Publications by authors named "Samantha N Atkinson"

Introduction: Sleeve gastrectomy (SG), results in improvement in hypertension. We have previously published that rodent SG improves hypertension independent of weight loss associated with unique shifts in the gut microbiome. We tested if the gut microbiome directly improves blood pressure by performing fecal material transfer (FMT) from post-SG rats to surgery-naïve animals.

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Background: Posttraumatic stress disorder (PTSD) is a common consequence of traumatic injury, yet certain biological factors contributing to PTSD are poorly understood. The gut microbiome may influence mental health outcomes, but its role in heterogeneous PTSD presentations requires elucidation.

Methods: Bacterial composition was examined in adults 2-4 years post-trauma with probable PTSD (n = 24) versus trauma-exposed controls without probable PTSD (n = 24).

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Enterococci are commensal members of the gastrointestinal tract and also major nosocomial pathogens. They possess both intrinsic and acquired resistance to many antibiotics, including intrinsic resistance to cephalosporins that target bacterial cell wall synthesis. These antimicrobial resistance traits make enterococcal infections challenging to treat.

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Objective: Pediatric nonalcoholic fatty liver disease (NAFLD) is a growing problem, but its underlying mechanisms are poorly understood. We used transcriptomic reporter cell assays to investigate differences in transcriptional signatures induced in hepatocyte reporter cells by the sera of children with and without NAFLD.

Methods: We studied serum samples from 45 children with NAFLD and 28 children without NAFLD.

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The soil-dwelling delta-proteobacterium is a model organism to study predation and competition. preys on a broad range of bacteria mediated by lytic enzymes, exopolysaccharides, Type-IV pilus-based motility, and specialized metabolites. Competition between and prey bacterial strains with various specialized metabolite profiles indicates a range of fitness, suggesting that specialized metabolites contribute to prey survival.

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Introduction: Kidney stone disease in children is rising disproportionate to the general population, representing a disease population with a distinct biological mechanism as compared to adults. Factors influencing recurrent kidney stone disease in children are poorly characterized and the associations of the intestinal microbiome within sub-populations of kidney stone formers, however, are not well described. We evaluated a pilot cohort of children with nephrolithiasis comparing patients based on recurrent kidney stone episodes and abnormal 24-h urinary parameters, with dual aims to compare the microbiome signal in children with initial and recurrent nephrolithiasis and to explore additional associations in microbiome composition and diversity within this population.

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Objectives: Percutaneous electrical nerve field stimulation (PENFS) has documented efficacy for irritable bowel syndrome (IBS) via plausible vagal neuromodulation effects. The vagus nerve may affect gut microbiome composition via brain-gut-microbiome signaling. We aimed to investigate gut microbiome alterations by PENFS therapy in adolescent IBS patients.

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Succinate produced by the commensal protist () stimulates chemosensory tuft cells, resulting in intestinal type 2 immunity. Tuft cells express the succinate receptor SUCNR1, yet this receptor does not mediate antihelminth immunity nor alter protist colonization. Here, we report that microbial-derived succinate increases Paneth cell numbers and profoundly alters the antimicrobial peptide (AMP) landscape in the small intestine.

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Pain is a debilitating symptom and leading reason for hospitalization of individuals with sickle cell disease. Chronic sickle cell pain is poorly managed because the biological basis is not fully understood. Using transgenic sickle cell mice and fecal material transplant, we determined that the gut microbiome drives persistent sickle cell pain.

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The increasing incidence of Type 1 diabetes has coincided with the emergence of the low-fiber, high-gluten Western diet and other environmental factors linked to dysbiosis. Since 299 v (Lp299v) supplementation improves gut barrier function and reduces systemic inflammation, we studied its effects in spontaneously diabetic DR rats provided a normal cereal diet (ND) or a gluten-free hydrolyzed casein diet (HCD). All rats provided ND developed diabetes (62.

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Enterococcus faecalis is an opportunistic pathogen and a major cause of severe nosocomial infections. Treatment options against enterococcal infections are declining due to the resistance of enterococci to numerous antibiotics. A key risk factor for developing enterococcal infections is treatment with cephalosporin antibiotics, to which enterococci are intrinsically resistant.

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Introduction: Roux-en-Y gastric bypass (RYGB) significantly alters the gut microbiome and may be a mechanism for post-operative cardiovascular disease improvement. We have previously found an association between the class of peri-operative, intravenous antibiotic administered at the time of RYGB and the resolution rate of hypertension suggesting the gut microbiome as a mechanism. In this study, we performed a prospective study of RYGB to determine if a single intravenous antibiotic could alter the gastrointestinal microbial composition.

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The incidence of type 1 diabetes (T1D) has increased, coinciding with lifestyle changes that have likely altered the gut microbiota. Dysbiosis, gut barrier dysfunction, and elevated systemic inflammation consistent with microbial antigen exposure, have been associated with T1D susceptibility and progression. A 6-week, single-arm, open-label pilot trial was conducted to investigate whether daily multi-strain probiotic supplementation could reduce this familial inflammation in 25 unaffected siblings of T1D patients.

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The gut microbiome plays an essential role in host energy homeostasis and influences the development of obesity and related conditions. Studies demonstrate that nicotinamide riboside (NR) supplementation for diet-induced obesity (DIO) reduces weight gain and increases energy expenditure in mice. NR is a vitamin B derivative and an NAD precursor with potential for treating human diseases arising from mitochondrial degeneration, including obesity and type 2 diabetes.

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Graft-versus-host disease (GVHD) remains a major complication after allogeneic hematopoietic stem cell transplantation (HSCT). An impaired intestinal epithelial barrier is an important component of GVHD pathogenesis. However, contributing host factors that modulate mucosal barrier integrity during GVHD are poorly defined.

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Introduction: Bariatric surgery results in resolution of hypertension in over 50% of patients. While weight loss is a critical component to hypertension resolution after bariatric surgery, there may also be weight loss-independent mechanisms.

Objectives: We hypothesized that sleeve gastrectomy (SG) initiates changes in the gut microbiome which reduce postoperative blood pressure.

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Two-component signaling systems (TCS) regulate bacterial responses to environmental signals through the process of protein phosphorylation. Specifically, sensor histidine kinases (SK) recognize signals and propagate the response via phosphorylation of a cognate response regulator (RR) that functions to initiate transcription of specific genes. Signaling within a single TCS is remarkably specific and cross-talk between TCS is limited.

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is a global pathogen of significant medical importance. A key aspect of its life cycle is the ability to enter into an altered physiological state of nonreplicating persistence during latency and resist elimination by the host immune system. One mechanism by which facilitates its survival during latency is by producing and metabolizing intracytoplasmic lipid droplets (LDs).

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Purpose Of Review: The influence of gut bacteria upon host physiology is increasingly recognized, but mechanistic links are lacking. Diseases of energetic imbalance such as obesity and diabetes represent major risk factors for cardiovascular diseases such as hypertension. Thus, here, we review current mechanistic contributions of the gut microbiota to host energetics.

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Myxococcus xanthus is an environmental bacterium with two forms of motility. One type, known as social motility, is dependent on extension and retraction of Type-IV pili (T4P) and production of extracellular polysaccharides (EPS). Several signaling systems have been linked to regulation of T4P-dependent motility.

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