Publications by authors named "Liam O' Mahony"

The underlying mechanisms used by the intestinal microbiota to shape disease outcomes of the host are poorly understood. Here, we show that the gut commensal protozoan, Tritrichomonas musculis (T.mu), remotely shapes the lung immune landscape to facilitate perivascular shielding of the airways by eosinophils.

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Protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and risk of long COVID has been associated with the depletion or over-abundance of specific taxa within the gut microbiome. However, the microbial mechanisms mediating these effects are not yet known. We hypothesized that altered microbial production of tryptophan and its downstream derivatives might contribute to inappropriate immune responses to viral infection.

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Article Synopsis
  • Rifampicin is an important antibiotic used to treat infections caused by staphylococci that form biofilms, especially in patients with orthopedic devices.
  • A pilot study showed that patients treated with rifampicin for these infections developed staphylococci strains resistant to rifampicin during treatment.
  • This antibiotic resistance persisted in patients for up to 2 months after they stopped taking rifampicin.
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Human skin is colonized with skin microbiota that includes commensal bacteria, fungi, arthropods, archaea and viruses. The composition of the microbiota varies at different anatomical locations according to changes in body temperature, pH, humidity/hydration or sebum content. A homeostatic skin microbiota is crucial to maintain epithelial barrier functions, to protect from invading pathogens and to interact with the immune system.

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This European Academy of Allergy and Clinical Immunology (EAACI) guideline provides recommendations for the management of IgE-mediated food allergy and was developed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Following the confirmation of IgE-mediated food allergy diagnosis, allergen avoidance and dietary advice (with support of a specialised dietitian, if possible) together with the provision of a written treatment plan, education on the recognition of allergic symptoms and prescription of medication including adrenaline using an auto-injector are essential. Patients with significant anxiety and requirement for coping strategies may benefit from support from a clinical psychologist.

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The prevalence of many chronic noncommunicable diseases has been steadily rising over the past six decades. During this time, over 350,000 new chemical substances have been introduced to the lives of humans. In recent years, the epithelial barrier theory came to light explaining the growing prevalence and exacerbations of these diseases worldwide.

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Background: Consumption of ultra-processed foods [UPFs] may be associated with negative health outcomes. Limited data exist regarding the potential role of UPFs in the occurrence of allergic diseases. The underlying mechanisms underpinning any such associations are also poorly elucidated.

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Article Synopsis
  • The study explored the link between maternal diet during pregnancy and infant diet diversity on the development of allergic diseases in children.
  • It used medical records and self-reported diet information to analyze the risk of various allergies between ages 1 and 4.
  • Findings showed that both better maternal diets and diverse infant diets at 1 year are associated with a lower risk of allergic diseases, highlighting important areas for preventive health strategies.
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The term long COVID (LC) effectively describes the broad long-term disease burden of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infections, encompassing individual suffering and significant socioeconomic impacts. However, its general use hampers precise epidemiological research, diagnostics and therapeutic strategies. Misinterpretations occur, for example, when population surveys are compared to studies using health record data, because both refer to these data as LC.

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Article Synopsis
  • * Key discussions included the prevalence of AD, advancements in treatment and management, and the importance of considering environmental and lifestyle factors affecting patients.
  • * The forum emphasizes the need for increased awareness and collaboration among stakeholders to close the gap between research advancements and practical applications in patient care.
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This systematic review and meta-analysis aimed to consolidate evidence on dietary interventions for atopic eczema/dermatitis (AD) skin symptoms in children without food allergies, following PRISMA 2020 guidelines. Systematic review updates were conducted in May 2022 and June 2023, focusing on randomized placebo-controlled trials (RCTs) involving children with AD but without food allergies. Specific diets or supplements, such as vitamins, minerals, probiotics, prebiotics, symbiotics, or postbiotics, were explored in these trials.

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Mechanisms underlying the disruption of self-tolerance in acquired autoimmunity remain unclear. Immunoglobulin A (IgA) nephropathy is an acquired autoimmune disease where deglycosylated IgA1 (IgA subclass 1) auto-antigens are recognized by IgG auto-antibodies, forming immune complexes that are deposited in the kidneys, leading to glomerulonephritis. In the intestinal microbiota of patients with IgA nephropathy, there was increased relative abundance of mucin-degrading bacteria, including .

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  • Guidelines for treating asthma exacerbations typically recommend bronchodilators and corticosteroids, but antibiotic use is often overlooked despite frequent prescriptions in practice.
  • A survey involving 252 healthcare professionals revealed a 19% antibiotic prescription rate for asthma exacerbations, with significant variation among different specialties like pediatrics, pulmonology, general practice, and allergy.
  • The study highlights the need for evidence-based guidelines to ensure more rational use of antibiotics in treating asthma exacerbations, especially considering factors like purulent sputum, fever, and comorbidities that influence prescription decisions.
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Background: Several hypotheses link reduced microbial exposure to increased prevalence of allergies. Here we capitalize on the opportunity to study a cohort of infants (CORAL), raised during COVID-19 associated social distancing measures, to identify the environmental exposures and dietary factors that contribute to early life microbiota development and to examine their associations with allergic outcomes.

Methods: Fecal samples were sequenced from infants at 6 (n = 351) and repeated at 12 (n = 343) months, using 16S sequencing.

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Article Synopsis
  • The study looked at how short chain fatty acids (SCFAs), which come from gut bacteria, might be connected to allergies.
  • They reviewed 37 papers, focusing on SCFAs during pregnancy and early childhood, and their relationship with allergic diseases like eczema and asthma.
  • The results suggested that certain SCFAs might help protect against allergies, but more research is needed to understand how and when they work best.
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Background: Allergic diseases, including respiratory and food allergies, as well as allergic skin conditions have surged in prevalence in recent decades. In allergic diseases, the gut microbiome is dysbiotic, with reduced diversity of beneficial bacteria and increased abundance of potential pathogens. Research findings suggest that the microbiome, which is highly influenced by environmental and dietary factors, plays a central role in the development, progression, and severity of allergic diseases.

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Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can result in a prolonged multisystem disorder termed long COVID, which may affect up to 10% of people following coronavirus disease 2019 (COVID-19). It is currently unclear why certain individuals do not fully recover following SARS-CoV-2 infection.

Summary: In this review, we examine immunological mechanisms that may underpin the pathophysiology of long COVID.

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Acute respiratory infections are a major cause of morbidity and mortality in children worldwide. Dietary and nutritional interventions, including minerals and vitamin supplementation, have been explored as potential treatments for these infections. However, the evidence on their efficacy is limited and inconclusive.

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Nutritional Immunity is one of the most ancient innate immune responses, during which the body can restrict nutrients availability to pathogens and restricts their uptake by the gut mucosa (mucosal block). Though this can be a beneficial strategy during infection, it also is associated with non-communicable diseases-where the pathogen is missing; leading to increased morbidity and mortality as micronutritional uptake and distribution in the body is hindered. Here, we discuss the acute immune response in respect to nutrients, the opposing nutritional demands of regulatory and inflammatory cells and particularly focus on some nutrients linked with inflammation such as iron, vitamins A, Bs, C, and other antioxidants.

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Immunoregulatory polysaccharides from probiotic bacteria have potential in biomedical engineering. Here, a negatively charged exopolysaccharide from with confirmed immunoregulatory activity (EPS624) was applied in multilayered polyelectrolyte coatings with positively charged chitosan. EPS624 and coatings (1, 5, and 10 layers and alginate-substituted) were characterized by the zeta potential, dynamic light scattering, size exclusion chromatography, scanning electron microscopy, and atomic force microscopy.

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This European Academy of Allergy and Clinical Immunology guideline provides recommendations for diagnosing IgE-mediated food allergy and was developed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Food allergy diagnosis starts with an allergy-focused clinical history followed by tests to determine IgE sensitization, such as serum allergen-specific IgE (sIgE) and skin prick test (SPT), and the basophil activation test (BAT), if available. Evidence for IgE sensitization should be sought for any suspected foods.

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Article Synopsis
  • The rapid advancement of precision diagnostic tools and omic technologies has led to the identification of new disease endotypes for allergic conditions, improving our understanding of diseases beyond just symptoms.
  • This shift has prompted a reevaluation of current disease classifications, ultimately leading to the development of a modern nomenclature for allergic diseases that acknowledges historical classifications.
  • The paper details a comprehensive framework for hypersensitivity reactions, categorizing them into nine types based on mechanisms and responses, with plans for a follow-up article addressing the practical implications in allergy treatment and management.
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Introduction: The CORAL study is a cohort of infants born during the first weeks of the first SARS-CoV-2 (COVID-19) lockdown. This cohort has had lower antibiotic exposure, higher breastfeeding rates and lower infection rates, especially in the first year of life. We hypothesized that the altered early-life environment of infants born during lockdown would change the incidence of allergic conditions.

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COVID-19, a systemic multi-organ disease resulting from infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is known to result in a wide array of disease outcomes, ranging from asymptomatic to fatal. Despite persistent progress, there is a continued need for more accurate determinants of disease outcomes, including post-acute symptoms after COVID-19. In this study, we characterised the serum metabolomic changes due to hospitalisation and COVID-19 disease progression by mapping the serum metabolomic trajectories of 71 newly hospitalised moderate and severe patients in their first week after hospitalisation.

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