Altered Gut Microbiota and Host Metabolite Profiles in Women With Human Immunodeficiency Virus

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.

Bacillus siamensis Improves the Immune Status and Intestinal Health of Weaned Piglets by Improving Their Intestinal Microbiota

Previous studies on the early interference of gut microbiota by Bacillus siamensis (B. siamensis) in weaned piglets are rarely reported, and the present trial is a preliminary study. This experiment was conducted to investigate the effects of B. siamensis supplementation on the growth performance, serum biochemistry, immune response, fecal short-chain fatty acids and microbiota of weaned piglets. Sixty weaned piglets were randomly divided into a control group (CON) and a B. siamensis group (BS), which were fed a basal diet and the basal diet supplemented with 5 × 1010 CFU B. siamensis per kg, respectively. Each group had 3 replicates and 10 piglets per replicate. The trial lasted for 28 days. The results showed that B. siamensis significantly increased the serum growth hormone (GH) and insulin-like growth factor (IGF) in piglets. Compared with the CON group, the levels of serum immunoglobulin and inflammatory factors in the BS group were significantly improved. In addition, the serum concentrations of zonulin and endotoxin (ET) in the BS group were lower. The dietary addition of B. siamensis significantly increased fecal short-chain fatty acid (SCFA) levels in piglets. Notably, B. siamensis improved the microbial composition by increasing beneficial genera, including Weissella, Lachnospiraceae_NK4A136_group and Bifidobacterium, and decreasing pathogenic genera, including Pantoea, Fusobacterium and Gemella, in piglet feces. Correlation analysis showed that the benefits of dietary B. siamensis supplementation were closely related to its improved microbial composition. In summary, the addition of B. siamensis can improve the immunity function, inflammatory response, gut permeability and SCFA levels of weaned piglets, which may be achieved through the improvement of their microbiota.

The menopause-related gut microbiome: associations with metabolomics, inflammatory protein markers, and cardiometabolic health in women with HIV

OBJECTIVE

This study aimed to identify menopause-related gut microbial features, as well as their related metabolites and inflammatory protein markers, and link with cardiometabolic risk factors in women with and without HIV.

METHODS

In the Women's Interagency HIV Study, we performed shotgun metagenomic sequencing on 696 stool samples from 446 participants (67% women with HIV), and quantified plasma metabolomics and serum proteomics in a subset (~86%). We examined the associations of menopause (postmenopausal vs premenopausal) with gut microbial features in a cross-sectional repeated-measures design and further evaluated those features in relation to metabolites, proteins, and cardiometabolic risk factors.

RESULTS

Different overall gut microbial composition was observed by menopausal status in women with HIV only. We identified a range of gut microbial features that differed between postmenopausal and premenopausal women with HIV (but none in women without HIV), including abundance of 32 species and functional potentials involving 24 enzymatic reactions and lower β-glucuronidase bacterial gene ortholog. Specifically, highly abundant species Faecalibacterium prausnitzii , Bacteroides species CAG:98 , and Bifidobacterium adolescentis were depleted in postmenopausal versus premenopausal women with HIV. Menopause-depleted species (mainly Clostridia ) in women with HIV were positively associated with several glycerophospholipids, while negatively associated with imidazolepropionic acid and fibroblast growth factor 21. Mediation analysis suggested that menopause may decrease plasma phosphatidylcholine plasmalogen C36:1 and C36:2 levels via reducing abundance of species F. prausnitzii and Acetanaerobacterium elongatum in women with HIV. Furthermore, waist-to-hip ratio was associated with menopause-related microbes, metabolites, and fibroblast growth factor 21 in women with HIV.

CONCLUSIONS

Menopause was associated with a differential gut microbiome in women with HIV, related to metabolite and protein profiles that potentially contribute to elevated cardiometabolic risk.

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.

Impaired gut microbiota-mediated short-chain fatty acid production precedes morbidity and mortality in people with HIV

Antiretroviral therapy (ART) has dramatically lengthened lifespan among people with HIV (PWH), but this population experiences heightened rates of inflammation-related comorbidities. HIV-associated inflammation is linked with an altered microbiome; whether such alterations precede inflammation-related comorbidities or occur as their consequence remains unknown. We find that ART-treated PWH exhibit depletion of gut-resident bacteria that produce short-chain fatty acids (SCFAs)-crucial microbial metabolites with anti-inflammatory properties. Prior reports establish that fecal SCFA concentrations are not depleted in PWH. We find that gut-microbiota-mediated SCFA production capacity is better reflected in serum than in feces and that PWH exhibit reduced serum SCFA, which associates with inflammatory markers. Leveraging stool and serum samples collected prior to comorbidity onset, we find that HIV-specific microbiome alterations precede morbidity and mortality in ART-treated PWH. Among these microbiome alterations, reduced microbiome-mediated conversion of lactate to propionate precedes mortality in PWH. Thus, gut microbial fiber/lactate conversion to SCFAs may modulate HIV-associated comorbidity risk.

Immune activation and inflammation in lactating women on combination antiretroviral therapy: role of gut dysfunction and gut microbiota imbalance

Introduction

Combination antiretroviral therapy (cART) effectively controls HIV; however, chronic low-level viremia and gut microbiota dysbiosis remain significant drivers of gut and systemic inflammation. In this study, we explored the relationship between gut microbiota composition, intestinal inflammation, microbial translocation, and systemic inflammation in women on cART in Sub-Saharan Africa.

Methods

We conducted a study in HIV-infected and HIV-uninfected lactating women followed up at 6 weeks and 6 months postpartum in Harare, Zimbabwe. We used 16S ribosomal Ribonucleic Acid (rRNA) sequencing and MesoScale Discovery V-Plex assays to examine the gut microbiome and to quantify plasma inflammatory biomarkers, respectively. In addition, we measured fecal calprotectin, plasma lipopolysaccharide-binding protein (LBP), and soluble cluster of differentiation 14 (sCD14) by enzyme-linked immunosorbent assay to assess gut inflammation, microbial translocation, and monocyte/macrophage activation.

Results

A group of 77 lactating women were studied, of which 35% were HIV-infected. Fecal calprotectin levels were similar by HIV status at both follow-up time points. In the HIV-infected group at 6 weeks postpartum, fecal calprotectin was elevated: median (interquartile range) [158.1 µg/g (75.3-230.2)] in women who had CD4+ T-lymphocyte counts <350 cells/µL compared with those with ≥350 cells/µL [21.1 µg/g (0-58.4)], p = 0.032. Plasma sCD14 levels were significantly higher in the HIV-infected group at both 6 weeks and 6 months postpartum, p < 0.001. Plasma LBP levels were similar, but higher levels were observed in HIV-infected women with elevated fecal calprotectin. We found significant correlations between fecal calprotectin, LBP, and sCD14 with proinflammatory cytokines. Gut microbial alpha diversity was not affected by HIV status and was not affected by use of antibiotic prophylaxis. HIV significantly affected microbial beta diversity, and significant differences in microbial composition were noted. The genera Slackia and Collinsella were relatively more abundant in the HIV-infected group, whereas a lower relative abundance of Clostriduim sensu_stricto_1 was observed. Our study also found correlations between gut microbial taxa abundance and systemic inflammatory biomarkers.

Discussion and conclusion

HIV-infected lactating women had increased immune activation and increased microbial translocation associated with increased gut inflammation. We identified correlations between the gut inflammation and microbial composition, microbial translocation, and systemic inflammation. The interplay of these parameters might affect the health of this vulnerable population.

Association of Gut Microbiota With Objective Sleep Measures in Women With and Without Human Immunodeficiency Virus Infection: The IDOze Study

BACKGROUND

Poor sleep health is an underrecognized health challenge, especially for people with human immunodeficiency virus (HIV). Gut microbiota related to sleep are underinvestigated.

METHODS

The IDOze microbiota substudy included 190 women (114 with HIV and 76 without HIV). Wrist actigraphy measured total sleep duration, sleep efficiency, number of wake bouts, wake after sleep onset, fragmentation index, and sleep timing. 16S rRNA gene sequencing identified gut microbial genera. Analysis of compositions of microbiomes with bias correction was used to investigate cross-sectional associations between gut microbiota and sleep. Abundances of sleep-related gut microbial genera were compared between women with and without HIV.

RESULTS

Enrichment of 7 short-chain fatty acid-producing genera (eg, Butyricimonas, Roseburia, and Blautia) was associated with lower fragmentation index. Enrichment of 9 genera (eg, Dorea) was associated with lower sleep efficiency and/or more wake after sleep onset. Enrichment of proinflammatory Acidaminococcus was associated with late sleep midpoint and offset time. These associations were largely consistent regardless of HIV status. The abundance of Butyricimonas was lower among women with HIV compared to those without HIV.

CONCLUSIONS

Seventeen genera were identified to be associated with sleep continuity or timing. Butyricimonas, a potentially beneficial genus associated with sleep continuity, was less abundant among women with HIV.

Microbial-Related Metabolites May Be Involved in Eight Major Biological Processes and Represent Potential Diagnostic Markers in Gastric Cancer

Metabolites associated with microbes regulate human immunity, inhibit bacterial colonization, and promote pathogenicity. Integrating microbe and metabolome research in GC provides a direction for understanding the microbe-associated pathophysiological process of metabolic changes and disease occurrence. The present study included 30 GC patients with 30 cancerous tissues and paired non-cancerous tissues (NCs) as controls. LC-MS/MS metabolomics and 16S rRNA sequencing were performed to obtain the metabolic and microbial characteristics. Integrated analysis of the microbes and metabolomes was conducted to explore the coexistence relationship between the microbial and metabolic characteristics of GC and to identify microbial-related metabolite diagnostic markers. The metabolic analysis showed that the overall metabolite distribution differed between the GC tissues and the NC tissues: 25 metabolites were enriched in the NC tissues and 42 metabolites were enriched in the GC tissues. The α and β microbial diversities were higher in the GC tissues than in the NC tissues, with 11 differential phyla and 52 differential genera. In the correlation and coexistence integrated analysis, 66 differential metabolites were correlated and coexisted, with specific differential microbes. The microbes in the GC tissue likely regulated eight metabolic pathways. In the efficacy evaluation of the microbial-related differential metabolites in the diagnosis of GC, 12 differential metabolites (area under the curve [AUC] >0.9) exerted relatively high diagnostic efficiency, and the combined diagnostic efficacy of 5 to 6 microbial-related differential metabolites was higher than the diagnostic efficacy of a single feature. Therefore, microbial diversity and metabolite distribution differed between the GC tissues and the NC tissues. Microbial-related metabolites may be involved in eight major metabolism-based biological processes in GC and represent potential diagnostic markers.

Bifidobacterium infantis supplementation versus placebo in early life to improve immunity in infants exposed to HIV: a protocol for a randomized trial

INTRODUCTION

Infants who are born from mothers with HIV (infants who are HIV exposed but uninfected; iHEU) are at higher risk of morbidity and display multiple immune alterations compared to infants who are HIV-unexposed (iHU). Easily implementable strategies to improve immunity of iHEU, and possibly subsequent clinical health outcomes, are needed. iHEU have altered gut microbiome composition and bifidobacterial depletion, and relative abundance of Bifidobacterium infantis has been associated with immune ontogeny, including humoral and cellular vaccine responses. Therefore, we will assess microbiological and immunological phenotypes and clinical outcomes in a randomized, double-blinded trial of B. infantis Rosell®-33 versus placebo given during the first month of life in South African iHEU.

METHODS

This is a parallel, randomised, controlled trial. Two-hundred breastfed iHEU will be enrolled from the Khayelitsha Site B Midwife Obstetric Unit in Cape Town, South Africa and 1:1 randomised to receive 8 × 109 CFU B. infantis Rosell®-33 daily or placebo for the first 4 weeks of life, starting on day 1-3 of life. Infants will be followed over 36 weeks with extensive collection of meta-data and samples. Primary outcomes include gut microbiome composition and diversity, intestinal inflammation and microbial translocation and cellular vaccine responses. Additional outcomes include biological (e.g. gut metabolome and T cell phenotypes) and clinical (e.g. growth and morbidity) outcome measures.

DISCUSSION

The results of this trial will provide evidence whether B. infantis supplementation during early life could improve health outcomes for iHEU.

ETHICS AND DISSEMINATION

Approval for this study has been obtained from the ethics committees at the University of Cape Town (HREC Ref 697/2022) and Seattle Children's Research Institute (STUDY00003679).

TRIAL REGISTRATION

Pan African Clinical Trials Registry Identifier: PACTR202301748714019.

CLINICAL

TRIALS

gov: NCT05923333.

PROTOCOL VERSION

Version 1.8, dated 18 July 2023.

PTBGRP: predicting phage-bacteria interactions with graph representation learning on microbial heterogeneous information network

Identifying the potential bacteriophages (phage) candidate to treat bacterial infections plays an essential role in the research of human pathogens. Computational approaches are recognized as a valid way to predict bacteria and target phages. However, most of the current methods only utilize lower-order biological information without considering the higher-order connectivity patterns, which helps to improve the predictive accuracy. Therefore, we developed a novel microbial heterogeneous interaction network (MHIN)-based model called PTBGRP to predict new phages for bacterial hosts. Specifically, PTBGRP first constructs an MHIN by integrating phage-bacteria interaction (PBI) and six bacteria-bacteria interaction networks with their biological attributes. Then, different representation learning methods are deployed to extract higher-level biological features and lower-level topological features from MHIN. Finally, PTBGRP employs a deep neural network as the classifier to predict unknown PBI pairs based on the fused biological information. Experiment results demonstrated that PTBGRP achieves the best performance on the corresponding ESKAPE pathogens and PBI dataset when compared with state-of-art methods. In addition, case studies of Klebsiella pneumoniae and Staphylococcus aureus further indicate that the consideration of rich heterogeneous information enables PTBGRP to accurately predict PBI from a more comprehensive perspective. The webserver of the PTBGRP predictor is freely available at http://120.77.11.78/PTBGRP/.

The Role of Bifidobacterium in COVID-19: A Systematic Review

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, mainly causes respiratory and intestinal symptoms and changes in the microbiota of patients. We performed a systematic search in major databases using "Bifidobacterium" and "COVID-19" or "SARS-CoV-2" as key terms to assess the relationship of the genus to COVID-19. After the selection steps, 25 articles were analyzed. Of these, eighteen were observational, and seven were interventional articles that evaluated the use of Bifidobacterium alone or in mix as probiotics for additional treatment of patients with COVID-19. All stages and severities were contemplated, including post-COVID-19 patients. Overall, Bifidobacterium was associated with both protective effects and reduced abundance in relation to the disease. The genus has been found to be abundant in some cases and linked to disease severity. The studies evaluating the use of Bifidobacterium as probiotics have demonstrated the potential of this genus in reducing symptoms, improving pulmonary function, reducing inflammatory markers, alleviating gastrointestinal symptoms, and even contributing to better control of mortality. In summary, Bifidobacterium may offer protection against COVID-19 through its ability to modulate the immune response, reduce inflammation, compete with pathogenic microbes, and maintain gut barrier function. The findings provide valuable insights into the relationship between the disease and the genus Bifidobacterium, highlighting the potential of microbiota modulation in the treatment of COVID-19.

Comparison of the Fecal Bacteriome of HIV-Positive and HIV-Negative Older Adults

HIV infection is considered a scenario of accelerated aging. Previous studies have suggested a link between aging, frailty, and gut dysbiosis, but there is a knowledge gap regarding the HIV population. Our objective was to compare the fecal bacteriome of older people with HIV (PWH) and non-HIV controls, and to assess potential links between gut dysbiosis and frailty. A total of 36 fecal samples (24 from PWH and 12 from non-HIV controls) were submitted to a metataxonomic analysis targeting the V3-V4 hypervariable region of the 16S rRNA gene. High-quality reads were assembled and classified into operational taxonomic units. Alpha diversity, assessed using the Shannon index, was higher in the control group than in the HIV group (p < 0.05). The relative abundance of the genus Blautia was higher in the HIV group (p < 0.001). The presence of Blautia was also higher in PWH with depression (p = 0.004), whereas the opposite was observed for the genus Bifidobacterium (p = 0.004). Our study shows shifts in the composition of the PWH bacteriome when compared to that of healthy controls. To our knowledge, this is the first study suggesting a potential link between depression and gut dysbiosis in the HIV population.

Therapeutically targeting the consequences of HIV-1-associated gastrointestinal dysbiosis: Implications for neurocognitive and affective alterations

Approximately 50 % of the individuals living with human immunodeficiency virus type 1 (HIV-1) are plagued by debilitating neurocognitive impairments (NCI) and/or affective alterations. Sizeable alterations in the composition of the gut microbiome, or gastrointestinal dysbiosis, may underlie, at least in part, the NCI, apathy, and/or depression observed in this population. Herein, two interrelated aims will be critically addressed, including: 1) the evidence for, and functional implications of, gastrointestinal microbiome dysbiosis in HIV-1 seropositive individuals; and 2) the potential for therapeutically targeting the consequences of this dysbiosis for the treatment of HIV-1-associated NCI and affective alterations. First, gastrointestinal microbiome dysbiosis in HIV-1 seropositive individuals is characterized by decreased alpha (α) diversity, a decreased relative abundance of bacterial species belonging to the Bacteroidetes phylum, and geographic-specific alterations in Bacillota (formerly Firmicutes) spp. Fundamentally, changes in the relative abundance of Bacteroidetes and Bacillota spp. may underlie, at least in part, the deficits in γ-aminobutyric acid and serotonin neurotransmission, as well as prominent synaptodendritic dysfunction, observed in this population. Second, there is compelling evidence for the therapeutic utility of targeting synaptodendritic dysfunction as a method to enhance neurocognitive function and improve motivational dysregulation in HIV-1. Further research is needed to determine whether the therapeutics enhancing synaptic efficacy exert their effects by altering the gut microbiome. Taken together, understanding gastrointestinal microbiome dysbiosis resulting from chronic HIV-1 viral protein exposure may afford insight into the mechanisms underlying HIV-1-associated neurocognitive and/or affective alterations; mechanisms which can be subsequently targeted via novel therapeutics.

Gut microbiota, circulating inflammatory markers and metabolites, and carotid artery atherosclerosis in HIV infection

BACKGROUND

Alterations in gut microbiota have been implicated in HIV infection and cardiovascular disease. However, how gut microbial alterations relate to host inflammation and metabolite profiles, and their relationships with atherosclerosis, have not been well-studied, especially in the context of HIV infection. Here, we examined associations of gut microbial species and functional components measured by shotgun metagenomics with carotid artery plaque assessed by B-mode carotid artery ultrasound in 320 women with or at high risk of HIV (65% HIV +) from the Women's Interagency HIV Study. We further integrated plaque-associated microbial features with serum proteomics (74 inflammatory markers measured by the proximity extension assay) and plasma metabolomics (378 metabolites measured by liquid chromatography tandem mass spectrometry) in relation to carotid artery plaque in up to 433 women.

RESULTS

Fusobacterium nucleatum, a potentially pathogenic bacteria, was positively associated with carotid artery plaque, while five microbial species (Roseburia hominis, Roseburia inulinivorans, Johnsonella ignava, Odoribacter splanchnicus, Clostridium saccharolyticum) were inversely associated with plaque. Results were consistent between women with and without HIV. Fusobacterium nucleatum was positively associated with several serum proteomic inflammatory markers (e.g., CXCL9), and the other plaque-related species were inversely associated with proteomic inflammatory markers (e.g., CX3CL1). These microbial-associated proteomic inflammatory markers were also positively associated with plaque. Associations between bacterial species (especially Fusobacterium nucleatum) and plaque were attenuated after further adjustment for proteomic inflammatory markers. Plaque-associated species were correlated with several plasma metabolites, including the microbial metabolite imidazole-propionate (ImP), which was positively associated with plaque and several pro-inflammatory markers. Further analysis identified additional bacterial species and bacterial hutH gene (encoding enzyme histidine ammonia-lyase in ImP production) associated with plasma ImP levels. A gut microbiota score based on these ImP-associated species was positively associated with plaque and several pro-inflammatory markers.

CONCLUSION

Among women living with or at risk of HIV, we identified several gut bacterial species and a microbial metabolite ImP associated with carotid artery atherosclerosis, which might be related to host immune activation and inflammation. Video Abstract.

HIV, opioid use, and alterations to the gut microbiome: elucidating independent and synergistic effects

Background

The microbiome is essential to immune development, defense against pathogens, and modulation of inflammation. Microbial dysbiosis has been reported in various diseases including human immunodeficiency virus (HIV) and opioid use disorder (OUD). Notably, people living with HIV (PLWH) have been reported to both have higher rates of OUD and use opioids at higher rates than the general public. Thus, studying gut microbial alterations in people living with HIV and with OUD could elucidate mechanisms pertaining to how these conditions both shape and are shaped by the microbiome. However, to date few studies have investigated how HIV and OUD in combination impact the microbiome.

Aim of review

Here, we review previous studies outlining interactions between HIV, opioid use, and microbial dysbiosis and describe attempts to treat this dysbiosis with fecal microbial transplantation, probiotics, and dietary changes.

Key scientific concepts of review

While the limited number of studies prevent overgeneralizations; accumulating data suggest that HIV and opioid use together induce distinct alterations in the gut microbiome. Among the three existing preclinical studies of HIV and opioid use, two studies reported a decrease in Lachnospiraceae and Ruminococcaceae, and one study reported a decrease in Muribaculaceae in the combined HIV and opioid group relative to HIV-alone, opioid-alone, or control groups. These bacteria are known to modulate immune function, decrease colonic inflammation, and maintain gut epithelial barrier integrity in healthy individuals. Accordingly, modulation of the gut microbiome to restore gut homeostasis may be attempted to improve both conditions. While mixed results exist regarding treating dysbiosis with microbial restoration in PLWH or in those with opioid dependency, larger well-defined studies that can improve microbial engraftment in hosts hold much promise and should still be explored.

Gut microbiota alterations after switching from a protease inhibitor or efavirenz to raltegravir in a randomized, controlled study

OBJECTIVE

To study gut microbiota before and 24 weeks after a single antiretroviral agent switch.

DESIGN

HIV-positive patients with efavirenz (EFV) or a protease inhibitor (PI)-based antiretroviral therapy (ART) were randomized to switch EFV or PI to raltegravir (RAL group, n = 19) or to continue unchanged ART (EFV/PI group, n = 22). Age and weight-matched HIV-negative participants (n = 10) were included for comparison.

METHODS

Microbiota was analyzed using 16S rRNA sequencing. Serum intestinal fatty acid-binding protein (I-FABP) and serum lipopolysaccharide-binding protein (LBP) were measured as gut permeability markers. Three-day food diaries were collected.

RESULTS

At week 24, microbiota diversity (Chao1 index) was higher in RAL than the EFV/PI group (P = 0.014), and RAL group did not differ from HIV-negative participants. In subgroup analysis switching from EFV (P = 0.043), but not from a PI to RAL increased Chao1. At week 24, RAL and EFV/PI group differed in the relative abundance of Prevotella 9 (higher in RAL, P = 0.01), Phascolarctobacterium and Bacteroides (lower in RAL, P = 0.01 and P = 0.03). Dietary intakes did not change during the study and do not explain microbiota differences. Also, I-FABP and LBP remained unchanged.

CONCLUSION

Here we demonstrate that a single ART agent switch caused microbiota alterations, most importantly, an increase in diversity with EFV to RAL switch. Previously, we reported weight gain, yet reduced inflammation in this cohort. The observed microbiota differences between RAL and EFV/PI groups may be associated with reduced inflammation and/or increase in weight. Further studies are needed to evaluate inflammatory and metabolic capacity of microbiota with ART switches.

The Gut Microbiome, Microbial Metabolites, and Cardiovascular Disease in People Living with HIV

PURPOSE OF REVIEW

To synthesize recent evidence relating the gut microbiome and microbial metabolites to cardiovascular disease (CVD) in people living with HIV (PLWH).

RECENT FINDINGS

A few cross-sectional studies have reported on the gut microbiome and cardiovascular outcomes in the context of HIV, with no consistent patterns emerging. The largest such study found that gut Fusobacterium was associated with carotid artery plaque. More studies have evaluated microbial metabolite trimethylamine N-oxide with CVD risk in PLWH, but results were inconsistent, with recent prospective analyses showing null effects. Studies of other microbial metabolites are scarce. Microbial translocation biomarkers (e.g., lipopolysaccharide binding protein) have been related to incident CVD in PLWH. Microbial translocation may increase CVD risk in PLWH, but there is insufficient and/or inconsistent evidence regarding specific microbial species and microbial metabolites associated with cardiovascular outcomes in PLWH. Further research is needed in large prospective studies integrating the gut microbiome, microbial translocation, and microbial metabolites with cardiovascular outcomes in PLWH.

Antenatal gut microbiome profiles and effect on pregnancy outcome in HIV infected and HIV uninfected women in a resource limited setting

BACKGROUND

Human immunodeficiency virus (HIV) severely damages the epithelial cells of the gut lining leading to an inflamed leaky gut, translocation of microbial products, and dysbiosis resulting in systemic immune activation. Also, microbiota composition and maternal gut function can be altered in pregnancy through changes in the immune system and intestinal physiology. The aim of this study was to investigate the gut microbiota in HIV-infected and HIV-uninfected pregnant women and to compare and identify the association between gut microbial composition and adverse birth outcomes.

RESULTS

A total of 94 pregnant women (35 HIV-infected and 59 HIV-uninfected controls) were recruited in Harare from 4 polyclinics serving populations with relatively poor socioeconomic status. Women were of a median age of 28 years (interquartile range, IQR: 22.3-32.0) and 55% of women were 35 weeks gestational age at enrolment (median 35.0 weeks, IQR: 32.5-37.2). Microbiota profiling in these participants showed that species richness was significantly lower in the HIV-infected pregnant women compared to their HIV-uninfected peers and significant differences in β-diversity using Bray-Curtis dissimilarity were observed. In contrast, there was no significant difference in α-diversity between immune-compromised (CD4⁺  < 350 cells/µL) and immune-competent HIV-infected women (CD4⁺  ≥ 350 cells/µL) even after stratification by viral load suppression. HIV infection was significantly associated with a reduced abundance of Clostridium, Turicibacter, Ruminococcus, Parabacteroides, Bacteroides, Bifidobacterium, Treponema, Oscillospira, and Faecalibacterium and a higher abundance of Actinomyces, and Succinivibrio. Low infant birth weight (< 2500 g) was significantly associated with high abundances of the phylum Spirochaetes, the families Spirochaeteceae, Veillonellaceae, and the genus Treponema.

CONCLUSION

The results reported here show that the species richness and taxonomy composition of the gut microbiota is altered in HIV-infected pregnant women, possibly reflecting intestinal dysbiosis. Some of these taxa were also associated with low infant birth weight.

The altered metabolites contributed by dysbiosis of gut microbiota are associated with microbial translocation and immune activation during HIV infection

Background

The immune activation caused by microbial translocation has been considered to be a major driver of HIV infection progression. The dysbiosis of gut microbiota has been demonstrated in HIV infection, but the interplay between gut microbiota and its metabolites in the pathogenesis of HIV is seldom reported.

Methods

We conducted a case-controlled study including 41 AIDS patients, 39 pre-AIDS patients and 34 healthy controls. Both AIDS group and pre-AIDS group were divided according to clinical manifestations and CD4 + T cell count. We collected stool samples for 16S rDNA sequencing and untargeted metabolomics analysis, and examined immune activation and microbial translocation for blood samples.

Results

The pre-AIDS and AIDS groups had higher levels of microbial translocation and immune activation. There were significant differences in gut microbiota and metabolites at different stages of HIV infection. Higher abundances of pathogenic bacteria or opportunistic pathogen, as well as lower abundances of butyrate-producing bacteria and bacteria with anti-inflammatory potential were associated with HIV severity. The metabolism of tryptophan was disordered after HIV infection. Lower level of anti-inflammatory metabolites and phosphonoacetate, and higher level of phenylethylamine and polyamines were observed in HIV infection. And microbial metabolic pathways related to altered metabolites differed. Moreover, disrupted metabolites contributed by altered microbiota were found to be correlated to microbial translocation and immune activation.

Conclusions

Metabolites caused by dysbiosis of gut microbiota and related metabolic function are correlated to immune activation and microbial translocation, suggesting that the effect of microbiota on metabolites is related to intestinal barrier disruption in HIV infection.

Gut microbiota and plasma metabolites associated with bone mineral density in women with or at risk of HIV infection

OBJECTIVE

To evaluate gut microbiota (GMB) alterations and metabolite profile perturbations associated with bone mineral density (BMD) in the context of HIV infection.

DESIGN

Cross-sectional studies of 58 women with chronic HIV infection receiving antiretroviral therapy and 33 women without HIV infection.

METHODS

We examined associations of GMB and metabolites with BMD among 91 women. BMD was measured by dual-energy X-ray absorptiometry (DXA), and T -scores of lumbar spine or total hip less than -1 defined low BMD. GMB was measured by 16S rRNA V4 region sequencing on fecal samples, and plasma metabolites were measured by liquid chromatography-tandem mass spectrometry. Associations of GMB with plasma metabolites were assessed in a larger sample (418 women; 280 HIV+ and 138 HIV-).

RESULTS

Relative abundances of five predominant bacterial genera ( Dorea , Megasphaera , unclassified Lachnospiraceae, Ruminococcus , and Mitsuokella ) were higher in women with low BMD compared with those with normal BMD (all linear discriminant analysis (LDA) scores >2.0). A distinct plasma metabolite profile was identified in women with low BMD, featuring lower levels of several metabolites belonging to amino acids, carnitines, caffeine, fatty acids, pyridines, and retinoids, compared with those with normal BMD. BMD-associated bacterial genera, especially Megasphaera , were inversely associated with several BMD-related metabolites (e.g. 4-pyridoxic acid, C4 carnitine, creatinine, and dimethylglycine). The inverse association of Megasphaera with dimethylglycine was more pronounced in women with HIV infection compared with those without HIV infection ( P for interaction = 0.016).

CONCLUSION

Among women with and at risk of HIV infection, we identified altered GMB and plasma metabolite profiles associated with low BMD.

Gut Microbiota and Cognitive Function Among Women Living with HIV

BACKGROUND

Altered gut microbiota has been associated with cognitive dysfunction and Alzheimer's disease, but little is known among people living with HIV.

OBJECTIVE

To examine associations between gut microbiota and cognitive impairment among women with or without HIV.

METHODS

This is a cross-sectional study of 446 women (302 HIV+) who had completed a neuropsychological test battery and stool sample collected within 1 year. Gut microbiota composition was quantified using 16SV4 rRNA gene sequencing and microbial functional pathways were predicted using PICRUSt. Cognitive domains included attention, executive function, learning, memory, fluency, processing speed, and motor function. Cognitive impairment was defined as two or more domains with T scores < 1 SD below mean. ANCOM-II was used to identify taxa and functional pathways associated with cognitive impairment, and the associations were further examined by multivariable logistic regression.

RESULTS

In overall sample, adjusting for multiple covariates including HIV status, we found that higher abundance of Methanobrevibacter, Odoribacter, Pyramidobacter, Eubacterium, Ruminococcus, and Gemmiger, and lower abundance of Veillonella were associated with cognitive impairment. The associations between these taxa and cognitive impairment were more profound in HIV+ women compared to HIV- women. Most associations with bacterial taxa were observed for learning and memory. We found accompanying microbial functional differences associated with cognitive impairment, including twelve enriched pathways and three depleted pathways.

CONCLUSIONS

In women with or without HIV infection, this study identified multiple altered gut bacterial taxa and functional pathways associated with cognitive impairment, supporting the potential role of gut microbiota in cognitive dysfunction and Alzheimer's disease.

Multiomic analysis reveals microbiome-related relationships between cocaine use and metabolites

OBJECTIVE

Over 19 million individuals globally have a cocaine use disorder, a significant public health crisis. Cocaine has also been associated with a pro-inflammatory state and recently with imbalances in the intestinal microbiota as compared to nonuse. The objective of this pilot study was to characterize the gut microbiota and plasma metabolites in people with HIV (PWH) who use cocaine compared with those who do not.

DESIGN

Cross-sectional study.

METHODS

A pilot study in PWH was conducted on 25 cocaine users and 25 cocaine nonusers from the Miami Adult Studies on HIV cohort. Stool samples and blood plasma were collected. Bacterial composition was characterized using 16S rRNA sequencing. Metabolomics in plasma were determined using gas and liquid chromatography/mass spectrometry.

RESULTS

The relative abundances of the Lachnopspira genus, Oscillospira genus, Bifidobacterium adolescentis species, and Euryarchaeota phylum were significantly higher in the cocaine- using PWH compared to cocaine-nonusing PWH. Cocaine-use was associated with higher levels of several metabolites: products of dopamine catabolism (3-methoxytyrosine and 3-methoxytyramine sulfate), phenylacetate, benzoate, butyrate, and butyrylglycine.

CONCLUSIONS

Cocaine use was associated with higher abundances of taxa and metabolites known to be associated with pathogenic states that include gastrointestinal conditions. Understanding key intestinal bacterial functional pathways that are altered due to cocaine use in PWH will provide a better understanding of the relationships between the host intestinal microbiome and potentially provide novel treatments to improve health.

Evolution of the Gut Microbiome in HIV-Exposed Uninfected and Unexposed Infants during the First Year of Life

HIV-exposed uninfected infants (HEU) have abnormal immunologic functions and increased infectious morbidity in the first 6 months of life, which gradually decreases thereafter. The mechanisms underlying HEU immune dysfunctions are unknown. We hypothesized that unique characteristics of the HEU gut microbiota associated with maternal HIV status may underlie the HEU immunologic dysfunctions. We characterized the infant gut, maternal gut, and breast milk microbiomes of mother-infant pairs, including 123 with HEU and 117 with HIV-uninfected infants (HUU), from South Africa. Pan-bacterial 16S rRNA gene sequencing was performed on (i) infant stool at 6, 28, and 62 weeks; (ii) maternal stool at delivery and 62 weeks; and (iii) breast milk at 6 weeks. Infant gut alpha and beta diversities were similar between groups. Microbial composition significantly differed, including 12 genera, 5 families and 1 phylum at 6 weeks; 12 genera and 2 families at 28 weeks; and 2 genera and 2 families at 62 weeks of life. Maternal gut microbiomes significantly differed in beta diversity and microbial composition, and breast milk microbiomes differed in microbial composition only. Infant gut microbiotas extensively overlapped with maternal gut and minimally with breast milk microbiotas. Nevertheless, exclusively breastfed HEU and HUU had less divergent microbiomes than nonexclusively breastfed infants. Feeding pattern and maternal gut microbiome imprint the HEU gut microbiome. Compared to HUU, the HEU gut microbiome prominently differs in early infancy, including increased abundance of taxa previously observed to be present in excess in adults with HIV. The HEU and HUU gut microbiome compositions converge over time, mirroring the kinetics of HEU infectious morbidity risk.

Astragali Radix-Codonopsis Radix-Jujubae Fructus water extracts ameliorate exercise-induced fatigue in mice via modulating gut microbiota and its metabolites

BACKGROUD

Astragali Radix (AR) and Codonopsis Radix (CR) are widely used as the tonic herbal medicine with efficacy of tonifying qi in traditional Chinese medicine (TCM), which showed significant antifatigue activities. In this study, AR and CR were combined, with Jujubae Fructus (JF) further added to improve the taste, to afford the ACJ extracts in the ratio of 2:1:2.

RESULTS

The results showed that ACJ water extract exhibited antifatigue effect by the weight-loaded exhaustive swimming test in mice. The untargeted fecal metabolomic approach and 16S rRNA gene sequencing analysis showed that ACJ could improve exercise performance by regulating changes of gut metabolites and microbiota to alleviate fatigue. Four pathways were determined as the key pathways relating with its antifatigue effect, which included sphingolipid metabolism, glycerophospholipid metabolism, valine, leucine and isoleucine biosynthesis and d-arginine and d-ornithine metabolism. Correlation analysis showed the complex association among bacteria, metabolites and phenotypes.

CONCLUSION

In conclusion, this study revealed new perspectives to study the antifatigue mechanism of ACJ extracts from the gut microbiota, which provided the basis for further functional food development. © 2022 Society of Chemical Industry.

Gut Microbiota, Plasma Metabolomic Profiles, and Carotid Artery Atherosclerosis in HIV Infection

BACKGROUND

Alterations in gut microbiota and blood metabolomic profiles have been implicated in HIV infection and cardiovascular disease. However, it remains unclear whether alterations in gut microbiota may contribute to disrupted host blood metabolomic profiles in relation to atherosclerosis, especially in the context of HIV infection.

METHODS

We analyzed cross-sectional associations between gut microbiota features and carotid artery plaque in 361 women with or at high risk of HIV (67% HIV+), and further integrated plaque-associated microbial features with plasma lipidomic/metabolomic profiles. Furthermore, in 737 women and men, we examined prospective associations of baseline gut bacteria-associated lipidomic and metabolomic profiles with incident carotid artery plaque over 7-year follow-up.

RESULTS

We found 2 potentially pathogenic bacteria, Fusobacterium and Proteus, were associated with carotid artery plaque; while the beneficial butyrate producer Odoribacter was inversely associated with plaque. Fusobacterium and Proteus were associated with multiple lipids/metabolites which were clustered into 8 modules in network. A module comprised of 9 lysophosphatidylcholines and lysophosphatidylethanolamines and a module comprised of 9 diglycerides were associated with increased risk of carotid artery plaque (risk ratio [95% CI], 1.34 [1.09-1.64] and 1.24 [1.02-1.51] per SD increment, respectively). Functional analyses identified bacterial enzymes in lipid metabolism associated with these plasma lipids. In particular, phospholipase A1 and A2 are the key enzymes in the reactions producing lysophosphatidylcholines and lysophosphatidylethanolamines.

CONCLUSIONS

Among individuals with or at high risk of HIV infection, we identified altered gut microbiota and related functional capacities in the lipid metabolism associated with disrupted plasma lipidomic profiles and carotid artery atherosclerosis.

Exploring the Anal Microbiome in HIV Positive and High-Risk HIV Negative Women

This exploratory study sought to characterize the anal microbiome and explore associations among the anal microbiome, risk factors for anal cancer, and clinical factors. A pilot sample of 50 HIV infected and high-risk HIV negative women were recruited from the former Women's Interagency HIV Study. Microbiome characterization by 16S rRNA gene sequencing and datasets were analyzed using QIIME 2™. Composition of the anal microbiome and its associations with anal cancer risk factors and clinical factors were analyzed using linear decomposition model and permutational multivariate analysis of variance. Composition of the anal microbiome among HIV positive and high-risk negative women was dominated by Bacteroides, Prevotella, and Campylobacter. The overall taxonomic composition and microbial diversity of the anal microbiome did not significantly differ by HIV status. However, the abundance of Ruminococcus 1 belonging to the Rumincoccaceae family was associated with HIV status (q = .05). No anal cancer risk factors were associated with the anal microbiome composition. Clinical factors marginally associated with the anal microbiome composition included body mass index (BMI; p = .05) and hepatitis C virus (HCV; p = .05). Although HIV and risk factors for anal cancer were not associated with the composition of the anal microbiome in this pilot sample, other clinical factors such as BMI and HCV, may be worth further investigation in a larger study. Future research can build on these findings to explore the role of the microbiome and HIV comorbidities in women.

Evaluation of lipid metabolism imbalance in HIV-infected patients with metabolic disorders using high-performance liquid chromatography-tandem mass spectrometry

Human immunodeficiency virus (HIV) infection and highly active antiretroviral therapy use are associated with the disruption of lipid and glucose metabolism. Herein, a sensitive and robust high-performance liquid chromatography-tandem mass spectrometry method for the quantitation of lysophosphatidylcholines (LPCs) and acylcarnitines (ACs) in human blood serum was developed and validated to investigate them as markers of metabolic disorders in HIV-infected patients. Under optimal extraction and detection conditions, the lower limits of quantification reached 5 ng/mL (LPCs) and 0.1 ng/mL (ACs), and precision and accuracy for both intra- and inter-day analyses were generally below 15%. Serum samples were stable for at least six months when stored at - 80 °C and for at least 12 h when stored at 4 °C or 25 °C. We investigated inter-group differences and associations between the biomarkers and observed a particular volatilitytrend of LPCs and ACs for HIV-infected patients with metabolic disorders. Thus, the developed method can be used for the rapid and sensitive quantitation of LPCs and ACs in vivo to further appraise the process of HIV infection, evaluate interveningmeasures, conduct mechanistic investigations, and further study the utility of LPCs and ACs as biomarkers of HIV infection coupled with metabolic disorders.

The Roles of the Gut Microbiota and Chronic Low-Grade Inflammation in Older Adults With Frailty

Frailty is a major public issue that affects the physical health and quality of life of older adults, especially as the population ages. Chronic low-grade inflammation has been speculated to accelerate the aging process as well as the development of age-related diseases such as frailty. Intestinal homeostasis plays a crucial role in healthy aging. The interaction between the microbiome and the host regulates the inflammatory response. Emerging evidence indicates that in older adults with frailty, the diversity and composition structure of gut microbiota are altered. Age-associated changes in gut microbiota composition and in their metabolites contribute to increased gut permeability and imbalances in immune function. In this review, we aim to: identify gut microbiota changes in the aging and frail populations; summarize the role of chronic low-grade inflammation in the development of frailty; and outline how gut microbiota may be related to the pathogenesis of frailty, more specifically, in the regulation of gut-derived chronic inflammation. Although additional research is needed, the regulation of gut microbiota may represent a safe, easy, and inexpensive intervention to counteract the chronic inflammation leading to frailty.

Gut Microbiota Dysbiosis Accelerates Prostate Cancer Progression Through Increased LPCAT1 Expression and Enhanced DNA Repair Pathways

Gut microbiota dysbiosis is related to cancer development and progression. Our previous study showed that Ruminococcus was more abundant in CRPC (Castration-resistant prostate cancer) than HSPC (Hormone-sensitive prostate cancer) individuals. Here, we determined the potential mechanism of microbiota dysbiosis in prostate cancer (PCa) progression. Metagenomics was used to verify the gut microbial discrepancies between CRPC and HSPC individuals. Fecal microbiota transplantation (FMT) was performed by transferring the fecal suspension of CRPC or HSPC individuals to TRAMP mice. Afterwards, the mice’s prostate histopathology and gut microbiota composition were determined. Since Ruminococcus was demonstrated to correlate with phospholipid metabolism, we used lipidomics to examine the mice’s fecal lipid profiles. The expression of LPCAT1 the key enzyme for phospholipid remodeling in mice prostate was also examined. Meanwhile, both microbial functions prediction and LPCAT1 GSEA analysis (Gene Set Enrichment Analysis) indicated DNA repair pathways, we further determined the expressions of RAD51 and DNA-PKcs in mice prostate. The results showed that gut Ruminococcus was significantly more abundant in CRPC individuals. FMT using CRPC feces accelerated mice’s PCa progression and increased their gut Ruminococcus abundance. Majority of fecal lipids including lysophosphatidylcholine and phosphatidylcholine were upregulated in CRPC FMT treated mice, accompanied with enhanced expressions of LPCAT1, RAD51, and DNA-PKcs in mice prostate. We reported an abundant colonization of Ruminococcus in the gut of CRPC individuals and mice receiving their fecal suspensions, and revealed the promotive capability of Ruminococcus in PCa progression via upregulating LPCAT1 and DNA repair protein expressions. The bacterium and its downstream pathways may become the targets of therapies for PCa in the future.

Gut Microbiota Diversity in HIV-Infected Patients on Successful Antiretroviral Treatment is Linked to Sexual Preferences but not CD4 Nadir

The effects of HIV infection and antiretroviral therapy (ART) on the gut microbiome are poorly understood and the literature data are inconsistent. The aim of this study was to assess the alpha and beta diversity of the fecal microbiota in HIV-infected patients on successful antiretroviral therapy with regard to sexual preferences and CD4 nadir. Thirty-six HIV-infected ART-treated patients with HIV viremia below 20 copies/ml and CD4 > 500 cells/μl were divided into two subgroups based on CD4 nadir. The composition of the intestinal microbiota was assessed by 16SrRNA sequencing (MiSeq Illumina). The alpha and beta diversity were analyzed according to CD4 nadir count and sexual preference. Several alpha diversity indexes were significantly higher in the MSM group than in heterosexual patients. The alpha diversity did not differ significantly between patients with CD4 nadir > 500 cells/μl and CD4 nadir < 200 cells/μl. Beta diversity was also associated with sexual preference. A significant difference in Weighted Unifrac was observed between all MSM and all non-MSM participants (p = 0.001). The MSM group was more diverse and demonstrated greater distances in Weighted Unifrac than the non-MSM group. The relative abundance of the Prevotella enterotype was higher in the MSM than the non-MSM group. Sexual preferences demonstrated a stronger influence on alpha and beta diversity in HIV-infected patients following successful antiretroviral treatment than HIV infection itself. The observed lack of association between CD4 nadir and alpha and beta diversity may be caused by the restoration of the faecal microbiota following antiretroviral treatment.

Gut Microbiome Profiles and Associated Metabolic Pathways in HIV-Infected Treatment-Naïve Patients

The normal composition of the intestinal microbiota is a key factor for maintaining healthy homeostasis, and accordingly, dysbiosis is well known to be present in HIV-1 patients. This article investigates the gut microbiota profile of antiretroviral therapy-naive HIV-1 patients and healthy donors living in Latin America in a cohort of 13 HIV positive patients (six elite controllers, EC, and seven non-controllers, NC) and nine healthy donors (HD). Microbiota compositions in stool samples were determined by sequencing the V3-V4 region of the bacterial 16S rRNA, and functional prediction was inferred using PICRUSt. Several taxa were enriched in EC compared to NC or HD groups, including Acidaminococcus, Clostridium methylpentosum, Barnesiella, Eubacterium coprostanoligenes, and Lachnospiraceae UCG-004. In addition, our data indicate that the route of infection is an important factor associated with changes in gut microbiome composition, and we extend these results by identifying several metabolic pathways associated with each route of infection. Importantly, we observed several bacterial taxa that might be associated with different viral subtypes, such as Succinivibrio, which were more abundant in patients infected by HIV subtype B, and Streptococcus enrichment in patients infected by subtype C. In conclusion, our data brings a significant contribution to the understanding of dysbiosis-associated changes in HIV infection and describes, for the first time, differences in microbiota composition according to HIV subtypes. These results warrant further confirmation in a larger cohort of patients.

Menopausal status and observed differences in the gut microbiome in women with and without HIV infection

OBJECTIVE

Gut microbiota respond to host physiological phenomena, yet little is known regarding shifts in the gut microbiome due to menopausal hormonal and metabolic changes in women. HIV infection impacts menopause and may also cause gut dysbiosis. We therefore sought to determine the association between menopausal status and gut microbiome composition in women with and without HIV.

METHODS

Gut microbiome composition was assessed in stool from 432 women (99 premenopausal HIV+, 71 premenopausal HIV-, 182 postmenopausal HIV+, 80 postmenopausal HIV-) via 16S rRNA gene sequencing. We examined cross-sectional associations of menopause with gut microbiota overall diversity and composition, and taxon and inferred metagenomic pathway abundance. Models were stratified by HIV serostatus and adjusted for age, HIV-related variables, and other potential confounders.

RESULTS

Menopause, ie post- versus premenopausal status, was associated with overall microbial composition only in women with HIV (permutational MANOVA of Jensen Shannon Divergence: P = 0.01). In women with HIV, menopause was associated with enrichment of gram-negative order Enterobacteriales, depletion of highly abundant taxa within Prevotella copri, and alterations in other low-abundance taxa. Additionally, menopause in women with HIV was associated with enrichment of metagenomic pathways related to Enterobacteriales, including degradation of amino acids and phenolic compounds, biosynthesis of enterobactin, and energy metabolism pathways. Menopause-related differences in some low-abundance taxa were also observed in women without HIV.

CONCLUSIONS

A changing gut microbiome may be an overlooked phenomenon of reproductive aging in women with HIV. Longitudinal assessments across all reproductive stages are necessary to confirm these findings and identify health implications.

Metabolic Profiling of Blood and Urine for Exploring the Functional Role of the Microbiota in Human Health

The quantification of metabolites in blood and urine allows nurses to explore new hypotheses about the microbiome. This review summarizes findings from recent studies with a focus on how the state of the science can influence future nursing research initiatives. Metabolomics can advance nursing research by identifying physiologic/pathophysiologic processes underlying patients' symptoms and can be useful for testing the effects of nursing interventions. To date, metabolomics has been used to study cardiovascular, respiratory, endocrine, autoimmune, and infectious conditions, with research focused on understanding the microbial metabolism of substrates resulting in circulating/excreted biomarkers such as trimethylamine N-oxide. This review provides specific recommendations for the collection of specimens and goals for future studies.

The gut microbiome and frailty

The human microbiome is constituted by an extensive network of organisms that lie at the host/environment interface and transduce signals that play vital roles in human health and disease across the lifespan. Frailty is a critical aging-related syndrome marked by diminished physiological reserve and heightened vulnerability to stress, predictive of major adverse clinical outcomes including death. While recent studies suggest the microbiome may impact key pathways critical to frailty pathophysiology, direct evaluation of the microbiome-frailty relationship remains limited. In this article, we review the complex interplay of biological, behavioral, and environmental factors that may influence shifts in gut microbiome composition and function in aging populations and the putative implications of such shifts for progression to frailty. We discuss HIV infection as a key prototype for elucidating the complex pathways via which the microbiome may precipitate frailty. Finally, we review considerations for future research efforts.

Influence of HIV Infection and Antiretroviral Therapy on Bone Homeostasis

The human immunodeficiency virus type 1 (HIV)/AIDS pandemic represents the most significant global health challenge in modern history. This infection leads toward an inflammatory state associated with chronic immune dysregulation activation that tilts the immune-skeletal interface and its deep integration between cell types and cytokines with a strong influence on skeletal renewal and exacerbated bone loss. Hence, reduced bone mineral density is a complication among HIV-infected individuals that may progress to osteoporosis, thus increasing their prevalence of fractures. Highly active antiretroviral therapy (HAART) can effectively control HIV replication but the regimens, that include tenofovir disoproxil fumarate (TDF), may accelerate bone mass density loss. Molecular mechanisms of HIV-associated bone disease include the OPG/RANKL/RANK system dysregulation. Thereby, osteoclastogenesis and osteolytic activity are promoted after the osteoclast precursor infection, accompanied by a deleterious effect on osteoblast and its precursor cells, with exacerbated senescence of mesenchymal stem cells (MSCs). This review summarizes recent basic research data on HIV pathogenesis and its relation to bone quality. It also sheds light on HAART-related detrimental effects on bone metabolism, providing a better understanding of the molecular mechanisms involved in bone dysfunction and damage as well as how the HIV-associated imbalance on the gut microbiome may contribute to bone disease.