Poor health-related quality of life in postural orthostatic tachycardia syndrome in comparison with a sex- and age-matched normative population.

PURPOSE: The effect of postural orthostatic tachycardia syndrome (POTS) on health-related quality of life (HrQoL) remains poorly studied. Here, we sought to compare the HrQoL in individuals with POTS to a normative age-/sex-matched population. METHODS: Participants enrolled in the Australian POTS registry between 5 August 2021 and 30 June 2022 were compared with propensity-matched local normative population data from the South Australian Health Omnibus Survey. The EQ-5D-5L instrument was used to assess HrQoL across the five domains (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) with global health rating assessed with a visual analog scale (EQ-VAS). A population-based scoring algorithm was applied to the EQ-5D-5L data to calculate utility scores. Hierarchical multiple regression analyses were undertaken to explore predictors of low utility scores. RESULTS: A total of 404 participants (n = 202 POTS; n = 202 normative population; median age 28 years, 90.6% females) were included. Compared with the normative population, the POTS cohort demonstrated significantly higher burden of impairment across all EQ-5D-5L domains (all P < 0.001), lower median EQ-VAS (p < 0.001), and lower utility scores (p < .001). The lower EQ-VAS and utility scores in the POTS cohort were universal in all age groups. Severity of orthostatic intolerance symptoms, female sex, fatigue scores, and comorbid diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome were independent predictors of reduced HrQoL in POTS. The disutility in those with POTS was lower than many chronic health conditions. CONCLUSIONS: This is the first study to demonstrate significant impairment across all subdomains of EQ-5D-5L HrQoL in the POTS cohort as compared with a normative population. TRIAL REGISTRATION: ACTRN12621001034820.

Primate genome architecture influences structural variation mechanisms and functional consequences.

Although nucleotide resolution maps of genomic structural variants (SVs) have provided insights into the origin and impact of phenotypic diversity in humans, comparable maps in nonhuman primates have thus far been lacking. Using massively parallel DNA sequencing, we constructed fine-resolution genomic structural variation maps in five chimpanzees, five orang-utans, and five rhesus macaques. The SV maps, which are comprised of thousands of deletions, duplications, and mobile element insertions, revealed a high activity of retrotransposition in macaques compared with great apes. By comparison, nonallelic homologous recombination is specifically active in the great apes, which is correlated with architectural differences between the genomes of great apes and macaque. Transcriptome analyses across nonhuman primates and humans revealed effects of species-specific whole-gene duplication on gene expression. We identified 13 gene duplications coinciding with the species-specific gain of tissue-specific gene expression in keeping with a role of gene duplication in the promotion of diversification and the acquisition of unique functions. Differences in the present day activity of SV formation mechanisms that our study revealed may contribute to ongoing diversification and adaptation of great ape and Old World monkey lineages.

Effect of amoxicillin on the gut microbiome of children with severe acute malnutrition in Madarounfa, Niger: a retrospective metagenomic analysis of a placebo-controlled trial.

BACKGROUND: Children with severe acute malnutrition are treated with antibiotics as outpatients. We aimed to determine the effect of 7 days of amoxicillin on acute and long-term changes to the gut microbiome and antibiotic resistome in children treated for severe acute malnutrition. METHODS: We conducted a secondary analysis of a randomised, double-blinded, placebo-controlled trial (NCT01613547) of amoxicillin in children (aged 6-59 months) with severe acute malnutrition treated as outpatients in Madarounfa, Niger. We randomly selected 161 children from the overall cohort (n=2399) for initial 12-week follow-up from Sept 23, 2013 to Feb 3, 2014. We selected a convenience sample of those 161 children, on the basis of anthropometric measures, for follow-up 2 years later (Sept 28 to Oct 27, 2015). Children provided faecal samples at baseline, week 1, week 4, week 8, week 12, and, for those in the 2-year follow-up cohort, week 104. We conducted metagenomic sequencing followed by microbiome and resistome profiling of faecal samples. 38 children without severe acute malnutrition and six children with severe acute malnutrition matching the baseline ages of the original cohort were used as reference controls. FINDINGS: In the 12-week follow-up group, amoxicillin led to an immediate decrease in gut microbiome richness from 37·6 species (95% CI 32·6-42·7) and Shannon diversity index (SDI) 2·18 (95% CI 1·97-2·39) at baseline to 27·7 species (95% CI 22·9-32·6) species and SDI 1·55 (95% CI 1·35-1·75) at week 1. Amoxicillin increased gut antibiotic resistance gene abundance to 6044 reads per kilobase million (95% CI 4704-7384) at week 1, up from 4800 (3391-6208) at baseline, which returned to baseline 3 weeks later. 35 children were included in the 2-year follow-up; the amoxicillin-treated children (n=22) had increased number of species in the gut microbiome compared with placebo-treated children (n=13; 60·7 [95% CI 54·7-66·6] vs 36·9 [29·4-44·3]). Amoxicillin-treated children had increased Prevotella spp and decreased Bifidobacterium spp relative to age-matched placebo-treated children, indicating a more mature, adult-like microbiome. INTERPRETATION: Amoxicillin treatment led to acute but not sustained increases in antimicrobial resistance genes and improved gut microbiome maturation 2 years after severe acute malnutrition treatment. FUNDING: Bill & Melinda Gates Foundation; Médecins sans Frontières Operational Center Paris; National Institute of Allergy and Infectious Diseases; National Institute of General Medical Sciences; Eunice Kennedy Shriver National Institute of Child Health and Human Development; Edward Mallinckrodt Jr Foundation; Doris Duke Foundation.

High Incidence of Autonomic Dysfunction and Postural Orthostatic Tachycardia Syndrome in Patients with Long COVID: Implications for Management and Health Care Planning.

BACKGROUND: Autonomic dysfunction, including postural orthostatic tachycardia syndrome (POTS), has been reported in individuals with post-acute sequelae of COVID-19 (PASC). However, the degree of dysautonomia in PASC has not been compared to those with POTS and healthy controls. METHODS: All participants were prospectively enrolled between August 5, 2021 and October 31, 2022. Autonomic testing included beat-to-beat hemodynamic monitoring to assess respiratory sinus arrhythmia, Valsalva ratio, and orthostatic changes during a 10-minute active standing test, as well as sudomotor assessment. The Composite Autonomic Symptom Score (COMPASS-31) was used to assess symptoms and the EuroQuol 5-Dimension survey (EQ-5D-5L) was used to assess health-related quality of life (HrQoL) measures. RESULTS: A total of 99 participants (n = 33 PASC, n = 33 POTS, and n = 33 healthy controls; median age 32 years, 85.9% females) were included. Compared with healthy controls, the PASC and POTS cohorts demonstrated significantly reduced respiratory sinus arrhythmia (P < .001), greater heart rate increase during 10-minute active standing test (P < .001), greater burden of autonomic dysfunction evidenced by higher COMPASS-31 scores across all subdomains (all P < .001), and poor HrQoL across all EQ-5D-5L domains (all P < .001), lower median EuroQol-visual analogue scale (P < .001), and lower utility scores (P < .001). The majority (79%) of those with PASC met the internationally established criteria for POTS. CONCLUSION: The prevalence of autonomic symptomology for POTS was high in those with PASC, leading to poor HrQoL and high health disutility. Autonomic testing should be routinely undertaken in those with PASC to aid diagnosis and direct appropriate management to improve health outcomes.

Microbiota restoration reduces antibiotic-resistant bacteria gut colonization in patients with recurrent Clostridioides difficile infection from the open-label PUNCH CD study.

BACKGROUND: Once antibiotic-resistant bacteria become established within the gut microbiota, they can cause infections in the host and be transmitted to other people and the environment. Currently, there are no effective modalities for decreasing or preventing colonization by antibiotic-resistant bacteria. Intestinal microbiota restoration can prevent Clostridioides difficile infection (CDI) recurrences. Another potential application of microbiota restoration is suppression of non-C. difficile multidrug-resistant bacteria and overall decrease in the abundance of antibiotic resistance genes (the resistome) within the gut microbiota. This study characterizes the effects of RBX2660, a microbiota-based investigational therapeutic, on the composition and abundance of the gut microbiota and resistome, as well as multidrug-resistant organism carriage, after delivery to patients suffering from recurrent CDI. METHODS: An open-label, multi-center clinical trial in 11 centers in the USA for the safety and efficacy of RBX2660 on recurrent CDI was conducted. Fecal specimens from 29 of these subjects with recurrent CDI who received either one (N = 16) or two doses of RBX2660 (N = 13) were analyzed secondarily. Stool samples were collected prior to and at intervals up to 6 months post-therapy and analyzed in three ways: (1) 16S rRNA gene sequencing for microbiota taxonomic composition, (2) whole metagenome shotgun sequencing for functional pathways and antibiotic resistome content, and (3) selective and differential bacterial culturing followed by isolate genome sequencing to longitudinally track multidrug-resistant organisms. RESULTS: Successful prevention of CDI recurrence with RBX2660 correlated with taxonomic convergence of patient microbiota to the donor microbiota as measured by weighted UniFrac distance. RBX2660 dramatically reduced the abundance of antibiotic-resistant Enterobacteriaceae in the 2 months after administration. Fecal antibiotic resistance gene carriage decreased in direct relationship to the degree to which donor microbiota engrafted. CONCLUSIONS: Microbiota-based therapeutics reduce resistance gene abundance and resistant organisms in the recipient gut microbiome. This approach could potentially reduce the risk of infections caused by resistant organisms within the patient and the transfer of resistance genes or pathogens to others. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01925417 ; registered on August 19, 2013.

Understanding the impact of antibiotic perturbation on the human microbiome.

The human gut microbiome is a dynamic collection of bacteria, archaea, fungi, and viruses that performs essential functions for immune development, pathogen colonization resistance, and food metabolism. Perturbation of the gut microbiome's ecological balance, commonly by antibiotics, can cause and exacerbate diseases. To predict and successfully rescue such perturbations, first, we must understand the underlying taxonomic and functional dynamics of the microbiome as it changes throughout infancy, childhood, and adulthood. We offer an overview of the healthy gut bacterial architecture over these life stages and comment on vulnerability to short and long courses of antibiotics. Second, the resilience of the microbiome after antibiotic perturbation depends on key characteristics, such as the nature, timing, duration, and spectrum of a course of antibiotics, as well as microbiome modulatory factors such as age, travel, underlying illness, antibiotic resistance pattern, and diet. In this review, we discuss acute and chronic antibiotic perturbations to the microbiome and resistome in the context of microbiome stability and dynamics. We specifically discuss key taxonomic and resistance gene changes that accompany antibiotic treatment of neonates, children, and adults. Restoration of a healthy gut microbial ecosystem after routine antibiotics will require rationally managed exposure to specific antibiotics and microbes. To that end, we review the use of fecal microbiota transplantation and probiotics to direct recolonization of the gut ecosystem. We conclude with our perspectives on how best to assess, predict, and aid recovery of the microbiome after antibiotic perturbation.

Impact of Amoxicillin-Clavulanate followed by Autologous Fecal Microbiota Transplantation on Fecal Microbiome Structure and Metabolic Potential.

Strategies to prevent multidrug-resistant organism (MDRO) infections are scarce, but autologous fecal microbiota transplantation (autoFMT) may limit gastrointestinal MDRO expansion. AutoFMT involves banking one's feces during a healthy state for later use in restoring gut microbiota following perturbation. This pilot study evaluated the effect of autoFMT on gastrointestinal microbiome taxonomic composition, resistance gene content, and metabolic capacity after exposure to amoxicillin-clavulanic acid (Amox-Clav). Ten healthy participants were enrolled. All received 5 days of Amox-Clav. Half were randomized to autoFMT, derived from stool collected pre-antimicrobial exposure, by enema, and half to saline enema. Participants submitted stool samples pre- and post-Amox-Clav and enema and during a 90-day follow-up period. Shotgun metagenomic sequencing revealed taxonomic composition, resistance gene content, and metabolic capacity. Amox-Clav significantly altered gut taxonomic composition in all participants (n = 10, P < 0.01); however, only three participants exhibited major changes at the phylum level following exposure. In the cohort as a whole, beta-lactamase genes were enriched following Amox-Clav (P < 0.05), and predicted metabolic capacity was significantly altered (P < 0.01). Species composition, metabolic capacity, and beta-lactamase abundance returned to pre-antimicrobial exposure state 7 days after either autoFMT or saline enema (P > 0.05, compared to enrollment). Alterations to microbial metabolic capacity occurred following antimicrobial exposure even in participants without substantial taxonomic disruption, potentially creating open niches for pathogen colonization. Our findings suggest that metabolic potential is an important consideration for complete assessment of antimicrobial impact on the microbiome. AutoFMT was well tolerated and may have contributed to phylogenetic recovery. (This study has been registered at ClinicalTrials.gov under identifier NCT02046525.)IMPORTANCE The spread of multidrug resistance among pathogenic organisms threatens the efficacy of antimicrobial treatment options. The human gut serves as a reservoir for many drug-resistant organisms and their resistance genes, and perturbation of the gut microbiome by antimicrobial exposure can open metabolic niches to resistant pathogens. Once established in the gut, antimicrobial-resistant bacteria can persist even after antimicrobial exposure ceases. Strategies to prevent multidrug-resistant organism (MDRO) infections are scarce, but autologous fecal microbiota transplantation (autoFMT) may limit gastrointestinal MDRO expansion. AutoFMT involves banking one's feces during a healthy state for later use in restoring gut microbiota following perturbation. This pilot study evaluated the effect of amoxicillin-clavulanic acid (Amox-Clav) exposure and autoFMT on gastrointestinal microbiome taxonomic composition, resistance gene content, and metabolic capacity. Importantly, we found that metabolic capacity was perturbed even in cases where gross phylogeny remained unchanged and that autoFMT was safe and well tolerated.

The effects of antibiotics on the microbiome throughout development and alternative approaches for therapeutic modulation.

The widespread use of antibiotics in the past 80 years has saved millions of human lives, facilitated technological progress and killed incalculable numbers of microbes, both pathogenic and commensal. Human-associated microbes perform an array of important functions, and we are now just beginning to understand the ways in which antibiotics have reshaped their ecology and the functional consequences of these changes. Mounting evidence shows that antibiotics influence the function of the immune system, our ability to resist infection, and our capacity for processing food. Therefore, it is now more important than ever to revisit how we use antibiotics. This review summarizes current research on the short-term and long-term consequences of antibiotic use on the human microbiome, from early life to adulthood, and its effect on diseases such as malnutrition, obesity, diabetes, and Clostridium difficile infection. Motivated by the consequences of inappropriate antibiotic use, we explore recent progress in the development of antivirulence approaches for resisting infection while minimizing resistance to therapy. We close the article by discussing probiotics and fecal microbiota transplants, which promise to restore the microbiota after damage of the microbiome. Together, the results of studies in this field emphasize the importance of developing a mechanistic understanding of gut ecology to enable the development of new therapeutic strategies and to rationally limit the use of antibiotic compounds.

What's new is old: resolving the identity of Leptothrix ochracea using single cell genomics, pyrosequencing and FISH.

Leptothrix ochracea is a common inhabitant of freshwater iron seeps and iron-rich wetlands. Its defining characteristic is copious production of extracellular sheaths encrusted with iron oxyhydroxides. Surprisingly, over 90% of these sheaths are empty, hence, what appears to be an abundant population of iron-oxidizing bacteria, consists of relatively few cells. Because L. ochracea has proven difficult to cultivate, its identification is based solely on habitat preference and morphology. We utilized cultivation-independent techniques to resolve this long-standing enigma. By selecting the actively growing edge of a Leptothrix-containing iron mat, a conventional SSU rRNA gene clone library was obtained that had 29 clones (42% of the total library) related to the Leptothrix/Sphaerotilus group (≤96% identical to cultured representatives). A pyrotagged library of the V4 hypervariable region constructed from the bulk mat showed that 7.2% of the total sequences also belonged to the Leptothrix/Sphaerotilus group. Sorting of individual L. ochracea sheaths, followed by whole genome amplification (WGA) and PCR identified a SSU rRNA sequence that clustered closely with the putative Leptothrix clones and pyrotags. Using these data, a fluorescence in-situ hybridization (FISH) probe, Lepto175, was designed that bound to ensheathed cells. Quantitative use of this probe demonstrated that up to 35% of microbial cells in an actively accreting iron mat were L. ochracea. The SSU rRNA gene of L. ochracea shares 96% homology with its closet cultivated relative, L. cholodnii, This establishes that L. ochracea is indeed related to this group of morphologically similar, filamentous, sheathed microorganisms.