Immunomodulation and Generation of Tolerogenic Dendritic Cells by Probiotic Bacteria in Patients with Inflammatory Bowel Disease

Probiotic Lactobacillus plantarum GUANKE effectively alleviates allergic rhinitis symptoms by modulating functions of various cytokines and chemokines

Background

Currently, the prevalence of allergic rhinitis (AR) remains high and there is a great need to develop better and safer ways to alleviate AR symptoms. The Lactobacillus plantarum GUANKE probiotic was reported as an immunomodulator through maintaining Th1/Th2 balance. This study aimed to determine the efficacy of GUANKE in AR subjects.

Methods

Adults aged from 18 to 60 years old and previously suffered from AR were recruited and received GUANKE probiotics treatment for 4 weeks. The questionnaires of Total nasal symptom scores (TNSS), total non-nasal symptom score (TNNSS), and rhinitis control assessment test (RCAT) were used to assess the effectiveness before and after treatment. The serum allergen-specific IgE and cytokines were also determined at baseline and after 4 weeks of probiotics administration.

Results

The results showed that TNSS and TNNSS were significantly reduced and the RCAT score was significantly increased compared to baseline. The sub-symptom score of rhinorrhea, itching, sneezing, and tearing in each questionnaire also showed significant changes, and the serum IgE level was markedly decreased. We further measured inflammatory-related proteins in serum and found that a total of 20 proteins (6 upregulated and 14 downregulated) were significantly changed compared to baseline, including IL-4, IL-7, IL-20, IL-33, CXCL1, CXCL5, CXCL6, CXCL11, CCL4, CCL23, TGF-alpha, LAP-TGF-beta-1, MMP-1, MMP-10, AXIN1, NT-3, OSM, SCF, CD6, and NRTN. Enrichment analysis showed that these significantly altered proteins were mainly enriched in cytokine and chemokine-related signaling pathways.

Conclusion

Taken together, this study demonstrated the Lactobacillus plantarum GUANKE can serve as an effective immunobiotic for the treatment of AR, which is realized through maintaining the Th1/Th2 balance by modulating the functions of various cytokines and chemokines.

Glyburide-treated human monocyte-derived dendritic cells loaded with insulin represent tolerogenic features with anti-inflammatory responses and modulate autologous T cell responses in vitro

Tolerogenic dendritic cells (TolDCs) are attractive therapeutic options for autoimmune disorders because they suppress autologous T-cell responses. Dendritic cells (DCs) are equipped with pattern recognition receptors (PRR), including nucleotide-binding and oligomerization domain-like receptors (NLRs) such as NLRP3. Abnormal NLRP3 activation has been reported to be correlated with the occurrence of autoimmune disorders. Accordingly, we hypothesized that glyburide treatment of DCs by blocking the ATP-sensitive K+ (kATP) channels generates TolDCs by inhibiting NLRP3. Insulin was even loaded on a group of glyburide-treated mature DCs (mDCs) to investigate the antigen (Ag) loading effects on glyburide-treated mDCs' phenotypical and functional features. Consequently, T lymphocytes' mediated responses ensuing co-culture of them with control mDCs, insulin loaded and unloaded glyburide treated mDCs were evaluated to determine generated TolDCs' capacity in inhibition of T cell responses that are inducer of destruction in insulin-producing pancreatic beta cells in Type 1 Diabetes Mellitus (T1DM). Our findings indicated that glyburide generates desirable TolDCs with decreased surface expression of maturation and Ag presentation related markers and diminished level of inflammatory but increased level of anti-inflammatory cytokines, which even insulin loading demonstrated more anti-inflammatory functions. In addition, co-cultured T cells showed regulatory or T helper 2 phenotype instead of T helper 1 features. Our findings suggested that insulin-loaded and unloaded glyburide-treated DCs are promising therapeutic approaches for autoimmune patients, specifically DCs loaded with insulin for T1DM patients. However, further research is required before this technique can be applied in clinical practice.

Dendritic cells: the yin and yang in disease progression

Dendritic cells (DCs) are antigen presenting cells that link innate and adaptive immunity. DCs have been historically considered as the most effective and potent cell population to capture, process and present antigens to activate naïve T cells and originate favorable immune responses in many diseases, such as cancer. However, in the last decades, it has been observed that DCs not only promote beneficial responses, but also drive the initiation and progression of some pathologies, including inflammatory bowel disease (IBD). In line with those notions, different therapeutic approaches have been tested to enhance or impair the concentration and role of the different DC subsets. The blockade of inhibitory pathways to promote DCs or DC-based vaccines have been successfully assessed in cancer, whereas the targeting of DCs to inhibit their functionality has proved to be favorable in IBD. In this review, we (a) described the general role of DCs, (b) explained the DC subsets and their role in immunogenicity, (c) analyzed the role of DCs in cancer and therapeutic approaches to promote immunogenic DCs and (d) analyzed the role of DCs in IBD and therapeutic approaches to reduced DC-induced inflammation. Therefore, we aimed to highlight the "yin-yang" role of DCs to improve the understand of this type of cells in disease progression.

Modulation of the Immune System Mechanisms using Probiotic Bacteria in Allergic Diseases: Focus on Allergic Retinitis and Food Allergies

Allergic illnesses occur when an organism's immune system is excessively responsive to certain antigens, such as those that are presented in the environment. Some people suffer from a wide range of immune system-related illnesses including allergic rhinitis, asthma, food allergies, hay fever, and even anaphylaxis. Immunotherapy and medications are frequently used to treat allergic disorders. The use of probiotics in bacteriotherapy has lately gained interest. Probiotics are essential to human health by modulating the gut microbiota in some ways. Due to probiotics' immunomodulatory properties present in the gut microbiota of all animals, including humans, these bacterial strains can prevent a wide variety of allergic disorders. Probiotic treatment helps allergy patients by decreasing inflammatory cytokines and enhancing intestinal permeability, which is important in the battle against allergy. By altering the balance of Th1 and Th2 immune responses in the intestinal mucosa, probiotics can heal allergic disorders. Numerous studies have shown a correlation between probiotics and a reduced risk of allergy disorders. A wide range of allergic disorders, including atopic dermatitis, asthma, allergic retinitis and food allergies has been proven to benefit from probiotic bacteria. Therefore, the use of probiotics in the treatment of allergic diseases offers a promising perspective. Considering that probiotic intervention in the treatment of diseases is a relatively new field of study, more studies in this regard seem necessary.

Intraspecific difference of Latilactobacillus sakei in inflammatory bowel diseases: Insights into potential mechanisms through comparative genomics and metabolomics analyses

Inflammatory bowel diseases (IBDs) are chronic inflammatory diseases of the gastrointestinal tract that have become a global health burden. Studies have revealed that Latilactobacillus sakei can effectively alleviate various immune diseases, including colitis, rheumatoid arthritis, and metabolic disorders. Here, we obtained 72 strains of L. sakei from 120 fermentation and fecal samples across China. In total, 16 strains from different sources were initially screened in an in vitro Caco-2 model induced by dextran sulfate sodium. Subsequently, six strains (four exhibiting effectiveness and two exhibiting ineffectiveness) were selected for further validation in an in vivo colitis mouse model. The results demonstrated that L. sakei strains exhibited varying degrees of amelioration of the colitis disease process. Notably, L. sakei CCFM1267, the most effective strain, significantly restored colon length and tight-junction protein expression, and reduced the levels of cytokines and associated inflammatory enzymes. Moreover, L. sakei CCFM1267 upregulated the abundance of Enterorhabdus, Alloprevotella, and Roseburia, leading to increased levels of acetic acid and propionic acid. Conversely, the other four strains (L. sakei QJSSZ1L4, QJSSZ4L10, QGZZYRHMT1L6, and QGZZYRHMT2L6) only exhibited a partial remission effect, while L. sakei QJSNT1L10 displayed minimal impact. Therefore, L. sakei CCFM1267 and QJSNT1L10 were selected for further exploration of the mechanisms underlying their differential mitigating effects. Comparative genomics analysis revealed significant variations between the two strains, particularly in genes associated with carbohydrate-active enzymes, such as the glycoside hydrolase family, which potentially contribute to the diverse profiles of short-chain fatty acids in vivo. Additionally, metabolome analysis demonstrated that acetylcholine and indole-3-acetic acid were the main differentiating metabolites of the two strains. Therefore, the strains of L. sakei exhibited varying degrees of effectiveness in alleviating IBD-related symptoms, and the possible reasons for these variations were attributed to discrepancies in the carbohydrate-active enzymes and metabolites among the strains.

Significant improvement of systemic lupus erythematosus manifestation in children after autologous dendritic cell transfer: a case report and review of literature

Dendritic cells (DC) are postulated to play a role in autoimmune diseases such as Systemic Lupus Erythematosus (SLE). We reported a 13-year-old female SLE patient who presents with chronic arthritis accompanied by persistent fever, dyspnea, sleep disturbance, headache, stomatitis, rash, and muscle weakness. The supporting examinations showed abnormal blood cell counts, positive antinuclear antibody profile, serositis, and neuropathy. Immunosuppressants failed to improve the condition. DC-based vaccine derived from autologous peripheral blood which was introduced with SARS-CoV-2 protein was given to this patient. There was a significant improvement in clinical and laboratory findings. Thus, DC immunotherapy appears to be a potential novel therapy for SLE that needs to be studied.

Factors associated with treatment failure, and possible applications of probiotic bacteria in the arsenal against Helicobacter pylori

INTRODUCTION

Helicobacter pylori is a widespread helical Gram-negative bacterium, which causes a variety of stomach disorders, such as peptic ulcer, chronic atrophic gastritis, and gastric cancer. This microbe frequently colonizes the mucosal layer of the human stomach and survives in the inhospitable microenvironment, by adapting to this hostile milieu.

AREAS COVERED

In this extensive review, we describe conventional antibiotic treatment regimens used against H. pylori including, empirical, tailored, and salvage therapies. Then, we present state-of-the-art information about reasons for treatment failure against H. pylori. Afterward, the latest advances in the use of probiotic bacteria against H. pylori infection are discussed. Finally, we propose a polymeric bio-platform to provide efficient delivery of probiotics for H. pylori infection.

EXPERT OPINION

For effective probiotic delivery systems, it is necessary to avoid the early release of probiotics at the acidic stomach pH, to protect them against enzymes and antimicrobials, and precisely target H. pylori bacteria which have colonized the antrum area of the stomach (basic pH).

Bifidobacterium bifidum FJSWX19M5 alleviated 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced chronic colitis by mitigating gut barrier injury and increasing regulatory T cells

Probiotics have been evaluated as alternative approaches for preventing the relapse of Crohn's disease (CD). Previously, we observed strain-specific anti-inflammatory properties of Bifidobacterium bifidum in 2,4,6-trinitrobenzene sulfonic acid (TNBS) acute colitis models. In this study, we further assessed the effects of several B. bifidum strains on colonic damage, fibrosis, inflammatory factors, intestinal microbial and metabolic profiles, and peripheral regulatory T cells (Tregs) in the context of TNBS chronic colitis in mice. These results indicated that B. bifidum FJSWX19M5, but not FXJWS17M4, ameliorated body weight loss, reduced colonic shortening and injury, decreased markers of gut inflammation, and rebalanced colonic metabolism in TNBS-treated mice. FJSWX19M5 supplementation also promoted Treg cell differentiation and intestinal barrier restoration compared to other strains. All living B. bifidum strains (FJSWX19M5, FXJWS17M4 and FHENJZ3M6) seemed to restore the disruption of the gut microbiota caused by TNBS. The co-culture of B. bifidum strains and mesenteric lymph node cells from TNBS-treated mice showed that those strains with anti-colitis could induce higher IL-10 levels and a lower ratio of IL-22/IL-10 and IL-17/IL-10 when compared to those strains that were not protective. Furthermore, heat-killed FJSWX19M5 exhibited a relief effect on colitis-related symptoms (including body weight loss, colonic shortening and injury). These data imply that specific B. bifidum strains or their lysates may be the current therapeutic alternatives for CD.

Gut microbiome and mycobiome in inflammatory bowel disease patients with Clostridioides difficile infection

Background

Clostridium difficile infection (CDI) is common in patients with inflammatory bowel disease (IBD) and has been reported as a risk factor for poor outcome. However, gut microbiome and mycobiome of IBD patients with CDI have been barely investigated. This study aimed to assess the gut microbiome and mycobiome in IBD patients with CDI.

Methods

We collected fecal samples from patients with active IBD and concomitant CDI (IBD-CDI group, n=25), patients with active IBD and no CDI (IBD-only group, n=51), and healthy subjects (HC, n=40). Patients' characteristics including demographic data, disease severity, and medication history were collected. Metagenomic sequencing, taxonomic and functional analysis were carried out in the samples.

Results

We found that the bacterial alpha diversity of the IBD-CDI group was decreased. The bacterial and fungal beta diversity variations between IBD patients and HC were significant, regardless of CDI status. But the IBD-CDI group did not significantly cluster separately from the IBD-only group. Several bacterial taxa, including Enterococcus faecium, Ruminococcus gnavus, and Clostridium innocuum were overrepresented in the IBD-CDI group. Furthermore, IBD patients with CDI were distinguished by several fungal taxa, including overrepresentation of Saccharomyces cerevisiae. We also identified functional differences in IBD patients with CDI include enrichment of peptidoglycan biosynthesis. The network analysis indicated specific interactions between microbial markers in IBD-CDI patients.

Conclusion

IBD patients with CDI had pronounced microbial dysbiosis. Gut micro-ecological changes in IBD patients with CDI might provide insight into the pathological process and potential strategies for diagnosis and treatment in this subset of patients.

Emerging Role of Dendritic Cell Intervention in the Treatment of Inflammatory Bowel Disease

Dendritic cells (DCs) are the most important antigen-presenting cells and are pivotal in initiating effective adaptive immune responses to induce immune tolerance and maintain immune homeostasis. Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, is chronic, intestinal inflammatory and autoimmune disorder. DCs participate in IBD pathogenesis. This review is aimed at briefly discussing the role of DCs in IBD and the relationship between them and highlighting the prominent role of these cells in the treatment of these disorders.

Research Advances in the Treatment of Allergic Rhinitis by Probiotics

Allergic rhinitis (AR) impairs the quality of life of patients and reduces the efficiency of social work, it is an increasingly serious public medical and economic problem in the world. Conventional anti-allergic drugs for the treatment of allergic rhinitis (AR) can cause certain side effects, which limit the quality of life of patients. Therefore, it makes sense to look for other forms of treatment. Several studies in recent years have shown that probiotics have shown anti-allergic effects in various mouse and human studies. For example, the application of certain probiotic strains can effectively relieve the typical nasal and ocular symptoms of allergic rhinitis in children and adults, thereby improving the quality of life and work efficiency. At the same time, previous studies in humans and mice have found that probiotics can produce multiple effects, such as reduction of Th2 cell inflammatory factors and/or increase of Th1 cell inflammatory factors, changes in allergy-related immunoglobulins and cell migration, regulate Th1/Th2 balance or restore intestinal microbiota disturbance. For patients with limited activity or allergic rhinitis with more attacks and longer attack duration, oral probiotics have positive effects. The efficacy of probiotics in the prevention and treatment of allergic rhinitis is remarkable, but its specific mechanism needs further study. This review summarizes the research progress of probiotics in the treatment of allergic rhinitis in recent years.

Probiotic-Based Intervention in the Treatment of Ulcerative Colitis: Conventional and New Approaches

Although there are number of available therapies for ulcerative colitis (UC), many patients are unresponsive to these treatments or experience secondary failure during treatment. Thus, the development of new therapies or alternative strategies with minimal side effects is inevitable. Strategies targeting dysbiosis of gut microbiota have been tested in the management of UC due to the unquestionable role of gut microbiota in the etiology of UC. Advanced molecular analyses of gut microbiomes revealed evident dysbiosis in UC patients, characterized by a reduced biodiversity of commensal microbiota. Administration of conventional probiotic strains is a commonly applied approach in the management of the disease to modify the gut microbiome, improve intestinal barrier integrity and function, and maintain a balanced immune response. However, conventional probiotics do not always provide the expected health benefits to a patient. Their benefits vary significantly, depending on the type and stage of the disease and the strain and dose of the probiotics administered. Their mechanism of action is also strain-dependent. Recently, new candidates for potential next-generation probiotics have been discovered. This could bring to light new approaches in the restoration of microbiome homeostasis and in UC treatment in a targeted manner. The aim of this paper is to provide an updated review on the current options of probiotic-based therapies, highlight the effective conventional probiotic strains, and outline the future possibilities of next-generation probiotic and postbiotic supplementation and fecal microbiota transplantation in the management of UC.

Strategies for the Identification and Assessment of Bacterial Strains with Specific Probiotic Traits

Early in the 1900s, it was proposed that health could be improved and senility delayed by manipulating gut microbiota with the host-friendly bacteria found in yogurt. Later, in 1990, the medical community reconsidered this idea and today probiotics represent a developed area of research with a billion-dollar global industry. As a result, in recent decades, increased attention has been paid to the isolation and characterization of novel probiotic bacteria from fermented foods and dairy products. Most of the identified probiotic strains belong to the lactic acid bacteria group and the genus Bifidobacterium. However, current molecular-based knowledge has allowed the identification and culture of obligatory anaerobic commensal bacteria from the human gut, such as Akkermansia spp. and Faecalibacterium spp., among other human symbionts. We are aware that the identification of new strains of these species does not guarantee their probiotic effects and that each effect must be proved through in vitro and in vivo preclinical studies before clinical trials (before even considering it as a probiotic strain). In most cases, the identification and characterization of new probiotic strain candidates may lack the appropriate set of in vitro experiments allowing the next assessment steps. Here, we address some innovative strategies reported in the literature as alternatives to classical characterization: (i) identification of alternatives using whole-metagenome shotgun sequencing, metabolomics, and multi-omics analysis; and (ii) probiotic characterization based on molecular effectors and/or traits to target specific diseases (i.e., inflammatory bowel diseases, colorectal cancer, allergies, among others).

The Activity of Prebiotics and Probiotics in Hepatogastrointestinal Disorders and Diseases Associated with Metabolic Syndrome

The components of metabolic syndrome (MetS) and hepatogastrointestinal diseases are widespread worldwide, since many factors associated with lifestyle and diet influence their development and correlation. Due to these growing health problems, it is necessary to search for effective alternatives for prevention or adjuvants in treating them. The positive impact of regulated microbiota on health is known; however, states of dysbiosis are closely related to the development of the conditions mentioned above. Therefore, the role of prebiotics, probiotics, or symbiotic complexes has been extensively evaluated; the results are favorable, showing that they play a crucial role in the regulation of the immune system, the metabolism of carbohydrates and lipids, and the biotransformation of bile acids, as well as the modulation of their central receptors FXR and TGR-5, which also have essential immunomodulatory and metabolic activities. It has also been observed that they can benefit the host by displacing pathogenic species, improving the dysbiosis state in MetS. Current studies have reported that paraprobiotics (dead or inactive probiotics) or postbiotics (metabolites generated by active probiotics) also benefit hepatogastrointestinal health.

Mucosa-Colonizing Microbiota Correlate With Host Autophagy Signaling in Patients With Inflammatory Bowel Disease

Both bacteria and autophagy are implicated in inflammatory bowel disease (IBD) pathogenesis. However, how bacteria crosstalk with autophagy signaling remains largely known, especially in intestinal mucosa. This study aimed to profile the internal complex autophagy signaling cascade and their external correlation with these bacteria, and consequently provide a systematic and precise target for future IBD diagnosis and therapy. We found the Ulcerative colitis (UC) patients exhibited more severe dysbiosis than the Crohn’s disease (CD) patients, as represented by alpha diversity, community phenotypes, and functional annotation compared with the control population. Meanwhile, CD patients showed greater transcriptional signaling activities of autophagy, endoplasmic reticulum (ER) stress, and bile acid production. Dominant bacteria (e.g., Rhodococcus, Escherichia, Shigella, and Enterococcus) were positively correlated and low-abundance bacteria (e.g., Bacillus, Acidovorax, Acinetobacter, and Stenotrophomonas) were negatively correlated with the autophagy signaling cascade (184 autophagy genes, 52 ER stress genes, and 22 bile acid production genes). Our observations suggested UC patients showed temporary and widespread microbiota turbulence and CD patients showed processive and local autophagy activity during IBD progression. Intestinal mucosa-colonizing bacteria were correlated with the bile/ER stress/autophagy signaling axis in IBD pathogenesis.

The Effects of Vitamins and Micronutrients on Helicobacter pylori Pathogenicity, Survival, and Eradication: A Crosstalk between Micronutrients and Immune System

Helicobacter pylori as a class I carcinogen is correlated with a variety of severe gastroduodenal diseases; therefore, H. pylori eradication has become a priority to prevent gastric carcinogenesis. However, due to the emergence and spread of multidrug and single drug resistance mechanisms in H. pylori, as well as serious side effects of currently used antibiotic interventions, achieving successful H. pylori eradication has become exceedingly difficult. Recent studies expressed the intention of seeking novel strategies to improve H. pylori management and reduce the risk of H. pylori-associated intestinal and extragastrointestinal disorders. For which, vitamin supplementation has been demonstrated in many studies to have a tight interaction with H. pylori infection, either directly through the regulation of the host inflammatory pathways or indirectly by promoting the host immune response. On the other hand, H. pylori infection is reported to result in micronutrient malabsorption or deficiency. Furthermore, serum levels of particular micronutrients, especially vitamin D, are inversely correlated to the risk of H. pylori infection and eradication failure. Accordingly, vitamin supplementation might increase the efficiency of H. pylori eradication and reduce the risk of drug-related adverse effects. Therefore, this review aims at highlighting the regulatory role of micronutrients in H. pylori-induced host immune response and their potential capacity, as intrinsic antioxidants, for reducing oxidative stress and inflammation. We also discuss the uncovered mechanisms underlying the molecular and serological interactions between micronutrients and H. pylori infection to present a perspective for innovative in vitro investigations, as well as novel clinical implications.

Native and Engineered Probiotics: Promising Agents against Related Systemic and Intestinal Diseases

Intestinal homeostasis is a dynamic balance involving the interaction between the host intestinal mucosa, immune barrier, intestinal microecology, nutrients, and metabolites. Once homeostasis is out of balance, it will increase the risk of intestinal diseases and is also closely associated with some systemic diseases. Probiotics (Escherichia coli Nissle 1917, Akkermansia muciniphila, Clostridium butyricum, lactic acid bacteria and Bifidobacterium spp.), maintaining the gut homeostasis through direct interaction with the intestine, can also exist as a specific agent to prevent, alleviate, or cure intestinal-related diseases. With genetic engineering technology advancing, probiotics can also show targeted therapeutic properties. The aims of this review are to summarize the roles of potential native and engineered probiotics in oncology, inflammatory bowel disease, and obesity, discussing the therapeutic applications of these probiotics.

Immune Responses in Pregnant Sows Induced by Recombinant Lactobacillus johnsonii Expressing the COE Protein of Porcine Epidemic Diarrhea Virus Provide Protection for Piglets against PEDV Infection

Porcine epidemic diarrhea (PED) induced by porcine epidemic diarrhea virus (PEDV) is an intestinal infectious disease in pigs that causes serious economic losses to the pig industry. To develop an effective oral vaccine against PEDV infection, we used a swine-origin Lactobacillus johnsonii (L. johnsonii) as an antigen delivery carrier. A recombinant strain pPG-T7g10-COE/L. johnsonii (L. johnsonii-COE) expressing COE protein (a neutralizing epitope of the viral spike protein) was generated. The immunomodulatory effect on dendritic cell in vitro and immunogenicity in pregnant sows was evaluated following oral administration. L. johnsonii-COE could activate monocyte-derived dendritic cell (MoDC) maturation and triggered cell immune responses. After oral vaccination with L. johnsonii-COE, levels of anti-PEDV-specific serum IgG, IgA, and IgM antibodies as well as mucosal secretory immunoglobulin A (SIgA) antibody were induced in pregnant sows. High levels of PEDV-specific SIgA and IgG antibodies were detected in the maternal milk, which provide effective protection for the piglets against PEDV infection. In summary, oral L. johnsonii-COE was able to efficiently activate anti-PEDV humoral and cellular immune responses, demonstrating potential as a vaccine for use in sows to provide protection of their piglets against PEDV.

Prebiotics, Probiotics, Synbiotics, Paraprobiotics and Postbiotic Compounds in IBD

The increasing incidence of inflammatory bowel diseases (IBD) and the increasing severity of the course of these diseases create the need for developing new methods of therapy. The gut microbiome is extensively studied as a factor influencing the development and course of IBD. The composition of intestinal microbiota can be relatively easily modified by diet (i.e., prebiotics, mainly dietary fibers) and bacterial supplementation using beneficial bacteria strains called probiotics. Additionally, the effects of the improved microbiome could be enhanced or gained by using paraprobiotics (non-viable, inactivated bacteria or their components) and/or postbiotics (products of bacterial metabolism or equal synthetic products that beneficially modulate immunological response and inflammation). This study summarizes the recent works on prebiotics, probiotics, synbiotics (products merging pre- and probiotics), paraprobiotics and postbiotics in IBD.

Evaluation of Microbiome Alterations Following Consumption of BIOHM, a Novel Probiotic

Gastrointestinal microbiome dysbiosis may result in harmful effects on the host, including those caused by inflammatory bowel diseases (IBD). The novel probiotic BIOHM, consisting of Bifidobacterium breve, Saccharomyces boulardii, Lactobacillus acidophilus, L. rhamnosus, and amylase, was developed to rebalance the bacterial–fungal gut microbiome, with the goal of reducing inflammation and maintaining a healthy gut population. To test the effect of BIOHM on human subjects, we enrolled a cohort of 49 volunteers in collaboration with the Fermentation Festival group (Santa Barbara, CA, USA). The profiles of gut bacterial and fungal communities were assessed via stool samples collected at baseline and following 4 weeks of once-a-day BIOHM consumption. Mycobiome analysis following probiotic consumption revealed an increase in Ascomycota levels in enrolled individuals and a reduction in Zygomycota levels (p value < 0.01). No statistically significant difference in Basidiomycota was detected between pre- and post-BIOHM samples and control abundance profiles (p > 0.05). BIOHM consumption led to a significant reduction in the abundance of Candida genus in tested subjects (p value < 0.013), while the abundance of C. albicans also trended lower than before BIOHM use, albeit not reaching statistical significance. A reduction in the abundance of Firmicutes at the phylum level was observed following BIOHM use, which approached levels reported for control individuals reported in the Human Microbiome Project data. The preliminary results from this clinical study suggest that BIOHM is capable of significantly rebalancing the bacteriome and mycobiome in the gut of healthy individuals, suggesting that further trials examining the utility of the BIOHM probiotic in individuals with gastrointestinal symptoms, where dysbiosis is considered a source driving pathogenesis, are warranted.

Probiotic-Induced Tolerogenic Dendritic Cells: A Novel Therapy for Inflammatory Bowel Disease?

Inflammatory bowel diseases (IBDs) are immune-mediated, chronic relapsing diseases with a rising prevalence worldwide in both adult and pediatric populations. Treatment options for immune-mediated diseases, including IBDs, are traditional steroids, immunomodulators, and biologics, none of which are capable of inducing long-lasting remission in all patients. Dendritic cells (DCs) play a fundamental role in inducing tolerance and regulating T cells and their tolerogenic functions. Hence, modulation of intestinal mucosal immunity by DCs could provide a novel, additional tool for the treatment of IBD. Recent evidence indicates that probiotic bacteria might impact immunomodulation both in vitro and in vivo by regulating DCs’ maturation and producing tolerogenic DCs (tolDCs) which, in turn, might dampen inflammation. In this review, we will discuss this evidence and the mechanisms of action of probiotics and their metabolites in inducing tolDCs in IBDs and some conditions associated with them.

Lactobacillus johnsonii activates porcine monocyte derived dendritic cells maturation to modulate Th cellular immune response

Lactobacilli are abundant in the intestinal tract where they constantly regulate immune system via interacting with a great diversity of immune cells, such as dendritic cells (DCs). Notably, DCs are powerful antigen-presenting cells and they are capable of initiating primary immune responses. In this study, we studied the effects of Lactobacillus johnsonii (L. johnsonii) and Lactobacillus johnsonii cell-free supernatant (L. johnsonii-CFS) on the activation of porcine monocyte-derived dendritic cells (MoDCs) and their regulation of Th cellular immune responses in vitro. The MoDCs generated from porcine peripheral blood monocytes were stimulated by L. johnsonii and L. johnsonii-CFS, respectively. Pre-incubation with L. johnsonii increased expression of CD172a, CD80, major histocompatibility complex class II (MHCII) in MoDCs, and enhanced the ability of MoDCs to induce the proliferation of CD4⁺ T cell, while pre-incubation with L. johnsonii-CFS merely upregulated the expression of MHCII. Analysis of the cytokines showed that L. johnsonii stimulated up-regulation of Th1-type cytokines (IL-12p40, IFN-γ, TNF-α), pro-inflammatory cytokine IL-1β, chemokine CCL20, and Treg-type / anti-inflammatory cytokines IL-10 in MoDCs. Notably, a high production of IL-10 was observed in the MoDCs treated with L. johnsonii-CFS, indicating L. johnsonii-CFS exerted anti-inflammatory effects. Furthermore, L. johnsonii induced up-regulation of TLR2 and TLR6, but L. johnsonii-CFS not. Moreover, MoDCs stimulated by L. johnsonii mainly promoted T cell differentiate into Th1/Th2/Treg cells and plays an important role in improving the balance between Th1/Th2/Treg-type cells, whereas MoDCs stimulated by L. johnsonii-CFS mainly directed T cell to Th2/Treg subset polarization. In conclusion, L. johnsonii and L. johnsonii-CFS exhibited the ability of modulating innate immunity by regulating immunological functions of MoDCs in vitro, suggesting their potential ability to use as microecological preparations and medicines.