dextran sodium sulfate (DSS)-induced colitis.

Methods

Eight-week-old BALB/c mice were separated into five groups at random (control, DSS, DSS+B9 [B. infantis 1×10⁹ CFU], DSS+B8 [B. infantis 1×10⁸ CFU], and DSS+B7 [B. infantis 1×10⁷ CFU]). Colitis was induced by 5% DSS ad libitum for 7 days, at which time we assessed weight, the disease activity index (DAI) score, and the histological damage score. The nuclear transcription factor Foxp3 (a marker of Treg cells), cytokines interleukin-10 (IL-10) and transforming growth factor β1 (TGF-β1), and related proteins (programmed cell death ligand 1 [PD-L1] and programmed cell death 1 [PD-1]) were detected by an immunohistochemical method and Western blot.

Results

B. infantis increased weight, decreased DAI scores and histological damage scores, increased the protein expression of Foxp3 (p<0.05) and cytokines IL-10 and TGF-β1 in mouse colon tissue (p<0.05), and increased the expression of PD-L1 in the treatment groups relative to that in the DSS group (p<0.05). The effect of B. infantis on Foxp3 and PD-L1 was dose dependent in the treatment groups (p<0.05). PD-L1 was positively correlated with Foxp3, IL-10, and TGF-β1.

Conclusions

In a mouse model of IBD, B. infantis can alleviate intestinal epithelial injury and maintain intestinal immune tolerance and thus may have potential therapeutic value for the treatment of immune damage in IBD.

Porphyromonas gingivalis and Lactobacillus rhamnosus GG regulate the Th17/Treg balance in colitis via TLR4 and TLR2

OBJECTIVES

CD4⁺ T cells are the key to many immune-inflammatory diseases mediated by microbial disorders, especially inflammatory bowel disease (IBD). The purpose of this study was to explore how pathogenic and probiotic bacteria directly affect the T helper (Th)17 and T regulatory (Treg) cell balance among CD4⁺ T cells to regulate inflammation.

METHODS

Porphyromonas gingivalis (Pg; ATCC 33277) and Lactobacillus rhamnosus GG (LGG; CICC 6141) were selected as representative pathogenic and probiotic bacteria, respectively. Bacterial extracts were obtained via ultrasonication and ultracentrifugation. Flow cytometry, RT-qPCR, ELISAs, immunofluorescence and a Quantibody cytokine array were used. The dextran sodium sulphate (DSS)-induced colitis model was selected for verification.

RESULTS

The Pg ultrasonicate induced the apoptosis of CD4⁺ T cells and upregulated the expression of the Th17-associated transcription factor RoRγt and the production of the proinflammatory cytokines IL-17 and IL-6, but downregulated the expression of the essential Treg transcription factor Foxp3 and the production of the anti-inflammatory factors TGF-β and IL-10 via the TLR4 pathway. However, LGG extract maintained Th17/Treg homeostasis by decreasing the IL-17⁺ Th17 proportion and increasing the CD25⁺ Foxp3⁺ Treg proportion via the TLR2 pathway. In vivo, Pg-stimulated CD4⁺ T cells aggravated DSS-induced colitis by increasing the Th17/Treg ratio in the colon and lamina propria lymphocytes (LPLs), and Pg + LGG-stimulated CD4⁺ T cells relieved colitis by decreasing the Th17/Treg ratio via the JAK-STAT signalling pathway.

CONCLUSIONS

Our findings suggest that pathogenic Pg and probiotic LGG can directly regulate the Th17/Treg balance via different TLRs.

Characterization of the fecal microbiome in cats with inflammatory bowel disease or alimentary small cell lymphoma

Feline chronic enteropathy (CE) is a common gastrointestinal disorder in cats and mainly comprises inflammatory bowel disease (IBD) and small cell lymphoma (SCL). Both IBD and SCL in cats share features with chronic enteropathies such as IBD and monomorphic epitheliotropic intestinal T-cell lymphoma in humans. The aim of this study was to characterize the fecal microbiome of 38 healthy cats and 27 cats with CE (13 cats with IBD and 14 cats with SCL). Alpha diversity indices were significantly decreased in cats with CE (OTU p = 0.003, Shannon Index p = 0.008, Phylogenetic Diversity p = 0.019). ANOSIM showed a significant difference in bacterial communities, albeit with a small effect size (P = 0.023, R = 0.073). Univariate analysis and LEfSE showed a lower abundance of facultative anaerobic taxa of the phyla Firmicutes (families Ruminococcaceae and Turicibacteraceae), Actinobacteria (genus Bifidobacterium) and Bacteroidetes (i.a. Bacteroides plebeius) in cats with CE. The facultative anaerobic taxa Enterobacteriaceae and Streptococcaceae were increased in cats with CE. No significant difference between the microbiome of cats with IBD and those with SCL was found. Cats with CE showed patterns of dysbiosis similar to those in found people with IBD.

Immunomodulatory Effect of Gut Microbiota-Derived Bioactive Peptides on Human Immune System from Healthy Controls and Patients with Inflammatory Bowel Disease

Bioactive peptides secreted by probiotic Bifidobacterium longum (peptide B7) and opportunistic pathogen Bacteroides fragilis (peptide B12) modulate the intestinal cytokine milieu in health. Here, we characterized their capacity to modulate both the mucosal cytokine production and the phenotype of circulating antigen presenting cells (APCs) in active inflammatory bowel disease (IBD). The IBD mucosa produced higher levels of pro-inflammatory cytokines referred to healthy controls (HCs). Peptides B7 and B12, however, did not ameliorate the mucosal cytokine milieu in IBD. Human circulating APCs (B-cells, monocytes, plasmacytoid dendritic cells (pDCs), and conventional dendritic cells (cDCs)) were characterized by flow cytometry in presence/absence of the peptides. Circulating B-cells, monocytes, and cDCs from IBD patients were more activated than those from HCs. Peptide B7, but not B12, decreased CCR2 expression on all APC subsets from HC, but not IBD patients. Moreover, both peptides tend to further increase their pro-inflammatory profile in IBD. In summary, IBD patients display mucosal and circulating APC pro-inflammatory properties. Peptide B7 immunomodulatory capacity elicited over circulating APCs from HC, but not IBD patients, suggests the presence of disrupted modulatory mechanisms for this peptide in IBD. Future studies should address the effect of bacteria-derived immunomodulatory peptides in non-inflamed (quiescent) IBD patients.

Dose-dependent effects of kefir on colitis induced by trinitrobenzene sulfonic acid in rats

Evidence suggests that gut microbiota dysbiosis plays a critical role in the initiation and promotion of inflammatory bowel disease (IBD). Kefir is a fermented dairy product including yeast and bacterial species. We aimed to investigate the effect of kefir on trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats using two different doses. Fifty-four Wistar rats were divided into six groups. For 14 days, the normal control and colitis control groups were given tap water, kefir10 control, kefir10 colitis, and kefir30 control, and the kefir30 colitis groups were given phosphate-buffered saline containing 10% or 30% kefir, respectively, instead of tap water. Colitis was induced by intracolonically administrating TNBS in the colitis control, kefir10 colitis, and kefir30 colitis groups. On the 14th day, the rats were sacrificed. The weights and lengths of the colons were measured and macroscopically evaluated, and the distal 10 cm segments were subjected to a histopathological examination. The incidence of bloody stool and diarrhea in the kefir10 colitis group was found to be less than the colitis control and kefir30 colitis groups. The colonic weight/length ratio in the kefir10 colitis group was lower than that in the colitis control and kefir30 colitis groups. We detected that the 10% kefir treatment reduced TNBS-induced macroscopic colonic damage, while it was exacerbated by the 30% kefir treatment. No significant difference was observed between the colitis groups in terms of microscopic colonic damage scoring. These results indicate that kefir, with a careful dose selection, may be a useful agent in the treatment of IBD.

Astragaloside IV alleviates the symptoms of experimental ulcerative colitis in vitro and in vivo

Ulcerative colitis (UC) is a chronic and relapsing inflammatory intestinal disease. Although the morbidity of UC has increased notably in recent years, effective therapeutic treatment remains unsatisfactory. Astragaloside IV (ASI), a monomeric compound isolated from the traditional Chinese medicine herb Ligusticum chuanxiong, exhibits anti-inflammatory effects. The present study aimed to investigate the therapeutic effects of ASI on experimental UC in vitro and in vivo. Cell proliferation was detected via a Cell Counting Kit-8 assay in vitro. In addition, the concentrations of the inflammatory factors myeloperoxidase (MPO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and nitric oxide (NO) in the colon tissues were determined by ELISA. Western blot analysis was used to examine phosphorylated transcription factor p65 (p-p65), p-inhibitor of NF-κB (IκB), claudin-1 and tight junction protein ZO-1 (ZO-1) protein levels in vitro and in vivo, respectively. The results indicated that lipopolysaccharide (LPS) significantly increased the pro-inflammatory cytokines TNF-α, IL-1β and IL-6 in CCD-18Co cells, which was markedly ameliorated by ASI. In addition to the inhibition of pro-inflammatory cytokines, ASI decreased the levels of p-p65 and p-IκB proteins. In addition, ASI decreased the disease activity index scores, and increased colon lengths in dextran sulfate sodium-induced UC mice. ASI also decreased the levels of the pro-inflammatory factors MPO, TNF-α, IL-1β, IL-6 and NO, and upregulated the expression of claudin-1 and ZO-1 in colon tissues. Therefore, ASI was effective in ameliorating experimental UC in vitro and in vivo via the inhibition of inflammatory molecules, and the downregulation of NF-κB signaling. In conclusion, ASI may serve as a potential therapeutic agent for the treatment of UC.

Bifidobacteria and Mucosal-Associated Invariant T (MAIT) Cells: A New Approach to Colorectal Cancer Prevention?

Colorectal cancer is the most preventable form of cancer worldwide. The pathogenesis of colorectal cancer includes gut inflammation, genetic and microbial composition factors. İmpairment of the gut microbiota has been associated with development of colorectal cancer. The genus Bifidobacterium is an important component of the commensal gut microbiota. Bifidobacteria are considered to have important roles in multiple homeostatic functions: immunologic, hormonal and metabolic. Mucosal-associated invariant T cells (MAIT) are components of the immune system involved in protection against infectious pathogens and regulate the pathogenesis of various inflammatory diseases and, potentially, colorectal cancer. Engagement between Bifidobacterium and MAIT cells could exert a beneficial effect on colorectal cancer prevention and treatment.

Cutting Edge: Probiotics and Fecal Microbiota Transplantation in Immunomodulation

Probiotics are commensal or nonpathogenic microbes that confer beneficial effects on the host through several mechanisms such as competitive exclusion, antibacterial effects, and modulation of immune responses. Some probiotics have been found to regulate immune responses via immune regulatory mechanisms. T regulatory (Treg) cells, T helper cell balances, dendritic cells, macrophages, B cells, and natural killer (NK) cells can be considered as the most determinant dysregulated mediators in immunomodulatory status. Recently, fecal microbiota transplantation (FMT) has been defined as the transfer of distal gut microbial communities from a healthy individual to a patient's intestinal tract to cure some immune disorders (mainly inflammatory bowel diseases). The aim of this review was followed through the recent literature survey on immunomodulatory effects and mechanisms of probiotics and FMT and also efficacy and safety of probiotics and FMT in clinical trials and applications.

The ameliorative effect of a Lactobacillus strain with good adhesion ability against dextran sulfate sodium-induced murine colitis

The objective of this study was to effectively screen out a Lactobacillus strain with excellent adhesion ability and ameliorative effect on the disease symptoms of a murine ulcerative colitis model.

Implications of Probiotics on the Maternal-Neonatal Interface: Gut Microbiota, Immunomodulation, and Autoimmunity

Probiotics are being investigated for the treatment of autoimmune disease by re-balancing dysbiosis induced changes in the immune system. Pregnancy is a health concern surrounding autoimmune disease, both for the mother and her child. Probiotics for maternity are emerging on the market and have gained significant momentum in the literature. Thus far, evidence supports that probiotics alter the structure of the normal microbiota and the microbiota changes significantly during pregnancy. The interaction between probiotics-induced changes and normal changes during pregnancy is poorly understood. Furthermore, there is emerging evidence that the maternal gut microbiota influences the microbiota of offspring, leading to questions on how maternal probiotics may influence the health of neonates. Underpinning the development and balance of the immune system, the microbiota, especially that of the gut, is significantly important, and dysbiosis is an agent of immune dysregulation and autoimmunity. However, few studies exist on the implications of maternal probiotics for the outcome of pregnancy in autoimmune disease. Is it helpful or harmful for mother with autoimmune disease to take probiotics, and would this be protective or pathogenic for her child? Controversy surrounds whether probiotics administered maternally or during infancy are healthful for allergic disease, and their use for autoimmunity is relatively unexplored. This review aims to discuss the use of maternal probiotics in health and autoimmune disease and to investigate their immunomodulatory properties.

The Cheese Matrix Modulates the Immunomodulatory Properties of Propionibacterium freudenreichii CIRM-BIA 129 in Healthy Piglets

Propionibacterium freudenreichii is a beneficial bacterium, used as a cheese starter, which presents versatile probiotic properties. These properties are strain-dependent. We hypothesized they may also be delivery vehicle-dependent. In this study, we thus explored in healthy piglets how the cheese matrix affects the immunomodulatory properties of P. freudenreichii. During 2 weeks, three groups of weaned piglets consumed, respectively, P. freudenreichii as a liquid culture (PF-culture), P. freudenreichii under the form of a cheese (PF-cheese), or a control sterile cheese matrix (Cheese-matrix). The in vivo metabolic activity of P. freudenreichii was assessed by determining short chain fatty acids (SCFA) concentration and bifidobacteria population in feces. Whatever the delivery vehicle, P. freudenreichii was metabolically active in piglets' colon and enhanced both bifidobacteria and SCFA in feces. P. freudenreichii consumption decreased the secretion of TNFα and of IL-10 by peripheral blood mononuclear cells (PBMC). It did not alter IL-10, IFNγ, IL-17, and TNFα secretion in mesenteric lymph node immune cells (MLNC). PF-cheese enhanced significantly Treg phenotype, while PF-culture decreased significantly Th17 phenotype in PBMC and MLNC. Remarkably, only PF-cheese induced an increase of Th2 phenotype in PBMC and MLNC. Ex vivo stimulation of PBMC and MLNC by Lipopolysaccharides and Concanavalin A emphasized the difference in the immunomodulatory responses between PF-culture and PF-cheese group, as well as between PBMC and MLNC. This study shows the importance to consider the delivery vehicle for probiotic administration. It confirms the anti-inflammatory potential of P. freudenreichii. It opens new perspectives for the use propionibacteria-fermented products as preventive agents for inflammatory bowel diseases and intestinal infectious diseases.

Goji Berry Modulates Gut Microbiota and Alleviates Colitis in IL-10-Deficient Mice

SCOPE

This study examines the beneficial effects of Goji berry against spontaneous colitis and its prebiotic role in IL-10-deficient mice.

METHODS

IL-10-deficient mice are assigned to a standard rodent diet (control) or a control diet supplemented with Goji (1% of dry feed weight) for 10 weeks, at which point colonic tissues and fecal contents are collected.

RESULTS

Goji supplementation decreases colonic pathobiological scores and mRNA expression of Il17a and Tgfb1, while it enhances Muc1 expression and fecal IgA content. Illumina MiSeq sequencing reveals that Goji supplementation increases Actinobacteria phylum, resulting in a bloom of Bifidobacteria in gut microbiota. Additionally, dietary Goji promotes butyrate-producing bacteria including Lachnospiraceae-Ruminococcaceae family and Roseburia spp. under Clostridium cluster XIVa. Furthermore, butyrate-producers Clostridium leptum and its dominant constituent Fecalibacterium prazusnitzii are markedly increased in the Goji group. Moreover, the gene-encoding butyryl-coenzyme A CoA transferase, a key enzyme responsible for butyrate synthesis in butyrate-producing bacteria, is increased sixfold in the fecal samples of Goji group associated with increased fecal butyrate content.

CONCLUSION

Data collectively show that dietary Goji results in the blooming of Bifidobacteria and butyrate-producing bacteria. These bacteria may cross-feed each other, conferring preventative effects against colitis in IL-10-deficient mice.

Effect of Milk Fermented with Lactobacillus fermentum on the Inflammatory Response in Mice

Currently, the effect of fermented milk on the T-helper 17 response in inflammatory bowel diseases (IBDs) is unknown. The aim of the present study was to evaluate the effect of milks fermented with Lactobacillus fermentum on the Th1/Th17 response in a murine model of mild IBD. Exopolysaccharide (EPS), lactic acid (LA), and total protein (TP) contents and bacterial concentration were determined. Male C57Bl/6 mice intragastrically received either raw (FM) or pasteurized (PFM) fermented milk before and during a dextran sulfate infusion protocol. Blood, spleen, and colon samples were collected at Weeks 6 and 10. IL-6, IL-10, and TNFα were determined in serum, and IL-17, IL-23, and IFNγ were determined in intestinal mucosa and serum. The FM groups did not differ in cell concentration, LA, or TP content (p > 0.05); FM-J28 had the highest EPS content. Spleen weight and colon length did not differ among the FM groups (p > 0.05). In the FM-J20 and PFM-J20 groups, IL-17 and IFNγ decreased, and the IL-10 concentration was enhanced (p < 0.05) at Week 6. IL-6, TNFα, IL-23, and IFNγ did not differ in serum and mucosa (p > 0.05), and IL-17 was lowest in FM-J28 and FM-J20. Therefore, FM appears to potentially play a role in decreasing the Th17 response. However, further studies are needed to elucidate the FM-mediated anti-inflammatory mechanisms in IBD.

Probiotic Mixture Protects Dextran Sulfate Sodium-Induced Colitis by Altering Tight Junction Protein Expressions and Increasing Tregs

Bifico is a probiotic mixture containing Bifidobacterium, Lactobacillus acidophilus, and Enterococcus. Studies support that Bifico has a protective effect in experimental colitis (IL-10-deficient and TNBS) models and in patients with inflammatory bowel disease (IBD). However, the mechanism underlying the protective effects of this mixture of probiotic bacteria remains incompletely clear. Here, we investigated the effect of Bifico on intestinal inflammation. In an in vivo experiment, dextran sulfate sodium was used to induce colitis. Bifico treatment significantly attenuated the severity of colitis in this model. Bifico increased the expression of tight junction proteins (TJs). In addition, Bifico increased the number of Tregs, but reduced the number of total CD4⁺ T cells in the peripheral blood. Furthermore, the expression of colonic CD4 protein was decreased while the level of forkhead box P3 (Foxp3) was upregulated. These results suggested that Bifico exerts beneficial effects on experimental colitis by increasing the expressions of TJs, upregulating the number of Tregs, and reducing the total CD4⁺ T cell number in both colon and peripheral blood. The intestinal damage in the pretreated + treated-Bifico-colitis group was more severe than that in only the pretreated-Bifico-colitis group. This suggested that Bifico might aggravate intestinal damage when the mucosal barrier is impaired.

Use of Probiotics to Prevent Celiac Disease and IBD in Pediatrics

The incidence of chronic inflammatory diseases (CIDs) is increasing worldwide. Their dramatic rise associated with limited effective strategies to slow down these epidemics calls for a better understanding of their pathophysiology in order to decrease the burdens on childhood. Several cross-sectional studies have demonstrated the association between intestinal dysbiosis and active diseases. Although informative, these studies do not mechanistically link alterations of the microflora with disease pathogenesis and, therefore, with potential therapeutic targets. More prospective studies are needed to determine whether intestinal dysbiosis plays a causative role in the onset and development of CIDs. Furthermore, given the complexity of the microflora interaction with the host, it is necessary to design a systems-level model of interactions between the host and the development of disease by integrating microbiome, metagenomics, metatranscriptomics, and metabolomics with either clinical either environmental data.In this chapter we will discuss the current knowledge regarding the microbiome's contribution to celiac disease and inflammatory bowel disease with a particular focus on how probiotics may be used as potential preventive therapy for CIDs.

Exploring the role of the microbiota member Bifidobacterium in modulating immune-linked diseases

The gut-associated microbiota is essential for multiple physiological processes, including immune development. Acquisition of our initial pioneer microbial communities, including the dominant early life genus Bifidobacterium, occurs at a critical period of immune maturation and programming. Bifidobacteria are resident microbiota members throughout our lifetime and have been shown to modulate specific immune cells and pathways. Notably, reductions in this genus have been associated with several diseases, including inflammatory bowel disease. In this review, we provide an overview of bifidobacteria profiles throughout life and how different strains of bifidobacteria have been implicated in immune modulation in disease states. The focus will be examining preclinical models and outcomes from clinical trials on immune-linked chronic conditions. Finally, we highlight some of the important unresolved questions in relation to Bifidobacterium-mediated immune modulation and implications for future directions, trials, and development of new therapies.

Experimental colitis delays and reduces the severity of collagen-induced arthritis in mice

Amongst extraintestinal manifestations (EIM) occurring in IBD patients, rheumatologic manifestations are the most frequent. Understanding the relationships between arthritis and colitis is a prerequisite to improving the management of these patients. Microbiota of patients with IBD or rheumatologic diseases, like spondyloarthritis (SpA) is modified compared to healthy individual. Thus, we have evaluated the impact of colitis in the development of arthritis in mice and we have analyzed microbiota changes. Collagen-induced arthritis (CIA) was induced at day 0 in DBA1 mice exposed or not to Dextran Sodium Sulfate (DSS) to induce colitis between day 14 and day 21. Animals were monitored regularly for arthritis and colitis severity (clinical score, hindpaw edema). Fecal microbiota was studied by 16S rRNA deep sequencing at critical time points (D14, D14, D21 & D41). At day 41, histological scoring of the intestines and ankles were performed at the end of experiment. Induction of colitis slightly delayed arthritis onset (2 ± 1 days of delay) and reduced its severity (5.75 ± 1.62 in arthritis only group vs 4.00 ± 1.48 in arthritis + colitis group (p = 0.02 at day 28) macroscopically and histologically. In contrast, colitis severity was not influenced by arthritis development. Induction of colitis promoted a modification of microbiota composition and a decrease of α-diversity. Fecal microbiota composition was different between “colitis” and “arthritis+colitis” groups during colitis development. Interestingly a milder decrease of bacterial diversity in the “arthritis+colitis” group was observed. Concomitant experimental colitis protects mice against collagen-induced arthritis and this is associated with changes in gut microbiome composition.

Vitamin D/VDR, Probiotics, and Gastrointestinal Diseases

Vitamin D is an important factor in regulating inflammation, immune responses, and carcinoma inhibition via action of its receptor, vitamin D receptor (VDR). Recent studies have demonstrated the role of vitamin D/VDR in regulating host-bacterial interactions. Probiotics are beneficial bacteria with the power of supporting or favoring life on the host. In the current review, we will discuss the recent progress on the roles of vitamin D/VDR in gut microbiome and inflammation. We will summarize evidence of probiotics in modulating vitamin D/VDR and balancing gut microbiota in health and gastrointestinal diseases. Moreover, we will review the clinical application of probiotics in prevention and therapy of IBD or colon cancer. Despite of the gains, there remain several barriers to advocate broad use of probiotics in clinical therapy. We will also discuss the limits and future direction in scientific understanding of probiotics, vitamin D/VDR, and host responses.

Lactobacillus rhamnosus HN001 and Lactobacillus acidophilus La-14 Attenuate Gardnerella vaginalis-Infected Bacterial Vaginosis in Mice

Oral administration of a probiotic mixture (PM; Respecta^®) consisting of Lactobacillus rhamnosus HN001 (L1), Lactobacillus acidophilus La-14 (L2), and lactoferrin RCXTM results in colonization of these probiotics in the vagina of healthy women. Therefore, we examined whether vaginal colonization of the PM ingredients L1 and L2 could attenuate bacterial vaginosis (BV). BV was induced in mice via β-estradiol-3-benzoate-induced immunosuppression and intravaginal inoculation with Gardnerella vaginalis (GV). Inflammatory markers were analyzed using enzyme-linked immunosorbent assay, immunoblotting, quantitative polymerase chain reaction, and flow cytometry. Oral or intravaginal administration of PM resulted in colonization of L1 and L2 in the vagina. Oral or intravaginal administration of L1, L2, or PM significantly inhibited GV-induced epithelial cell disruption, myeloperoxidase activity, NF-κB activation, and IL-1β and TNF-α expression (p < 0.05). Administration of these probiotics also inhibited IL-17 and RORγt expression but increased IL-10 and Foxp3 expression. Of these probiotics, L2 most effectively attenuated GV-induced BV, followed by L1 and PM. Oral administration was more effective against GV-induced BV than intravaginal administration. L1 and L2 also significantly inhibited the adherence of GV to HeLa cells (a human cervical cancer cell line) and GV growth in vitro. In addition, L1 and L2 inhibited lipopolysaccharide-induced NF-κB activation in macrophages and the differentiation of splenocytes into Th17 cells in vitro, but increased their differentiation into Treg cells. Our study suggests that L1, L2, and PM attenuated GV-induced vaginosis by regulating both vaginal and systemic innate and adaptive immune responses rather than direct competition or killing of GV in the vagina.

Effect of probiotics on clinical and immune parameters in enthesitis-related arthritis category of juvenile idiopathic arthritis

Gut microflora and dysbiosis as an environmental factor has been linked to the pathogenesis of enthesitis-related arthritis (JIA-ERA); thus, we performed a proof-of-concept study of probiotics to modulate the gut-flora and study the effects on immune and clinical parameters of children having JIA-ERA. Forty-six children with active JIA-ERA were randomized to placebo or probiotic therapy along with non-steroidal anti-inflammatory drugs (NSAIDs) for 12 weeks. Patients were assessed using a six-point composite disease activity index (mJSpADA) based on morning stiffness, joint count, enthesitis count, sacroiliitis/inflammatory back pain, uveitis and erythrocyte sedimentation rate/C-reactive protein (ESR/CRP). Frequencies of T helper type 1 (Th1), Th2, Th17 and regulatory T cells in blood were measured using flow cytometry. Serum cytokines interferon (IFN)-γ, interleukin (IL)-4, IL-17, IL-10, tumour necrosis factor (TNF)-α and IL-6 were measured by cytokine bead array using flow cytometer. The average age of 46 children (44 boys) was 15 ± 2.5 years and duration of disease was 3.5 ± 3 years. There was no significant difference in improvement in mJSpADA between the two groups (P = 0·16). Serum IL-6 levels showed a decrease (P < 0·05) in the probiotic-group. Th2 cell frequency (P < 0·05) and serum IL-10 levels (P < 0·01) showed an increase in the placebo group, but again the probiotic use did not show a significant change in immune parameters when compared to the placebo. Adverse effects among the probiotic and placebo groups were diarrhea (36 versus 45%), abdominal pain (9 versus 20%), minor infections (4·5 versus 20%) and flatulence (23 versus 15%), respectively. Thus, we can conclude that probiotic therapy in JIA-ERA children is well tolerated, but failed to show any significant immune or clinical effects over NSAID therapy.

Tolerogenic probiotics: potential immunoregulators in Systemic Lupus Erythematosus

Probiotics are commensal or nonpathogenic microbes that colonize the gastrointestinal tract and confer beneficial effects on the host through several mechanisms such as competitive exclusion, anti-bacterial effects, and modulation of immune responses. There is growing evidence supporting the immunomodulatory ability of some probiotics. Several experimental and clinical studies have been shown beneficial effect of some probiotic bacteria, particularly Lactobacillus and Bifidobacteria strains, on inflammatory and autoimmune diseases. Systemic lupus erythematosus (SLE) is an autoimmune disease that is mainly characterized by immune intolerance towards self-antigens. Some immunomodulatory probiotics have been found to regulate immune responses via tolerogenic mechanisms. Dendritic and T regulatory (Treg) cells, IL-6, IFN-γ, IL-17, and IL-23 can be considered as the most determinant dysregulated mediators in tolerogenic status. As demonstrated by documented experimental and clinical trials on inflammatory and autoimmune diseases, a number of probiotic bacterial strains can restore tolerance in host through modification of such dysregulated mediators. Since there are limited reports regarding to impact of probiotic supplementation in SLE patients, the preset review was aimed to suggest a number of probiotics bacteria, mainly from Bifidobacteria and Lactobacillus strains that are able to ameliorate immune responses. The aim was followed through literature survey on immunoregulatory probiotics that can restore tolerance and also modulate the important dysregulated pro/anti-inflammatory cytokines contributing to the pathogenesis of SLE.

Selection, identification and application of DNA aptamers for the detection of Bifidobacterium breve

In the present study, a single-stranded DNA (ssDNA) aptamer binding toBifidobacterium brevewith high avidity and selectivity was selected through a whole-bacterium-based SELEX process.

Kluyveromyces marxianus and Saccharomyces boulardii Induce Distinct Levels of Dendritic Cell Cytokine Secretion and Significantly Different T Cell Responses In Vitro

Interactions between members of the intestinal microbiota and the mucosal immune system can significantly impact human health, and in this context, fungi and food-related yeasts are known to influence intestinal inflammation through direct interactions with specialized immune cells in vivo. The aim of the present study was to characterize the immune modulating properties of the food-related yeast Kluyveromyces marxianus in terms of adaptive immune responses indicating inflammation versus tolerance and to explore the mechanisms behind the observed responses. Benchmarking against a Saccharomyces boulardii strain with probiotic effects documented in clinical trials, we evaluated the ability of K. marxianus to modulate human dendritic cell (DC) function in vitro. Further, we assessed yeast induced DC modulation of naive T cells toward effector responses dominated by secretion of IFNγ and IL-17 versus induction of a T_reg response characterized by robust IL-10 secretion. In addition, we blocked relevant DC surface receptors and investigated the stimulating properties of β-glucan containing yeast cell wall extracts. K. marxianus and S. boulardii induced distinct levels of DC cytokine secretion, primarily driven by Dectin-1 recognition of β-glucan components in their cell walls. Upon co-incubation of yeast exposed DCs and naive T cells, S. boulardii induced a potent IFNγ response indicating T_H1 mobilization. In contrast, K. marxianus induced a response dominated by Foxp3⁺ T_reg cells, a characteristic that may benefit human health in conditions characterized by excessive inflammation and positions K. marxianus as a strong candidate for further development as a novel yeast probiotic.

Bifidobacterium animalis ssp. lactis CNCM-I2494 Restores Gut Barrier Permeability in Chronically Low-Grade Inflamed Mice

Growing evidence supports the efficacy of many probiotic strains in the management of gastrointestinal disorders associated with deregulated intestinal barrier function and/or structure. In particular, bifidobacteria have been studied for their efficacy to both prevent and treat a broad spectrum of animal and/or human gut disorders. The aim of the current work was thus to evaluate effects on intestinal barrier function of Bifidobacterium animalis ssp. lactis CNCM-I2494, a strain used in fermented dairy products. A chronic dinitrobenzene sulfonic acid (DNBS)-induced low-grade inflammation model causing gut dysfunction in mice was used in order to study markers of inflammation, intestinal permeability, and immune function in the presence of the bacterial strain. In this chronic low-grade inflammation mice model several parameters pointed out the absence of an over active inflammation process. However, gut permeability, lymphocyte populations, and colonic cytokines were found to be altered. B. animalis ssp. lactis CNCM-I2494 was able to protect barrier functions by restoring intestinal permeability, colonic goblet cell populations, and cytokine levels. Furthermore, tight junction (TJ) proteins levels were also measured by qRT-PCR showing the ability of this strain to specifically normalize the level of several TJ proteins, in particular for claudin-4. Finally, B. lactis strain counterbalanced CD4⁺ lymphocyte alterations in both spleen and mesenteric lymphoid nodes. It restores the Th1/Th2 ratio altered by the DNBS challenge (which locally augments CD4⁺ Th1 cells) by increasing the Th2 response as measured by the increase in the production of major representative Th2 cytokines (IL-4, IL-5, and IL-10). Altogether, these data suggest that B. animalis ssp. lactis CNCM-I2494 may efficiently prevent disorders associated with increased barrier permeability.

Resilience of the intestinal microbiota following pathogenic bacterial infection is independent of innate immunity mediated by NOD1 or NOD2

The innate immune receptors, NOD1 and NOD2, are key regulators of intestinal homeostasis. NOD2 deficiency is linked to increased risk for Crohn's disease, a type of inflammatory bowel disease characterized by chronic inflammatory pathology and dysbiosis within resident microbial communities. However, the relationship between NOD protein-regulated immune functions and dysbiosis remains unclear. We hypothesized that the relationship between NOD1 or NOD2 deficiency and altered community structure during chronic disease may arise via NOD-dependent impairment of community resilience over time. Using the Salmonella ΔaroA model of chronic colitis with littermate mice to control for environmental influences on the microbiota, we show that NOD proteins exert a relatively minor impact on the chronic inflammatory environment and do not significantly contribute to bacterial abundance or community resilience following infection. Rather, temporal shifts in relative abundance of targeted bacterial groups correlated with inflammatory phenotype driven by presence of the pathogen and the ensuing complex immune response.

Th17 responses and natural IgM antibodies are related to gut microbiota composition in systemic lupus erythematosus patients

Intestinal dysbiosis, characterized by a reduced Firmicutes/Bacteroidetes ratio, has been reported in systemic lupus erythematosus (SLE) patients. In this study, in vitro cultures revealed that microbiota isolated from SLE patient stool samples (SLE-M) promoted lymphocyte activation and Th17 differentiation from naïve CD4⁺ lymphocytes to a greater extent than healthy control-microbiota. Enrichment of SLE-M with Treg-inducing bacteria showed that a mixture of two Clostridia strains significantly reduced the Th17/Th1 balance, whereas Bifidobacterium bifidum supplementation prevented CD4⁺ lymphocyte over-activation, thus supporting a possible therapeutic benefit of probiotics containing Treg-inducer strains in order to restore the Treg/Th17/Th1 imbalance present in SLE. In fact, ex vivo analyses of patient samples showed enlarged Th17 and Foxp3⁺ IL-17⁺ populations, suggesting a possible Treg-Th17 trans-differentiation. Moreover, analyses of fecal microbiota revealed a negative correlation between IL-17⁺ populations and Firmicutes in healthy controls, whereas in SLE this phylum correlated directly with serum levels of IFNγ, a Th1 cytokine slightly reduced in patients. Finally, the frequency of Synergistetes, positively correlated with the Firmicutes/Bacteroidetes ratio in healthy controls, tended to be reduced in patients when anti-dsDNA titers were increased and showed a strong negative correlation with IL-6 serum levels and correlated positively with protective natural IgM antibodies against phosphorylcholine.

Specific probiotic dietary supplementation leads to different effects during remission and relapse in murine chronic colitis

Although interest in using probiotics to prevent and treat intestinal diseases is increasing, the effects of specific probiotic strains still remain unclear. Here, we assess the therapeutic effects of two probiotic strains, Lactobacillus rhamnosus NutRes 1 and Bifidobacterium breve NutRes 204 on a dextran sodium sulphate (DSS)-induced chronic murine colitis model. The chronic colitis was induced by two DSS treatment cycles with a rest period of 10 days (the remission or resolution phase). The probiotic supplementation was started during the resolution phase, after the first DSS treatment cycle, and continued until the end of the experiment. In addition to clinical observations made during the experiment, cellular infiltration was measured along with mRNA expression of pro-inflammatory cytokines, T cell-associated cytokines, and Toll like receptors (TLR) in the inflamed colon after second DSS treatment cycle. L. rhamnosus, but not B. breve, rapidly and effectively improved the DSS-induced bloody diarrhoea during the resolution phase. However, a contradictory effect by both probiotic strains on the faecal condition was found after re-induction of colitis. The worsening of the faecal condition was accompanied by a reduced number of neutrophils and increased expression of interferon-γ in the colons of DSS-treated mice. Furthermore, an increased expression of TLR2, TLR6 and pro-inflammatory markers including chemokine (C-C motif) ligand 2, interleukin (IL)-1β, tumour necrosis factor α and IL-6 was found in DSS-treated mice with L. rhamnosus supplementation. These results indicate that therapeutic administration of specific probiotics might be beneficial during the resolution phase of colitis. However, caution should be taken as specific probiotic treatments reduce neutrophil influx, which may be the reason of exacerbation of chronic colitis.

Lactobacillus plantarum NCU116 Attenuates Cyclophosphamide-Induced Immunosuppression and Regulates Th17/Treg Cell Immune Responses in Mice

The balance of T helper cells 17 (Th17)/regulatory T cells (Treg) plays a key role in maintaining a normal immune response. It is well-known that cyclophosphamide (CTX) applied at high dose often damages the immune system by inhibiting immune cell proliferation. In this study, the immunomodulating effects of Lactobacillus plantarum NCU116 in CTX-induced immunosuppression mice were investigated. Results showed that the levels of cytokines interleukin (IL)-17 and IL-21 were significantly increased after 10 days of treatment with a high dose of NCU116 (46.92 ± 4.28 and 119.92 ± 10.89, respectively) compared with the model group (36.20 ± 2.63, 61.00 ± 6.92, respectively), and the levels of cytokines IL-23 and TGF-β3 of the three NCU116 treatment groups were significantly higher than that of the model group (90.48 ± 6.33 and 140.45 ± 14.30, respectively) (p < 0.05) and close to 62 and 69% of the normal group's level (140.98 ± 14.74 and 266.95 ± 23.11, respectively) at 10 days. The bacterium was also found to increase the expression levels of Th17 immune response and Treg immune response specific transcription factors RORγt and Foxp3. In addition, the bacterium significantly increased the number of CD4(+)T cells and dendrtic cells (DCs) and up-regulated mRNA expression of Toll-like receptors (TLRs). These findings demonstrated that NCU116 has the potential ability to enhance intestinal mucosa immunity and regulate the Th17/Treg balance, which may be attributed to the TLR pathway in DCs.

Effects of Lactobacillus plantarum NCU116 on Intestine Mucosal Immunity in Immunosuppressed Mice

The effects of Lactobacillus plantarum (L. plantarum) NCU116 isolated from pickled vegetables on intestine mucosal immunity in cyclophosphamide treated mice were investigated. Animals were divided into six groups: normal group (NIM), immunosuppression group (IM), immunosuppression plus L. plantarum NCU116 groups with three different doses (NCU-H, NCU-M, and NCU-L), and plus Bifidobacterium BB12 as positive control group (BB12). Results showed that the thymus indexes of the four treatment groups were significantly higher than that of the IM group (2.02 ± 0.16) (p < 0.05) and close to the index of the NIM group (2.61 ± 0.37) at 10 days. The level of immune factor IL-2 notably increased (IM, 121 ± 9.0) (p < 0.05) and was close to 65% of NIM group's level (230 ± 10.7). The levels of other immune factors (IFN-γ, IL-10, IL-12p70, and sIgA), the gene expression levels of IL-2 and IFN-γ, and the number of IgA-secreting cells showed similar patterns (p < 0.05). However, the level of immune factor IL-4 remarkably decreased (IM, 128 ± 10.2) (p < 0.05) and was only approximately 50% of the NIM group (154 ± 18.2). The levels of other immune factors (IL-6 and IgE) and the gene expression level of IL-6 at 10 days exhibited similar changes (p < 0.05) but showed a slight recovery at 20 days, accompanied by the altered protein expression levels of T-bet and GATA-3 in the small intestine. These findings suggest that L. plantarum NCU116 enhanced the immunity of the small intestine in the immunosuppressed mice.

Administration of Bifidobacterium breve Decreases the Production of TNF-α in Children with Celiac Disease

BACKGROUND

Increasing evidence suggests that not only genetics, but also environmental factors like gut microbiota dysbiosis play an important role in the pathogenesis of celiac disease (CD).

AIM

The aim of our study was to investigate the effect of two probiotic strains Bifidobacterium breve BR03 and B. breve B632 on serum production of anti-inflammatory cytokine interleukin 10 (IL-10) and pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) in children with CD.

METHODS

The study was a double-blinded, placebo-controlled trial that included 49 children with CD on gluten-free diet (GFD) randomized into two groups and 18 healthy children in the control group. The first group (24 children with CD) daily received B. breve BR03 and B632 (2 × 10(9) colony-forming units) and the second group (25 children with CD) received placebo for 3 months.

RESULTS

TNF-α levels were significantly decreased in the first group after receiving B. breve for 3 months. On follow-up, 3 months after receiving probiotics, TNF-α levels increased again. Children with CD who were on GFD for less than 1 year showed similar baseline TNF-α levels as children who were on GFD for more than 1 year. IL-10 levels were in all groups of patients below detection level.

CONCLUSIONS

Probiotic intervention with B. breve strains has shown a positive effect on decreasing the production of pro-inflammatory cytokine TNF-α in children with CD on GFD.