The role of the gut microbiome in eye diseases

Microglial-mediated immune mechanisms in autoimmune uveitis: Elucidating pathogenic pathways and targeted therapeutics

This review offers a comprehensive examination of the role of microglia in the pathogenesis of autoimmune uveitis, an inflammatory eye disease with significant potential for vision impairment. Central to our discussion is the dual nature of microglial cells, which act as both protectors and potential perpetrators in the immune surveillance of the retina. We explore the mechanisms of microglial activation, highlighting the key signaling pathways involved, such as NF-κB, JAK/STAT, MAPK, and PI3K/Akt. The review also delves into the genetic and environmental factors influencing microglial behavior, underscoring their complex interaction in disease manifestation. Advanced imaging techniques and emerging biomarkers for microglial activation, pivotal in diagnosing and monitoring the disease, are critically assessed. Additionally, we discuss current and novel therapeutic strategies targeting microglial activity, emphasizing the shift towards more precise and personalized interventions. This article aims to provide a nuanced understanding of microglial dynamics in autoimmune uveitis, offering insights into potential avenues for effective treatment and management.

Study on the relationship between adolescent myopia and gut microbiota via 16S rRNA sequencing

Myopia has become a global public health problem, with a high incidence among adolescents. In recent years, the correlation between gut microbiota and various diseases has become a research hotspot. This paper analyzes the relationship between myopia and gut microbiota in adolescents based on 16S rRNA sequencing, opening up a new avenue for the prevention and control of myopia. 80 adolescents aged 6-15 years were included; fecal samples were collected to compare their diversity and species differences. There was no significant difference in α diversity when considering richness and evenness at the same time (P > 0.05). While the group difference in β diversity reached a significant level (R2 = 0.022, P < 0.05). The absolute quantification and relative abundance of phylum level Firmicutes and Actinobacteriota are different; among the top 30 genera, myopic group only one genus decreased in absolute quantification, while 13 genera decreased in relative quantification; so LEfSe analysis was performed, and the result showed that microbial community composition changed under Linear discriminant analysis (LDA) score, the top ten changes are shown in the figure; the Wilcoxon Rank sum test also found some significant changes in the absolute abundance of differential microbiota among different groups, at the phylum level, one bacterial phylum decreased and three bacterial phyla increased; at the genus level, 2 bacteria genera decreased and 29 bacteria genera increased. Functional pathways prediction found many myopic-related pathways were functionally enhanced in myopic patients (P < 0.05). Multivariate logistic regression analysis results showed that the area under the curve (AUC) of myopic patients predicted was close to or equal to 1. In conclusion, adolescent myopia is closely related to the gut microbiota, and the characteristic gut microbiota can distinguish myopia from healthy controls to a large extent. Therefore, it can be considered to regulate these characteristic gut microbiota to prevent and control myopia.

Neonatal gut microbiota profile and the association with retinopathy of prematurity in preterm infants

BACKGROUND

To explore the role of gut microbiota in preterm infants at high risk of developing retinopathy of prematurity (ROP).

METHODS

Preterm infants with gestational age (GA) < 32 weeks and/or birth weight (BW) < 1500 g born between 2020 and 2021 were prospectively enrolled. Their faecal samples were collected and analysed at different postnatal ages of life using 16S rRNA gene sequencing on the Miseq platform. The main outcome measures were the microbial diversity, taxonomy, relative abundance, bacterial predicted functional analysis, and their associations with different ROP groups. Subgroup analyses were performed by matching their GA and BW across different ROP groups.

RESULTS

A total of 268 stool samples were collected from 110 preterm infants, including 13 with type 1 ROP, 44 with type 2 or mild ROP, and 53 without ROP. Type 1 ROP showed no significant difference in microbial diversity up to 8 postnatal weeks (p = 0.057), while type 2 and no ROP groups displayed increased diversity (p = 0.0015 and p = 0.049, respectively). Bifidobacterium genera was notably less abundant in type 1 ROP group at first postnatal week (p = 0.022) and remained low in subsequent weeks. Predicted functional analysis revealed enriched pathways in membrane transport, carbohydrate metabolism, amino acid metabolism, and replication and repair.

CONCLUSIONS

Reduced gut microbial diversity may be associated with ROP development in high-risk preterm infants. Further research is needed to comprehend how early-life Bifidobacterium reduction affects metabolism and how targeting microbiome may help for ROP prevention and management.

Hallmarks of aging in age-related macular degeneration and age-related neurological disorders: novel insights into common mechanisms and clinical relevance

Age-related macular degeneration (AMD) and age-related neurological diseases (ANDs), such as Alzheimer's and Parkinson's Diseases, are increasingly prevalent conditions that significantly contribute to global morbidity, disability, and mortality. The retina, as an accessible part of the central nervous system (CNS), provides a unique window to study brain aging and neurodegeneration. By examining the associations between AMD and ANDs, this review aims to highlight novel insights into fundamental mechanisms of aging and their role in neurodegenerative disease progression. This review integrates knowledge from the emerging field of aging research, which identifies common denominators of biological aging, specifically loss of proteostasis, impaired macroautophagy, mitochondrial dysfunction, and inflammation. Finally, we emphasize the clinical relevance of these pathways and the potential for cross-disease therapies that target common aging hallmarks. Identifying these shared pathways could open avenues to develop therapeutic strategies targeting mechanisms common to multiple degenerative diseases, potentially attenuating disease progression and promoting the healthspan.

The impact of gut microbiota on morbidities in preterm infants

The gut microbiota undergoes substantial development from birth, and its development in the initial years of life has a potentially lifelong effect on the health of the individual. However, various factors can disrupt the development of the gut microbiota, leading to a condition known as dysbiosis, particularly in preterm infants. Current studies involving adults have suggested that the gut microbiota not only influences the gut but also has multidimensional effects on remote organs; these pathways are often referred to as the gut-organ axis. Imbalance of the gut microbiota may lead to the development of multiple diseases. Recent studies have revealed that gut dysbiosis in preterm infants may cause several acute morbidities-such as necrotizing enterocolitis, late-onset sepsis, bronchopulmonary dysplasia, and retinopathy of prematurity-and it may also influence long-term outcomes including neurodevelopment and somatic growth. This review mainly presents the existing evidence regarding the relationships between the gut microbiota and these morbidities in preterm infants and explores the role of the gut-organ axis in these morbidities. This paper thus offers insights into the future perspectives on microbiota interventions for promoting the health of preterm infants.

Gut microbiota-derived indole-3-acetic acid suppresses high myopia progression by promoting type I collagen synthesis

High myopia (HM) is a leading cause of blindness worldwide with currently no effective interventions available. A major hurdle lies in its often isolated perception as a purely ocular morbidity, disregarding potential systemic implications. Recent evidence suggests the existence of a gut-eye axis; however, the role of gut microbiota in the pathogenesis of HM remains largely unexplored. Herein, we provide a potential crosstalk among HM's gut dysbiosis, microbial metabolites, and scleral remodeling. Utilizing 16S rRNA gene sequencing, we observed an altered gut microbiota profile in HM patients with a significant reduction in probiotic abundance compared with healthy controls. Subsequent targeted metabolic profiling revealed a notable decrease in plasma levels of the gut microbiota-derived metabolite indole-3-acetic acid (3-IAA) among HM patients, which is closely associated with the reduced probiotics, both negatively correlated with HM severity. Genetic analyses determined that gut microbiota are causally associated with myopia risk. Importantly, when mice subjected to HM modeling receive fecal microbiota transplantation from healthy donors, there is an increase in 3-IAA plasma levels and simultaneous retardation of HM progression along with better maintenance of collagen type I alpha 1 (COL1A1) expression in the sclera. Furthermore, 3-IAA gavage achieves similar effects. Mechanistic investigations confirm the transcriptional activation of COL1A1 by 3-IAA via promoting the enrichment of SP1 to its promoter. Together, our findings provide novel insights into the gut microbiota-eye axis in the pathogenesis of HM and propose new strategies for HM intervention by remodeling the gut microbiota and indole supplementation.

The Relationship Between Gut Microbiome and Ophthalmologic Diseases: A Comprehensive Review

The gut microbiome has been studied in recent years due to its association with various pathological pathways involved in different diseases, caused by its structure, function, and diversity alteration. The knowledge of this mechanism has generated interest in the investigation of its relationship with ophthalmologic diseases. Recent studies infer the existence of a gut-eye microbiota axis, influenced by the intestinal barrier, the blood-retina barrier, and the immune privilege of the eye. A common denominator among ophthalmologic diseases that have been related to this axis is inflammation, which is perpetuated by dysbiosis, causing an alteration of the intestinal barrier leading to increased permeability and, in turn, the release of components such as lipopolysaccharides (LPS), trimethylamine oxide (TMAO), and bacterial translocation. Some theories explain that depending on how the microbiome is composed, a different type of T cells will be activated, while others say that some bacteria can pre-activate T cells that mimic ocular structures and intestinal permeability that allow leakage of metabolites into the circulation. In addition, therapies such as probiotics, diet, and fecal microbiota transplantation (FMT) have been shown to favor the presence of a balanced population of microorganisms that limit inflammation and, in turn, generate a beneficial effect in these eye pathologies. This review aims to analyze how the intestinal microbiome influences various ocular pathologies based on microbial composition and pathological mechanisms, which may provide a better understanding of the diseases and their therapeutic potential.

Let food be your medicine - dietary fiber

Dietary fiber (DF) cannot be digested and absorbed by the digestive tract, nor can it provide the energy needed to be burned for metabolic activities. Therefore, from the 1950s to the 1980s, DF received little attention in nutrition studies. With in-depth research and developments in global nutrition, people have gradually paid attention to the fact that DF occupies an essential position in the structure of nutrition, and it can ensure the healthy development of human beings. As early as 390 B.C., the ancient Greek physician Hippocrates proposed, "Let your food be your medicine, and your medicine be your food". This concept has been more systematically validated in modern scientific research, with numerous epidemiological studies showing that the dietary intake of DF-rich foods such as whole grains, root vegetables, legumes, and fruits has the potential to regulate the balance of the gut microbiota and thereby prevent diseases. However, the crosstalk between different types of DF and the gut microbiota is quite complex, and the effects on the organism vary. In this paper, we discuss research on DF and the gut microbiota and related diseases, aiming to understand the relationship between all three better and provide a reference basis for the risk reduction of related diseases.

Effects of glyphosate exposure on intestinal microbiota, metabolism and microstructure: a systematic review

Glyphosate is the most commercialized herbicide in Brazil and worldwide, and this has become a worrying scenario in recent years. In 2015 glyphosate was classified as potentially carcinogenic by the World Health Organization, which opened avenues for numerous debates about its safe use regarding non-target species' health, including humans. This review aimed to observe the impacts of glyphosate and its formulations on the gut microbiota, as well as on the gut microstructure and animal metabolism. A systematic review was conducted based on the PRISMA recommendations, and the search for original articles was performed in Pubmed/Medline, Scopus and Web of Science databases. The risk of bias in the studies was assessed using the SYRCLE strategy. Our findings revealed that glyphosate and its formulations are able to induce intestinal dysbiosis by altering bacterial metabolism, intestinal permeability, and mucus secretion, as well as causing damage to the microvilli and the intestinal lumen. Additionally, immunological, enzymatic and genetic changes were also observed in the animal models. At the metabolic level, damage was observed in lipid and energy metabolism, the circulatory system, cofactor and vitamin metabolism, and replication, repair, and translation processes. In this context, we pointed out that the studies revealed that these alterations, caused by glyphosate-based herbicides, can lead to intestinal and systemic diseases, such as Crohn's disease and Alzheimer's disease.

Retinal Vein Occlusion-Background Knowledge and Foreground Knowledge Prospects-A Review

Thrombosis of retinal veins is one of the most common retinal vascular diseases that may lead to vascular blindness. The latest epidemiological data leave no illusions that the burden on the healthcare system, as impacted by patients with this diagnosis, will increase worldwide. This obliges scientists to search for new therapeutic and diagnostic options. In the 21st century, there has been tremendous progress in retinal imaging techniques, which has facilitated a better understanding of the mechanisms related to the development of retinal vein occlusion (RVO) and its complications, and consequently has enabled the introduction of new treatment methods. Moreover, artificial intelligence (AI) is likely to assist in selecting the best treatment option for patients in the near future. The aim of this comprehensive review is to re-evaluate the old but still relevant data on the RVO and confront them with new studies. The paper will provide a detailed overview of diagnosis, current treatment, prevention, and future therapeutic possibilities regarding RVO, as well as clarifying the mechanism of macular edema in this disease entity.

Visualizing set relationships: EVenn's comprehensive approach to Venn diagrams

Venn diagrams serve as invaluable tools for visualizing set relationships due to their ease of interpretation. Widely applied across diverse disciplines such as metabolomics, genomics, transcriptomics, and proteomics, their utility is undeniable. However, the operational complexity has been compounded by the absence of standardized data formats and the need to switch between various platforms for generating different Venn diagrams. To address these challenges, we introduce the EVenn platform, a versatile tool offering a unified interface for efficient data exploration and visualization of diverse Venn diagrams. EVenn (http://www.ehbio.com/test/venn) streamlines the data upload process with a standardized format, enhancing the capabilities for multimodule analysis. This comprehensive protocol outlines various applications of EVenn, featuring representative results of multiple Venn diagrams, data uploads in the centralized data center, and step-by-step case demonstrations. Through these functionalities, EVenn emerges as a valuable and user-friendly tool for the in-depth exploration of multiomics data.

Unveiling the gut microbiota and metabolite profiles in guinea pigs with form deprivation myopia through 16S rRNA gene sequencing and untargeted metabolomics

Aim

The aim of this study was to confirm the presence of the form deprivation myopia (FDM) guinea pig eye-gut axis and investigate the relationship between serum vasoactive intestinal peptide (VIP), lipopolysaccharides (LPS), specific gut microbiota and their metabolites.

Method

20 specific-pathogen-free (SPF) guinea pigs were divided into the FDM and the control(Con) group. Following model induction, serum levels of VIP and LPS were quantified. A combination of 16S ribosomal ribosomal Ribonucleic Acid (rRNA) gene sequencing, non-targeted metabolomics and bioinformatics analysis were employed to identify disparities in gut microbiota and metabolites between the two groups of guinea pigs.

Result

Compared to the control group, FDM guinea pigs exhibited a significant trend towards myopia, along with significantly elevated concentrations of LPS and VIP (p < 0.0001). Furthermore, Ruminococcus_albus emerged as the predominant bacterial community enriched in FDM (p < 0.05), and demonstrated positive correlations with 10 metabolites, including l-Glutamic acid, Additionally, Ruminococcus_albus exhibited positive correlations with VIP and LPS levels (p < 0.05).

Conclusion

The findings suggest that the Ruminococcus_Albus and glutamate metabolic pathways play a significant role in myopia development, leading to concurrent alterations in serum VIP and LPS levels in FDM guinea pigs. This underscores the potential of specific gut microbiota and their metabolites as pivotal biomarkers involved in the pathogenesis of myopia.

The gut microbiome and HLA-B27-associated anterior uveitis: a case-control study

BACKGROUND

The human gut microbiome (GM) is involved in inflammation and immune response regulation. Dysbiosis, an imbalance in this ecosystem, facilitates pathogenic invasion, disrupts immune equilibrium, and potentially triggers diseases including various human leucocyte antigen (HLA)-B27-associated autoinflammatory and autoimmune diseases such as inflammatory bowel disease (IBD) and spondyloarthropathy (SpA). This study assesses compositional and functional alterations of the GM in patients with HLA-B27-associated non-infectious anterior uveitis (AU) compared to healthy controls.

METHODS

The gut metagenomes of 20 patients with HLA-B27-associated non-infectious AU, 21 age- and sex-matched HLA-B27-negative controls, and 6 HLA-B27-positive healthy controls without a history of AU were sequenced using the Illumina NovaSeq 6000 platform for whole metagenome shotgun sequencing. To identify taxonomic and functional features with significantly different relative abundances between groups and to identify associations with clinical metadata, the multivariate association by linear models (MaAsLin) R package was applied.

RESULTS

Significantly higher levels of the Eubacterium ramulus species were found in HLA-B27-negative controls (p = 0.0085, Mann-Whitney U-test). No significant differences in microbial composition were observed at all other taxonomic levels. Functionally, the lipid IVA biosynthesis pathway was upregulated in patients (p < 0.0001, Mann-Whitney U-test). A subgroup analysis comparing patients with an active non-infectious AU to their age- and sex-matched HLA-B27-negative controls, showed an increase of the species Phocaeicola vulgatus in active AU (p = 0.0530, Mann-Whitney U-test). An additional analysis comparing AU patients to age- and sex-matched HLA-B27-positive controls, showed an increase of the species Bacteroides caccae in controls (p = 0.0022, Mann-Whitney U-test).

CONCLUSION

In our cohort, non-infectious AU development is associated with compositional and functional alterations of the GM. Further research is needed to assess the causality of these associations, offering potentially novel therapeutic strategies.

The Conjunctival Microbiome and Dry Eye: What We Know and Controversies

ABSTRACT

Dry eye disease is a common multifactorial condition that may be idiopathic or associated with autoimmune conditions, such as Sjogren syndrome. Commensal microorganisms modify immune responses, so it is relevant to understand how they modify such immune-mediated diseases. Microbiota in the gut regulate inflammation in the eye, and conversely, severe inflammation of the ocular surface results in alteration of gut microbiome. The conjunctiva microbiome can be analyzed using 16S or shotgun metagenomics. The amount of microbial DNA in ocular surface mucosa relative to human DNA is limited compared with the case of the intestinal microbiome. There are challenges in defining, harvesting, processing, and analyzing the microbiome in the ocular surface mucosa. Recent studies have shown that the conjunctiva microbiome depends on age, presence of local and systemic inflammation, and environmental factors. Microbiome-based therapy, such as the use of oral probiotics to manage dry eye disease, has initial promising results. Further longitudinal studies are required to investigate the alteration of the conjunctival microbiome after local therapy and surgery.

Mechanisms of blood-retinal barrier disruption related to intraocular inflammation and malignancy

Blood-retinal barrier (BRB) disruption is a common accompaniment of intermediate, posterior and panuveitis causing leakage into the retina and macular oedema resulting in vision loss. It is much less common in anterior uveitis or in patients with intraocular lymphoma who may have marked signs of intraocular inflammation. New drugs used for chemotherapy (cytarabine, immune checkpoint inhibitors, BRAF inhibitors, EGFR inhibitors, bispecific anti-EGFR inhibitors, MET receptor inhibitors and Bruton tyrosine kinase inhibitors) can also cause different types of uveitis and BRB disruption. As malignant disease itself can cause uveitis, particularly from breast, lung and gastrointestinal tract cancers, it can be clinically difficult to sort out the cause of BRB disruption. Immunosuppression due to malignant disease and/or chemotherapy can lead to infection which can also cause BRB disruption and intraocular infection. In this paper we address the pathophysiology of BRB disruption related to intraocular inflammation and malignancy, methods for estimating the extent and effect of the disruption and examine why some types of intraocular inflammation and malignancy cause BRB disruption and others do not. Understanding this may help sort and manage these patients, as well as devise future therapeutic approaches.

A narrative review on dietary components and patterns and age-related macular degeneration

Age-related macular degeneration (AMD) is one of the most prevalent eye diseases among the ageing population worldwide. It is a leading cause of blindness in individuals over 55, particularly in industrialised Western countries. The prevalence of AMD increases with age, and genetic factors and environmental influences are believed to contribute to its development. Among the environmental factors, diet plays a significant role in AMD. This review explores the association between dietary components, dietary patterns and AMD. Various nutrients, non-nutrient substances and dietary models that have the potential to counteract oxidative stress and inflammation, which are underlying mechanisms of AMD, are discussed. Consuming fruits, vegetables, fish and seafood, whole grains, olive oil, nuts and low-glycaemic-index foods has been highlighted as beneficial for reducing the risk of AMD. Adhering to the Mediterranean diet, which encompasses these elements, can be recommended as a dietary pattern for AMD. Furthermore, the modulation of the gut microbiota through dietary interventions and probiotics has shown promise in managing AMD.

Microbiome and Inherited Retinal Degenerations

Inherited retinal degenerations (IRDs) represent a genetically and clinically heterogeneous group of progressive and visually debilitating disorders that can lead to irreversible visual loss. Our understanding of IRD pathogenesis at both the genetic and cellular levels has increased tremendously over the past two decades, but the exact pathogenic mechanisms remain incompletely understood. Enhanced understanding of the pathophysiology of these diseases can result in new treatment targets. Alterations in the human gut microbiome play a key role in the pathogenesis of many ocular and nonocular diseases, such as age-related macular degeneration, neurologic and metabolic disorders, and autoimmune conditions. The gut microbiome regulates the susceptibility of mice to develop experimental autoimmune uveitis, a model for autoimmune disease of the posterior portion of the eye elicited by the systemic response to retinal antigens. Because of the mounting evidence in favor of a role for local and systemic inflammatory and autoimmune-mediated components to IRD pathogenesis, this review presents the current knowledge of gut microbiome in IRDs and discusses the association between possible changes in gut microbiome and pathogenesis of these diseases, with special attention to their possible contribution to the inflammatory underpinnings of IRDs.

Lutein combined with EGCG improved retinitis pigmentosa against N-methyl-N nitrosourea-induced

In order to investigate the synergistic improving effect of lutein (LUT) and epigallocatechin-3-gallate (EGCG) treatment on retinitis pigmentosa (RP), an N-methyl-N-nitrosourea (MNU)-induced mouse model was conducted in the present study. Compared to the LUT alone treatment group, in the LUT combined with EGCG (LUT-EGCG) treatment group, the accumulation content of LUT was significantly increased by 50.24% in the liver. The morphological results indicated that LUT-EGCG treatment significantly improved the retina structure with the thickness of the outer nuclear layer restored to 185.28 ± 0.29 μm, showing no significant difference compared to the control group. The LUT-EGCG treatment also increased the production of short-chain fatty acids, such as acetic and propionic acids. Compared with the LUT alone treatment, the LUT-EGCG treatment significantly increased the relative abundance of Lachnospiraceae and Helicobacteraceae. RT-qPCR results indicated that LUT-EGCG treatment significantly increased the antiapoptotic gene Bcl-2 expression. In addition, the expression of IL-6 was significantly down-regulated in the LUT-EGCG group, while there was no significance in NF-κβ, TNF-α, IL-1β, and IL-18 compared with the LUT group. Correlation analysis supported the conclusion that LUT combined with EGCG may improve RP by modulating antiapoptotic gene expression and regulating the abundance of gut microbiota. However, the underlying mechanism still needs further research.

Modulation of Gut Microbiome as a Therapeutic Modality for Auditory Disorders

The gut microbiome has been shown to play a pivotal role in health and disease. Recently, there has been increased interest within the auditory community to explore the role of the gut microbiome in the auditory system and its implications for hearing disorders such as sensorineural hearing loss (SNHL), otitis media, and tinnitus. Studies have suggested that modulating the gut microbiome using probiotics as well as with diets high in monounsaturated and omega-3 fatty acids is associated with a reduction in inflammation prevalence in auditory disorders. This review aims to evaluate the current literature on modulation of the gut microbiome and its effects on otological conditions. The probiotic conversion of nondigestible carbohydrates into short-chain fatty acids has been shown to provide benefits for improving hearing by maintaining an adequate vascular supply. For acute and secretory otitis media, studies have shown that a combination therapy of probiotics with a decreased dose of antibiotics yields better clinical outcomes than aggressive antibiotic treatment alone. Gut microbiome modulation also alters neurotransmitter levels and reduces neuroinflammation, which may provide benefits for tinnitus by preventing increased neuronal activity. Further studies are warranted to evaluate the efficacy of probiotics, natural health products, and micronutrients on auditory disorders, paving the way to develop novel interventions.

Causal Effects of Gut Microbiota on Age-Related Macular Degeneration: A Mendelian Randomization Study

Purpose

Recently, the association between gut microbiota and age-related macular degeneration (AMD) through the gut-retina axis has attracted great interest. However, the causal relationship between them has not been elucidated. Using publicly available genome-wide association study summary statistics, we conducted a two-sample Mendelian randomization (MR) analysis to examine the causal relationship between the gut microbiota and the occurrence of AMD.

Methods

The study used a variety of quality control techniques to select instrumental single nucleotide polymorphisms (SNPs) with strong exposure associations. We used a set of SNPs as instrumental variable that were below the genome-wide statistical significance threshold (5 × 10-8). Additionally, a separate group of SNPs below the locus-wide significance level (1 × 10-5) were selected as instrumental variables to ensure a comprehensive conclusion. Inverse variance-weighted (IVW) analysis was the primary technique we used to examine causality in order to confirm the validity of our findings. The MR-Egger intercept test, Cochran's Q test, and leave-one-out sensitivity analysis were used to evaluate the horizontal pleiotropy, heterogeneities, and stability of the genetic variants.

Results

IVW results showed that genus Anaerotruncus (P = 5.00 × 10-3), genus Candidatus Soleaferrea (P = 1.83 × 10-2), and genus unknown id.2071 (P = 3.12 × 10-2) were protective factors for AMD. The Eubacterium oxidoreducens group (P = 3.17 × 10-2), genus Faecalibacterium (P = 2.67 × 10-2), and genus Ruminococcaceae UCG-011 (P = 4.04 × 10-2) were risk factors of AMD. No gut microbiota (GM) taxa were found to be causally related to AMD at the phylum, class, order, and family levels (P > 0.05). The robustness of MR results were confirmed by heterogeneity and pleiotropy analysis. (P > 0.05). We also performed a bidirectional analysis, which showed that genus Anaerotruncus, genus Candidatus Soleaferrea, genus unknown id.2071 and the Eubacterium oxidoreducens group had an interaction with AMD, whereas genus Faecalibacterium showed only a unilateral unfavorable effect on AMD.

Conclusions

We confirmed a causal relationship between AMD and GM taxa, including the Eubacterium oxidoreducens group, Faecalibacterium, Ruminococcaceae UCG-011, Anaerotruncus, and Candidatus Soleaferrea. These strains have the potential to serve as new biomarkers, offering valuable insights into the treatment and prevention of AMD.

Targeting the Gut-Eye Axis: An Emerging Strategy to Face Ocular Diseases

The human microbiota refers to a large variety of microorganisms (bacteria, viruses, and fungi) that live in different human body sites, including the gut, oral cavity, skin, and eyes. In particular, the presence of an ocular surface microbiota with a crucial role in maintaining ocular surface homeostasis by preventing colonization from pathogen species has been recently demonstrated. Moreover, recent studies underline a potential association between gut microbiota (GM) and ocular health. In this respect, some evidence supports the existence of a gut-eye axis involved in the pathogenesis of several ocular diseases, including age-related macular degeneration, uveitis, diabetic retinopathy, dry eye, and glaucoma. Therefore, understanding the link between the GM and these ocular disorders might be useful for the development of new therapeutic approaches, such as probiotics, prebiotics, symbiotics, or faecal microbiota transplantation through which the GM could be modulated, thus allowing better management of these diseases.

Autoimmune Inflammatory Eye Disease: Demystifying Clinical Presentations for the Internist

PURPOSE OF REVIEW

Provide a framework for recognizing key symptoms and clinical findings in patients with autoimmune inflammatory eye disease.

RECENT FINDINGS

The most common manifestations of autoimmune inflammatory eye disease are episcleritis, scleritis, uveitis (anterior, intermediate, posterior, and panuveitis), and keratoconjunctivitis sicca. Etiologies can be idiopathic or in association with a systemic autoimmune condition. Referral of patients who may have scleritis is critical for patients presenting with red eyes. Referral of patients who may have uveitis is critical for patients presenting often with floaters and vision complaints. Attention should also be directed to aspects of the history that might suggest a diagnosis of a systemic autoimmune condition, immunosuppression, drug-induced uveitis, or the possibility of a masquerade condition. Infectious etiologies should be ruled out in all cases. Patients with autoimmune inflammatory eye disease may present with ocular or systemic symptoms alone, or in combination. Collaboration with ophthalmologists and other relevant specialists is vital to optimal long-term medical care.

Roles and Mechanisms of NLRP3 in Influenza Viral Infection

Pathogenic viral infection represents a major challenge to human health. Due to the vast mucosal surface of respiratory tract exposed to the environment, host defense against influenza viruses has perpetually been a considerable challenge. Inflammasomes serve as vital components of the host innate immune system and play a crucial role in responding to viral infections. To cope with influenza viral infection, the host employs inflammasomes and symbiotic microbiota to confer effective protection at the mucosal surface in the lungs. This review article aims to summarize the current findings on the function of NACHT, LRR and PYD domains-containing protein 3 (NLRP3) in host response to influenza viral infection involving various mechanisms including the gut-lung crosstalk.

Investigating the Ocular Surface Microbiome: What Can It Tell Us?

While pathogens of the eye have been studied for a very long time, the existence of resident microbes on the surface of healthy eyes has gained interest only recently. It appears that commensal microbes are a normal feature of the healthy eye, whose role and properties are currently the subject of extensive research. This review provides an overview of studies that have used 16s rRNA gene sequencing and whole metagenome shotgun sequencing to characterize microbial communities associated with the healthy ocular surface from kingdom to genus level. Bacteria are the primary colonizers of the healthy ocular surface, with three predominant phyla: Proteobacteria, Actinobacteria, and Firmicutes, regardless of the host, environment, and method used. Refining the microbial classification to the genus level reveals a highly variable distribution from one individual and study to another. Factors accounting for this variability are intriguing - it is currently unknown to what extent this is attributable to the individuals and their environment and how much is artifactual. Clearly, it is technically challenging to accurately describe the microorganisms of the ocular surface because their abundance is relatively low, thus, permitting substantial contaminations. More research is needed, including better experimental standards to prevent biases, and the exploration of the ocular surface microbiome's role in a spectrum of healthy to pathological states. Outcomes from such research include the opportunity for therapeutic interventions targeting the microbiome.