Oral delivery of a probiotic induced changes at the nasal mucosa of seasonal allergic rhinitis subjects after local allergen challenge: a randomised clinical trial

The Impact of Cytokines on Health-Related Quality of Life in Adolescents with Allergic Rhinitis

BACKGROUND

Frequent episodes of nasal symptoms are the usual clinical manifestations (CM) of allergic rhinitis (AR) and have a significant negative impact on health-related quality of life (HRQoL) in adolescents. The purpose of this cross-sectional study was to test the hypothesis that cytokines in nasal mucus may be associated with HRQoL in adolescents with AR.

METHODS

European Quality of Life 5 Dimensions 3 Level Version (EQ-5D-3L), "The Adolescent Rhinoconjunctivitis Quality of Life Questionnaire" (AdolRQLQ) and the Total 4 Symptom Score (T4SS) scoring system were administered to 113 adolescents with AR, nonallergic rhinitis (NAR) and to healthy control subjects. Nasal secretions were sampled and tested for 13 cytokines using a multiplex flow cytometric bead assay.

RESULTS

The AR group had significantly lower EQ-5D-3L (0.661 ± 0.267 vs. 0.943 ± 0.088; p < 0.001) and higher AdolRQLQ total scores (2.76 ± 1.01 vs. 1.02 ± 0.10; p < 0.001) compared to the control group. The AR group had higher concentrations of IL-1β (p = 0.002), IL-6 (p = 0.031), IL-8 (p < 0.001), IL17-A (p = 0.013) and IL-18 (p = 0.014) compared to the control group, and IL-1β, IL-6, IL17-A and IL-18 were significantly (p < 0.050) increased with disease progression. Cytokines IL-1β, IL-6, as well as severe CM, were identified as significant predictors of lower HRQoL in adolescents with AR.

CONCLUSIONS

This study identified IL-1β, IL-6, as well as severe CM, as predictors of lower HRQoL in adolescents with AR. However, these results should only serve as a starting point for additional confirmation research.

Efficacy and safety of gastrointestinal microbiome supplementation for allergic rhinitis: A systematic review and meta-analysis with trial sequential analysis

BACKGROUND

Allergic rhinitis (AR) is a non-infective chronic inflammatory disease of nasal mucosa.

PURPOSE

To evaluate the efficacy and safety of gastrointestinal microbiome supplementation (GMS) for patients with allergic rhinitis (AR), concerning improvement on symptoms and signs, laboratory outcomes, quality of life, and medication scores.

METHODS

Five English databases were searched up to Dec 12th, 2022. Probiotics, prebiotics, and synbiotics were main therapies or adjuvants in experimental groups. Systematic reviews and meta-analyses were conducted based on the Cochrane systematic review method by using RevMan 5.4 Software, with meta-influence analyses, subgroup-analyses, meta-regression, and publication bias performed for exploration of heterogeneity by Stata V.14. Trial sequential analyses were performed by TSA 0.9, and quality of the results was accessed through the GRADE-pro GDT.

RESULTS

Finally, extracted from 53 articles, 65 RCTs involving 3,634 participants with sound worldwide representativeness were included. Primary results showed better improvement in GMS groups on TNSS (WMD=1.05, P for WMD=0.004, 95%CI:0.34 to 1.76), overall nasal condition (WMD=1.25, P for WMD<0.001, 95%CI:0.90 to 1.61), overall quality of life (WMD=6.16, P for WMD<0.001, 95%CI:4.92 to 7.40) and medication score (WMD=0.42, P for WMD=0.42, 95%CI:-0.06 to 0.90).However, GMS groups were inferior than the controls concerning reduction on serum total IgE (WMD=-1.81) and ratios of serum Th1/Th2 (WMD=-1.06). Meta-regressions suggested significant (p<0.05) variations of the effects in some comparisons. In addition, results of sub-group analyses firstly revealed potential influence between final results and the variables above. Instantly after intervention, the GRADE levels of evidence were sound, including "High ⨁⨁⨁⨁" in 10, "Moderate ⨁⨁⨁◯" in 33, and "Low ⨁⨁◯◯" in nine comparisons. However, overall certainties decreased obviously during follow-ups.

CONCLUSION

Overall, our pooled results firstly revealed that GMS yielded acceptable benefits for patients with AR compared with controls with sound certainties, after balancing the benefits and harms.

IL-1β and Allergy: Focusing on Its Role in Allergic Rhinitis

Allergic rhinitis (AR) is a chronic upper airway immune-inflammation response mediated by immunoglobulin E (IgE) to allergens and can seriously affect the quality of life and work efficiency. Previous studies have shown that interleukin-1β (IL-1β) acts as a key cytokine to participate in and promote the occurrence and development of allergic diseases. It has been proposed that IL-1β may be a potential biomarker of AR. However, its definitive role and potential mechanism in AR have not been fully elucidated, and the clinical sample collection and detection methods were inconsistent among different studies, which have limited the use of IL-1β as a clinical diagnosis and treatment marker for AR. This article systematically summarizes the research advances in the roles of IL-1β in allergic diseases, focusing on the changes of IL-1β in AR and the possible interventions. In addition, based on the findings by our team, we provided new insights into the use of IL-1β in AR diagnosis and treatment, in an attempt to further promote the clinical application of IL-1β in AR and other allergic diseases.

A Meta-Analysis of Probiotics for the Treatment of Allergic Airway Diseases in Children and Adolescents

BACKGROUND

Allergic airway disease is a chronic airway allergic inflammatory disease including allergic rhinitis (AR) and allergic asthma which is common in children and adolescents. Recently the probiotics has been becoming a supplementary or alternative therapy to allergic diseases, however the effect of them has not been clearly established.

OBJECTIVE

The purpose of the present meta-analysis was to evaluate the effectiveness of probiotics on allergic airway disease including AR and allergic asthma in children and adolescents.

METHODS

We performed a comprehensive search on PubMed, Cochrane Library, EMBASE for relevant publications from 1 Jan 2000 to 1 July 2021. Physical examinations, Pediatric Rhinoconjunctivitis Quality of Life Questionnaires (PRQLQs), Total Nasal Symptom Score (TNSS), Nasal or Eye Symptom Score (NSS or ESS), serum allergen-specific IgE, and eosinophil were used as evaluating indicators for AR and allergic asthma in children and adolescents. The meta-analysis was performed using Review Manager (RevMan, Version 5.3).

RESULTS

15 randomized controlled trials (RCTs) with a total of 1388 participants were included for the meta-analysis. Among them, 729 patients treated with probiotics served as the probiotics group, and 659 patients with placebo as control group. Significantly greater reduction in PRQLQs from baseline to endpoint (SMD = -2.57, 95% CI [ - 4.66, -0.48] P < 0.01), NSS (SMD = -1.43, 95% CI [ - 1.63, - 1.23], P < 0.01) and ESS (total MD = -1.67, 95% CI [ - 1.79, - 1.55], P < 0.01) were observed in probiotics group compared to control group. Probiotics have no significant effect to serum IgE and eosinophils (P > 0.01).

CONCLUSION

The results of this meta-analysis indicated that probiotics treatment may reduce PRQLQs, NSS, ESS in patients with allergic airway disease. More research involving the mechanism of probiotics are needed to clarify the role of probiotics in AR and allergic asthma in children and adolescents.

The Beneficial Role of Probiotic Lactobacillus in Respiratory Diseases

Respiratory diseases cause a high incidence and mortality worldwide. As a natural immunobiotic, Lactobacillus has excellent immunomodulatory ability. Administration of some Lactobacillus species can alleviate the symptoms of respiratory diseases such as respiratory tract infections, asthma, lung cancer and cystic fibrosis in animal studies and clinical trials. The beneficial effect of Lactobacillus on the respiratory tract is strain dependent. Moreover, the efficacy of Lactobacillus may be affected by many factors, such as bacteria dose, timing and host background. Here, we summarized the beneficial effect of administered Lactobacillus on common respiratory diseases with a focus on the mechanism and safety of Lactobacillus in regulating respiratory immunity.

Influence of probiotics on the periodontium, the oral microbiota and the immune response during orthodontic treatment in adolescent and adult patients (ProMB Trial): study protocol for a prospective, double-blind, controlled, randomized clinical trial

Background

Orthodontic treatment with fixed appliances is often necessary to correct malocclusions in adolescence or adulthood. However, oral hygiene is complicated by appliances, and prior studies indicate that they may trigger oral inflammation and dysbiosis of the oral microbiota, especially during the first 3 months after insertion, and, thus, may present a risk for inflammatory oral diseases. In recent periodontal therapeutic studies, probiotics have been applied to improve clinical parameters and reduce local inflammation. However, limited knowledge exists concerning the effects of probiotics in orthodontics. Therefore, the aim of our study is to evaluate the impact of probiotics during orthodontic treatment.

Methods

This study is a monocentric, randomized, double blind, controlled clinical study to investigate the effectiveness of daily adjuvant use of Limosilactobacillus reuteri (Prodentis®-lozenges, DSM 17938, ATCC PTA 5289) versus control lozenges during the first three months of orthodontic treatment with fixed appliances. Following power analysis, a total of 34 adolescent patients (age 12–17) and 34 adult patients (18 years and older) undergoing orthodontic treatment at the University Hospital Erlangen will be assigned into 2 parallel groups using a randomization plan for each age group. The primary outcome measure is the change of the gingival index after 4 weeks. Secondary outcomes include the probing pocket depth, the modified plaque index, the composition of the oral microbiota, the local cytokine expression and—only for adults—serum cytokine levels and the frequencies of cells of the innate and adaptive immune system in peripheral blood.

Discussion

Preventive strategies in everyday orthodontic practice include oral hygiene instructions and regular dental cleaning. Innovative methods, like adjuvant use of oral probiotics, are missing. The aim of this study is to analyse, whether probiotics can improve clinical parameters, reduce inflammation and prevent dysbiosis of the oral microbiota during orthodontic treatment. If successful, this study will provide the basis for a new strategy of prophylaxis of oral dysbiosis-related diseases during treatment with fixed appliances.

Trial registration

This trial is registered at ClinicalTrials.gov in two parts under the number NCT04598633 (Adolescents, registration date 10/22/2020), and NCT04606186 (Adults, registration date 10/28/2020).

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.

Turkish Guideline for Diagnosis and Treatment of Allergic Rhinitis (ART)

OBJECT

To prepare a national guideline for Otorhinolaryngologist who treat allergic rhinitis patients.

METHODS

The study was conducted by three authors, namely the writing support team. The support team made the study plan, determined the writing instructions, chose the subgroups including the advisory committee, the advisors for authors and the authors. A workshop was organized at the very beginning to explain the details of the study to the team. Advisors took the chance to meet their coworkers in their subgroups and determined the main headings and subheadings of the guideline, together with the authors. After key words were determined by the authors, literature search was done in various databases. The authors keep in touch with the advisors and the advisors with the advisory committee and the support group at every stage of the study. National and International published articles as well as the abstracts of unpublished studies, imperatively presented in National Congresses, were included in this guideline. Only Guideline and meta-analyses published in last seven years (2013-2017) and randomized controlled studies published in last two years (2015-2017) were included. After all work was completed by the subgroups, support team brought all work together and edited the article.

RESULTS

A detailed guideline about all aspects of allergic rhinitis was created.

CONCLUSION

The authors believe that this guideline will enable a compact and up-to-date information on allergic rhinitis to healthcare professionals. This guideline is the first in the field of Otolaryngology in Turkey. It should be updated at regular intervals.

A significant decrease in the gene expression of interleukin-17 following the administration of synbiotic in patients with allergic rhinitis who underwent immunotherapy: A placebo-controlled clinical trial

Background:

Allergic Rhinitis (AR) is the most common allergic disease worldwide. The present study, evaluated effects of synbiotic on gene expression of interferon-gamma (IFN-γ), interleukin-4 (IL-4), interleukin-10 (IL-10), interleukin-17 (IL-17), transforming growth factor beta (TGF-β), and forkhead box P3 (FoxP3) in AR patients who received concomitant immunotherapy in a placebo-controlled clinical trial.

Materials and Methods:

Twenty AR patients were randomized in synbiotic and placebo groups and received cluster immunotherapy for 2 months. RNA was extracted from peripheral PBMCs, then the cDNA synthesized. Subsequently, SYBR Green real-time Reverse transcription polymerase chain reaction technique was employed for studying the expression of mentioned genes. In addition, SNOT-22 and mini-Rhinoconjunctivitis Quality of Life Questionnaire questionnaires were completed by patients. Data were analyzed before and also 2 and 6 months after intervention.

Results:

Clinical symptoms and quality of life were improved with immunotherapy, but there was no significant difference between the placebo and synbiotic groups. Gene expression of IFN-γ, TGF-β, and FoxP3 was increased whereas the gene expression of IL-4 and IL-10 decreased, but not significant. Interestingly, the gene expression of IL-17 in the synbiotic group was significantly decreased versus placebo after 2 months (P = 0.001) and also at the end of intervention (P = 0.0001) comparing with the time zero.

Conclusion:

Significant reduction in the IL-17 gene expression following administration of synbiotic versus placebo shows the importance of synbiotic in control of the immunopathogenesis of AR. Further studies with more samples are recommended. In addition, evaluating the effects of synbiotic in patients who do not undergo immunotherapy is suggested to get a better conclusion.

Nutritional Modulation of Immune Function: Analysis of Evidence, Mechanisms, and Clinical Relevance

It is well-established that the nutritional deficiency or inadequacy can impair immune functions. Growing evidence suggests that for certain nutrients increased intake above currently recommended levels may help optimize immune functions including improving defense function and thus resistance to infection, while maintaining tolerance. This review will examine the data representing the research on prominent intervention agents n-3 polyunsaturated fatty acids (PUFA), micronutrients (zinc, vitamins D and E), and functional foods including probiotics and tea components for their immunological effects, working mechanisms, and clinical relevance. Many of these nutritive and non-nutritive food components are related in their functions to maintain or improve immune function including inhibition of pro-inflammatory mediators, promotion of anti-inflammatory functions, modulation of cell-mediated immunity, alteration of antigen-presenting cell functions, and communication between the innate and adaptive immune systems. Both animal and human studies present promising findings suggesting a clinical benefit of vitamin D, n-3 PUFA, and green tea catechin EGCG in autoimmune and inflammatory disorders, and vitamin D, vitamin E, zinc, and probiotics in reduction of infection. However, many studies report divergent and discrepant results/conclusions due to various factors. Chief among them, and thus call for attention, includes more standardized trial designs, better characterized populations, greater consideration for the intervention doses used, and more meaningful outcome measurements chosen.

Microbiome and Allergic Diseases

Allergic diseases, such as respiratory, cutaneous, and food allergy, have dramatically increased in prevalence over the last few decades. Recent research points to a central role of the microbiome, which is highly influenced by multiple environmental and dietary factors. It is well established that the microbiome can modulate the immune response, from cellular development to organ and tissue formation exerting its effects through multiple interactions with both the innate and acquired branches of the immune system. It has been described at some extent changes in environment and nutrition produce dysbiosis in the gut but also in the skin, and lung microbiome, inducing qualitative and quantitative changes in composition and metabolic activity. Here, we review the potential role of the skin, respiratory, and gastrointestinal tract (GIT) microbiomes in allergic diseases. In the GIT, the microbiome has been proven to be important in developing either effector or tolerant responses to different antigens by balancing the activities of Th1 and Th2 cells. In the lung, the microbiome may play a role in driving asthma endotype polarization, by adjusting the balance between Th2 and Th17 patterns. Bacterial dysbiosis is associated with chronic inflammatory disorders of the skin, such as atopic dermatitis and psoriasis. Thus, the microbiome can be considered a therapeutical target for treating inflammatory diseases, such as allergy. Despite some limitations, interventions with probiotics, prebiotics, and/or synbiotics seem promising for the development of a preventive therapy by restoring altered microbiome functionality, or as an adjuvant in specific immunotherapy.

Do probiotics have a role in the treatment of allergic rhinitis? A comprehensive systematic review and meta-analysis

OBJECTIVE

To investigate clinical evidence for the efficacy of probiotics in the treatment of allergic rhinitis (AR).

METHODS

A systematic search was conducted to review the results of all randomized, double-blind, placebo-controlled trials by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement. Primary outcome measurements were total nasal and ocular symptom scores (SS) and quality of life (QoL) questionnaires. Secondary outcome measurements were individual nasal SS and immunologic parameters.

RESULTS

Twenty-two randomized, double-blind, placebo-controlled studies were included. Seventeen trials showed significant benefit of probiotics clinically, whereas eight trials showed significant improvement in immunologic parameters compared with placebo. All five studies with Lactobacillus paracasei (LP) strains demonstrated clinically significant improvements compared with placebo. Probiotics showed significant reduction in nasal and ocular SS (standardized mean difference [SMD], -1.23, p < 0.001; and SMD, -1.84, p < 0.001; respectively), total, nasal, and ocular QoL scores compared with placebo (SMD, -1.84, p < 0.001; SMD, -2.30, p = 0.006; and SMD, -3.11, p = 0.005; respectively). Although heterogeneity was high, in subgroup analysis, SMD for total nasal and ocular symptoms with patients with seasonal AR and for nasal QoL scores for studies with LP-33 strain were significant and homogenous. Scores of nasal blockage, rhinorrhea, and nasal itching were significantly lower in the probiotic group compared with placebo. The meta-analysis studies SS the Japanese guidelines revealed a significant, homogenous SMD score of -0.34 for individual nasal SS, above the minimal important clinical difference value of 0.3. The T-helper 1 to T-helper 2 ratio was significantly lower in the probiotic group compared with placebo (SMD, -0.78; p = 0.045).

CONCLUSION

Despite high variability among the studies, synthesis of available data provided significant evidence of beneficial clinical and immunologic effects of probiotics in the treatment of AR, especially with seasonal AR and LP-33 strains. With the rising pool of studies, the most promising strains in specific allergies can be revealed and adjuvant therapy with probiotics can be recommended for the treatment of AR.

Individual strains of Lactobacillus paracasei differentially inhibit human basophil and mouse mast cell activation

INTRODUCTION

The microbiota controls a variety of biological functions, including immunity, and alterations of the microbiota in early life are associated with a higher risk of developing allergies later in life. Several probiotic bacteria, and particularly lactic acid bacteria, were described to reduce both the induction of allergic responses and allergic manifestations. Although specific probiotic strains were used in these studies, their protective effects on allergic responses also might be common for all lactobacilli.

METHODS

To determine whether allergic effector cells inhibition is a common feature of lactobacilli or whether it varies among lactobacilli strains, we compared the ability of 40 strains of the same Lactobacillus paracasei species to inhibit IgE-dependent mouse mast cell and human basophil activation.

RESULTS

We uncovered a marked heterogeneity in the inhibitory properties of the 40 Lactobacillus strains tested. These segregated into three to four clusters depending on the intensity of inhibition. Some strains inhibited both mouse mast cell and human basophil activation, others strains inhibited only one cell type and another group induced no inhibition of activation for either cell type.

CONCLUSIONS

Individual Lactobacillus strains of the same species differentially inhibit IgE-dependent activation of mouse mast cells and human basophils, two cell types that are critical in the onset of allergic manifestations. Although we failed to identify specific bacterial genes associated with inhibition by gene-trait matching analysis, our findings demonstrate the complexity of the interactions between the microbiota and the host. These results suggest that some L. paracasei strains might be more beneficial in allergies than others strains and provide the bases for a rational screening of lactic acid bacteria strains as next-generation probiotics in the field of allergy.

Oral administration of Lactobacillus paracasei NCC 2461 for the modulation of grass pollen allergic rhinitis: a randomized, placebo-controlled study during the pollen season

Background

The efficacy of Lactobacillus paracasei NCC 2461 in modulating allergic rhinitis was previously evaluated in two exploratory clinical studies. Oral administration with NCC 2461 reduced specific subjective symptoms following nasal provocation tests with controlled grass pollen allergen concentrations. Our aim was to confirm the anti-allergic effect of NCC 2461 in grass pollen allergic subjects exposed to natural doses of allergens during the pollen season.

Findings

A double-blind, randomized, placebo-controlled, parallel study was conducted with 131 grass pollen allergic subjects from May to July 2012 in concomitance with the pollen season in Berlin. NCC 2461 or placebo was administered daily for an 8-week period to adult subjects with clinical history of allergic rhinitis to grass pollen, positive skin prick test and IgE to grass pollen. During the 8 weeks, symptoms and quality of life questionnaires were filled out, and plasma was collected for IgE analysis at screening and at the end of the intervention. All subjects were included within a 5-day interval, ensuring exposure to similar air pollen counts for each individual during the trial period. The results obtained show that symptoms increased with pollen loads, confirming a natural exposure to the allergen and presence of pollen-induced allergic rhinitis in the subjects. However, no significant differences were observed in allergic rhinitis symptoms scores, quality of life, or specific IgE levels between subjects receiving NCC 2461 as compared to placebo administration.

Conclusion

In contrast to previous findings, oral administration of NCC 2461 did not show a beneficial effect on allergic rhinitis in a field trial. The influence of study design, allergen exposure and intervention window on the efficacy of NCC 2461 in modulating respiratory allergy should be further evaluated.

Electronic supplementary material

The online version of this article (doi:10.1186/s13601-015-0085-4) contains supplementary material, which is available to authorized users.

Trek1 contributes to maintaining nasal epithelial barrier integrity

Epithelial barrier integrity is critical to maintain the homeostasis in the body. The regulatory mechanism of the epithelial barrier function has not been fully understood. This study aims to elucidate the role of the TWIK-related potassium channel-1 (Trek1) in the regulation of the epithelial barrier function of the nasal mucosa. In this study, the levels of Trek1 were assessed by real time RT-PCR and Western blotting. The epithelial barrier function of the rat nasal epithelia was evaluated by the Ussing chamber system. The results showed that Trek1 was detected in the human and rat nasal epithelia, which were significantly lower in patients and rats with allergic rhinitis than that in healthy controls. Exposure to the signature T helper 2 cytokine, interleukin (IL)-4, markedly suppressed the expression of Trek1 in the nasal mucosa via up regulating the expression of the histone deacetylase (HDAC)1. The IL-4-induced rat nasal epithelial barrier dysfunction could be blocked by HDAC1 inhibitor (Trichostatin A), or sodium butyrate, or administration of Clostridium Butyricum. We conclude that Trek1 is critical to maintain the nasal epithelial barrier function.

House dust mite allergy: environment evaluation and disease prevention

There are two groups of dust mites, house dust mites (HDMs) and storage mites (SMs), that have been identified in the household environment. Both could induce airway inflammation through activation of innate and adaptive immunity and lead to asthma. In order to monitor environmental dust mite infestation, different methods can be used to detect their presence, such as the use of floating methods, monoclonal antibodies, and nanostructured biosensor. SM could be identified in the storage room, mainly in contaminated food such as mushrooms and corn starch. In HDM-sensitive subjects and mice that were challenged with HDM or SM after sensitization, these mites could up-regulate IgE levels, T helper 2 associated cytokine production and airway hypersensitivity. Different age groups of subjects were sensitized by different species of mites. More subjects above 70 years were sensitized by SM and more subjects below the age of 40 years were sensitized to HDM. Different allergenic components of dust mite extracts, such as Der p 1, Der p 2, could activate innate immunity through activating pattern recognition receptor (PRR) and then lead to allergic inflammation. The best modality to treat HDM allergy is immunomodulation through Treg cells and IgA production. In the recent years, many studies indicated probiotics could increase IgA secretion and the number of Treg cells. However, some studies conducted in adults have contradictory effects in reducing allergic symptoms. Therefore, probiotics confer inconclusive benefits on the allergic symptoms.

Current recommendations and emerging options for the treatment of allergic rhinitis

Allergic rhinitis (AR) is one of the most common diseases and represents a global health problem, currently affecting up to 30% of the general population, with a continuously increasing prevalence and significant comorbidities and complications. The aim of this review is to provide an update on AR treatment, with a focus on current therapies defined by AR and its impact on asthma guidelines and with a particular emphasis on new and future therapeutic perspectives.