The probiotic strain Escherichia coli Nissle 1917 prevents papain-induced respiratory barrier injury and severe allergic inflammation in mice

Co-exposure to polyethylene microplastics and house dust mites aggravates airway epithelial barrier dysfunction and airway inflammation via CXCL1 signaling pathway in a mouse model

BACKGROUND

Environmental pollutants have been found to contribute to the development and acute exacerbation of asthma. Microplastics (MPs) have received widespread attention as an emerging global pollutant. Airborne MPs can cause various adverse health effects. Due to their hydrophobicity, MPs can act as a carrier for other pollutants, pathogens, and allergens. This carrier effect of MPs may adsorb allergens and thus make the body exposed to MPs and a large number of allergens simultaneously. We hypothesized that co-exposure to inhaled MPs and aeroallergens may promote the development of airway inflammation of asthma by disrupting the airway epithelial barrier.

METHODS

The effects of co-exposure to Polyethylene microplastics (PE-MPs) and allergens on allergic airway inflammation and airway epithelial barrier were examined in a mouse model of asthma. The mice were divided into four groups: (i) Control group, treated only with PBS; (ii) MP group, exposed to PE-MPs and PBS; (iii) HDM group, mice were sensitized and challenged with HDM, and intranasally treated with PBS; (iv) HDM + MP group, mice were sensitized and challenged with HDM, and intranasally treated with PE-MPs. Histology and ELISA assays were used to evaluate the severity of airway inflammation. FITC-dextran permeability assay, immunofluorescence assay, and RT-PCR were used to evaluate the airway epithelial barrier function and the expression of relevant molecules. Transcriptomics analysis with lung tissue sequencing was conducted to identify possible pathways responsible for the effects of PE-MPs.

RESULTS

Co-exposure of mice to PE-MPs and HDM induced a higher degree of inflammatory cell infiltration, bronchial goblet cell hyperplasia, collagen deposition, allergen sensitization, and Th2 immune bias than exposure to HDM alone. Co-exposure to PE-MPs and HDM aggravated oxidative stress injury in the lung and the production of cytokine IL-33 in the BALF. In addition, co-exposure of mice to PE-MPs and HDM resulted in a more pronounced decrease in the expression of relevant molecules of the airway epithelial barrier and more significant increase in the permeability of airway epithelia. Lung tissue transcriptomics analysis revealed that PE-MPs exposure was associated with CXCL1 signaling and neutrophil activation.

CONCLUSION

Co-exposure to MPs and HDM may promote airway inflammation and airway epithelial barrier disruption and induce immune responses characterized by CXCL1 signaling and neutrophilic inflammation.

Gestational diabetes exacerbates intrauterine microbial exposure induced intestinal microbiota change in offspring contributing to increased immune response

BACKGROUND

maternal health during pregnancy can affect the intestinal microbial community of offspring, but currently the impact of intrauterine environmental changes resulting from gestational diabetes mellitus (GDM) on the microbiota of offspring as well as its interaction with the immune system remains unclear.

AIMS

to explore the impact of intrauterine microbial exposure during pregnancy of gestational diabetes mellitus on the development of neonate's intestinal microbiota and activation of immune responses.

METHODS

Levels of lipopolysaccharides in cord blood from GDM and expression of microbial recognition-related proteins in the placenta were measured. To evaluate embryonic intestinal colonization, pregnant mice with GDM were administered with labeled Escherichia coli or Lactobacillus. The intestinal colonization of pups was analyzed through 16S rRNA gene sequencing and labeled microbial culture. Additionally, memory T lymphocyte and dendritic cell co-culture experiments were conducted to elucidate the immune memory of intestinal microbes during the embryonic stages.

RESULT

Gestational diabetes mellitus led to elevated umbilical cord blood LPS level and increased GFP labeled Escherichia coli in the offspring's intestine after gestational microbial exposure. The mouse model of GDM exhibited increased immune markers including TLR4, TLR5, IL-22 and IL-23 in the placenta and a recall response from memory T cells in offspring's intestines, with similar observations found in human experiments. Furthermore, reduced intestinal microbiome diversity and an increased ratio of Firmicutes/Bacteroidetes was found in GDM progeny, with the stability of bacterial colonization been interfered.

CONCLUSIONS

Our investigation has revealed a noteworthy correlation between gestational diabetes and intrauterine microbial exposure, as well as alterations in the neonatal microbiota and activation of immune responses. These findings highlight the gestational diabetes's role on offspring's gut microbiota and immune system interactions with early-life pathogen exposure.

Modulation of Bronchial Epithelial Barrier Integrity by Low Molecular Weight Components from Birch Pollen

Pollen, in addition to allergens, comprise low molecular weight components (LMC) smaller than 3 kDa. Emerging evidence indicates the relevance of LMC in allergic immune responses. However, the interaction of birch pollen (BP)-derived LMC and epithelial cells has not been extensively studied. We investigated epithelial barrier modifications induced by exposure to BP LMC, using the human bronchial epithelial cell line 16HBE14o-. Epithelial cell monolayers were apically exposed to the major BP allergen Bet v 1, aqueous BP extract or BP-derived LMC. Barrier integrity after the treatments was monitored by measuring transepithelial electrical resistance at regular intervals and by using the xCELLigence Real-Time Cell Analysis system. The polarized release of cytokines 24 h following treatment was measured using a multiplex immunoassay. Epithelial barrier integrity was significantly enhanced upon exposure to BP LMC. Moreover, BP LMC induced the repair of papain-mediated epithelial barrier damage. The apical release of CCL5 and TNF-α was significantly reduced after exposure to BP LMC, while the basolateral release of IL-6 significantly increased. In conclusion, the results of our study demonstrate that BP-derived LMC modify the physical and immunological properties of bronchial epithelial cells and thus regulate airway epithelial barrier responses.

Regulation effect of the intestinal flora and intervention strategies targeting the intestinal flora in alleviation of pulmonary fibrosis development

Pulmonary fibrosis is an end-stage respiratory disease characterized by fibroblast proliferation and accumulation of extracellular matrix and collagen, which is accompanied by inflammatory damage. The disease is mainly based on pulmonary dysfunction and respiratory failure, the incidence of it is increasing year by year, and the current treatment methods for it are limited. In recent years, it has been found that gut microbes play a crucial role in the pathogenesis and development of pulmonary fibrosis. The microecological disturbance caused by changes in the composition of the intestinal flora can affect the course of pulmonary fibrosis. The regulatory network or information exchange system for gut-lung crosstalk is called the "gut-lung axis". This review focuses on the frontier research on entero-pulmonary regulation in pulmonary fibrosis and on intervention strategies for changing the gut microbiota to improve pulmonary fibrosis, including fecal microbiota transplantation, traditional Chinese medicine interventions, and supplementation with probiotics. In addition, the present problems in this field are also raised in order to provide strong theoretical and strategic support for the future exploration of regulatory mechanisms and therapeutic drug development. This paper reviews the interaction of the intestinal flora with pulmonary fibrosis, introduces the research progress for improving pulmonary fibrosis through interventions targeted at the intestinal flora, and provides new ideas for the treatment of pulmonary fibrosis.

The potential mechanism of the progression from latent to active tuberculosis based on the intestinal microbiota alterations

INTRODUCTION

Tuberculosis (TB) poses a serious challenge to global health systems. The altered intestinal microbiota is associated with the pathogenesis of TB, but the exact links remain unclear.

METHODS

16 S rDNA sequencing was performed to comprehensively detect the changes in the intestinal microbiota of feces from active TB (ATB), latent TB infection (LTBI) and healthy controls (HC).

RESULTS

The rarefaction curves demonstrated the sequencing results' validity. The alpha diversity was lowest in ATB, while highest in HC. Boxplot of beta diversity showed significant differences in every two groups. LDA Effect Size (LEfSe) Analysis revealed differences in probiotic bacteria like Romboutsia, Bifidobacterium and Lactobacillus in LTBI, and pro-inflammatory bacteria like R. gnavus, Streptococcus and Erysipelatoclostridium in ATB, corresponding to the cluster analysis. PICRUST2 analysis revealed the pentose phosphate pathway was active in ATB and LTBI (more active in ATB). The differences between the groups are statistically significant at the P<0.05 level.

CONCLUSION

Our study indicated that from LTBI to ATB, some intestinal microbiota inhibit the synthesis of interferon (INF)-γ and interleukin (IL)-17, promoting the survival and spread of Mycobacterium tuberculosis (M. tb). In addition, the metabolites secreted by intestinal microbiota and dysbiosis in intestine also have an effect on the development of LTBI to ATB.

Engineering Escherichia coli Nissle 1917 as a microbial chassis for therapeutic and industrial applications

Genetically engineered microbes, especially Escherichia coli, have been widely used in the biosynthesis of proteins and metabolites for medical and industrial applications. As a traditional probiotic with a well-established safety record, E. coli Nissle 1917 (EcN) has recently emerged as a microbial chassis for generating living therapeutics, drug delivery vehicles, and microbial platforms for industrial production. Despite the availability of genetic tools for engineering laboratory E. coli K-12 and B strains, new genetic engineering systems are still greatly needed to expand the application range of EcN. In this review, we have summarized the latest progress in the development of genetic engineering systems in EcN, as well as their applications in the biosynthesis and delivery of valuable small molecules and biomacromolecules of medical and/or industrial interest, followed by a glimpse of how this rapidly growing field will evolve in the future.

Lactobacillus rhamnosus 76 alleviates airway inflammation in ovalbumin-allergic mice and improves mucus secretion by down-regulating STAT6/SPDEF pathway

Previous studies have reported a correlation between the dysregulation of intestinal microbiota and the occurrence of asthma. This study aimed to investigate the effect of probiotic Lactobacillus rhamnosus 76 (LR76) on ovalbumin (OVA)-allergic mice and the mechanism of LR76 affecting mucus secretion in asthma. OVA-allergic mice were supplemented with LR76, and 16HBE cells induced by interleukin-13 (IL-13) were treated with LR76 supernatant (LR76-s) to observe the effect of LR76. In OVA-sensitized mice, LR76 alleviated the inflammatory cell infiltration in lung tissue and reduced the inflammatory cell counts of BALF. The expression level of mRNA, including Il4, Il5, Il13, Il25, Tgfb1, Il10, and Ifng, was decreased in the lung tissue of mice in the LR76 group compared with the OVA group. MUC5AC expression was down-regulated, while SCGB1A1 was up-regulated in the lung tissue of OVA-allergic mice after being supplemented with LR76 and in 16HBE cells induced by IL-13 after incubating with LR76-s. LR76 and LR76-s down-regulated the expression of proteins, including STAT6, p-STAT6, and SPDEF, and mRNA of STAT6 and SPDEF. In conclusion, LR76 alleviated airway inflammation and Th2 response in OVA-allergic mice and improved the mucus secretion of mouse lung tissue and 16HBE cells in the asthma model by down-regulating STAT6/SPDEF pathway.

Cell-Free Supernatant from Lactobacillus and Streptococcus Strains Modulate Mucus Production via Nf-κB/CREB Pathway in Diesel Particle Matter-Stimulated NCI-H292 Airway Epithelial Cells

Airway epithelial cells are a major site of airway inflammation and may play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Diesel particulate matter (DPM) is associated with mucus hypersecretion and airway inflammation and has been reported to overexpress airway mucin in the NCI-H292 airway epithelial cells. Therefore, regulation of mucin hypersecretion is essential for developing novel anti-inflammatory agents. This study aimed to investigate the effects of cell-free supernatant (CFS) from Lactobacillus and Streptococcus on nitro oxide (NO) production in RAW264.7 and proteins associated with mucus production in NCI-H292 cells. We observed that NO production was reduced by CFS from Lactobacillus and Streptococcus in RAW 264.7, and MUC4, MUC5AC, and MUC5B gene expression was increased by phosphorylation of nuclear factor kappa B (NF-κB) p65 and cAMP response element-binding protein (CREB) in DPM-stimulated NCI-H292 cells. However, CFS from L. paracasei MG4272, MG4577, L. gasseri MG4247, and S. thermophilus MG5140 inhibited mRNA expression related to mucus production by downregulating the CREB/NfκB signaling pathway. These results suggest that CFS from L. paracasei MG4272, MG4577, L. gasseri MG4247, and S. thermophilus MG5140 can contribute as a strategic candidate to the prevention of airway inflammatory diseases caused by DPM.

Nattokinase enhances the preventive effects of Escherichia coli Nissle 1917 on dextran sulfate sodium-induced colitis in mice

Nattokinase with excellent anti-thrombotic, anti-inflammatory, anti-tumor, and anti-hypertension properties has been used in the development of several healthcare products in many countries. The probiotic Escherichia coli Nissle 1917 (EcN) with anti-inflammatory effect is commonly used to treat inflammatory bowel disease. To determine whether nattokinase could enhance the therapeutic efficacy of EcN in colitis, a recombinant E. coli Nissle 1917 strain (EcNnatto) with nattokinase-expressing ability was successfully constructed, and the protective effect of the engineered strain on mice with experimental chronic colitis was investigated. Although both EcN and EcNnatto strains substantially alleviated the clinical symptoms and pathological abnormalities in colitis mice by regulating gut flora and maintaining intestinal barrier function, the EcNnatto strain was found to perform better than the control strain, based on a further increase in colon length and a downregulation in pro-inflammatory cytokines (IL-6 and TNF-α). Nattokinase expressed in EcN attenuated DSS-induced epithelial damage and restored the mucosal integrity by upregulating the levels of tight junction proteins, including ZO-1 and occludin. The expression level of Lgr5, a marker of intestinal stem cells, was also increased. Moreover, constitutively expressed nattokinase in EcN reversed the gut microbial richness and diversity in colitis mice. Based on our findings, nattokinase could strengthen the capacity of EcN to treat intestinal inflammation.

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 Escherichia coli NISSLE 1917 for inflammatory bowel disease applications

Escherichia coli NISSLE 1917 (EcN) is a Gram-negative strain with many prominent probiotic properties in the treatment of intestinal diseases such as diarrhea and inflammatory bowel disease (IBD), in particular ulcerative colitis. EcN not only exhibits antagonistic effects on a variety of intestinal pathogenic bacteria, but also regulates the secretion of immune factors in vivo and enhances the ability of host immunity. In this review, the mechanisms of EcN in the remission of inflammatory bowel disease are proposed and recent advances on the functionalized EcN are compiled to provide novel therapeutic strategies for the prevention and treatment of IBD.

Effect of Probiotics on Respiratory Tract Allergic Disease and Gut Microbiota

Allergy is a hypersensitivity reaction triggered by specific cell or antibody-mediated immune mechanisms. Allergies have increased in industrialized countries in recent decades. The rise in allergic respiratory diseases such as allergic rhinitis (AR) and allergic asthma (AA) is a potential threat to public health. Searches were conducted using PubMed, Google Scholar and Medline using the following key terms: allergic rhinitis OR asthma AND probiotics, allergic airway inflammation AND immune disorders, probiotics OR gut microbiota AND allergic disease, probiotics AND inflammatory. Studies from all years were included, specifically those published within the last 10 years. Some review articles and their reference lists were searched to identify related articles. The role of microbiota in respiratory allergic diseases has attracted more and more attention. Pieces of evidence suggested that the development of allergic diseases causes a possible imbalance in the composition of the gut microbiota. Compared to colonized mice, germ-free mice exhibit exaggerated allergic airway responses, suggesting that microbial host interactions play an important role in the development of allergic diseases. Probiotics modulate both the innate and adaptive inflammatory immune responses, often used as dietary supplements to provide health benefits in gastrointestinal disorders. Probiotics may serve as immunomodulators and activators of host defense pathways. Besides, oral probiotics can modulate the immune response in the respiratory system. Recently, studies in humans and animals have demonstrated the role of probiotic in RA and AA. To understand the characterization, microbiota, and the potential role of probiotics intervention of AA/AR, this review provides an overview of clinical features of AA and AR, probiotics for the prevention and treatment of AR, AA, changes in gut microbiota, and their mechanisms of action.

Review: The Nose as a Route for Therapy. Part 2 Immunotherapy

The nose provides a route of access to the body for inhalants and fluids. Unsurprisingly it has a strong immune defense system, with involvement of innate (e.g., epithelial barrier, muco- ciliary clearance, nasal secretions with interferons, lysozyme, nitric oxide) and acquired (e.g., secreted immunoglobulins, lymphocytes) arms. The lattice network of dendritic cells surrounding the nostrils allows rapid uptake and sampling of molecules able to negotiate the epithelial barrier. Despite this many respiratory infections, including SARS-CoV2, are initiated through nasal mucosal contact, and the nasal mucosa is a significant "reservoir" for microbes including Streptococcus pneumoniae, Neisseria meningitidis and SARS -CoV-2. This review includes consideration of the augmentation of immune defense by the nasal application of interferons, then the reduction of unnecessary inflammation and infection by alteration of the nasal microbiome. The nasal mucosa and associated lymphoid tissue (nasopharynx-associated lymphoid tissue, NALT) provides an important site for vaccine delivery, with cold-adapted live influenza strains (LAIV), which replicate intranasally, resulting in an immune response without significant clinical symptoms, being the most successful thus far. Finally, the clever intranasal application of antibodies bispecific for allergens and Intercellular Adhesion Molecule 1 (ICAM-1) as a topical treatment for allergic and RV-induced rhinitis is explained.

Probiotics for the Management of Sepsis: Advances in Animal Models and Intensive Care Unit Environments

Sepsis frequently leads to multiple organ failure and is a major cause of morbidity and mortality in critically ill patients. Although intensive care protocols and antibiotic therapy have improved sepsis treatment, specific management is lacking with respect to efficient protection from tissue damage and long-term outcomes. Probiotics are live microbes that modulate the immune system and inflammation and colonize the gut. In this narrative review, we have traced the evolution of the administration of probiotics in an animal model of sepsis and treatment alternatives in the intensive care unit setting. First, probiotics are categorized by species before describing their modulation of the microbiota, repair of tissue-specific damage, immune response, and molecular pathways to prevent complications. The impact on therapy for infant and adult patients is also addressed. Finally, we have emphasized the challenges and gaps in current studies as well as future perspectives for further investigation. The present review can open up avenues for new strategies that employ promising probiotic strains for the treatment of sepsis and discusses their ability to prevent disease-associated long-term complications.

Probiotics as a biological detoxification tool of food chemical contamination: A review

Nowadays, people are exposed to diverse environmental and chemical pollutants produced by industry and agriculture. Food contaminations such as persistent organic pollutants (POPs), heavy metals, and mycotoxins are a serious concern for global food safety with economic and public health implications especially in the newly industrialized countries (NIC). Mounting evidence indicates that chronic exposure to food contaminants referred to as xenobiotics exert a negative effect on human health such as inflammation, oxidative stress, and intestinal disorders linked with perturbation of the composition and metabolic profile of the gut microflora. Although the physicochemical technologies for food decontamination are utilized in many cases but require adequate conditions which are often not feasible to be met in many industrial sectors. At present, one promising approach to reduce the risk related to the presence of xenobiotics in foodstuffs is a biological detoxification done by probiotic strains and their enzymes. Many studies confirmed that probiotics are an effective, feasible, and inexpensive tool for preventing xenobiotic-induced dysbiosis and alleviating their toxicity. This review aims to summarize the current knowledge of the direct mechanisms by which probiotics can influence the detoxification of xenobiotics. Moreover, probiotic-xenobiotic interactions with the gut microbiota and the host response were also discussed.

Severity of Experimental Autoimmune Uveitis Is Reduced by Pretreatment with Live Probiotic Escherichia coli Nissle 1917

Non-infectious uveitis is considered an autoimmune disease responsible for a significant burden of blindness in developed countries and recent studies have linked its pathogenesis to dysregulation of the gut microbiota. We tested the immunomodulatory properties of two probiotics, Escherichia coli Nissle 1917 (EcN) and E. coli O83:K24:H31 (EcO), in a model of experimental autoimmune uveitis (EAU). To determine the importance of bacterial viability and treatment timing, mice were orally treated with live or autoclaved bacteria in both preventive and therapeutic schedules. Disease severity was assessed by ophthalmoscopy and histology, immune phenotypes in mesenteric and cervical lymph nodes were analyzed by flow cytometry and the gut immune environment was analyzed by RT-PCR and/or gut tissue culture. EcN, but not EcO, protected against EAU but only as a live organism and only when administered before or at the time of disease induction. Successful prevention of EAU was accompanied by a decrease in IRBP-specific T cell response in the lymph nodes draining the site of immunization as early as 7 days after the immunization and eye-draining cervical lymph nodes when the eye inflammation became apparent. Furthermore, EcN promoted an anti-inflammatory response in Peyer’s patches, increased gut antimicrobial peptide expression and decreased production of inducible nitric oxide synthase in macrophages. In summary, we show here that EcN controls inflammation in EAU and suggest that probiotics may have a role in regulating the gut–eye axis.

The Gut Microbiota and Respiratory Diseases: New Evidence

Human body surfaces, such as the skin, intestines, and respiratory and urogenital tracts, are colonized by a large number of microorganisms, including bacteria, fungi, and viruses, with the gut being the most densely and extensively colonized organ. The microbiome plays an essential role in immune system development and tissue homeostasis. Gut microbiota dysbiosis not only modulates the immune responses of the gastrointestinal (GI) tract but also impacts the immunity of distal organs, such as the lung, further affecting lung health and respiratory diseases. Here, we review the recent evidence of the correlations and underlying mechanisms of the relationship between the gut microbiota and common respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), lung cancer, and respiratory infection, and probiotic development as a therapeutic intervention for these diseases.

Contribution of Non-immune Cells to Activation and Modulation of the Intestinal Inflammation

The mucosal immune system constitutes a physical and dynamic barrier against foreign antigens and pathogens and exerts control mechanisms to maintain intestinal tolerance to the microbiota and food antigens. Chronic alterations of the intestinal homeostasis predispose to inflammatory diseases of the gastrointestinal tract, such as Inflammatory Bowel Diseases (IBD). There is growing evidence that the frequency and severity of these diseases are increasing worldwide, which may be probably due to changes in environmental factors. Several stromal and immune cells are involved in this delicate equilibrium that dictates homeostasis. In this review we aimed to summarize the role of epithelial cells and fibroblasts in the induction of mucosal inflammation in the context of IBD. It has been extensively described that environmental factors are key players in this process, and the microbiome of the gastrointestinal tract is currently being intensively investigated due to its profound impact the immune response. Recent findings have demonstrated the interplay between dietary and environmental components, the gut microbiome, and immune cells. "Western" dietary patterns, such as high caloric diets, and pollution can induce alterations in the gut microbiome that in turn affect the intestinal and systemic homeostasis. Here we summarize current knowledge on the influence of dietary components and air particulate matters on gut microbiome composition, and the impact on stromal and immune cells, with a particular focus on promoting local inflammation.