Multi-omics Analysis of a Fecal Microbiota Transplantation Trial Identifies Novel Aspects of Acute GVHD Pathogenesis.

Acute GVHD (aGVHD) is a major complication of allogeneic hematopoietic cell transplantation (alloHCT) associated with gut microbiota disruptions. However, whether therapeutic microbiota modulation prevents aGVHD is unknown. We conducted a randomized, placebo-controlled trial of third-party fecal microbiota transplantation (FMT) administered at the peak of microbiota injury in 100 patients with acute myeloid leukemia receiving induction chemotherapy and alloHCT recipients. Despite improvements in microbiome diversity, expansion of commensals, and shrinkage of potential pathogens, aGVHD occurred more frequently after FMT than placebo. Although this unexpected finding could be explained by clinical differences between the two arms, we asked whether a microbiota explanation might be also present. To this end, we performed multi-omics analysis of preintervention and postintervention gut microbiome and serum metabolome. We found that postintervention expansion of Faecalibacterium, a commensal genus with gut-protective and anti-inflammatory properties under homeostatic conditions, predicted a higher risk for aGVHD. Faecalibacterium expansion occurred predominantly after FMT and was due to engraftment of unique donor taxa, suggesting that donor Faecalibacterium-derived antigens might have stimulated allogeneic immune cells. Faecalibacterium and ursodeoxycholic acid (an anti-inflammatory secondary bile acid) were negatively correlated, offering an alternative mechanistic explanation. In conclusion, we demonstrate context dependence of microbiota effects where a normally beneficial bacteria may become detrimental in disease. While FMT is a broad, community-level intervention, it may need precision engineering in ecologically complex settings where multiple perturbations (e.g., antibiotics, intestinal damage, alloimmunity) are concurrently in effect. SIGNIFICANCE: Post-FMT expansion of Faecalibacterium, associated with donor microbiota engraftment, predicted a higher risk for aGVHD in alloHCT recipients. Although Faecalibacterium is a commensal genus with gut-protective and anti-inflammatory properties under homeostatic conditions, our findings suggest that it may become pathogenic in the setting of FMT after alloHCT. Our results support a future trial with precision engineering of the FMT product used as GVHD prophylaxis after alloHCT.

An In-Vitro Evaluation of the Antimicrobial Efficacy of a Novel Irrigant Using Next-Generation Sequencing.

INTRODUCTION: To evaluate the antimicrobial activity of Triton irrigation versus 4% NaOCl utilizing a direct contact test and an extracted tooth model. METHODS: In the first experiment, a direct contact test was conducted to compare bacterial DNA removal and microbial diversity changes following irrigation with sodium hypochlorite (4% NaOCl) or Triton. Hydroxyapatite and dentin discs were inoculated with subgingival human-derived dental plaque for 2 weeks utilizing a CDC biofilm reactor and subsequently challenged with the root canal irrigants for 5 min. In the second experiment, teeth contaminated with a multispecies biofilm (n=24) were assigned into two treatment groups, NaOCl or Triton irrigation. Samples were obtained for qPCR and next-generation sequencing (NGS) analysis before and after instrumentation. The Shannon and Chao1 indices were used to measure alpha diversity. The Bray-Curtis dissimilarity and ANOSIM was used to measure beta diversity. Differences in abundances of genera were evaluated using Kruskal-Wallis test with Bonferroni corrections. RESULTS: The direct contact test revealed no significant differences in the bacterial load based on 16S rRNA gene molecules/µL, reads, or differences in the Shannon index among groups. In the extracted tooth model, a bacterial load reduction of log10 3.08 ± 0.69 and 2.76 ± 0.91 were found for NaOCl and Triton respectively (P = 0.348). NGS showed fewer reads, lower Chao1 and beta diversity values when pre- and post-treatment samples were assessed in both experimental groups (P < 0.0001). The Kruskal Wallis analysis found that 17 genera of bacteria were overrepresented in minimal values in the Triton post-treatment group, 14 of these genera represented less than 1% of the microbial community. CONCLUSIONS: Both irrigants had limited antimicrobial activity in the direct contact test. When used in conjunction with mechanical instrumentation both irrigants were able to reduce the bacterial DNA load and diversity in comparison with pretreatment communities. The NaOCl irrigation, followed by EDTA flush, was more effective in decreasing DNA counts from low-abundance organisms.

Management of Choledocholithiasis in a Community Hospital: Laparoscopic Common Bile Duct Exploration Versus Endoscopic Retrograde Cholangiopancreatography.

BACKGROUND: Approximately 10% of intraoperative cholangiograms identify choledocholithiasis (CDL), stones in the common bile duct. Choledocholithiasis management options include endoscopic retrograde cholangiopancreatography (ERCP) followed by cholecystectomy, laparoscopic cholecystectomy (LC) followed by ERCP (LC + ERCP), cholecystectomy with open common bile duct exploration, or laparoscopic cholecystectomy with laparoscopic common bile duct exploration (LC + LCBDE). The goal of these interventions is to clear the obstruction from CDL. METHODS: Patients from a single-center community hospital undergoing LC with intraoperative cholangiogram (LC + IOC) progressing to LC + LCBDE from July 2020 to August 2022 were evaluated for hospital length of stay (LOS), operative times, and complications. These were compared to the prior standard practice of pre/post-operative ERCP. RESULTS: The results were evaluated using ANOVA, Student-Newman-Keuls, and chi square analysis. In comparison of LC + CBDE to ERCP + cholecystectomy, LOS was reduced (1.8 vs 4.6 days P < .0001). No difference in LOS between LC + IOC and LC + CBDE (1.4 vs 1.8 days, P > .05) was found. No difference in complication rates was found. Mean operative time differed between LC + IOC and LC + CBDE (63 vs 113 minutes, P < .0001). Fifty-five attempts of LC + CBDE were performed with only 10 requiring post-operative ERCP. DISCUSSION: Since implementation of LC + CBDE, there has been reduced LOS without increasing complication rates. Operative times are increased with LC + CBDE but offset by reduced LOS, additional anesthesia events, and procedures. Our institution will continue to pursue LC + CBDE when indicated with efforts to improve resource allocation.

Long- and short-term effects of fecal microbiota transplantation on antibiotic resistance genes: results from a randomized placebo-controlled trial.

In small series, third-party fecal microbiota transplantation (FMT) has been successful in decolonizing the gut from clinically relevant antibiotic resistance genes (ARGs). Less is known about the short- and long-term effects of FMT on larger panels of ARGs. We analyzed 226 pre- and post-treatment stool samples from a randomized placebo-controlled trial of FMT in 100 patients undergoing allogeneic hematopoietic cell transplantation or receiving anti-leukemia induction chemotherapy for 47 ARGs. These patients have heavy antibiotic exposure and a high incidence of colonization with multidrug-resistant organisms. Samples from each patient spanned a period of up to 9 months, allowing us to describe both short- and long-term effects of FMT on ARGs, while the randomized design allowed us to distinguish between spontaneous changes vs. FMT effect. We find an overall bimodal pattern. In the first phase (days to weeks after FMT), low-level transfer of ARGs largely associated with commensal healthy donor microbiota occurs. This phase is followed by long-term resistance to new ARGs as stable communities with colonization resistance are formed after FMT. The clinical implications of these findings are likely context-dependent and require further research. In the setting of cancer and intensive therapy, long-term ARG decolonization could translate into fewer downstream infections.

Successful Treatment of Recurrent Clostridioides difficile Infection Using a Novel, Drinkable, Oral Formulation of Fecal Microbiota.

BACKGROUND: Fecal microbiota transplants can be administered orally in encapsulated form or require invasive procedures to administer liquid formulations. There is a need for an oral liquid formulation of fecal microbiota for patients who are unable to swallow capsules, especially if they require multiple, repeated administrations. AIMS: These studies were conducted to develop a protocol to manufacture an organoleptically acceptable powdered fecal microbiota formulation that can be suspended in a liquid carrier and used for fecal microbiota transplantation. METHODS: Several processing steps were investigated, including extra washes of microbiota prior to lyophilization and an addition of a flavoring agent. The viability of bacteria in the transplant formulation was tested using live/dead microscopy staining and engraftment into antibiotic-treated mice. After development of a clinical protocol for suspension of the powdered microbiota, the new formulation was tested in three elderly patients with recurrent Clostridioides difficile infections and who have difficulties in swallowing capsules. Changes in the microbial community structure in one of the patients were characterized using 16S rRNA gene profiling and engraftment analysis. RESULTS: The processing steps used to produce an organoleptically acceptable suspension of powdered fecal microbiota did not result in loss of its viability. The powder could be easily suspended in a liquid carrier. The use of the new formulation was associated with abrogation of the cycle of C. difficile infection recurrences in the three patients. CONCLUSION: We developed a novel organoleptically acceptable liquid formulation of fecal microbiota that is suitable for use in clinical trials for patients with difficulties in swallowing capsules.

Pharmacomicrobiomics: Immunosuppressive Drugs and Microbiome Interactions in Transplantation.

The human microbiome is associated with human health and disease. Exogenous compounds, including pharmaceutical products, are also known to be affected by the microbiome, and this discovery has led to the field of pharmacomicobiomics. The microbiome can also alter drug pharmacokinetics and pharmacodynamics, possibly resulting in side effects, toxicities, and unanticipated disease response. Microbiome-mediated effects are referred to as drug-microbiome interactions (DMI). Rapid advances in the field of pharmacomicrobiomics have been driven by the availability of efficient bacterial genome sequencing methods and new computational and bioinformatics tools. The success of fecal microbiota transplantation for recurrent Clostridioides difficile has fueled enthusiasm and research in the field. This review focuses on the pharmacomicrobiome in transplantation. Alterations in the microbiome in transplant recipients are well documented, largely because of prophylactic antibiotic use, and the potential for DMI is high. There is evidence that the gut microbiome may alter the pharmacokinetic disposition of tacrolimus and result in microbiome-specific tacrolimus metabolites. The gut microbiome also impacts the enterohepatic recirculation of mycophenolate, resulting in substantial changes in pharmacokinetic disposition and systemic exposure. The mechanisms of these DMI and the specific bacteria or communities of bacteria are under investigation. There are little or no human DMI data for cyclosporine A, corticosteroids, and sirolimus. The available evidence in transplantation is limited and driven by small studies of heterogeneous designs. Larger clinical studies are needed, but the potential for future clinical application of the pharmacomicrobiome in avoiding poor outcomes is high.

Effect of ginger supplementation on the fecal microbiome in subjects with prior colorectal adenoma.

Ginger has been associated with a decreased incidence of colorectal cancer (CRC) through reduction in inflammatory pathways and inhibition of tumor growth. Recent pre-clinical models have implicated changes in the gut microbiome as a possible mediator of the ginger effect on CRC. We hypothesized that, in adults previously diagnosed with a colorectal adenoma, ginger supplementation would alter the fecal microbiome in the direction consistent with its CRC-inhibitory effect. Sixty-eight adults were randomized to take either ginger or placebo daily for 6 weeks, with a 6-week washout and longitudinal stool collection throughout. We performed 16S rRNA sequencing and evaluated changes in overall microbial diversity and the relative abundances of pre-specified CRC-associated taxa using mixed-effects logistic regression. Ginger supplementation showed no significant effect on microbial community structure through alpha or beta diversity. Of 10 pre-specified CRC-associated taxa, there were significant decreases in the relative abundances of the genera Akkermansia (p < 0.001), Bacteroides (p = 0.018), and Ruminococcus (p = 0.013) after 6-week treatment with ginger compared to placebo. Ginger supplementation led to decreased abundances of Akkermansia and Bacteroides, which suggests that ginger may have an inhibitory effect on CRC-associated taxa. Overall, ginger supplementation appears to have a limited effect on gut microbiome in patients with colorectal adenomas.

The effect of ultrasonic and multisonic irrigation on root canal microbial communities: An ex vivo study.

AIM: To analyse the effect of ultrasonic irrigant activation (UIA) and the GentleWave (GW) multisonic irrigation (GW) with minimal instrumentation on the root canal microbial diversity in an ex vivo model that used extracted molars with a history of pulp necrosis. METHODOLOGY: Twenty-three mandibular molars were prepared ex vivo for collection of superficial (surface control), pre-treatment and post-treatment samples 24 h after extraction. Samples were divided into two groups: UIA using 6% NaOCl (n = 11) and GW group (n = 12). All samples were processed using quantitative real-time polymerase chain reaction (qPCR) and 16S rRNA next-generation sequencing to measure microbial diversity before and after the antimicrobial treatment. For qPCR, a t-test (α = .05) was used to compare the log10 reduction. The Chao1 and Shannon indices evaluated alpha diversity. Differences in community composition (beta diversity) were evaluated by analysis of similarity (ANOSIM). Kruskal-Wallis test with Bonferroni corrections was performed to evaluate the differences in abundances genera in the samples. RESULTS: Quantitative real-time polymerase chain reaction revealed an estimated 1.6 and 2.6 log10 reduction for UIA and GW groups respectively (p = .048). An average of 5 ± 4 and 3 ± 5 operational taxonomic units (OTUs) were found in surface's samples in the UIA and GW group respectively. These values were significantly lower (p < .001) compared to the number of preoperative OTUs in those groups (155 ± 79 and 187 ± 121). In assessing beta diversity, there were no significant differences found in pre-treatment samples (R = .090, p = .070 ANOSIM with Bonferroni corrections). Also, no significant differences in community composition were observed in post-treatment samples (R = -.05, p = .829). After treatment, there was a significant reduction of Eubacterium using conventional treatment with UIA and a significant reduction of Prevotella using minimal instrumentation with GW irrigation (p = .007 and p = .002 respectively). CONCLUSION: Quantitative PCR analysis revealed a significant reduction in microbial load for GW group. Overall, diversity changes were similar between UIA and GW irrigation in this ex vivo model that used extracted teeth with a history of pulp necrosis. OTUs obtained from the surface sample were negligible and did not affect the statistical outcome of the study.

Hepatic lipid-associated macrophages mediate the beneficial effects of bariatric surgery against MASH.

For patients with obesity and metabolic syndrome, bariatric procedures such as vertical sleeve gastrectomy (VSG) have a clear benefit in ameliorating metabolic dysfunction-associated steatohepatitis (MASH). While the effects of bariatric surgeries have been mainly attributed to nutrient restriction and malabsorption, whether immuno-modulatory mechanisms are involved remains unclear. Here we report that VSG ameliorates MASH progression in a weight loss-independent manner. Single-cell RNA sequencing revealed that hepatic lipid-associated macrophages (LAMs) expressing the triggering receptor expressed on myeloid cells 2 (TREM2) increase their lysosomal activity and repress inflammation in response to VSG. Remarkably, TREM2 deficiency in mice ablates the reparative effects of VSG, suggesting that TREM2 is required for MASH resolution. Mechanistically, TREM2 prevents the inflammatory activation of macrophages and is required for their efferocytotic function. Overall, our findings indicate that bariatric surgery improves MASH through a reparative process driven by hepatic LAMs, providing insights into the mechanisms of disease reversal that may result in new therapies and improved surgical interventions.

Diet-induced shifts in the gut microbiota influence anastomotic healing in a murine model of colonic surgery.

Host diet and gut microbiota interact to contribute to perioperative complications, including anastomotic leak (AL). Using a murine surgical model of colonic anastomosis, we investigated how diet and fecal microbial transplantation (FMT) impacted the intestinal microbiota and if a predictive signature for AL could be determined. We hypothesized that a Western diet (WD) would impact gut microbial composition and that the resulting dysbiosis would correlate with increased rates of AL, while FMT from healthy, lean diet (LD) donors would reduce the risk of AL. Furthermore, we predicted that surgical outcomes would allow for the development of a microbial preclinical translational tool to identify AL. Here, we show that AL is associated with a dysbiotic microbial community characterized by increased levels of Bacteroides and Akkermansia. We identified several key taxa that were associated with leak formation, and developed an index based on the ratio of bacteria associated with the absence and presence of leak. We also highlight a modifiable connection between diet, microbiota, and anastomotic healing, potentially paving the way for perioperative modulation by microbiota-targeted therapeutics to reduce AL.

Dysfunctional T Follicular Helper Cells Cause Intestinal and Hepatic Inflammation in NASH.

Nonalcoholic steatohepatitis (NASH), characterized by hepatic inflammation and cellular damage, is the most severe form of nonalcoholic fatty liver disease and the fastest-growing indication for a liver transplant. The intestinal immune system is a central modulator of local and systemic inflammation. In particular, Peyer's patches (PPs) contain T follicular helper (Tfh) cells that support germinal center (GC) responses required for the generation of high-affinity intestinal IgA and the maintenance of intestinal homeostasis. However, our understanding of the mechanisms regulating mucosal immunity during the pathogenesis of NASH is incomplete. Here, using a preclinical mouse model that resembles the key features of human disease, we discovered an essential role for Tfh cells in the pathogenesis of NASH. We have found that mice fed a high-fat high-carbohydrate (HFHC) diet have an inflamed intestinal microenvironment, characterized by enlarged PPs with an expansion of Tfh cells. Surprisingly, the Tfh cells in the PPs of NASH mice showed evidence of dysfunction, along with defective GC responses and reduced IgA+ B cells. Tfh-deficient mice fed the HFHC diet showed compromised intestinal permeability, increased hepatic inflammation, and aggravated NASH, suggesting a fundamental role for Tfh cells in maintaining gut-liver homeostasis. Mechanistically, HFHC diet feeding leads to an aberrant increase in the expression of the transcription factor KLF2 in Tfh cells which inhibits its function. Thus, transgenic mice with reduced KLF2 expression in CD4 T cells displayed improved Tfh cell function and ameliorated NASH, including hepatic steatosis, inflammation, and fibrosis after HFHC feeding. Overall, these findings highlight Tfh cells as key intestinal immune cells involved in the regulation of inflammation in the gut-liver axis during NASH.

Potential of Fecal Microbiota Transplantation to Prevent Acute GVHD: Analysis from a Phase II Trial.

PURPOSE: Intestinal microbiota disruptions early after allogeneic hematopoietic cell transplantation have been associated with increased risk for acute GVHD (aGVHD). In our recent randomized phase II trial of oral, encapsulated, third-party fecal microbiota transplantation (FMT) versus placebo, FMT at the time of neutrophil recovery was safe and ameliorated dysbiosis. Here, we evaluated in post hoc analysis whether donor microbiota engraftment after FMT may protect against aGVHD. EXPERIMENTAL DESIGN: We analyzed pre- and post-FMT stool samples and estimated donor microbiota engraftment (a preplanned secondary endpoint) by determining the fraction of post-FMT microbiota formed by unique donor taxa (donor microbiota fraction; dMf). RESULTS: dMf was higher in patients who later developed grade I or no aGVHD (median 33.9%; range, 1.6%-74.3%) than those who developed grade II-IV aGVHD (median 25.3%; range, 2.2%-34.8%; P = 0.006). The cumulative incidence of grade II-IV aGVHD by day 180 was lower in the group with greater-than-median dMf than the group with less-than-median dMf [14.3% (95% confidence interval, CI, 2.1-37.5) vs. 76.9% (95% CI, 39.7-92.8), P = 0.008]. The only determinant of dMf in cross-validated least absolute shrinkage and selection operator (LASSO)-regularized regression was the patient's pre-FMT microbiota diversity (Pearson correlation coefficient -0.82, P = 1.6 × 10-9), indicating more potent microbiota modulation by FMT in patients with more severe dysbiosis. Microbiota network analysis revealed major rewiring including changes in the most central nodes, without emergence of keystone species, as a potential mechanism of FMT effect. CONCLUSIONS: FMT may have protective effects against aGVHD, especially in patients with more severe microbiota disruptions.

Temporal variation in oral microbiome composition of patients undergoing autologous hematopoietic cell transplantation with keratinocyte growth factor.

INTRODUCTION: Autologous hematopoietic cell transplantation (AHCT) is a well-established treatment for lymphoma. Unintended effects of this therapy include oral mucositis (OM) and gastrointestinal toxicities, resulting in poor clinical outcomes. The gut microbiome has been previously linked to transplant toxicities among allogeneic recipients, but little is known about the effects of AHCT on the oral microbiome. METHODS: Seven patients with non-Hodgkin or Hodgkin lymphoma undergoing AHCT with palifermin (keratinocyte growth factor) were included. Buccal swab samples were collected at baseline and 14- and 28-days post-treatment. Oral microbial communities were characterized with 16 S rRNA amplicon sequencing. Temporal trends in community composition, alpha diversity, and beta diversity were investigated. RESULTS: A significant reduction in the relative abundance of the genera Gemella and Actinomyces were observed from baseline. No significant temporal differences in alpha diversity were observed. Significant changes in beta diversity were recorded. CONCLUSION: Results of this pilot study suggest treatment with AHCT and palifermin affects the oral microbiome, resulting in temporal shifts in oral microbial community composition. Future studies are warranted to confirm these trends and further investigate the effects of AHCT on the oral microbiome and how these shifts may affect health outcomes.

Fecal Microbiota Restoration Modulates the Microbiome in Inflammation-Driven Colorectal Cancer.

Chronic inflammation of the colon (colitis) is a known risk factor for inflammatory-driven colorectal cancers (id-CRCs), and intestinal microbiota has been implicated in the etiology of id-CRCs. Manipulation of the microbiome is a clinically viable therapeutic approach to limiting id-CRCs. To understand the microbiome changes that occur over time in id-CRCs, we used a mouse model of id-CRCs with the treatment of azoxymethane (AOM) and dextran sodium sulfate (DSS) and measured the microbiome over time. We included cohorts where the microbiome was restored using cage bedding swapping and where the microbiome was depleted using antibiotics to compare to untreated animals. We identified consistent increases in Akkermansia in mice receiving horizontal microbiome transfer (HMT) via cage bedding swapping, while the control cohort had consistent longitudinal increases in Anaeroplasma and Alistipes. Additionally, fecal lipocalin-2 (Lcn-2), a marker of intestinal inflammation, was elevated in unrestored animals compared to restored and antibiotic-treated counterparts following HMT. These observations suggest a potential role for Akkermansia, Anaeroplasma, and Alistipes in regulating colonic inflammation in id-CRCs.

Randomized Double-Blind Phase II Trial of Fecal Microbiota Transplantation Versus Placebo in Allogeneic Hematopoietic Cell Transplantation and AML.

PURPOSE: Gut microbiota injury in allogeneic hematopoietic cell transplantation (HCT) recipients and patients with AML has been associated with adverse clinical outcomes. Previous studies in these patients have shown improvements in various microbiome indices after fecal microbiota transplantation (FMT). However, whether microbiome improvements translate into improved clinical outcomes remains unclear. We examined this question in a randomized, double-blind, placebo-controlled phase II trial. METHODS: Two independent cohorts of allogeneic HCT recipients and patients with AML receiving induction chemotherapy were randomly assigned in a 2:1 ratio to receive standardized oral encapsulated FMT versus placebo upon neutrophil recovery. After each course of antibacterial antibiotics, patients received a study treatment. Up to three treatments were administered within 3 months. The primary end point was 4-month all-cause infection rate. Patients were followed for 9 months. RESULTS: In the HCT cohort (74 patients), 4-month infection density was 0.74 and 0.91 events per 100 patient-days in FMT and placebo arms, respectively (infection rate ratio, 0.83; 95% CI, 0.48 to 1.42; P = .49). In the AML cohort (26 patients), 4-month infection density was 0.93 in the FMT arm and 1.25 in the placebo arm, with an infection rate ratio of 0.74 (95% CI, 0.32 to 1.71; P = .48). Unique donor bacterial sequences comprised 25%-30% of the fecal microbiota after FMT. FMT improved postantibiotic recovery of microbiota diversity, restored several depleted obligate anaerobic commensals, and reduced the abundance of expanded genera Enterococcus, Streptococcus, Veillonella, and Dialister. CONCLUSION: In allogeneic HCT recipients and patients with AML, third-party FMT was safe and ameliorated intestinal dysbiosis, but did not decrease infections. Novel findings from this trial will inform future development of FMT trials.

The root canal microbiome diversity and function. A whole-metagenome shotgun analysis.

AIM: To evaluate the root canal microbiome composition and bacterial functional capability in cases of primary and secondary apical periodontitis utilizing whole-metagenome shotgun sequencing. METHODOLOGY: Twenty-two samples from patients with primary root canal infections, and 18 samples obtained from previously treated teeth currently diagnosed with apical periodontitis were analysed with whole-metagenome shotgun sequencing at a depth of 20 M reads. Taxonomic and functional gene annotations were made using MetaPhlAn3 and HUMAnN3 software. The Shannon and Chao1 indices were utilized to measure alpha diversity. Differences in community composition were evaluated utilizing analysis of similarity (ANOSIM) using Bray-Curtis dissimilarities. The Wilcoxon rank sum test was used to compare differences in taxa and functional genes. RESULTS: Microbial community variations within a community were significantly lower in secondary relative to primary infections (alpha diversity p = .001). Community composition was significantly different in primary versus secondary infection (R = .11, p = .005). The predominant taxa observed among samples (>2.5%) were Pseudopropionibacterium propionicum, Prevotella oris, Eubacterium infirmum, Tannerella forsythia, Atopobium rimae, Peptostreptococcus stomatis, Bacteroidetes bacterium oral taxon 272, Parvimonas micra, Olsenella profusa, Streptococcus anginosus, Lactobacillus rhamnosus, Porphyromonas endodontalis, Pseudoramibacter alactolyticus, Fusobacterium nucleatum, Eubacterium brachy and Solobacterium moorei. The Wilcoxon rank test revealed no significant differences in relative abundances of functional genes in both groups. Genes with greater relative abundances (top 25) were associated with genetic, signalling and cellular processes including the iron and peptide/nickel transport system. Numerous genes encoding toxins were identified: exfoliative toxin, haemolysins, thiol-activated cytolysin, phospholipase C, cAMP factor, sialidase, and hyaluronic glucosaminidase. CONCLUSIONS: Despite taxonomic differences between primary and secondary apical periodontitis, the functional capability of the microbiomes was similar.

Opioid Prescribing Behavior in the Emergency Department During Routine Orthopedic Manipulations.

BACKGROUND: The emergency department (ED) often represents the first exposure orthopedic trauma patients have to prescription opioids and thus a critical opportunity for prevention of potential long-term opioid use. This study will analyze the impact of opioid prescribing patterns among both ED providers and orthopedic surgery residents on the utilization of opioids during routine orthopedic trauma manipulations. MATERIALS AND METHODS: This retrospective study reviewed opioid utilization among patients with an ankle or distal radius fracture at a large, urban, level 1 trauma center. Data on clinical providers, patient demographics, and injury severity score (ISS) were collected. Total opioid use was reported in oral morphine milligram equivalents (MME). Regression analyses were performed to determine how provider opioid prescribing intensity affected administered MME. RESULTS: Five-hundred and ninety-five patients were included. The mean MME administered was 40.84 (SD 30.0) and was inversely associated with ISS (R = -.05; P = .40). Patients treated by a high-intensity ED prescriber had approximately three times higher odds of receiving over 40.84 MME (OR 2.8, 95% CI 1.33-5.90 P = .07). For those with an ISS score less than 15, the presence of a low-intensity orthopedic resident decreased the odds of receiving over 40.84 MME from 2.25 to 1.78 in the presence of a high-intensity ED prescriber. CONCLUSION: For isolated orthopedic manipulations in the ED, involvement of a low-intensity prescribing orthopedic resident significantly decreased the quantity of opioids administered for those with lower ISS injuries, thus effectively mitigating the effect of high-intensity prescribing behavior prescriber.

Pulmonary Arterial Hypertension Patients Have a Proinflammatory Gut Microbiome and Altered Circulating Microbial Metabolites.

Rationale: Inflammation drives pulmonary arterial hypertension (PAH). Gut dysbiosis causes immune dysregulation and systemic inflammation by altering circulating microbial metabolites; however, little is known about gut dysbiosis and microbial metabolites in PAH. Objectives: To characterize the gut microbiome and microbial metabolites in patients with PAH. Methods: We performed 16S ribosomal RNA gene and shotgun metagenomics sequencing on stool from patients with PAH, family control subjects, and healthy control subjects. We measured markers of inflammation, gut permeability, and microbial metabolites in plasma from patients with PAH, family control subjects, and healthy control subjects. Measurements and Main Results: The gut microbiome was less diverse in patients with PAH. Shannon diversity index correlated with measures of pulmonary vascular disease but not with right ventricular function. Patients with PAH had a distinct gut microbial signature at the phylogenetic level, with fewer copies of gut microbial genes that produce antiinflammatory short-chain fatty acids (SCFAs) and secondary bile acids and lower relative abundances of species encoding these genes. Consistent with the gut microbial changes, patients with PAH had relatively lower plasma concentrations of SCFAs and secondary bile acids. Patients with PAH also had enrichment of species with the microbial genes that encoded the proinflammatory microbial metabolite trimethylamine. The changes in the gut microbiome and circulating microbial metabolites between patients with PAH and family control subjects were not as substantial as the differences between patients with PAH and healthy control subjects. Conclusions: Patients with PAH have proinflammatory gut dysbiosis, in which lower circulating SCFAs and secondary bile acids may facilitate pulmonary vascular disease. These findings support investigating modulation of the gut microbiome as a potential treatment for PAH.