Publications by authors named "Michael Hoggard"

Article Synopsis
  • Global rise in metabolic disorders like type 2 diabetes, especially in Asian populations, demands new dietary intervention strategies.
  • The Tū Ora study assessed the effects of a higher-protein nut bar (HP-NB) versus a higher-carbohydrate cereal bar (HC-CB) on gut microbiomes in 84 Chinese participants over 12 weeks.
  • Results showed minimal differences in gut microbiome composition between the two diets, indicating that the dietary changes might not be substantial enough to significantly impact the gut microbiome and its relation to metabolic health.
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Viruses are key members of microbial communities that exert control over host abundance and metabolism, thereby influencing ecosystem processes and biogeochemical cycles. Aquifers are known to host taxonomically diverse microbial life, yet little is known about viruses infecting groundwater microbial communities. Here, we analysed 16 metagenomes from a broad range of groundwater physicochemistries.

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Obesity-related metabolic diseases such as type 2 diabetes (T2D) are major global health issues, affecting hundreds of millions of people worldwide. The underlying factors are both diverse and complex, incorporating biological as well as cultural considerations. A role for ethnicity - a measure of self-perceived cultural affiliation which encompasses diet, lifestyle and genetic components - in susceptibility to metabolic diseases such as T2D is well established.

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Introduction: Paediatric tonsillar hyperplasia (TH) is associated with a spectrum of presentations ranging from recurrent tonsillitis (RT) to sleep-disordered breathing (SDB). The underlying pathogenesis of tonsillar hyperplasia remains poorly understood. Previous studies have implicated bacterial microcolonies as targets of host inflammatory cells and as a potential driver of the chronic inflammation seen in TH.

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Introduction: The pathophysiology and temporal dynamics of affected tissues in chronic rhinosinusitis (CRS) remain poorly understood. Here, we present a multiomics-based time-series assessment of nasal polyp biopsies from three patients with CRS, assessing natural variability over time and local response to systemic corticosteroid therapy.

Methods: Polyp tissue biopsies were collected at three time points over two consecutive weeks.

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Background: Chronic rhinosinusitis (CRS) is a spectrum of complex inflammatory conditions of the sinonasal mucosa. Identification of biomarkers that enable classification and improved delineation among CRS endotypes is of increasing interest. However, the extent to which less invasive sampling methods identify genuine tissue inflammatory patterns is not well understood.

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There is a pressing need for longitudinal studies which examine the stability of the sinonasal microbiota. In this study, we investigated bacterial and fungal community composition of the sinuses of four healthy individuals every month for one year, then once every three months for an additional year to capture seasonal variation. Sequencing of bacterial 16S rRNA genes and fungal ITS2 revealed communities that were mainly dominated by members of Actinobacteria and Basidiomycota, respectively.

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Chronic rhinosinusitis (CRS) is a heterogeneous condition characterized by persistent sinus inflammation and microbial dysbiosis. This study aimed to identify clinically relevant subgroups of CRS patients based on distinct microbial signatures, with a comparison to the commonly used phenotypic subgrouping approach. The underlying drivers of these distinct microbial clusters were also investigated, together with associations with epithelial barrier integrity.

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Introduction: Adenotonsillar and middle ear diseases result in some of the most frequently performed operations in the pediatric population worldwide. The pathogen reservoir hypothesis (PRH) suggests that the adenoids act as a reservoir of bacteria which play a potential pathogenic role in otitis media. Evidence supporting this hypothesis is limited.

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A complex mix of inflammatory and microbial associations underscores the chronic inflammatory condition chronic rhinosinusitis (CRS), and the etiology remains poorly understood. Recent work has begun to delineate between variants (endotypes) of CRS on the basis of inflammatory biomarkers. This study aimed to assess inflammatory patterns in CRS phenotypes, identify putative endotypes of CRS, and to assess inflammatory associations with the sinonasal microbiota.

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Interest in the human microbiome has increased dramatically in the last decade. However, much of this research has focused on bacteria, while the composition and roles of their fungal counterparts remain less understood. Furthermore, a variety of methodological approaches have been applied, and the comparability between studies is unclear.

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Introduction: Culture-independent methods, based on bacterial 16 S rRNA gene sequencing, have been used previously to investigate the adenotonsillar microbiota. However, these studies have focused on a single sampling site (usually a surface swab). We aimed to investigate potential differences in adenotonsillar microbiota according to sampling location, both on and within the adenoids and palatine tonsils.

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Introduction: Obstructive sleep apnea (OSA) is now a more common indication for tonsillectomy than recurrent tonsillitis (RT) [1,2]. Few studies have addressed possible differences in pathogenesis between these two conditions. Children with RT and OSA are often being treated in the community with multiple courses of antibiotics before surgery.

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Background: Antibiotics and corticosteroids are prescribed to patients with chronic rhinosinusitis (CRS) to reduce bacterial burden and mucosal inflammation. Unfortunately, clinical improvement is often short-lived and symptoms frequently recur following cessation of treatment. The impact of these systemic therapies on bacterial communities is not well understood.

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Background: The complex relationships between the human microbiota, the immune system, and the brain play important roles in both health and disease, and have been of increasing interest in the study of chronic inflammatory mucosal conditions. We hypothesized that the sinonasal microbiota may act as a modifier of interkingdom neural signaling and, subsequently, mental health, in the upper respiratory inflammatory condition chronic rhinosinusitis (CRS). In this study we investigated associations between the sinonasal microbiota; local concentrations of the neurotransmitters serotonin, dopamine, and γ-aminobutyric acid (GABA); and depression severity in a cohort of 14 CRS patients and 12 healthy controls.

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Chronic rhinosinusitis (CRS) encompasses a heterogeneous group of debilitating chronic inflammatory sinonasal diseases. Despite considerable research, the etiology of CRS remains poorly understood, and debate on potential roles of microbial communities is unresolved. Modern culture-independent (molecular) techniques have vastly improved our understanding of the microbiology of the human body.

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Chronic rhinosinusitis (CRS) is a common, debilitating condition characterized by long-term inflammation of the nasal cavity and paranasal sinuses. The role of the sinonasal bacteria in CRS is unclear. We conducted a meta-analysis combining and reanalysing published bacterial 16S rRNA sequence data to explore differences in sinonasal bacterial community composition and predicted function between healthy and CRS affected subjects.

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Background: Despite considerable research, the pathogenesis of chronic rhinosinusitis (CRS) remains poorly understood. Potential microbial roles in the etiology or progression of CRS have long been hypothesized, yet few specific associations have been identified. In this study we investigate associations between patterns in resident bacterial communities and clinical variants of CRS.

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Background: Endoscopic sinus surgery (ESS) improves symptoms for many chronic rhinosinusitis (CRS) patients by enlarging the size of sinus ostia, improving mucociliary clearance, and facilitating access for topical therapies. However, the effect of surgery on the sinonasal microbiota remains poorly understood. This study examined changes in bacterial communities in CRS patients before and after surgery.

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Chronic suppurative otitis media (CSOM) presents with purulent otorrhea (ear discharge), is characterized by chronic inflammation of the middle ear and mastoid cavity, and contributes to a significant disease burden worldwide. Current antibiotic therapy is guided by swab culture results. In the absence of detailed molecular microbiology studies of CSOM patients, our current understanding of the microbiota of CSOM (and indeed of the healthy ear) remains incomplete.

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Sponges (phylum Porifera) are important members of almost all aquatic ecosystems, and are renowned for hosting often dense and diverse microbial communities. While the specificity of the sponge microbiota seems to be closely related to host phylogeny, the environmental factors that could shape differences within local sponge-specific communities remain less understood. On tropical coral reefs, sponge habitats can span from shallow areas to deeper, mesophotic sites.

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Background: The role of bacteria in the pathogenesis of chronic rhinosinusitis (CRS) remains uncertain. Recent evidence suggests that bacteria are able to establish microcolonies within the underlying mucosa. However, to date there has been no systematic comparison of bacterial community composition and diversity in the surface mucosa with that of the underlying tissue.

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Chronic rhinosinusitis (CRS) affects approximately 5% of the adult population in Western societies and severely reduces the patient's quality of life. The role of bacteria in the pathogenesis of this condition has not yet been established with certainty. However, recent reports of bacterial and fungal biofilms in CRS highlight a potential role for these microorganisms.

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Sponges are an important component of temperate subtidal marine ecosystems, with a range of important functional roles and extensive symbiotic relationships with microorganisms. However, much remains unknown about their relationships with these symbiotic microorganisms, and specifically, the role that these symbionts play in sponge physiology, feeding and adaptation to local environmental conditions. Changes in environmental factors may alter relationships between sponges and their symbionts, which could conceivably influence the abundance and distribution patterns of some temperate sponge species.

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