Topical probiotics as a therapeutic alternative for chronic rhinosinusitis: A preclinical proof of concept

Host-microbe interactions in chronic rhinosinusitis biofilms and models for investigation

Chronic rhinosinusitis (CRS) is a debilitating condition characterized by long-lasting inflammation of the paranasal sinuses. It affects a significant portion of the population, causing a considerable burden on individuals and healthcare systems. The pathogenesis of CRS is multifactorial, with bacterial infections playing a crucial role in CRS development and persistence. In recent years, the presence of biofilms has emerged as a key contributor to the chronicity of sinusitis, further complicating treatment and exacerbating symptoms. This review aims to explore the role of biofilms in CRS, focusing on the involvement of the bacterial species Staphylococcus aureus and Pseudomonas aeruginosa, their interactions in chronic infections, and model systems for studying biofilms in CRS. These species serve as an example of how microbial interplay can influence disease progression and exemplify the need for continued investigation and innovation in CRS research.

Role of probiotics in chronic rhinosinusitis: a systematic review of randomised, controlled trials

OBJECTIVE

This review evaluated the safety profile and efficacy of probiotics in chronic rhinosinusitis and was registered with Prospero (Centre for Reviews and Dissemination number: 42020193529).

METHOD

Literature databases were searched through inception to August 2022. Randomised, controlled trials exploring adjunctive probiotics in adult chronic rhinosinusitis patients were included. From 948 records screened, 4 randomised, controlled trials were included.

RESULTS

Probiotics-associated adverse effects comprised epistaxis and abdominal pain. No reduction in Sino-Nasal Outcome Test values before 4 weeks (p = 0.58) or beyond 8 weeks (p = 0.08) of treatment or reduction of severe symptom frequency (p = 0.75) was observed. Symptom relapse in probiotic-treated patients was significantly lower across all timepoints (p = 0.045). Lower sinusitis relapse risks during treatment (risk ratio = 0.49; p = 0.019) and 8 months post-treatment (risk ratio = 0.56, p = 0.013) were observed. Probiotics demonstrated potential in improving Sino-Nasal Outcome Test symptom subscales, including sleep, psychological and rhinology subscales.

CONCLUSION

The optimal mode of probiotic administration, treatment duration and target patient subgroups requires further study to evaluate the utility of probiotics.

Fabrication of a microfluidic device for probiotic drug's dosage screening: Precision Medicine for Breast Cancer Treatment

Breast cancer is the most common cancer in women; it has been affecting the lives of millions each year globally and microfluidic devices seem to be a promising method for the future advancements in this field. This research uses a dynamic cell culture condition in a microfluidic concentration gradient device, helping us to assess breast anticancer activities of probiotic strains against MCF-7 cells. It has been shown that MCF-7 cells could grow and proliferate for at least 24 h; however, a specific concentration of probiotic supernatant could induce more cell death signaling population after 48 h. One of our key findings was that our evaluated optimum dose (7.8 mg/L) was less than the conventional static cell culture treatment dose (12 mg/L). To determine the most effective dose over time and the percentage of apoptosis versus necrosis, flowcytometric assessment was performed. Exposing the MCF-7 cells to probiotic supernatant after 6, 24 and 48 h, confirmed that the apoptotic and necrotic cell death signaling were concentration and time dependent. We have shown a case that these types of microfluidics platforms performing dynamic cell culture could be beneficial in personalized medicine and cancer therapy.

Chronic Rhinosinusitis, S. aureus Biofilm and Secreted Products, Inflammatory Responses, and Disease Severity

Chronic rhinosinusitis (CRS) is a persistent inflammation of the nasal cavity and paranasal sinuses associated with tissue remodelling, dysfunction of the sinuses’ natural defence mechanisms, and induction of different inflammatory clusters. The etiopathogenesis of CRS remains elusive, and both environmental factors, such as bacterial biofilms and the host’s general condition, are thought to play a role. Bacterial biofilms have significant clinical relevance due to their potential to cause resistance to antimicrobial therapy and host defenses. Despite substantial medical advances, some CRS patients suffer from recalcitrant disease that is unresponsive to medical and surgical treatments. Those patients often have nasal polyps with tissue eosinophilia, S. aureus-dominant mucosal biofilm, comorbid asthma, and a severely compromised quality of life. This review aims to summarise the contemporary knowledge of inflammatory cells/pathways in CRS, the role of bacterial biofilm, and their impact on the severity of the disease. Here, an emphasis is placed on S. aureus biofilm and its secreted products. A better understanding of these factors might offer important diagnostic and therapeutic perceptions for recalcitrant disease.

Antituberculosis Therapy and Gut Microbiota: Review of Potential Host Microbiota Directed-Therapies

Tuberculosis (TB) remains a major public health concern with millions of deaths every year. The overlap with HIV infections, long treatment duration, and the emergence of drug resistance are significant obstacles to the control of the disease. Indeed, the standard first-line regimen TB treatment takes at least six months and even longer for the second-line therapy, resulting in relapses, drug resistance and re-infections. Many recent reports have also shown prolonged and significant damage of the gut microbial community (dysbiosis) from anti-TB drugs that can detrimentally persist several months after the cessation of treatment and could lead to the impairment of the immune response, and thus re-infections and drug resistance. A proposed strategy for shortening the treatment duration is thus to apply corrective measures to the dysbiosis for a faster bacterial clearance and a better treatment outcome. In this review, we will study the role of the gut microbiota in both TB infection and treatment, and its potential link with treatment duration. We will also discuss, the new concept of "Host Microbiota Directed-Therapies (HMDT)" as a potential adjunctive strategy to improve the treatment effectiveness, reduce its duration and or prevent relapses. These strategies include the use of probiotics, prebiotics, gut microbiota transfer, and other strategies. Application of this innovative solution could lead to HMDT as an adjunctive tool to shorten TB treatment, which will have enormous public health impacts for the End TB Strategy worldwide.

The Role of Probiotics in Chronic Rhinosinusitis Treatment: An Update of the Current Literature

Chronic rhinosinusitis (CRS) is a significant health problem. It affects 5–12% of the general population. The causes that underlie the onset of CRS are not yet well known. However, many factors may contribute to its onset, such as environmental factors and the host’s general condition. Medical treatment mainly uses local corticosteroids, nasal irrigation, and antibiotics. In recent years, a new therapeutic approach that employs the use of probiotics emerged. Probiotics have been extensively studied as a therapy for dysbiosis and inflammatory pathologies of various parts of the body. We aimed to examine the studies in vivo and in vitro and clinicals reports in the existing literature to update probiotics’ role in rhinosinusitis chronic medical treatment.

In vitro and in vivo evaluation of probiotic properties of Corynebacterium accolens isolated from the human nasal cavity

Corynebacterium accolens strains are increasingly recognized as beneficial bacteria that can confer a health benefit on the host. In the current study, the probiotic potential of three C. accolens strains, C779, C781 and C787 derived from a healthy human nasal cavity were investigated. These strains were examined for their adhesion to HNECs, competition with Staphylococcus aureus for adhesion, toxicity, induction of IL-6, antibiotic susceptibility and the presence of antibiotic resistance and virulence genes. Furthermore, the safety and efficacy of strains were evaluated in vivo using Caenorhabditis elegans. The adhesion capacity of C. accolens to HNECs was strain-dependent. Highest adhesion was observed for strain C781. None of the C. accolens strains tested caused cell lysis. All strains were able to outcompete S. aureus for cell adhesion and caused a significant decrease of IL-6 production by HNECs co-exposed to S. aureus when compared to the control groups. All strains were sensitive or showed intermediate sensitivity to 10 different antibiotics. Whole Genome Sequence analysis showed C. accolens C781 and C787 did not possess antibiotic resistance genes whereas strain C779 harboured 5 genes associated with resistance to Aminoglycoside, Chloramphenicol and Erythromycin. In addition, no virulence genes were detected in any of the 3 strains. Moreover, the tested strains had no detrimental effect on worm survival and induced protection from S. aureus-mediated infection. Taken all together, C. accolens strains, C781 and C787 displayed probiotic potential and hold promise for use in clinical applications for combating dysbiosis in chronic rhinosinusitis.

The Upper Airway Microbiota, Environmental Exposures, Inflammation, and Disease

Along with playing vital roles in pathogen exclusion and immune system priming, the upper airways (UAs) and their microbiota are essential for myriad physiological functions such as conditioning and transferring inhaled air. Dysbiosis, a microbial imbalance, is linked with various diseases and significantly impedes the quality of one’s life. Daily inhaled exposures and/or underlying conditions contribute to adverse changes to the UA microbiota. Such variations in the microbial community exacerbate UA and pulmonary disorders via modulating inflammatory and immune pathways. Hence, exploring the UA microbiota’s role in maintaining homeostasis is imperative. The microbial composition and subsequent relationship with airborne exposures, inflammation, and disease are crucial for strategizing innovating UA diagnostics and therapeutics. The development of a healthy UA microbiota early in life contributes to normal respiratory development and function in the succeeding years. Although different UA cavities present a unique microbial profile, geriatrics have similar microbes across their UAs. This lost community segregation may contribute to inflammation and disease, as it stimulates disadvantageous microbial–microbial and microbial–host interactions. Varying inflammatory profiles are associated with specific microbial compositions, while the same is true for many disease conditions and environmental exposures. A shift in the microbial composition is also detected upon the administration of numerous therapeutics, highlighting other beneficial and adverse side effects. This review examines the role of the UA microbiota in achieving homeostasis, and the impact on the UAs of environmental airborne pollutants, inflammation, and disease.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

Microbiomics of irrigation with xylitol or Lactococcus lactis in chronic rhinosinusitis

OBJECTIVE

Topical sinonasal rinse therapies may alter the local microbiome and improve disease control in chronic rhinosinusitis (CRS). The objective of this study was to examine microbiome changes in post-surgical CRS patients when rinsing with commercially available products containing xylitol or Lactococcus lactis.

METHODS

A crossover-type protocol with a washout period was designed. Swab samples from anterior ethmoid cavities of CRS patients were collected prospectively at baseline. Subjects were provided packets containing either L. lactis W136 or xylitol in non-blinded fashion and instructed to add it to their rinse bottles daily for 28 days, after which another swab was taken. A saline wash-out period was completed and a third swab taken. A final 28-day regimen of the opposite product was followed by a final swab. DNA extraction and sequencing of the 16S rRNA gene allowed for global microbiome analysis.

RESULTS

We enrolled 25 subjects with CRS and 10 controls resulting in 70 adequate samples. Increased detection of Lactococcus was observed after use of L. lactis. No significant trends in alpha or beta diversity as a result of treatment were observed. SNOT-22 score did not change significantly following treatment with xylitol, L. lactis, or saline.

CONCLUSION

We did not detect any major clinical or microbiome-level effect due to treatment with two topical rinse products. Further research is needed to elucidate their clinical utility and possible probiotic effect.

LEVEL OF EVIDENCE

3.

[Neutrophil extracellular traps in the pathogenesis of chronic rhinosinusitis]

The review presents the current understanding of the pathogenesis of chronic rhinosinusitis. The causes of damage to the mucous membrane of the paranasal sinuses are most often the result of a combination of immunological, infectious and anatomical factors. This indicates the need for a multidisciplinary approach to the study of the pathogenesis of this pathology. There is no single universally recognized classification of chronic rhinosinusitis, which takes into account histological and immunological changes in the mucous membrane of the paranasal sinuses. The discovery of the mechanism of completion of the life cycle of neutrophils - the formation of a neutrophil extracellular trap or NETosis, different from necrosis and apoptosis, opened up new prospects in the study of the pathogenesis of inflammatory processes, including rhinosinusitis. Neutrophil extracellular traps reduce the permeability of the epithelial barrier in the mucous membrane of the paranasal sinuses. This determines their possible role in the etiopathogenesis of rhinosinusitis. In recent years, more and more attention has been paid to the feasibility, effectiveness and safety of therapy that affects the immune component of the inflammatory process, including NETosis. The data obtained in the study of extracellular traps can be used in clinical practice. It is neutrophil extracellular traps that can become a potential target in the treatment of patients with chronic rhinosinusitis.

Intranasal Application of Lactococcus lactis W136 Is Safe in Chronic Rhinosinusitis Patients With Previous Sinus Surgery

Objective: Modulation of the dysbiotic gut microbiome with “healthy” bacteria via a stool transplant or supplementation is increasingly practiced, however this approach has not been explored in the nasal passages. We wished to verify whether Lactococcus lactis W136 (L. lactis W136) bacteria could be safely applied via irrigation to the nasal and sinus passages in individuals with chronic rhinosinusitis (CRS) with previous undergone endoscopic sinus surgery, and whether this was accompanied by bacterial community flora modification.

Study Design: Prospective open-label pilot trial of safety and feasibility.

Setting: Academic tertiary hospital center.

Subjects and Methods: Twenty-four patients with CRS refractory to previous medical and surgical therapy received a 14-day course of BID sinus irrigations containing 1.2 × 10⁹ CFU live L. lactis W136. Patients were monitored for safety using questionnaire, sinus endoscopy, otoscopy, UPSIT-40 smell testing, and endoscopically-obtained conventional sinus culture and a swab for 16S microbiome profiling.

Results: All 24 patients receiving at least one treatment successfully completed treatment. L. lactis W136 probiotic treatment was safe, with no major adverse events or new infections. Treatment was associated with improvement in sinus symptoms, QOL, and mucosal scores, which remained improved during the subsequent 14-day observation period. Microbiome changes associated with treatment were limited to an increase of the pathobiont Dolosigranulum pigrum, a bacteria identified as potentially beneficial in the upper airways. Subgroup analysis suggested differences in microbiomes and responses for CRSsNP and CRSwNP phenotypes, but these did not attain significance.

Conclusion: Intranasal irrigation of live L. lactis W136 bacteria to patients with refractory chronic rhinosinusitis was safe, and was associated with effects on symptoms, mucosal aspect and microbiome composition. Intranasal bacteria may thus find a role as a treatment strategy for CRS.

Clinical Trials Registration:www.ClinicalTrials.gov. identifier: NCT04048174.

Lacticaseibacillus casei AMBR2 modulates the epithelial barrier function and immune response in a donor-derived nasal microbiota manner

Live biotherapeutic products (LBP) are emerging as alternative treatment strategies for chronic rhinosinusitis. The selection of interesting candidate LBPs often involves model systems that do not include the polymicrobial background (i.e. the host microbiota) in which they will be introduced. Here, we performed a screening in a simplified model system of upper respiratory epithelium to assess the effect of nasal microbiota composition on the ability to attach and grow of a potential LBP, Lacticaseibacillus casei AMBR2, in this polymicrobial background. After selecting the most permissive and least permissive donor, L. casei AMBR2 colonisation in their respective polymicrobial backgrounds was assessed in more physiologically relevant model systems. We examined cytotoxicity, epithelial barrier function, and cytokine secretion, as well as bacterial cell density and phenotypic diversity in differentiated airway epithelium based models, with or without macrophage-like cells. L. casei AMBR2 could colonize in the presence of both selected donor microbiota and increased epithelial barrier resistance in presence of donor-derived nasal bacteria, as well as anti-inflammatory cytokine secretion in the presence of macrophage-like cells. This study highlights the potential of L. casei AMBR2 as LBP and the necessity to employ physiologically relevant model systems to investigate host–microbe interaction in LBP research.

The impact of Lactococcus lactis (probiotic nasal rinse) co-culture on growth of patient-derived strains of Pseudomonas aeruginosa

BACKGROUND

The Lactococcus strain of bacteria has been introduced as a probiotic nasal rinse for alleged salubrious effects on the sinonasal bacterial microbiome. However, data regarding interactions with pathogenic bacteria within the sinuses are lacking. The purpose of this study is to assess the interaction between L. lactis and patient-derived Pseudomonas aeruginosa, an opportunistic pathogen in recalcitrant chronic rhinosinusitis (CRS).

METHODS

Commercially available probiotic suspension containing L. lactis W136 was grown in an anaerobic chamber and colonies were isolated. Colonies were co-cultured with patient-derived P. aeruginosa strains in the presence of porcine gastric mucin (mimicking human mucus) for 72 hours. P. aeruginosa cultures without L. lactis served as controls. Colony forming units (CFUs) were compared.

RESULTS

Six P. aeruginosa isolates collected from 5 CRS patients (3 isolates from cystic fibrosis [CF], 1 mucoid strain) and laboratory strain PAO1 were co-cultured with L. lactis. There was no statistical difference in CFUs of 5 P. aeruginosa isolates grown with L. lactis compared to CFUs without presence of L. lactis. CFU counts were much higher when the mucoid strain was co-cultured with L. lactis (CFU+L.lactis = 1.9 × 108 ± 1.44 × 107, CFU-L.lactis = 1.3 × 108 ± 8.9 × 106, p = 0.01, n = 7). L. lactis suppressed the growth of 1 P. aeruginosa strain (CFU+L.lactis = 2.15 × 108 ± 2.9 × 107, CFU-L.lactis = 3.95 × 108 ± 4.8 × 106, p = 0.03, n = 7).

CONCLUSION

L. lactis suppressed the growth of 1 patient P. aeruginosa isolate and induced growth of another (a mucoid strain) in in vitro co-culture setting in the presence of mucin. Further experiments are required to assess the underlying interactions between L. lactis and P. aeruginosa.

Future topical medications in chronic rhinosinusitis

BACKGROUND

Research has progressed rapidly in recent decades to better understand the etiopathogenesis and management paradigms of chronic rhinosinusitis (CRS). Although oral antibiotics often mitigate symptoms in acute CRS exacerbations, eradication of polymicrobial biofilms and multidrug-resistant bacteria remains a challenge. The goal of this review is to summarize and discuss the potential and pitfalls of topical medications in the treatment of CRS.

METHODS

A related literature review was performed using PubMed and Scopus, with only the English database included.

RESULTS

The main therapies were selected and separated in sections. Details regarding future topical treatments of CRS were summarized and discussed.

CONCLUSION

The ease of access of the sinonasal mucosa positions CRS as a disease with high potential for local topical treatment. The ultimate adoption of topical agents will require continued expansion of our understanding of novel local targets in CRS as well as improved methods to deliver and retain the drug of interest at the site of activity.

Health Benefits of Heat-Killed (Tyndallized) Probiotics: An Overview

Nowadays, the oral use of probiotics is widespread. However, the safety profile with the use of live probiotics is still a matter of debate. Main risks include: Cases of systemic infections due to translocation, particularly in vulnerable patients and pediatric populations; acquisition of antibiotic resistance genes; or interference with gut colonization in neonates. To avoid these risks, there is an increasing interest in non-viable microorganisms or microbial cell extracts to be used as probiotics, mainly heat-killed (including tyndallized) probiotic bacteria (lactic acid bacteria and bifidobacteria). Heat-treated probiotic cells, cell-free supernatants, and purified key components are able to confer beneficial effects, mainly immunomodulatory effects, protection against enteropathogens, and maintenance of intestinal barrier integrity. At the clinical level, products containing tyndallized probiotic strains have had a role in gastrointestinal diseases, including bloating and infantile coli-in combination with mucosal protectors-and diarrhea. Heat-inactivated probiotics could also have a role in the management of dermatological or respiratory allergic diseases. The reviewed data indicate that heat-killed bacteria or their fractions or purified components have key probiotic effects, with advantages versus live probiotics (mainly their safety profile), positioning them as interesting strategies for the management of common prevalent conditions in a wide variety of patients´ characteristics.

Cutting Edge: Probiotics and Fecal Microbiota Transplantation in Immunomodulation

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

Inflammation and Endotyping in Chronic Rhinosinusitis-A Paradigm Shift

Chronic rhinosinusitis (CRS) is a heterogeneous chronic inflammatory condition of the paranasal sinuses and nasal passage. It is characterized as inflammation of the sinonasal passage, presenting with two or more symptoms (nasal blockage, secretions, facial pain and headaches) for more than 12 weeks consecutively. The disease is phenotypically differentiated based on the presence of nasal polyps; CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). Traditionally, CRSwNP has been associated with a type 2 inflammatory profile, while CRSsNP has been associated with a type 1 inflammatory profile. Extensive work in characterizing the inflammatory profiles of CRS patients has challenged this dichotomy, with great variation both between and within populations described. Recent efforts of endotyping CRS based on underlying pathophysiology have further highlighted the heterogeneity of the disease, revealing mixed inflammatory profiles coordinated by a number of inflammatory cell types. This review will highlight the current understanding of inflammation in CRS, and discuss the importance and impact of refining this understanding in the development of appropriate treatment options for CRS sufferers.

The microbiome and chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a multifactorial condition in which the microbiota plays a pathogenic role. The nature of the interaction between the microbiota and the local immune system is very complex and has not been fully elucidated. Recent improvements in the microbiological techniques have greatly advanced our understanding of the complex nature of this interaction. This paper summarizes the current state of the rapidly evolving research on this subject. Defining the nature of the role of the microbiota in CRS is important because of the associated therapeutic implications.

Probiotics for the airways: Potential to improve epithelial and immune homeostasis

Probiotics are live microorganisms that, when administered in adequate amounts, confer health benefit on the host. The therapeutic effects of probiotics have been mostly studied in the gastrointestinal tract, but recent evidence points toward the potential of these bacteria to prevent and/or treat chronic airway diseases. In this review, possible mechanisms of action of probiotics in the airways are described, with a particular focus on their capacity to modulate the epithelial barrier function and their mode of interaction with the immune system. Indeed, probiotic bacteria, mostly lactobacilli, can promote the expression and regulation of tight junctions and adherence junctions, resulting in the restoration of a defective epithelial barrier. These bacteria interact with the epithelial barrier and immune cells through pattern recognition receptors, such as Toll-like receptors, which upon activation can stimulate or suppress various immune responses. Finally, the clinical potential of probiotics to treat inflammatory diseases of the upper and lower respiratory tract, and the difference between their mode of application (eg, oral or nasal) are discussed here.

Microbiota Composition and the Integration of Exogenous and Endogenous Signals in Reactive Nasal Inflammation

The prevalence of reactive nasal inflammatory conditions, for example, allergic rhinitis and chronic rhinosinusitis, is steadily increasing in parallel with significant environmental changes worldwide. Allergens and as yet undefined environmental agents may trigger these conditions via the involvement of host intrinsic factors, including the innate and adaptive immune system, the nasal epithelium, and the nasal nervous system. The critical role of the nasal microbiota in coordinating these components has emerged in recent studies documenting a significant association between microbial composition and the onset and progression of allergic or nonallergic inflammation. It is now clear that the local microbiota is a major player in the development of the mucosa-associated lymphoid tissue and in the regulation of such adaptive responses as IgA production and the function of effector and regulatory T cells. Microbial components also play a major role in the regulation of epithelial barrier functions, including mucus production and the control of paracellular transport across tight junctions. Bacterial components, including lipopolysaccharide, have also been shown to induce or amplify neuroinflammatory responses by engaging specific nociceptors. Finally, bacterial products may promote tissue remodeling processes, including nasal polyp formation, by interacting with formyl peptide receptors and inducing the expression of angiogenic factors and matrix-degrading enzymes.

Microbiota transplantation: concept, methodology and strategy for its modernization

Fecal microbiota transplantation (FMT) has become a research focus of biomedicine and clinical medicine in recent years. The clinical response from FMT for different diseases provided evidence for microbiota-host interactions associated with various disorders, including Clostridium difficile infection, inflammatory bowel disease, diabetes mellitus, cancer, liver cirrhosis, gut-brain disease and others. To discuss the experiences of using microbes to treat human diseases from ancient China to current era should be important in moving standardized FMT forward and achieving a better future. Here, we review the changing concept of microbiota transplantation from FMT to selective microbiota transplantation, methodology development of FMT and step-up FMT strategy based on literature and state experts' perspectives.

The Potential for Topical Probiotic Treatment of Chronic Rhinosinusitis, a Personal Perspective

This review describes the rationale for topical probiotic intervention, the obstacles we are facing and a strategy for future research in the use of probiotics to modify CRS symptoms and disease expression. Recent advances in molecular microbiology has revealed a plethora of microbial DNA in the nasal cavity and sinuses of healthy subjects as well as in chronic sinusitis (CRS) patients. An infection is today rather seen as an imbalance between the commensal microbiome and the bacterial pathogens, resulting in a reduction in commensal bacterial diversity, combined with an increase in the growth of microbes eliciting an inflammatory response. This will in turn lead to the clinical symptoms of sinusitis. Probiotics (microorganisms that confer a health benefit) can be used either as a form of living antibiotics treatment, or as an immune-modulatory intervention. Topical probiotics, which is the focus of this review, have shown efficacy in a limited number of trials in otitis media and tonsillitis, but to date not in CRS. Although bacterial interference capacity against pathogens can be determined in in vitro experiments, it may not translate to a health benefit. This limits the role of laboratory research in identifying probiotic strains with a clinical benefit. To gain more clinical experience without further delay, I recommend future research to focus on empirical clinical trials in well-defined CRS patient populations and study the underlying mechanisms in more detail once a clinical benefit has been established.

Therapy of Sinonasal Microbiome in CRS: A Critical Approach

PURPOSE OF REVIEW

Perturbations in local microbiota have been demonstrated in many chronic inflammatory diseases including chronic rhinosinusitis (CRS). The purpose of this paper is to review the latest microbiome research as it pertains to CRS and establish whether there is any evidence supporting the microbiome hypothesis for CRS. Treatment factors that may influence the sinonasal microbiome as well as the role of probiotics are also discussed.

RECENT FINDINGS

Despite significant heterogeneity in study design, tissue sampling, processing and bioinformatics analysis, consistent findings have emerged from the recent literature. Healthy individuals and CRS patients have similar overall bacterial burden of disease and share many common phylum. CRS patients, however, routinely show reductions in markers of biodiversity. Both medical and surgical treatments appear to influence the sinonasal microbiome, with certain bacterial strains associated with better treatment outcomes. The presence of microbial dysbiosis in CRS is now supported by numerous studies. Whether this dysbiosis is a cause or rather an association of the disease process still remains unclear. Although probiotic therapies show early promise, much larger studies are required to establish their real role as a treatment for CRS.

Probiotics for Modification of the Incidence or Severity of Respiratory Tract Infections

There is increasing interest in probiotics for therapy and prevention of infectious diseases. There are no published trials of probiotics as therapy for respiratory tract infections (RTIs) in children or adults. There is low quality, inconsistent evidence for the efficacy of probiotics for prevention of RTIs or ventilator-associated pneumonia or for modification of the severity of RTIs.