Alterations in Oral Microbiota in HIV Are Related to Decreased Pulmonary Function

Pulmonary comorbidities in people with HIV- the microbiome connection

PURPOSE OF REVIEW

To report recent evidence on associations between human microbiome, particularly airway and gut, and pulmonary comorbidities in people with HIV (PWH). Furthermore, we explore how changes in the microbiome may contribute to pulmonary immune dysregulation and higher rates of pulmonary comorbidities among PWH. Finally, we propose future directions in the field.

RECENT FINDINGS

Increased risk of pulmonary comorbidities and rapid lung function decline have been reported in even well treated PWH. Altered microbiota profiles have been reported in PWH with pulmonary comorbidities and rapid lung function decline as compared to those without. The most consistent data have been the association between HIV-related pulmonary comorbidities, lung and oral microbiota dysbiosis, which has been also associated with distinct respiratory mucosal inflammatory profiles and short-term mortality. However, a possible causal link remains to be elucidated.

SUMMARY

Associations between the lung and oral microbiome, HIV-associated pulmonary comorbidities and rapid lung function decline have been reported in recent studies. Yet the underlying mechanism underpinning the observed associations is largely unknown and substantial knowledge gaps remain. Future research is warranted to unveil the role and mechanism of human microbiome from different anatomical compartments in relation to pulmonary comorbidities in PWH.

Exploring the interplay between antiretroviral therapy and the gut-oral microbiome axis in people living with HIV

The gut and oral microbiome is altered in people living with HIV (PLWH). While antiretroviral treatment (ART) is pivotal in restoring immune function in PLWH, several studies have identified an association between specific antiretrovirals, particularly integrase inhibitors (INSTI), and weight gain. In our study, we explored the differences in the oral and gut microbiota of PLWH under different ART regimens, and its correlation to Body Mass Index (BMI). Fecal and salivary samples were collected from PLWH (n = 69) and healthy controls (HC, n = 80). We performed taxonomy analysis to determine the microbial composition and relationship between microbial abundance and ART regimens, BMI, CD4+T-cell count, CD4/CD8 ratio, and ART duration. PLWH showed significantly lower richness compared to HC in both the oral and gut environment. The gut microbiome composition of INSTI-treated individuals was enriched with Faecalibacterium and Bifidobacterium, whereas non-nucleotide reverse transcriptase inhibitor (NNRTI)-treated individuals were enriched with Gordonibacter, Megasphaera, and Staphylococcus. In the oral microenvironment, Veillonella was significantly more abundant in INSTI-treated individuals and Fusobacterium and Alloprevotella in the NNRTI-treated individuals. Furthermore, Bifidobacterium and Dorea were enriched in gut milieu of PLWH with high BMI. Collectively, our findings identify distinct microbial profiles, which are associated with different ART regimens and BMI in PLWH on successful ART, thereby highlighting significant effects of specific antiretrovirals on the microbiome.

The Oral-Lung Microbiome Axis in Connective Tissue Disease-Related Interstitial Lung Disease

Connective tissue disease-related interstitial lung disease (CTD-ILD) is a frequent and serious complication of CTD, leading to high morbidity and mortality. Unfortunately, its pathogenesis remains poorly understood; however, one intriguing contributing factor may be the microbiome of the mouth and lungs. The oral microbiome, which is a major source of the lung microbiome through recurrent microaspiration, is altered in ILD patients. Moreover, in recent years, several lines of evidence suggest that changes in the oral and lung microbiota modulate the pulmonary immune response and thus may play a role in the pathogenesis of ILDs, including CTD-ILD. Here, we review the existing data demonstrating oral and lung microbiota dysbiosis and possible contributions to the development of CTD-ILD in rheumatoid arthritis, Sjögren's syndrome, systemic sclerosis, and systemic lupus erythematosus. We identify several areas of opportunity for future investigations into the role of the oral and lung microbiota in CTD-ILD.

Commensal Oral Microbiota, Disease Severity, and Mortality in Fibrotic Lung Disease

Rationale: Oral microbiota associate with diseases of the mouth and serve as a source of lung microbiota. However, the role of oral microbiota in lung disease is unknown. Objectives: To determine associations between oral microbiota and disease severity and death in idiopathic pulmonary fibrosis (IPF). Methods: We analyzed 16S rRNA gene and shotgun metagenomic sequencing data of buccal swabs from 511 patients with IPF in the multicenter CleanUP-IPF (Study of Clinical Efficacy of Antimicrobial Therapy Strategy Using Pragmatic Design in IPF) trial. Buccal swabs were collected from usual care and antimicrobial cohorts. Microbiome data were correlated with measures of disease severity using principal component analysis and linear regression models. Associations between the buccal microbiome and mortality were determined using Cox additive models, Kaplan-Meier analysis, and Cox proportional hazards models. Measurements and Main Results: Greater buccal microbial diversity associated with lower FVC at baseline (mean difference, -3.60; 95% confidence interval [CI], -5.92 to -1.29% predicted FVC per 1-unit increment). The buccal proportion of Streptococcus correlated positively with FVC (mean difference, 0.80; 95% CI, 0.16 to 1.43% predicted per 10% increase) (n = 490). Greater microbial diversity was associated with an increased risk of death (hazard ratio, 1.73; 95% CI, 1.03-2.90), whereas a greater proportion of Streptococcus was associated with a reduced risk of death (HR, 0.85; 95% CI, 0.73 to 0.99). The Streptococcus genus was mainly composed of Streptococcus mitis species. Conclusions: Increasing buccal microbial diversity predicts disease severity and death in IPF. The oral commensal S. mitis spp associates with preserved lung function and improved survival.

Human immunodeficiency virus and oral microbiota: mutual influence on the establishment of a viral gingival reservoir in individuals under antiretroviral therapy

The role of the oral microbiota in the overall health and in systemic diseases has gained more importance in the recent years, mainly due to the systemic effects that are mediated by the chronic inflammation caused by oral diseases, such as periodontitis, through the microbial communities of the mouth. The chronic infection by the human immunodeficiency virus (HIV) interacts at the tissue level (e.g. gut, genital tract, brain) to create reservoirs; the modulation of the gut microbiota by HIV infection is a good example of these interactions. The purpose of the present review is to assess the state of knowledge on the oral microbiota (microbiome, mycobiome and virome) of HIV-infected patients in comparison to that of HIV-negative individuals and to discuss the reciprocal influence of HIV infection and oral microbiota in patients with periodontitis on the potential establishment of a viral gingival reservoir. The influence of different clinical and biological parameters are reviewed including age, immune and viral status, potent antiretroviral therapies, smoking, infection of the airway and viral coinfections, all factors that can modulate the oral microbiota during HIV infection. The analysis of the literature proposed in this review indicates that the comparisons of the available studies are difficult due to their great heterogeneity. However, some important findings emerge: (i) the oral microbiota is less influenced than that of the gut during HIV infection, although some recurrent changes in the microbiome are identified in many studies; (ii) severe immunosuppression is correlated with altered microbiota and potent antiretroviral therapies correct partially these modifications; (iii) periodontitis constitutes a major factor of dysbiosis, which is exacerbated in HIV-infected patients; its pathogenesis can be described as a reciprocal reinforcement of the two conditions, where the local dysbiosis present in the periodontal pocket leads to inflammation, bacterial translocation and destruction of the supporting tissues, which in turn enhances an inflammatory environment that perpetuates the periodontitis cycle. With the objective of curing viral reservoirs of HIV-infected patients in the future years, it appears important to develop further researches aimed at defining whether the inflamed gingiva can serve of viral reservoir in HIV-infected patients with periodontitis.

Lung microbiome: new insights into the pathogenesis of respiratory diseases

The lungs were long thought to be sterile until technical advances uncovered the presence of the lung microbial community. The microbiome of healthy lungs is mainly derived from the upper respiratory tract (URT) microbiome but also has its own characteristic flora. The selection mechanisms in the lung, including clearance by coughing, pulmonary macrophages, the oscillation of respiratory cilia, and bacterial inhibition by alveolar surfactant, keep the microbiome transient and mobile, which is different from the microbiome in other organs. The pulmonary bacteriome has been intensively studied recently, but relatively little research has focused on the mycobiome and virome. This up-to-date review retrospectively summarizes the lung microbiome's history, composition, and function. We focus on the interaction of the lung microbiome with the oropharynx and gut microbiome and emphasize the role it plays in the innate and adaptive immune responses. More importantly, we focus on multiple respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), fibrosis, bronchiectasis, and pneumonia. The impact of the lung microbiome on coronavirus disease 2019 (COVID-19) and lung cancer has also been comprehensively studied. Furthermore, by summarizing the therapeutic potential of the lung microbiome in lung diseases and examining the shortcomings of the field, we propose an outlook of the direction of lung microbiome research.

Effect of YuPingFeng granules on clinical symptoms of stable COPD: study protocol for a multicenter, double-blind, and randomized controlled trial

BACKGROUND

Reducing current clinical symptoms and the risks of future exacerbations is the main goal of stable COPD management. Traditional Chinese medicine has unique advantages in chronic disease management. YuPingFeng (YPF), as a classical prescription, has been proven to reduce the risk of exacerbations, but there is a lack of high-quality evidence for the assessment of clinical symptoms and quality of life, particularly for the assessment of treatment response of microecology and immunity.

METHODS/DESIGN

This is a prospective, multicentre, randomized, double-blind, placebo-controlled clinical trial. A total of 316 eligible subjects with moderate to severe COPD will be randomized 1:1 to receive YPF or placebo. Participants will receive either YPF or a placebo at 5 g three times daily for 52 weeks. The primary outcome will be the change in the COPD Assessment Test (CAT) score after 52 weeks of treatment. Secondary outcomes will include changes in the St George's Respiratory Questionnaire (SGRQ) score and clinical symptom score, among others. Outcomes will be measured at each visit. The study will continue for 52 weeks and will include six visits to each subject (at day 0 and weeks 4,12,24,36 and 52). In the event of exacerbations, subjects will be required to go back to the hospital once on the first day of exacerbation or when their condition permits.

DISCUSSION

This trial will provide research methods to evaluate the clinical efficacy, safety, and the possible mechanism of YPF in the treatment of stable moderate-to-severe COPD patients. In addition, we hope to provide more possibilities for TCM to participate in the management of stable COPD.

TRIAL REGISTRATION

The trial was registered at the Chinese Clinical Trials Registry on 3 June 2022 (ChiCTR2200060476; date recorded: 3/6/2022, https://www.chictr.org.cn/ ).

Integrated analysis of gut and oral microbiome in men who have sex with men with HIV Infection

IMPORTANCE

Our longitudinal integrated study has shown the marked alterations in the gut and oral microbiome resulting from acute and chronic HIV infection and from antiretroviral therapy. Importantly, the relationship between oral and gut microbiomes in people living with acute and chronic HIV infection and "healthy" controls has also been explored. These findings might contribute to a better understanding of the interactions between the oral and gut microbiomes and its potential role in HIV disease progression.

COPD in People with HIV: Epidemiology, Pathogenesis, Management, and Prevention Strategies

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory disorder characterized by airflow limitation and persistent respiratory symptoms. People with HIV (PWH) are particularly vulnerable to COPD development; PWH have demonstrated both higher rates of COPD and an earlier and more rapid decline in lung function than their seronegative counterparts, even after accounting for differences in cigarette smoking. Factors contributing to this HIV-associated difference include chronic immune activation and inflammation, accelerated aging, a predilection for pulmonary infections, alterations in the lung microbiome, and the interplay between HIV and inhalational toxins. In this review, we discuss what is known about the epidemiology and pathobiology of COPD among PWH and outline screening, diagnostic, prevention, and treatment strategies.

Pulmonary function tests and their associated factors in people living with HIV at Jimma medical center; Ethiopia: a comparative cross-sectional study

Background

People living with HIV (PLHIV) have a greater risk of developing respiratory disorders. The problems are linked to poor socio-economic status, high viral load, low CD4 counts, and antiretroviral therapy. Despite the high prevalence of respiratory disorders, the association between HIV infection and pulmonary function status, as well as the associated factors, is not well established in resource-limited countries.

Methods

A comparative cross-sectional study was conducted from September 24 to October 15 2020 at Jimma Medical Center among people living with HIV who were arranged into an age-sex-matched comparison group. Data were collected using a pretested structured questionnaire administered via face-to-face interviews. The collected data included socio-demographic, respiratory, HIV infection, and substance use variables. Pulmonary function tests were conducted using an SP10 spirometer. The collected data were entered and analyzed using SPSS version 26. Independent t-test and multiple linear regressions were carried out to identify factors associated with the pulmonary function status of the study participants.

Results

A total of 96 PLHIV and 96 matched control individuals participated in the study. The mean of pulmonary function test parameters among the PLHIV respondents was FVC (l) (67.35 ± 19.12, p0.003), FEV1s (l) (61.76 ± 16.04, p0.001), and PEFR (50.14 ± 23.32, p0.001), with a significant lowering in the study group. Female sex, respiratory symptoms, duration of HIV, duration of treatment, and khat chewing were associated with lowered FEV1s (l) (p < 0.05) in HIV-positive respondents.

Conclusion

PLHIV had significantly lower mean lung function parameters than HIV-uninfected participants. As a result, health providers should screen HIV-positive patients with respiratory symptoms, prolonged duration of HIV infection, prolonged treatment, and khat chewing for non-infectious lung disorders while treating them.

Mechanisms underlying the effects, and clinical applications, of oral microbiota in lung cancer: current challenges and prospects

The oral cavity contains a site-specific microbiota that interacts with host cells to regulate many physiological processes in the human body. Emerging evidence has suggested that changes in the oral microbiota can increase the risk of lung cancer (LC), and the oral microbiota is also altered in patients with LC. Human and animal studies have shown that oral microecological disorders and/or specific oral bacteria may play an active role in the occurrence and development of LC through direct and/or indirect mechanisms. These studies support the potential of oral microbiota in the clinical treatment of LC. Oral microbiota may therefore be used in the prevention and treatment of LC and to improve the side effects of anticancer therapy by regulating the balance of the oral microbiome. Specific oral microbiota in LC may also be used as screening or predictive biomarkers. This review summarizes the main findings in research on oral microbiome-related LC and discusses current challenges and future research directions.

Microbiota in the oral cavity of school-age children with HIV who started antiretroviral therapy at young ages in South Africa

BACKGROUND

Infancy is an important developmental period when the microbiome is shaped. We hypothesized that earlier antiretroviral therapy (ART) initiation would attenuate HIV effects on microbiota in the mouth.

METHODS

Oral swabs were collected from 477 children with HIV (CWH) and 123 children without (controls) at two sites in Johannesburg, South Africa. CWH had started ART less than 3 years of age; 63% less than 6 months of age. Most were well controlled on ART at median age 11 years when the swab was collected. Controls were age-matched and recruited from the same communities. Sequencing of V4 amplicon of 16S rRNA was done. Differences in microbial diversity and relative abundances of taxa were compared between the groups.

RESULTS

CWH had lower alpha diversity than controls. Genus-level abundances of Granulicatella, Streptococcus, and Gemella were greater and Neisseria and Haemophilus less abundant among CWH than controls. Associations were stronger among boys. Associations were not attenuated with earlier ART initiation. Shifts in genus-level taxa abundances in CWH relative to controls were most marked in children on lopinavir/ritonavir regimens, with fewer shifts seen if on efavirenz ART regimens.

CONCLUSION

A distinct profile of less diverse oral bacterial taxa was observed in school-aged CWH on ART compared with uninfected controls suggesting modulation of microbiota in the mouth by HIV and/or its treatments. Earlier ART initiation was not associated with microbiota profile. Proximal factors, including current ART regimen, were associated with contemporaneous profile of oral microbiota and may have masked associations with distal factors such as age at ART initiation.

HIV-associated lung disease

Lung disease encompasses acute, infectious processes and chronic, non-infectious processes such as chronic obstructive pulmonary disease, asthma and lung cancer. People living with HIV are at increased risk of both acute and chronic lung diseases. Although the use of effective antiretroviral therapy has diminished the burden of infectious lung disease, people living with HIV experience growing morbidity and mortality from chronic lung diseases. A key risk factor for HIV-associated lung disease is cigarette smoking, which is more prevalent in people living with HIV than in uninfected people. Other risk factors include older age, history of bacterial pneumonia, Pneumocystis pneumonia, pulmonary tuberculosis and immunosuppression. Mechanistic investigations support roles for aberrant innate and adaptive immunity, local and systemic inflammation, oxidative stress, altered lung and gut microbiota, and environmental exposures such as biomass fuel burning in the development of HIV-associated lung disease. Assessment, prevention and treatment strategies are largely extrapolated from data from HIV-uninfected people. Smoking cessation is essential. Data on the long-term consequences of HIV-associated lung disease are limited. Efforts to continue quantifying the effects of HIV infection on the lung, especially in low-income and middle-income countries, are essential to advance our knowledge and optimize respiratory care in people living with HIV.

Pathogenesis and management of emphysema in people with HIV

INTRODUCTION

Since early in the HIV epidemic, emphysema has been identified among people with HIV (PWH) and has been associated with increased mortality. Smoking cessation is key to risk reduction. Health maintenance for PWH and emphysema should ensure appropriate vaccination and lung cancer screening. Treatment should adhere to inhaler guidelines for the general population, but inhaled corticosteroid (ICS) should be used with caution. Frontiers in treatment include targeted therapeutics. Major knowledge gaps exist in the epidemiology of and optimal care for PWH and emphysema, particularly in low and middle-income countries (LMIC).

AREAS COVERED

Topics addressed include risk factors, pathogenesis, current treatment and prevention strategies, and frontiers in research.

EXPERT OPINION

There are limited data on the epidemiology of emphysema in LMIC, where more than 90% of deaths from COPD occur and where the morbidity of HIV is most heavily concentrated. The population of PWH is aging, and age-related co-morbidities such as emphysema will only increase in salience. Over the next 5 years, the authors anticipate novel trials of targeted therapy for emphysema specific to PWH, and we anticipate a growing body of evidence to inform optimal clinical care for lung health among PWH in LMIC.

Association between salivary microbiota and renal function in renal transplant patients during the perioperative period

Introduction

Renal transplantation is an effective treatment for the end stage renal disease (ESRD). However, how salivary microbiota changes during perioperative period of renal transplant recipients (RTRs) has not been elucidated.

Methods

Five healthy controls and 11 RTRs who had good recovery were enrolled. Saliva samples were collected before surgery and at 1, 3, 7, and 14 days after surgery. 16S rRNA gene sequencing was performed.

Results

There was no significant difference in the composition of salivary microbiota between ESRD patients and healthy controls. The salivary microbiota of RTRs showed higher operational taxonomic units (OTUs) amount and greater alpha and beta diversity than those of ESRD patients and healthy controls, but gradually stabilized over time. At the phylum level, the relative abundance of Actinobacteria, Tenericutes and Spirochaetes was about ten times different from ESRD patients or healthy controls for RTRs overall in time. The relative abundance of Bacteroidetes, Fusobacteria, Patescibacteria, Leptotrichiaceae and Streptococcaceae was correlated with serum creatinine (Scr) after renal transplantation.

Discussion

In short, salivary microbiota community altered in the perioperative period of renal transplantation and certain species of salivary microbiota had the potential to be a biomarker of postoperative recovery.

HIV-Positive Patients on Antiretroviral Therapy Have an Altered Mucosal Intestinal but Not Oral Microbiome

This study characterized compositional and functional shifts in the intestinal and oral microbiome in HIV-positive patients on antiretroviral therapy compared to HIV-negative individuals. Seventy-nine specimens were collected from 5 HIV-positive and 12 control subjects from five locations (colon brush, colon wash, terminal ileum [TI] brush, TI wash, and saliva) during colonoscopy and at patient visits. Microbiome composition was characterized using 16S rRNA sequencing, and microbiome function was predicted using bioinformatics tools (PICRUSt and BugBase). Our analysis indicated that the β-diversity of all intestinal samples (colon brush, colon wash, TI brush, and TI wash) from patients with HIV was significantly different from patients without HIV. Specifically, bacteria from genera Prevotella, Fusobacterium, and Megasphaera were more abundant in samples from HIV-positive patients. On the other hand, bacteria from genera Ruminococcus, Blautia, and Clostridium were more abundant in samples from HIV-negative patients. Additionally, HIV-positive patients had higher abundances of biofilm-forming and pathogenic bacteria. Furthermore, pathways related to translation and nucleotide metabolism were elevated in HIV-positive patients, whereas pathways related to lipid and carbohydrate metabolism were positively correlated with samples from HIV-negative patients. Our analyses further showed variations in microbiome composition in HIV-positive and negative patients by sampling site. Samples from colon wash, colon brush, and TI wash were significant between groups, while samples from TI brush and saliva were not significant. Taken together, here, we report altered intestinal microbiome composition and predicted function in patients with HIV compared to uninfected patients, though we found no changes in the oral microbiome. IMPORTANCE Over 37 million people worldwide are living with HIV. Although the availability of antiretroviral therapy has significantly reduced the number of AIDS-related deaths, individuals living with HIV are at increased risk for opportunistic infections. We now know that HIV interacts with the trillions of bacteria, fungi, and viruses in the human body termed the microbiome. Only a limited number of previous studies have compared variations in the oral and gastrointestinal microbiome with HIV infection. Here, we detail how the oral and gastrointestinal microbiome changes with HIV infection, having used 5 different sampling sites to gain a more comprehensive view of these changes by location. Our results show site-specific changes in the intestinal microbiome associated with HIV infection. Additionally, we show that while there were significant changes in the intestinal microbiome, there were no significant changes in the oral microbiome.

The initial interplay between HIV and mucosal innate immunity

Human Immunodeficiency Virus (HIV) is still one of the major global health issues, and despite significant efforts that have been put into studying the pathogenesis of HIV infection, several aspects need to be clarified, including how innate immunity acts in different anatomical compartments. Given the nature of HIV as a sexually transmitted disease, one of the aspects that demands particular attention is the mucosal innate immune response. Given this scenario, we focused our attention on the interplay between HIV and mucosal innate response: the different mucosae act as a physical barrier, whose integrity can be compromised by the infection, and the virus-cell interaction induces the innate immune response. In addition, we explored the role of the mucosal microbiota in facilitating or preventing HIV infection and highlighted how its changes could influence the development of several opportunistic infections. Although recent progress, a proper characterization of mucosal innate immune response and microbiota is still missing, and further studies are needed to understand how they can be helpful for the formulation of an effective vaccine.

Altered dental plaque microbiota correlated with salivary inflammation in female methamphetamine users

Poor oral health is the most immediate and overlooked hazard of methamphetamine abuse in humans. Previous studies have reported methamphetamine-associated alterations in saliva microbiota, but the cause of methamphetamine-induced alterations in the oral microenvironment remains unclear. The present study aimed to investigate the alterations in dental plaque microbiota in methamphetamine users, and to explore their relationship with local immune inflammation in the oral cavity. This may provide new ideas on the development of methamphetamine-related oral microenvironment changes. Questionnaires and samples were obtained from 30 female methamphetamine users and 15 sex- and age-matched healthy controls. Microbial profiles of supragingival dental plaque were analyzed using 16S rRNA gene sequencing. Inflammatory factors in saliva were measured using enzyme-linked immunosorbent assay. Methamphetamine users had worse oral self-evaluation. Compared with healthy controls, methamphetamine users showed no differences in oral dental plaque microbial diversity but exhibited differences in the relative abundance of several microbial taxa. At the phylum level, a higher abundance of Proteobacteria and a lower abundance of Firmicutes were detected in methamphetamine users. Moreover, function prediction using the MetaCyc database showed that 33 pathways were significantly upregulated in methamphetamine users; Only the glycolytic (Pyrococcus) pathway was enriched in the C group. Importantly, salivary inflammatory factors showed complex significant associations with bacterial genera in methamphetamine users. Specifically, the genus Neisseria was positively correlated with IL-17 levels in saliva, and both were high in methamphetamine users. In contrast, the genus Streptococcus, with a lower abundance, was positively correlated with lower IL-10 levels. Overall, This study is the first to provide evidence for a link between altered dental plaque microbiota and salivary inflammation in methamphetamine users. Further elucidation of the interactions between methamphetamine use and oral microenvironment would be beneficial for appropriate interventions to improve oral health.

Nonsurgical periodontal debridement affects subgingival bacterial diversity in human immunodeficiency virus (HIV)-1 infected patients with periodontitis

BACKGROUND

Following HIV-1 infection and antiretroviral therapy, the development of periodontal disease was shown to be favored. However, the influence of HIV-1 infection on the periodontal microbiota after nonsurgical periodontal debridement (NSPD) needs a broad comprehension. This work aimed to compare the subgingival microbiological content of HIV-infected and control patients with periodontitis undergoing NSPD.

METHODS

The bacterial profile of subgingival biofilm samples of HIV-1-infected (n = 18) and control (n = 14) patients with periodontitis was assessed using 16S rRNA gene sequencing. The samples were collected at baseline, 30 and 90 days after NSPD. The taxonomic analysis of gingival microbiota was performed using a ribosomal RNA database. The microbiota content was evaluated in the light of CD4 cell count and viral load.

RESULTS

Both HIV and control groups showed similar stages and grades of periodontitis. At baseline, the HIV group showed higher alpha diversity for both healthy (HS) and periodontal sites (PS). Streptococcus, Fusobacterium, Veillonella and Prevotella were the predominant bacterial genera. A low abundance of periodontopathogenic bacteria was observed, and the NSPD induced shifts in the subgingival biofilm of HIV-infected patients, leading to a microbiota similar to that of control patients.

CONCLUSION

Different subgingival microbiota profiles were identified - a less diverse microbiota was found in HIV-1-infected patients, in contrast to a more diverse microbiota in control patients. NSPD caused changes in the microbiota of both groups, with a greater impact on the HIV group, leading to a decrease in alpha diversity, and produced a positive impact on the serological immune markers in HIV-1-infected patients. Control of periodontitis should be included as part of an oral primary care, providing the oral health benefits and better control of HIV-1 infection. This article is protected by copyright. All rights reserved.

Association of Intestinal Microbial Dysbiosis With Chronic Obstructive Pulmonary Disease

Normal gut flora plays various beneficial roles for the human body, including the protection against inflammatory states and mucosal viral infections. It also influences the immune system of the body. The metabolites produced by the gut bacteria control local and other systemic organs' immune functions like the lungs and brain, playing a role in their response to acute and chronic illnesses. Probiotics have shown beneficial effects on lung health. On the contrary, dysbiosis is associated with several diseases, including asthma, chronic bronchitis, emphysema, allergies, and other acute viral infections. By altering the diet of patients with respiratory diseases like patients with chronic obstructive pulmonary diseases (COPD), we may be able to mitigate their conditions. This literature review aims to discuss the mechanisms altering the gastrointestinal flora, the pathophysiology of gut and lung axis, the role of diet in gut microbe health, and the association of COPD with gut dysbiosis and peptic ulcer disease (PUD). We have extracted the data from PubMed and Google Scholar, consisting of review articles, case-control studies, and animal studies. The studies showed an association between gut microbes and different lung diseases. It is found that gut dysbiosis not only disrupts intestinal immunity but may also facilitate the development of COPD. Present studies also show an increased seroprevalence of Helicobacter pylori in patients with COPD. The strategies that can improve lung functions, especially in COPD patients, include prebiotics and probiotic supplementation to a diet more balanced than the current average American diet.

Differential Signature of the Microbiome and Neutrophils in the Oral Cavity of HIV-Infected Individuals

HIV infection is associated with a wide range of changes in microbial communities and immune cell components of the oral cavity. The purpose of this study was to evaluate the oral microbiome in relationship to oral neutrophils in HIV-infected compared to healthy individuals. We evaluated oral washes and saliva samples from HIV-infected individuals (n=52) and healthy controls (n=43). Using 16S-rRNA gene sequencing, we found differential β-diversity using Principal Coordinate Analysis (PCoA) with Bray-Curtis distances. The α-diversity analysis by Faith’s, Shannon, and observed OTUs indexes indicated that the saliva samples from HIV-infected individuals harbored significantly richer bacterial communities compared to the saliva samples from healthy individuals. Notably, we observed that five species of Spirochaeta including Spirochaetaceae, Spirochaeta, Treponema, Treponema amylovorum, and Treponema azotonutricum were significantly abundant. In contrast, Helicobacter species were significantly reduced in the saliva of HIV-infected individuals. Moreover, we found a significant reduction in the frequency of oral neutrophils in the oral cavity of HIV-infected individuals, which was positively related to their CD4⁺ T cell count. In particular, we noted a significant decline in CD44 expressing neutrophils and the intensity of CD44 expression on oral neutrophils of HIV-infected individuals. This observation was supported by the elevation of soluble CD44 in the saliva of HIV-infected individuals. Overall, the core oral microbiome was distinguishable between HIV-infected individuals on antiretroviral therapy compared to the HIV-negative group. The observed reduction in oral neutrophils might likely be related to the low surface expression of CD44, resulting in a higher bacterial diversity and richness in HIV-infected individuals.

Alterations in the oral microbiome in HIV infection: causes, effects and potential interventions

ABSTRACT

A massive depletion of CD4+ T lymphocytes has been described in early and acute human immunodeficiency virus (HIV) infection, leading to an imbalance between the human microbiome and immune responses. In recent years, a growing interest in the alterations in gut microbiota in HIV infection has led to many studies; however, only few studies have been conducted to explore the importance of oral microbiome in HIV-infected individuals. Evidence has indicated the dysbiosis of oral microbiota in people living with HIV (PLWH). Potential mechanisms might be related to the immunodeficiency in the oral cavity of HIV-infected individuals, including changes in secretory components such as reduced levels of enzymes and proteins in saliva and altered cellular components involved in the reduction and dysfunction of innate and adaptive immune cells. As a result, disrupted oral immunity in HIV-infected individuals leads to an imbalance between the oral microbiome and local immune responses, which may contribute to the development of HIV-related diseases and HIV-associated non-acquired immunodeficiency syndrome comorbidities. Although the introduction of antiretroviral therapy (ART) has led to a significant decrease in occurrence of the opportunistic oral infections in HIV-infected individuals, the dysbiosis in oral microbiome persists. Furthermore, several studies with the aim to investigate the ability of probiotics to regulate the dysbiosis of oral microbiota in HIV-infected individuals are ongoing. However, the effects of ART and probiotics on oral microbiome in HIV-infected individuals remain unclear. In this article, we review the composition of the oral microbiome in healthy and HIV-infected individuals and the possible effect of oral microbiome on HIV-associated oral diseases. We also discuss how ART and probiotics influence the oral microbiome in HIV infection. We believe that a deeper understanding of composition and function of the oral microbiome is critical for the development of effective preventive and therapeutic strategies for HIV infection.

HIV-Associated Interactions Between Oral Microbiota and Mucosal Immune Cells: Knowledge Gaps and Future Directions

Even with sustained use of antiretroviral therapy (ART), HIV-infected individuals have an increased risk of systemic comorbid conditions and oral pathologies, including opportunistic infections, oral mucosal inflammation, and gingival and periodontal diseases. The immune-mediated mechanisms that drive this increased risk, in the context of sustained viral suppression, are unclear. HIV infection, even when controlled, alters microbial communities contributing to a chronic low-grade inflammatory state that underlies these non-HIV co-morbidities. The higher prevalence of dental caries, and mucosal and periodontal inflammation reported in HIV-infected individuals on ART is often associated with differentially abundant oral microbial communities, possibly leading to a heightened susceptibility to inflammation. This mini-review highlights current gaps in knowledge regarding the microbe-mediated oral mucosal immunity with HIV infection while discussing opportunities for future research investigations and implementation of novel approaches to elucidate these gaps. Interventions targeting both inflammation and microbial diversity are needed to mitigate oral inflammation-related comorbidities, particularly in HIV-infected individuals. More broadly, additional research is needed to bolster general models of microbiome-mediated chronic immune activation and aid the development of precise microbiota-targeted interventions to reverse or mitigate adverse outcomes.

Characterization of the Human Oropharyngeal Microbiomes in SARS-CoV-2 Infection and Recovery Patients

Respiratory tract microbiome is closely related to respiratory tract infections, while characterization of oropharyngeal microbiome in recovered coronavirus disease 2019 (COVID-19) patients is not studied. Herein, oropharyngeal swabs are collected from confirmed cases (CCs) with COVID-19 (73 subjects), suspected cases (SCs) (36), confirmed cases who recovered (21), suspected cases who recovered (36), and healthy controls (Hs) (140) and then completed MiSeq sequencing. Oropharyngeal microbial α-diversity is markedly reduced in CCs versus Hs. Opportunistic pathogens are increased, while butyrate-producing genera are decreased in CCs versus Hs. The classifier based on eight optimal microbial markers is constructed through a random forest model and reached great diagnostic efficacy in both discovery and validation cohorts. Notably, the classifier successfully diagnosed SCs with positive IgG antibody as CCs and is demonstrated from the perspective of the microbiome. Importantly, several genera with significant differences gradually increase and decrease along with recovery from COVID-19. Forty-four oropharyngeal operational taxonomy units (OTUs) are closely correlated with 11 clinical indicators of SARS-CoV-2 infection and Hs based on Spearman correlation analysis. Together, this research is the first to characterize oropharyngeal microbiota in recovered COVID-19 cases and suspected cases, to successfully construct and validate the diagnostic model for COVID-19 and to depict the correlations between microbial OTUs and clinical indicators.

Inflammatory biomarkers in the pathogenesis of respiratory dysfunction in people living with HIV

BACKGROUND

Although the association between HIV infection and airway obstruction is well known, its etiopathogenesis is not clear.

OBJECTIVES

Our aim was to analyze the association between biomarkers of systemic inflammation and bacterial translocation and pulmonary function tests in HIV-infected patients and compare the results between smokers and non-smokers.

METHOD

It was a cross-sectional, observational study. The inclusion criterion of the study was people living with HIV with undetectable plasma viral load. The exclusion criterion was other comorbidities associated with systemic inflammation. Outcome variables were spirometry and diffusing capacity for carbon monoxide; explanatory variables were inflammatory biomarkers (interleukin-6, tumor necrosis factor-alpha), bacterial translocation (soluble CD14 [sCD14] and bacterial 16S rDNA), and variables related to HIV infection. Associations were tested using the Pearson/Spearman correlation tests, the Student t-test, and multivariable linear regression.

RESULTS

We included 71 patients (54.9% smokers). We did not observe significant differences in pulmonary function tests according to biomarkers of inflammation or bacterial translocation. In non-smokers (n=32), sCD14 was negatively correlated with forced expiratory volume in 1 second (R = -0.35, P = 0.048) and forced vital capacity (R= -0.40, P=0.023). Age, time since HIV diagnosis, and CD4+ nadir were associated with alterations in PFTs. In smokers, the only association observed was between the pack-years and pulmonary obstruction.

CONCLUSION

In non-smokers, HIV patients' lung dysfunction can be, at least partially, related to bacterial translocation (sCD14), CD4+ nadir, and time since HIV diagnosis.

Airflow limitation and tongue microbiota in community-dwelling elderly individuals

Numerous oral indigenous microorganisms are constantly introduced into the stomach via the laryngopharynx, and a portion of these microorganisms irregularly reaches the lower airways and lungs. This study investigated the association between airflow limitation and the status of tongue microbiota, which is a primary source of ingested oral bacterial populations.

The study population consisted of 484 community-dwelling adults aged 70–80 years inhabiting Hisayama town, Japan, who underwent a regular health examination including dental examination and spirometry test in 2016. The bacterial density and composition of their tongue microbiota were determined using a previously used 16S rRNA gene to understand their relationship with oral health conditions. The present cross-sectional study compared the tongue microbiota status between elderly individuals with airflow limitation and those with normal airflow.

The total bacterial density of the tongue microbiota of individuals with airflow limitation was significantly higher than that of individuals with normal airflow. Logistic regression analysis demonstrated that a high-biomass tongue microbiota was significantly associated with airflow limitation after adjustment for smoking intensity and other covariates (adjusted OR 1.61, 95% CI 1.01–2.60). Of the predominant commensals, higher amounts of Prevotella melaninogenica and Actinomyces odontolyticus were associated with a higher prevalence of airflow limitation.

These results indicate that increased bacterial burden in the tongue microbiota is associated with a higher prevalence of airflow limitation.

Bacterial enrichment in the tongue microbiota is associated with airflow limitation characterising COPD in community-dwelling elderly adultshttps://bit.ly/36qMf6G

Recent advances in HIV-associated chronic lung disease clinical research

PURPOSE OF REVIEW

To highlight recently published, clinically focused research on chronic lung disease in adult persons with human immunodeficiency virus-1 (HIV) (PWH).

RECENT FINDINGS

Chronic lung disease was the most common comorbidity in hospitalized PWH in New York and second-most common condition in ambulatory PWH in Canada. The elevated risk of chronic obstructive pulmonary disease in PWH has been widely recognized, but PWH are also at higher risk for asthma and worse asthma outcomes. Expanded assessments of lung structure and function, such as single-breath diffusing capacity of carbon monoxide (DLCO), exhaled nitric oxide (FeNO), and chest computed tomography (CT) have provided new insights into HIV effects on the lungs. New biomarker analyses are emerging, but further studies are needed to validate predictive biomarkers for chronic lung disease in PWH. Clinical trials addressing chronic lung disease in PWH are few in number.

SUMMARY

Chronic lung disease is a common and high-impact comorbidity among PWH. Future studies should collect more comprehensive lung assessments such as DLCO, FeNO, and chest CT in order to better phenotype lung derangements in HIV. Clinical trials are desperately needed to reduce the rising burden of chronic lung disease in PWH.

Salivary microbial diversity at different stages of human immunodeficiency virus infection

Human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) disrupts the host microbial balance. During disease progression, the oral microbial environment is altered in untreated people living with HIV/AIDS (PLWHA); however, no studies have reported changes in salivary microbial diversity during different stages of HIV infection. Therefore, in this study, we aimed to assess the relationships between immune dysfunction and changes in saliva microbiota. To this end, we collected saliva samples from 11 HIV-negative individuals and 44 PLWHA during different stages based on the Centers for Disease Control and Prevention criteria (stage 0, early stage during the first 6 months after infection; stages 1, 2, and 3 associated with CD4⁺ T-lymphocyte counts of ≥500, 200-499, and ≤200 or opportunistic infection, respectively). We analyzed salivary microbial community diversity using polymerase chain reaction amplification and Illumina MiSeq sequencing. We found that HIV-positive individuals had significantly greater alpha-diversity in the microbial community composition compared with HIV-negative controls (P < 0.05) except for AIDS (stage 3); however, the predominant salivary microbiota in the five groups remained similar. Porphyromonas in the four positive groups was the only genus that was significantly less abundant in the HIV-positive groups than in the control group (P < 0.05). There were some consistencies between the general abundance of salivary microbiota and AIDS disease progression. Lots of bacterial abundances in the saliva increased dramatically during the acute HIV infection (stage 0), and some of the negligible and abnormally proliferating bacteria in the asymptomatic stage showed a downward trend. Additionally, in the AIDS stage, partial inhibition was observed. Notably, Porphyromonas was closely related to the immune activation of HIV, showing a decline in abundance once infected with HIV. Solobacterium, which induces inflammation, was negatively correlated with CD4 counts. Overall, our findings provided important insights into changes in salivary microbial diversity in PLWHA.

Chronic obstructive pulmonary disease in HIV

Introduction: Chronic obstructive pulmonary disease (COPD) is more prevalent in people with HIV (PWH) than in the general population and leads to an increased burden of morbidity and mortality in this population. The mechanisms behind COPD development and progression in PWH are not fully elucidated, and there are no PWH-specific guidelines for COPD management. Areas covered: The goal of this broad narrative review is to review the epidemiology of COPD in PWH globally, highlight proposed pathways contributing to increased COPD prevalence and progression in PWH, discuss structural and functional changes in the lungs in this population, assesses the excess mortality and comorbidities in PWH with COPD, and address management practices for this unique population. Expert opinion: Understanding how a chronic viral infection leads to COPD, independent of cigarette smoking, is of critical scientific importance. Further research should focus on the pathophysiology of the interaction between HIV and COPD, and determine the role of disease-modifying risk factors such as opportunistic pneumonia and air pollution, as well as generate data from randomized clinical trials on the safety and efficacy of specific therapies for this vulnerable patient population.

Identification of potential markers for internal exposure to ambient ozone in oral cavity of healthy adults

BACKGROUND

Ozone is a highly oxidative gaseous pollutant associated with adverse health outcomes, but markers for internal exposure to ambient ozone are not well-established.

METHODS

We aimed to evaluate the feasibility and suitability of the markers in oral microbiome for ambient ozone exposure. Between March and May in 2018, 97 healthy adults were examined on 2 or 3 occasions for oral swab sampling. Hourly concentrations of ambient ozone 1-7 days preceding sampling were collected. Mixed-effect models were fitted to examine the associations between ambient ozone and the diversity and taxon abundances of oral microbiome. Receiver operating characteristic (ROC) curves estimated the accuracies of markers to delineate between samples exposed to different concentrations of ambient ozone. The associations between the makers and lung function were further examined by linear mixed effect models.

RESULTS

The averages of daily mean concentrations of ambient ozone (O_3-daily), maximum 8-h means (O_3-8hmax) and 1-h maximums (O_3-1hmax) were respectively 72 μg/m³, 123 μg/m³ and 144 μg/m³. O_3-daily was positively associated with α-diversity of oral microbiome, but the exposure-response curves only yielded positive associations in the range of O_3-daily from 60 μg/m³ to 75 μg/m³. Results of O_3-8hmax and O_3-1hmax were consistent with these of O_3-daily. With an interquartile range increase in O_3-daily at lag04, the abundance of Proteobacteria decreased by 3.1% (95% CI: -4.0%, -2.2%) and Firmicutes increased by 3.3% (95% CI: 2.3%, 4.3%), whilst the Proteobacteria:Firmicutes ratio (P/F) decreased by 0.9 (95% CI: -1.5, -0.4). The areas under ROC curves for Proteobacteria, Firmicutes and P/F were 0.8535, 0.7569 and 0.8929, respectively. Proteobacteria and P/F were associated with forced expiratory volume in the first second and fractional exhaled nitric oxide significantly.

CONCLUSION

Ambient ozone disturbs oral microbial homeostasis. Proteobacteria, Firmicutes and their ratio may be potential markers for short-term ambient ozone exposure, and indicators of airway inflammation or lung function decline.

Impact of the Human Microbiome in Forensic Sciences: a Systematic Review

Numerous studies relate differences in microbial communities to human health and disease; however, little is known about microbial changes that occur postmortem or the possible applications of microbiome analysis in the field of forensic science. The aim of this review was to study the microbiome and its applications in forensic sciences and to determine the main lines of investigation that are emerging, as well as its possible contributions to the forensic field. A systematic review of the human microbiome in relation to forensic science was carried out by following PRISMA guidelines. This study sheds light on the role of microbiome research in the postmortem interval during the process of decomposition, identifying death caused by drowning or sudden death, locating the geographical location of death, establishing a connection between the human microbiome and personal items, sexual contact, and the identification of individuals. Actinomycetaceae, Bacteroidaceae, Alcaligenaceae, and Bacilli play an important role in determining the postmortem interval. Aeromonas can be used to determine the cause of death, and Corynebacterium or Helicobacter pylori can be used to ascertain personal identity or geographical location. Several studies point to a promising future for microbiome analysis in the different fields of forensic science, opening up an important new area of research.

Alveolar cells under mechanical stressed niche: critical contributors to pulmonary fibrosis

Pulmonary fibrosis arises from the repeated epithelial mild injuries and insufficient repair lead to over activation of fibroblasts and excessive deposition of extracellular matrix, which result in a mechanical stretched niche. However, increasing mechanical stress likely exists before the establishment of fibrosis since early micro injuries increase local vascular permeability and prompt cytoskeletal remodeling which alter cellular mechanical forces. It is noteworthy that COVID-19 patients with severe hypoxemia will receive mechanical ventilation as supportive treatment and subsequent pathology studies indicate lung fibrosis pattern. At advanced stages, mechanical stress originates mainly from the stiff matrix since boundaries between stiff and compliant parts of the tissue could generate mechanical stress. Therefore, mechanical stress has a significant role in the whole development process of pulmonary fibrosis. The alveoli are covered by abundant capillaries and function as the main gas exchange unit. Constantly subject to variety of damages, the alveolar epithelium injuries were recently recognized to play a vital role in the onset and development of idiopathic pulmonary fibrosis. In this review, we summarize the literature regarding the effects of mechanical stress on the fundamental cells constituting the alveoli in the process of pulmonary fibrosis, particularly on epithelial cells, capillary endothelial cells, fibroblasts, mast cells, macrophages and stem cells. Finally, we briefly review this issue from a more comprehensive perspective: the metabolic and epigenetic regulation.

Alterations in Oral-Nasal-Pharyngeal Microbiota and Salivary Proteins in Mouth-Breathing Children

Mouth breathing induces a series of diseases, while the influence on microbiota of oral cavity and salivary proteins remains unknown. In this study, for the first time, profiles of oral-nasal-pharyngeal microbiota among mouth-breathing children (MB group, n = 10) were compared with paired nose-breathing children (NB group, n = 10) using 16S ribosomal DNA (rDNA) (V3-V4 region) high-throughput sequencing. The differentially expressed salivary proteins were revealed using label-free quantification (LFQ) method, and their associations with bacterial abundance were measured by canonical correspondence analysis (CCA). The overall bacterial profiles differed between the two groups, and the differences were related to the duration of mouth breathing. The diversity of oral-pharyngeal microbiota was significantly higher, and the nasal-pharyngeal species tended to be consistent (unweighted UniFrac, p = 0.38) in the MB group. Opportunistic pathogens were higher in relative abundance as follows: Acinetobacter in the anterior supragingival plaque, Neisseria in unstimulated saliva, Streptococcus pneumoniae in the pharynx, and Stenotrophomonas in the nostrils. The expression level of oxidative-stress-related salivary proteins (lactoylglutathione lyase and peroxiredoxin-5) were upregulated, while immune-related proteins (integrin alpha-M and proteasome subunit alpha type-1) were downregulated in MB group. The differentially expressed proteins were associated with specific bacteria, indicating their potentials as candidate biomarkers for the diagnosis, putatively early intervention, and therapeutic target of mouth breathing. This study showed that mouth breathing influences the oral-nasal-pharyngeal microbiota and enriches certain pathogens, accompanied with the alterations in the salivary environment. Further research on the pathological mechanisms and dynamic changes in longitudinal studies are warranted.

Distinct lung microbiota associate with HIV-associated chronic lung disease in children

Chronic lung disease (CLD) is a common co-morbidity for HIV-positive children and adolescents on antiretroviral therapy (ART) in sub-Saharan Africa. In this population, distinct airway microbiota may differentially confer risk of CLD. In a cross-sectional study of 202 HIV-infected children aged 6-16 years in Harare, Zimbabwe, we determined the association of sputum microbiota composition (using 16S ribosomal RNA V4 gene region sequencing) with CLD defined using clinical, spirometric, or radiographic criteria. Forty-two percent of children were determined to have CLD according to our definition. Dirichlet multinomial mixtures identified four compositionally distinct sputum microbiota structures. Patients whose sputum microbiota was dominated by Haemophilus, Moraxella or Neisseria (HMN) were at 1.5 times higher risk of CLD than those with Streptococcus or Prevotella (SP)-dominated microbiota (RR = 1.48, p = 0.035). Cell-free products of HMN sputum microbiota induced features of epithelial disruption and inflammatory gene expression in vitro, indicating enhanced pathogenic potential of these CLD-associated microbiota. Thus, HIV-positive children harbor distinct sputum microbiota, with those dominated by Haemophilus, Moraxella or Neisseria associated with enhanced pathogenesis in vitro and clinical CLD.

The Oral Microbiome of Healthy Japanese People at the Age of 90

For a healthy oral cavity, maintaining a healthy microbiome is essential. However, data on healthy microbiomes are not sufficient. To determine the nature of the core microbiome, the oral-microbiome structure was analyzed using pyrosequencing data. Saliva samples were obtained from healthy 90-year-old participants who attended the 20-year follow-up Niigata cohort study. A total of 85 people participated in the health checkups. The study population consisted of 40 male and 45 female participants. Stimulated saliva samples were obtained by chewing paraffin wax for 5 min. The V3–V4 hypervariable regions of the 16S ribosomal RNA (rRNA) gene were amplified by PCR. Pyrosequencing was performed using MiSeq. Operational taxonomic units (OTUs) were assigned on the basis of a 97% identity search in the EzTaxon-e database. Using the threshold of 100% detection on the species level, 13 species were detected: Streptococcus sinensis, Streptococcus pneumoniae, Streptococcus salivarius, KV831974_s, Streptococcus parasanguinis, Veillonella dispar, Granulicatella adiacens, Streptococcus_uc, Streptococcus peroris, KE952139_s, Veillonella parvula, Atopobium parvulum, and AFQU_vs. These species represent potential candidates for the core make-up of the human microbiome.

Respiratory symptoms and chronic bronchitis in people with and without HIV infection

OBJECTIVES

High rates of respiratory symptoms and chronic bronchitis (CB) are reported in people with HIV infection (PWH). We investigated the prevalence of respiratory symptoms and CB in PWH and HIV-negative people in the Pharmacokinetic and clinical Observations in PeoPle over fiftY (POPPY) study.

METHODS

Assessment of respiratory symptoms and CB was undertaken using the modified form of the St. George's Respiratory Questionnaire for chronic obstructive pulmonary disease (COPD). Univariate (χ² tests, Mann-Whitney U tests and Spearman's rank correlation) and multivariable (linear and logistic regression) analyses were performed to consider associations of respiratory symptoms with demographic, lifestyle and HIV-related parameters, and with depressive symptoms and quality of life.

RESULTS

Among the 619 participants, respiratory Symptom scores were higher in older and younger PWH compared to older HIV-negative people, with median (interquartile range) scores of 17.7 (6.2, 39.5), 17.5 (0.9, 30.0) and 9.0 (0.9, 17.5), respectively (P = 0.0001); these differences remained significant after confounder adjustment. Sixty-three participants (10.2%) met the criteria for CB [44 (14.0%) older PWH, 14 (9.2%) younger PWH, and five (3.3%) older HIV-negative people; P = 0.002], with these differences also remaining after adjustment for confounding variables, particularly smoking status [older vs. younger PWH: odds ratio (OR) 4.48 (95% confidence interval (CI) 1.64, 12.30); P = 0.004; older PWH vs. HIV-negative people: OR 4.53 (95% CI 1.12, 18.28); P = 0.03]. Respiratory symptoms and CB were both associated with greater depressive symptom scores and poorer quality of life. No strong associations were reported between CB and immune function, HIV RNA or previous diagnosis of any AIDS event.

CONCLUSIONS

Respiratory symptoms and CB are more common in PWH than in demographically and lifestyle-similar HIV-negative people and are associated with poorer mental health and quality of life.

Enrichment of the airway microbiome in people living with HIV with potential pathogenic bacteria despite antiretroviral therapy

BACKGROUND

Long-term antiretroviral therapy (ART) enables people living with HIV (PLW-HIV) to be healthier and live longer; though they remain at greater risk of pneumonia and chronic lung disease than the general population. Lung microbial dysbiosis has been shown to contribute to respiratory disease.

METHODS

16S-rRNA gene sequencing on the Miseq-platform and qPCR for typical respiratory pathogens were performed on sputum samples collected from 64 PLW-HIV (median blood CD4 count 676 cells/μL) and 38 HIV-negative participants.

FINDING

Richness and α-diversity as well as the relative-abundance (RA) of the major taxa (RA>1%) were similar between both groups. In unweighted-Unifrac ß-diversity, the samples from PLW-HIV showed greater diversity, in contrast to the HIV negative samples which clustered together. Gut bacterial taxa such as Bilophila and members of Enterobacteriaceae as well as pathogenic respiratory taxa (Staphylococcus, Pseudomonas and Klebsiella) were significantly more frequent in PLW-HIV and almost absent in the HIV-negative group. Carriage of these taxa was correlated with the length of time between HIV diagnosis and initiation of ART (Spearman-rho=0·279, p=0·028).

INTERPRETATION

Although the core airway microbiome was indistinguishable between PLW-HIV on effective ART and HIV-negative participants, PLW-HIV's respiratory microbiome was enriched with potential respiratory pathogens and gut bacteria. The observed differences in PLW-HIV may be due to HIV infection altering the local lung microenvironment to be more permissive to harbour pathogenic bacteria that could contribute to respiratory comorbidities. Prompt start of ART for PLW-HIV may reduce this risk.