Objective-Weight-loss surgery results in significant changes in the anatomy, function and intralu... more Objective-Weight-loss surgery results in significant changes in the anatomy, function and intraluminal environment of the gastrointestinal tract affecting the gut microbiome. While bariatric surgery results in sustained weight loss, decreased appetite and hedonic eating; it is unknown if the surgery-induced alterations in gut microbiota play a role in the observed changes in hedonic eating. We explored the following hypotheses 1) Laparoscopic sleeve gastrectomy results in changes in gut microbial composition ; 2) Alterations in gut microbiota are related to weight loss; 3) Alterations in gut microbiome are associated with changes in appetite and hedonic eating. Methods-Eight obese women underwent LSG. Their BMI, body fat mass, food intake, hunger, hedonic eating scores, and stool samples were obtained at baseline and 1-month post-surgery. 16S ribosomal RNA gene sequencing was performed on stool samples. DESeq2 for changes in microbial abundance. Multilevel-sparse partial least squares discriminant analysis was applied to genus level abundance for discriminative microbial signatures. Results-LSG resulted in significant reductions in BMI, food intake and hedonic eating. A microbial signature comprised of 5 bacterial genera discriminated between pre and post-surgery status. Several bacterial genera were significantly associated with weight loss (Bilophila (q=3E-05), Faecalibacterium (q=4E-05)), lower appetite (Enterococcus, q=3E-05) and reduced hedonic eating (Akkermansia, q=0.037) after surgery. Conclusions-In this preliminary analysis, changes in gut microbial abundance discriminated between pre and postoperative status. Alterations in gut microbiome were significantly associated
which initiates inflammatory events; and (c) increased intercellular adhesion molecule-1 (ICAM-1)... more which initiates inflammatory events; and (c) increased intercellular adhesion molecule-1 (ICAM-1) and interleukin-6 (IL-6) levels (p,0.05). In addition, high amount of conjugated dienes and malondialdehyde along with significantly reduced superoxide dismutase activity were noted in the intestine of IR subjects, which indicates the presence of oxidative stress (p,0.05). Moreover, exposure of the intestine of IR subjects to proinflammatory lipopolysaccharides (LPS) or oxidative stress conditions unraveled an abnormal response magnitude. Indeed, IL-6 and conjugated dienes levels were further increased in presence of LPS and pro-oxidant conditions, respectively, in the intestine of IR subjects compared to IS subjects (p,0.05). Finally, the intestine of IR subjects showed increased de novo lipogenesis rate, higher expression of fatty acid binding proteins (L-FABP and I-FABP) and microsomal transfer protein (MTP), and stimulation of apo B-48 biogenesis, which collectively contributed to the exaggerated triglyceride-rich lipoprotein secretion (p ,0.05). Conclusion: Small intestine of IR obese subjects exhibits several markers of inflammation and oxidative stress in association with local insulin resistance and lipoprotein overproduction. These abnormalities may likely contribute to the development of diabetic dyslipidemia and evolution of the metabolic syndrome.
A growing body of preclinical and clinical literature suggests that brain-gut-microbiota interact... more A growing body of preclinical and clinical literature suggests that brain-gut-microbiota interactions may contribute to obesity pathogenesis. In this study, we use a machine learning approach to leverage the enormous amount of microstructural neuroimaging and fecal metabolomic data to better understand key drivers of the obese compared to overweight phenotype. Our findings reveal that although gut-derived factors play a role in this distinction, it is primarily brain-directed changes that differentiate obese from overweight individuals. Of the key gut metabolites that emerged from our model, many are likely at least in part derived or influenced by the gut-microbiota, including some amino-acid derivatives. Remarkably, key regions outside of the central nervous system extended reward network emerged as important differentiators, suggesting a role for previously unexplored neural pathways in the pathogenesis of obesity.
Functional neuroimaging studies in obesity have identified alterations in the connectivity within... more Functional neuroimaging studies in obesity have identified alterations in the connectivity within the reward network leading to decreased homeostatic control of ingestive behavior. However, the neural mechanisms underlying sex differences in the prevalence of food addiction in obesity is unknown. The aim of the study was to identify functional connectivity alterations associated with: (1) Food addiction, (2) Sex- differences in food addiction, (3) Ingestive behaviors. 150 participants (females: N = 103, males: N = 47; food addiction: N = 40, no food addiction: N = 110) with high BMI ≥ 25 kg/m2 underwent functional resting state MRIs. Participants were administered the Yale Food Addiction Scale (YFAS), to determine diagnostic criteria for food addiction (YFAS Symptom Count ≥ 3 with clinically significant impairment or distress), and completed ingestive behavior questionnaires. Connectivity differences were analyzed using a general linear model in the CONN Toolbox and images were segm...
Background: Polysaccharide A (PSA), a highly immunogenic capsular component of nontoxigenic Bacte... more Background: Polysaccharide A (PSA), a highly immunogenic capsular component of nontoxigenic Bacteroides fragilis NCTC 9343 (NTBF), has been reported to promote host mucosal immune system development and to suppress inflammation in the gut. Thus, NTBF is proposed for probiotic development to prevent colitis and colorectal cancer. In stark contrast, enterotoxigenic Bacteroides fragilis (ETBF) is highly associated with inflammatory bowel disease and colorectal cancer, and in murine hosts, ETBF rapidly induces an acute interleukin (IL)-17 colitis and tumorigenesis. The interactions of these distinct B. fragilis molecular subtypes were studied to determine the impact of NTBF on ETBF disease. Methods: Specific pathogen free (SPF) C57BL/6 wild type (WT) and multiple intestinal neoplasia (Min Apc716+/-) mice received different B. fragilis orogastric treatments: NTBF->ETBF, DPSA NTBF->ETBF, and NTBF+ETBF. At 2 weeks, WT mice were evaluated for cytokine gene expression (quantitative PCR), disease severity (histopathology), and fecal B. fragilis (quantitative PCR). At 3 months, Min mice were evaluated for tumor development and fecal B. fragilis (quantitative PCR). Immune responses were evaluated by flow cytometry. Mann-Whitney tests were used for statistical analyses. Results: In SPF WT and SPF Min mice, we show that B. fragilis sequential treatment (NTBF then ETBF three days later; NTBF->ETBF) diminished colitis (P = 0.0007) and decreased tumor development (P = 0.0053), respectively. Abrogated disease severity in sequentially treated mice was attributed to NTBF strain dominance and decreased levels of IL-17A, but ETBF colonization prior to NTBF (ETBF->NTBF) or simultaneous with NTBF (NTBF+ETBF) mitigated the anti-inflammatory effect of NTBF. For instance, NTBF+ETBF treated mice continued to exhibit severe colitis and pronounced tumor formation. Surprisingly, NTBF-mediated protection was independent of PSA, as sequentially infected mice receiving DPSA NTBF (DPSA NTBF->ETBF) exhibited similar levels of protection from colitis (P = <0.0001) and tumorigenesis (P = 0.0043). Further, SPF WT and SPF Min mice singly colonized with PSA-competent or PSA-deficient NTBF exhibited a similar colonic accumulation of regulatory (FOXP3 +), IL-17A + , and IFN-g + T cells. Daily NTBF probiotic treatment of mice stably colonized with ETBF failed to disrupt pathogenic ETBF strain dominance and did not improve the health of ETBF-colonized mice. Our findings demonstrate that NTBF, independent of PSA, may offer protection against ETBF colitis but may not act as a valid therapeutic treatment.
Neural circuitry regulating urine storage in humans has been largely inferred from fMRI during ur... more Neural circuitry regulating urine storage in humans has been largely inferred from fMRI during urodynamic studies driven by catheter infusion of fluid into the bladder. However, urodynamic testing may be confounded by artificially filling the bladder repeatedly at a high rate and examining associated time-locked changes in fMRI signals. Here we describe and test a more ecologically-valid paradigm to study the brain response to bladder filling by (1) filling the bladder naturally with oral water ingestion, (2) examining resting state fMRI (rs-fMRI) which is more natural since it is not linked with a specific stimulus, and (3) relating rs-fMRI measures to self-report (urinary urge) and physiologic measures (voided volume). To establish appropriate controls and analyses for future clinical studies, here we analyze data collected from healthy individuals (N = 62) as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network. Participants orally in...
Background. Recent evidence reveals an important role for colonic spore-forming bacteria (includi... more Background. Recent evidence reveals an important role for colonic spore-forming bacteria (including Clostridia) in stimulating 5-HT biosynthesis in the intestine and modulating GI sensorimotor function (Yano, 2015, Kashyap, 2014). Clostridiales-associated species are enriched in the fecal microbiome of a subset of IBS individuals and correlate with IBS symptom severity (Tap et al, 2016). Also, the composition of the gut microbiota correlates with alterations in brain structure in IBS compared to healthy controls (HC) (Labus et al, 2015). Aim. Test the hypothesis that abundance of serotonin-promoting Clostridia in the fecal microbiome correlates with functional connectivity of sensorimotor regions (basal ganglia, posterior insula and thalamus), as well as with evoked symptoms. Methods. 16S ribosomal DNA gene sequencing was performed on stool samples collected from 65 IBS patients (46 F) and 21 HCs (16 F) who also underwent structural and functional brain imaging studies. Regional indices of functional network centrality (degree strength, betweenness centrality, eigenvector centrality) were computed using graph theory. Known genera related to IBS symptom severity included Clostridiales-associated: g. Clostridium IV, g. Clostridium XlVb , and g. Oscillibacter. (Tap et al., 2016) Evoked symptoms were obtained via psychophysiological assessment. The interaction between the phenome (evoked symptoms), microbiome (stool microbial community) and connectome (brain connectivity) was determined by computing spearman correlations between different data types controlling for age and sex. Cytoscape was used to construct and compare microbiota, brain, and symptom interaction networks thresholded at p<.05 in HCs and IBS. Results. There were several significant interactions between the relative abundance of Clostridiales-associated genera with several perceptual measures (sensitivity, pain and discomfort during a 24mmHG rectal distension, pain and discomfort rating during a lactulose challenge), and functional connectivity of sensorimotor regions. Key findings include: 1) In HCs, Clostridium IV was associated with increased global connectivity bilaterally in the posterior insula. No association with evoked symptoms were observed. In IBS, there is an interaction between Clostridium IV, thalamus connectivity and pain and discomfort thresholds (Fig1). 2) In IBS, there was an extensive interaction between Oscillibacter, brain connectivity and symptoms. In contrast, Oscillibacter was not correlated with brain or evoked symptoms in HCs (Fig2). Conclusions. Clostridiales-associated bacterial genera showed interactions with sensory brain regions as well as evoked pain and discomfort in IBS. Even though the mechanisms mediating these interactions are unknown, the findings support a relationship between brain connectivity in sensory regions and gut microbial abundance.
over the entire circumference of GJA was performed. Additional series were carried out at 8-12 we... more over the entire circumference of GJA was performed. Additional series were carried out at 8-12 weeks until goal body weight was achieved. Patients received the same post-op diet. Primary Outcome: Weight loss at 6 months after the last endoscopic revision session as measured by percentage of total body weight loss (%TBWL). Statistical Analysis: Statistics were reported using mean±SD or median [range]. Means were compared using Student's t-test. A p-value of 0.05 was significant. Results: Part I: 44 patients underwent TORe+APC (83 APC sessions; 1.9 sessions after each TORe/patient). Baseline characteristics are shown in Table 1. At 6 months, patients lost 10.0±10.4 kg from baseline (p<0.0001), and BMI decreased from 39.6±9.1 to 36.3±9.1 kg/ m 2 (p<0.0001). This represented 10.5±10.4% TBWL. Part II: 25 consecutive RYGB patients undergoing TORe+APC were matched to 25 patients undergoing APC alone based on BMI, weight regain and GJA size (Table 2). At 6 months, the TORe+APC group had higher %TBWL compared to the APC alone group (9.4±6.0% TBWL vs 5.7±5.7% TBWL, p=0.019). Conclusion: APC is effective in treating weight regain in RYGB patients who fail to meet weight loss goals after TORe. Additionally, sequential therapy with TORe followed by APC is more effective than APC monotherapy alone. Table 1. Baseline Characteristics and Outcomes at 6 Months Between Patients Undergoing TORe + APC versus APC alone
Chronic pain is often measured with a severity score that overlooks its spatial distribution acro... more Chronic pain is often measured with a severity score that overlooks its spatial distribution across the body. This widespread pain is thought to be a marker of centralization, a central nervous system process that decouples pain perception from nociceptive input. Here, we investigated whether centralization is manifested at the level of the brain using data from 1079 participants in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research Network (MAPP) study. Participants with a clinical diagnosis of urological chronic pelvic pain syndrome (UCPPS) were compared to pain-free controls and fibromyalgia patients, the prototypical centralized pain disorder. Participants completed questionnaires capturing pain severity, function, and a body map of pain. A subset (UCPPS N=110; fibromyalgia N=23; healthy control N=49) underwent functional and structural magnetic resonance imaging. UCPPS patients reported pain ranging from localized (pelvic) to widespread (throughout the ...
Clinical phenotyping of urological chronic pelvic pain syndromes (UCPPSs) in men and women have f... more Clinical phenotyping of urological chronic pelvic pain syndromes (UCPPSs) in men and women have focused on end organ abnormalities to identify putative clinical subtypes. Initial evidence of abnormal brain function and structure in male pelvic pain has necessitated large-scale, multisite investigations into potential UCPPS brain biomarkers. We present the first evidence of regional white matter (axonal) abnormalities in men and women with UCPPS, compared with positive (irritable bowel syndrome, IBS) and healthy controls. Epidemiological and neuroimaging data were collected from participants with UCPPS (n = 52), IBS (n = 39), and healthy sex- and age-matched controls (n = 61). White matter microstructure, measured as fractional anisotropy (FA), was examined by diffusion tensor imaging. Group differences in regional FA positively correlated with pain severity, including segments of the right corticospinal tract and right anterior thalamic radiation. Increased corticospinal FA was spec...
carbonate. Diets were balanced for protein, fat and iron (0.036%). Heme concentration was assesse... more carbonate. Diets were balanced for protein, fat and iron (0.036%). Heme concentration was assessed by fluorescence and lipid peroxides were quantified by TBARs measurement in fecal water. Genotoxicity on colon mucosa was evaluated by alkaline comet assay. 18 gut bacterial communities were monitored by qPCR using GUt Low Density Array approach and metabolomic profiles of the same fecal homogenates were obtained though 1H NMR spectroscopy. Integration of data sets was performed using the R package mixOmics. Results: As expected, increase of fecal TBARs resulting from hemin-enriched diet (81.1+/-17.9 vs. control 37+/-10.4 µM, p<0.0001) was prevented by the supplementation of calcium in hemin-enriched diet (44.2+/-10.6 vs. control, ns), luminal heme being chelated by calcium carbonate. DNA mucosal damages were associated with elevated fecal TBARs levels, suggesting that chelation of heme by addition of calcium was sufficient to normalize both heme-induced lipoperoxidation and associated mucosal genotoxicity. Regularized canonical correlation analysis highlighted similar structuration of data sets from fecal microbiome and metabolome, consisting in segregation of relatives abundances of bacterial groups and metabolites according to diet (Figure 1). Enterobacteriaceae and Bacteroides fragilis were enriched in microbiota of rats fed with hemin whereas Roseburia spp. and Lactobacillus spp. were underrepresented. Addition of calcium in hemin-enriched diet normalized heme-induced increase of B. fragilis and reduction of Lactobacillus spp., suggesting that these bacterial groups were correlated with heme-induced lipoperoxidation. In parallel, fecal short chain fatty acids (acetate, propionate and butyrate), as well as succinate and several bile acids, covariated with lipoperoxidation status. Conclusion: This dietary study in rat provides a global overview of hemeinduced modulations within fecal bacterial communities and metabolites and identifies those that are closely linked with lipoperoxidation and genotoxicity status, two hallmarks of meat consumption and colorectal cancer risk.
We examine symptom variability in men and women with urological chronic pelvic pain syndrome (UCP... more We examine symptom variability in men and women with urological chronic pelvic pain syndrome (UCPPS). We describe symptom fluctuations as related to early symptom regression and its effect on estimated one-year symptom change. We then describe a method to quantify patient-specific symptom variability. Symptoms were assessed biweekly in 424 UCPPS subjects over one year. Subjects were classified as 'improved', 'no change', or 'worse' according to their rate of change using 1) all data, 2) excluding week 0, and 3) excluding weeks 0 and 2 to evaluate the impact of early symptom regression. Patient-specific time-varying variability was calculated at each interval using a sliding window approach. Patients were classified as high, medium, or low variability at each time and ultimately as high or low variability overall based on their variability for the majority of contacts. Prior to excluding early weeks to adjust for early symptom regression 25-38% and 5-6% of pat...
Background: Irritable Bowel Syndrome (IBS) is a multifactorial functional gastrointestinal disord... more Background: Irritable Bowel Syndrome (IBS) is a multifactorial functional gastrointestinal disorder; however, recent findings have shown a state of immune activation, increased TLR expression and intestinal epithelial diffusion of bacterial molecules to the gut mucosa, at least in a subgroup of patients. Aims: We sought to relate these factors by analyzing the expression of gut homing adhesion molecule (integrin α4β7), intestinal recruiting (CCR5: CC chemokine receptor-5) and activation (CD28) phenotype of T lymphocytes as well as the expression of cytokines and chemokines, when stimulated with Toll-like Receptor (TLR) ligands in IBS patients and controls. Methods: Twenty one IBS-Rome II patients and 19 controls were studied in Mexico. Isolated peripheral blood mononuclear cells (PBMCs) were stimulated with E. coli Lypopolysaccharide (LPS), S. aureus Peptidoglycan (PGN) and unmethylated Cytosine-phosphate-Guanine motifs Hu/MsCpG-C (CpG). The phenotype of T lymphocytes were investigated by flow cytometry after 24 hours of cell culture under TLR stimulation and compared with equally cultured cells without any stimulus. In addition, soluble cytokines and chemokines were measured from the culture supernatant. Results: Cultured T cells from patients with IBS displayed a higher proportion of CD8 cells expressing the α4β7+CCR5+ phenotype after LPS stimulation compared to controls (90.8±0.9 vs. 85.7±1.5%, p=0.006) and CD4 α4β7+CCR5+ after PGN stimulation (65.6±1.6 vs. 61.0±1.6%, p=0.048). In addition, we found lower expression of the co-activation CD28+ molecule in CD4 + α4β7+CCR5+ cells after LPS stimulation in IBS vs. controls (Mean Fluorescence Intensity: 1779±179.2 vs. 2337±47.2, p=0.008). There were no differences in the supernatant concentration of cytokines and chemokines except for lower IL8/CXCL8 in the non-stimulated condition in IBS vs. controls (3.77, 95%CI: 3.59-3.95 vs. 4.18, 95%CI: 3.94-4.42, p=0.006). Conclusions: Peripheral blood T cells expressing gut homing marker in IBS patients showed a co-expression of intestinal recruiting and activation phenotypes in response to TLR-extracellular ligands, while no differences were observed in the nonstimulated cells between the groups. These suggest that there is an interaction between an innate immune predisposition and microbial triggers as a possible underlying or exacerbating mechanism in IBS.
BACKGROUND: Insular cortex is the part of the limbic system that processes and modulates visceral... more BACKGROUND: Insular cortex is the part of the limbic system that processes and modulates visceral sensations. Recent fMRI study in human demonstrates that acid stimulation of the esophagus results in enhanced activation of insular cortex to non-painful esophageal distension. At the molecular level, transgenic overexpression of NMDA receptor subunit NR2B in the mice forebrain exhibits an increase in NMDA receptor-mediated excitatory postsynaptic currents in the insular cortex and behavioral sensitization. AIMS: To determine whether acute esophageal acid exposure in rats results in alteration in NMDA receptor subunits expression in insular cortex. METHODS: Two groups of adult Sprague-Dawley rats (n=4/ group) were used. Animals were anesthetized with sodium pentobarbital (40 mg/kg, ip), and an infusion catheter (PE-10) was inserted into the esophagus through an incision made 2cm below the upper esophageal sphincter. A second catheter (PE-160) was placed 1cm rostral to the incision catheter with the tip directed toward the pharynx to remove accumulated saliva and to prevent aspiration. Rats received 2ml of either 0.1N HCl or saline for 20 min at 0.1ml/min. Four hours later rats were anesthetized again and Evans blue dye (2μl) was administered into the insular region (coordinates A: 1.0 from bregma, L: 4.5 and H:-6 mm from meninges). The brain was removed quickly and 2mm3 region surrounding the dye-injected region was collected and stored under liquid nitrogen till further processing. Tissues were processed for the isolation of membrane proteins. In Westernblots, isolated proteins were evaluated using antibodies against NR1, NR2A and NR2B subunits. The results were expressed as relative intensity of expression against β-actin (mean ±SD). RESULTS: The mean intensity of expression for NR2A subunit in insular cortices from acid-treated rats was significantly higher compared with saline-treated controls (p<0.05). The relative intensity of expression also indicated a significant increase in NR2B subunits in insular cortices in acid-treated group compared with saline-treated controls (p<0.05). No significant difference was observed in the expression of NR1 subunit between acid and saline-treated groups. CONCLUSIONS: Upregulation of modulatory subunits NR2A and NR2B in insular cortex following acute esophageal acid exposure suggests that the acid-induced peripheral insult causes molecular alteration in cortical regions. These molecular changes in insular cortex may contribute to altered neural processing and development of symptoms induced by gastroesophageal acid reflux.
plasma ghrelin levels at 2 h after ICV UCN. UCN induces c-fos mRNA and Fos protein expression in ... more plasma ghrelin levels at 2 h after ICV UCN. UCN induces c-fos mRNA and Fos protein expression in the supraoptic nucleus, paraventricular nucleus of hypothalamus (PVN), locus coeruleus, solitary tract nucleus (NTS), and ventrolateral nucleus of medulla oblongata (VLM), known to influence sympathetic outflow. Fos expression in NTS was markedly suppressed by coadministration of RKT (control 84 ± 28, UCN 352 ± 130, UCN + RKT 48 ± 15; P , 0.05). UCN-induced Fos expression in VLM was also suppressed by RKT (control 35 ± 10, UCN 289 ± 94, UCN + RKT 133 ± 27), but not significant (P=0.08). RKT also suppressed UCN-induced c-fos expression in PVN. In contrast, the dorsal motor nucleus involved in vagal outflow did not show any changes in Fos and fos expression by RKT. Conclusions: These data indicate that a) RKT inhibits the activity of the neuron of NTS suggesting that RKT inhibits vagal input from the periphery to central nerves. b) As the result of inhibiton of vagal input, activity of hypothalamic satiety center, PVN is suppressed resulting in the inhibition of the sympathetic outflow from the central nerve to the periphery. RKT may restore disturbed appetite and ghrelin secretion through the restoration of balance of central autonomic nervous system.
Altered resting-state brain activity, as a measure of functional connectivity, is commonly observ... more Altered resting-state brain activity, as a measure of functional connectivity, is commonly observed in chronic pain. Identifying a reliable signature pattern of altered resting-state activity for chronic pain could provide strong mechanistic insights and serve as a highly beneficial neuroimaging-based diagnostic tool. We collected and analyzed resting-state fMRI data from female patients with urologic chronic pelvic pain syndrome (UCPPS, N = 45) and matched healthy participants (N = 45) as part of a NIDDK funded multicenter project (www.mappnetwork.org). Using dual regression and seed-based analyses, we observed significantly decreased functional connectivity of the default mode network (DMN) to two regions in the posterior medial cortex (PMC): the posterior cingulate cortex (PCC) and left precuneus (TFCE, FWE corrected p<0.05). Further investigation revealed that patients demonstrated increased functional connectivity between the PCC and several brain regions implicated in pain,...
Objective-Weight-loss surgery results in significant changes in the anatomy, function and intralu... more Objective-Weight-loss surgery results in significant changes in the anatomy, function and intraluminal environment of the gastrointestinal tract affecting the gut microbiome. While bariatric surgery results in sustained weight loss, decreased appetite and hedonic eating; it is unknown if the surgery-induced alterations in gut microbiota play a role in the observed changes in hedonic eating. We explored the following hypotheses 1) Laparoscopic sleeve gastrectomy results in changes in gut microbial composition ; 2) Alterations in gut microbiota are related to weight loss; 3) Alterations in gut microbiome are associated with changes in appetite and hedonic eating. Methods-Eight obese women underwent LSG. Their BMI, body fat mass, food intake, hunger, hedonic eating scores, and stool samples were obtained at baseline and 1-month post-surgery. 16S ribosomal RNA gene sequencing was performed on stool samples. DESeq2 for changes in microbial abundance. Multilevel-sparse partial least squares discriminant analysis was applied to genus level abundance for discriminative microbial signatures. Results-LSG resulted in significant reductions in BMI, food intake and hedonic eating. A microbial signature comprised of 5 bacterial genera discriminated between pre and post-surgery status. Several bacterial genera were significantly associated with weight loss (Bilophila (q=3E-05), Faecalibacterium (q=4E-05)), lower appetite (Enterococcus, q=3E-05) and reduced hedonic eating (Akkermansia, q=0.037) after surgery. Conclusions-In this preliminary analysis, changes in gut microbial abundance discriminated between pre and postoperative status. Alterations in gut microbiome were significantly associated
which initiates inflammatory events; and (c) increased intercellular adhesion molecule-1 (ICAM-1)... more which initiates inflammatory events; and (c) increased intercellular adhesion molecule-1 (ICAM-1) and interleukin-6 (IL-6) levels (p,0.05). In addition, high amount of conjugated dienes and malondialdehyde along with significantly reduced superoxide dismutase activity were noted in the intestine of IR subjects, which indicates the presence of oxidative stress (p,0.05). Moreover, exposure of the intestine of IR subjects to proinflammatory lipopolysaccharides (LPS) or oxidative stress conditions unraveled an abnormal response magnitude. Indeed, IL-6 and conjugated dienes levels were further increased in presence of LPS and pro-oxidant conditions, respectively, in the intestine of IR subjects compared to IS subjects (p,0.05). Finally, the intestine of IR subjects showed increased de novo lipogenesis rate, higher expression of fatty acid binding proteins (L-FABP and I-FABP) and microsomal transfer protein (MTP), and stimulation of apo B-48 biogenesis, which collectively contributed to the exaggerated triglyceride-rich lipoprotein secretion (p ,0.05). Conclusion: Small intestine of IR obese subjects exhibits several markers of inflammation and oxidative stress in association with local insulin resistance and lipoprotein overproduction. These abnormalities may likely contribute to the development of diabetic dyslipidemia and evolution of the metabolic syndrome.
A growing body of preclinical and clinical literature suggests that brain-gut-microbiota interact... more A growing body of preclinical and clinical literature suggests that brain-gut-microbiota interactions may contribute to obesity pathogenesis. In this study, we use a machine learning approach to leverage the enormous amount of microstructural neuroimaging and fecal metabolomic data to better understand key drivers of the obese compared to overweight phenotype. Our findings reveal that although gut-derived factors play a role in this distinction, it is primarily brain-directed changes that differentiate obese from overweight individuals. Of the key gut metabolites that emerged from our model, many are likely at least in part derived or influenced by the gut-microbiota, including some amino-acid derivatives. Remarkably, key regions outside of the central nervous system extended reward network emerged as important differentiators, suggesting a role for previously unexplored neural pathways in the pathogenesis of obesity.
Functional neuroimaging studies in obesity have identified alterations in the connectivity within... more Functional neuroimaging studies in obesity have identified alterations in the connectivity within the reward network leading to decreased homeostatic control of ingestive behavior. However, the neural mechanisms underlying sex differences in the prevalence of food addiction in obesity is unknown. The aim of the study was to identify functional connectivity alterations associated with: (1) Food addiction, (2) Sex- differences in food addiction, (3) Ingestive behaviors. 150 participants (females: N = 103, males: N = 47; food addiction: N = 40, no food addiction: N = 110) with high BMI ≥ 25 kg/m2 underwent functional resting state MRIs. Participants were administered the Yale Food Addiction Scale (YFAS), to determine diagnostic criteria for food addiction (YFAS Symptom Count ≥ 3 with clinically significant impairment or distress), and completed ingestive behavior questionnaires. Connectivity differences were analyzed using a general linear model in the CONN Toolbox and images were segm...
Background: Polysaccharide A (PSA), a highly immunogenic capsular component of nontoxigenic Bacte... more Background: Polysaccharide A (PSA), a highly immunogenic capsular component of nontoxigenic Bacteroides fragilis NCTC 9343 (NTBF), has been reported to promote host mucosal immune system development and to suppress inflammation in the gut. Thus, NTBF is proposed for probiotic development to prevent colitis and colorectal cancer. In stark contrast, enterotoxigenic Bacteroides fragilis (ETBF) is highly associated with inflammatory bowel disease and colorectal cancer, and in murine hosts, ETBF rapidly induces an acute interleukin (IL)-17 colitis and tumorigenesis. The interactions of these distinct B. fragilis molecular subtypes were studied to determine the impact of NTBF on ETBF disease. Methods: Specific pathogen free (SPF) C57BL/6 wild type (WT) and multiple intestinal neoplasia (Min Apc716+/-) mice received different B. fragilis orogastric treatments: NTBF->ETBF, DPSA NTBF->ETBF, and NTBF+ETBF. At 2 weeks, WT mice were evaluated for cytokine gene expression (quantitative PCR), disease severity (histopathology), and fecal B. fragilis (quantitative PCR). At 3 months, Min mice were evaluated for tumor development and fecal B. fragilis (quantitative PCR). Immune responses were evaluated by flow cytometry. Mann-Whitney tests were used for statistical analyses. Results: In SPF WT and SPF Min mice, we show that B. fragilis sequential treatment (NTBF then ETBF three days later; NTBF->ETBF) diminished colitis (P = 0.0007) and decreased tumor development (P = 0.0053), respectively. Abrogated disease severity in sequentially treated mice was attributed to NTBF strain dominance and decreased levels of IL-17A, but ETBF colonization prior to NTBF (ETBF->NTBF) or simultaneous with NTBF (NTBF+ETBF) mitigated the anti-inflammatory effect of NTBF. For instance, NTBF+ETBF treated mice continued to exhibit severe colitis and pronounced tumor formation. Surprisingly, NTBF-mediated protection was independent of PSA, as sequentially infected mice receiving DPSA NTBF (DPSA NTBF->ETBF) exhibited similar levels of protection from colitis (P = <0.0001) and tumorigenesis (P = 0.0043). Further, SPF WT and SPF Min mice singly colonized with PSA-competent or PSA-deficient NTBF exhibited a similar colonic accumulation of regulatory (FOXP3 +), IL-17A + , and IFN-g + T cells. Daily NTBF probiotic treatment of mice stably colonized with ETBF failed to disrupt pathogenic ETBF strain dominance and did not improve the health of ETBF-colonized mice. Our findings demonstrate that NTBF, independent of PSA, may offer protection against ETBF colitis but may not act as a valid therapeutic treatment.
Neural circuitry regulating urine storage in humans has been largely inferred from fMRI during ur... more Neural circuitry regulating urine storage in humans has been largely inferred from fMRI during urodynamic studies driven by catheter infusion of fluid into the bladder. However, urodynamic testing may be confounded by artificially filling the bladder repeatedly at a high rate and examining associated time-locked changes in fMRI signals. Here we describe and test a more ecologically-valid paradigm to study the brain response to bladder filling by (1) filling the bladder naturally with oral water ingestion, (2) examining resting state fMRI (rs-fMRI) which is more natural since it is not linked with a specific stimulus, and (3) relating rs-fMRI measures to self-report (urinary urge) and physiologic measures (voided volume). To establish appropriate controls and analyses for future clinical studies, here we analyze data collected from healthy individuals (N = 62) as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network. Participants orally in...
Background. Recent evidence reveals an important role for colonic spore-forming bacteria (includi... more Background. Recent evidence reveals an important role for colonic spore-forming bacteria (including Clostridia) in stimulating 5-HT biosynthesis in the intestine and modulating GI sensorimotor function (Yano, 2015, Kashyap, 2014). Clostridiales-associated species are enriched in the fecal microbiome of a subset of IBS individuals and correlate with IBS symptom severity (Tap et al, 2016). Also, the composition of the gut microbiota correlates with alterations in brain structure in IBS compared to healthy controls (HC) (Labus et al, 2015). Aim. Test the hypothesis that abundance of serotonin-promoting Clostridia in the fecal microbiome correlates with functional connectivity of sensorimotor regions (basal ganglia, posterior insula and thalamus), as well as with evoked symptoms. Methods. 16S ribosomal DNA gene sequencing was performed on stool samples collected from 65 IBS patients (46 F) and 21 HCs (16 F) who also underwent structural and functional brain imaging studies. Regional indices of functional network centrality (degree strength, betweenness centrality, eigenvector centrality) were computed using graph theory. Known genera related to IBS symptom severity included Clostridiales-associated: g. Clostridium IV, g. Clostridium XlVb , and g. Oscillibacter. (Tap et al., 2016) Evoked symptoms were obtained via psychophysiological assessment. The interaction between the phenome (evoked symptoms), microbiome (stool microbial community) and connectome (brain connectivity) was determined by computing spearman correlations between different data types controlling for age and sex. Cytoscape was used to construct and compare microbiota, brain, and symptom interaction networks thresholded at p<.05 in HCs and IBS. Results. There were several significant interactions between the relative abundance of Clostridiales-associated genera with several perceptual measures (sensitivity, pain and discomfort during a 24mmHG rectal distension, pain and discomfort rating during a lactulose challenge), and functional connectivity of sensorimotor regions. Key findings include: 1) In HCs, Clostridium IV was associated with increased global connectivity bilaterally in the posterior insula. No association with evoked symptoms were observed. In IBS, there is an interaction between Clostridium IV, thalamus connectivity and pain and discomfort thresholds (Fig1). 2) In IBS, there was an extensive interaction between Oscillibacter, brain connectivity and symptoms. In contrast, Oscillibacter was not correlated with brain or evoked symptoms in HCs (Fig2). Conclusions. Clostridiales-associated bacterial genera showed interactions with sensory brain regions as well as evoked pain and discomfort in IBS. Even though the mechanisms mediating these interactions are unknown, the findings support a relationship between brain connectivity in sensory regions and gut microbial abundance.
over the entire circumference of GJA was performed. Additional series were carried out at 8-12 we... more over the entire circumference of GJA was performed. Additional series were carried out at 8-12 weeks until goal body weight was achieved. Patients received the same post-op diet. Primary Outcome: Weight loss at 6 months after the last endoscopic revision session as measured by percentage of total body weight loss (%TBWL). Statistical Analysis: Statistics were reported using mean±SD or median [range]. Means were compared using Student's t-test. A p-value of 0.05 was significant. Results: Part I: 44 patients underwent TORe+APC (83 APC sessions; 1.9 sessions after each TORe/patient). Baseline characteristics are shown in Table 1. At 6 months, patients lost 10.0±10.4 kg from baseline (p<0.0001), and BMI decreased from 39.6±9.1 to 36.3±9.1 kg/ m 2 (p<0.0001). This represented 10.5±10.4% TBWL. Part II: 25 consecutive RYGB patients undergoing TORe+APC were matched to 25 patients undergoing APC alone based on BMI, weight regain and GJA size (Table 2). At 6 months, the TORe+APC group had higher %TBWL compared to the APC alone group (9.4±6.0% TBWL vs 5.7±5.7% TBWL, p=0.019). Conclusion: APC is effective in treating weight regain in RYGB patients who fail to meet weight loss goals after TORe. Additionally, sequential therapy with TORe followed by APC is more effective than APC monotherapy alone. Table 1. Baseline Characteristics and Outcomes at 6 Months Between Patients Undergoing TORe + APC versus APC alone
Chronic pain is often measured with a severity score that overlooks its spatial distribution acro... more Chronic pain is often measured with a severity score that overlooks its spatial distribution across the body. This widespread pain is thought to be a marker of centralization, a central nervous system process that decouples pain perception from nociceptive input. Here, we investigated whether centralization is manifested at the level of the brain using data from 1079 participants in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research Network (MAPP) study. Participants with a clinical diagnosis of urological chronic pelvic pain syndrome (UCPPS) were compared to pain-free controls and fibromyalgia patients, the prototypical centralized pain disorder. Participants completed questionnaires capturing pain severity, function, and a body map of pain. A subset (UCPPS N=110; fibromyalgia N=23; healthy control N=49) underwent functional and structural magnetic resonance imaging. UCPPS patients reported pain ranging from localized (pelvic) to widespread (throughout the ...
Clinical phenotyping of urological chronic pelvic pain syndromes (UCPPSs) in men and women have f... more Clinical phenotyping of urological chronic pelvic pain syndromes (UCPPSs) in men and women have focused on end organ abnormalities to identify putative clinical subtypes. Initial evidence of abnormal brain function and structure in male pelvic pain has necessitated large-scale, multisite investigations into potential UCPPS brain biomarkers. We present the first evidence of regional white matter (axonal) abnormalities in men and women with UCPPS, compared with positive (irritable bowel syndrome, IBS) and healthy controls. Epidemiological and neuroimaging data were collected from participants with UCPPS (n = 52), IBS (n = 39), and healthy sex- and age-matched controls (n = 61). White matter microstructure, measured as fractional anisotropy (FA), was examined by diffusion tensor imaging. Group differences in regional FA positively correlated with pain severity, including segments of the right corticospinal tract and right anterior thalamic radiation. Increased corticospinal FA was spec...
carbonate. Diets were balanced for protein, fat and iron (0.036%). Heme concentration was assesse... more carbonate. Diets were balanced for protein, fat and iron (0.036%). Heme concentration was assessed by fluorescence and lipid peroxides were quantified by TBARs measurement in fecal water. Genotoxicity on colon mucosa was evaluated by alkaline comet assay. 18 gut bacterial communities were monitored by qPCR using GUt Low Density Array approach and metabolomic profiles of the same fecal homogenates were obtained though 1H NMR spectroscopy. Integration of data sets was performed using the R package mixOmics. Results: As expected, increase of fecal TBARs resulting from hemin-enriched diet (81.1+/-17.9 vs. control 37+/-10.4 µM, p<0.0001) was prevented by the supplementation of calcium in hemin-enriched diet (44.2+/-10.6 vs. control, ns), luminal heme being chelated by calcium carbonate. DNA mucosal damages were associated with elevated fecal TBARs levels, suggesting that chelation of heme by addition of calcium was sufficient to normalize both heme-induced lipoperoxidation and associated mucosal genotoxicity. Regularized canonical correlation analysis highlighted similar structuration of data sets from fecal microbiome and metabolome, consisting in segregation of relatives abundances of bacterial groups and metabolites according to diet (Figure 1). Enterobacteriaceae and Bacteroides fragilis were enriched in microbiota of rats fed with hemin whereas Roseburia spp. and Lactobacillus spp. were underrepresented. Addition of calcium in hemin-enriched diet normalized heme-induced increase of B. fragilis and reduction of Lactobacillus spp., suggesting that these bacterial groups were correlated with heme-induced lipoperoxidation. In parallel, fecal short chain fatty acids (acetate, propionate and butyrate), as well as succinate and several bile acids, covariated with lipoperoxidation status. Conclusion: This dietary study in rat provides a global overview of hemeinduced modulations within fecal bacterial communities and metabolites and identifies those that are closely linked with lipoperoxidation and genotoxicity status, two hallmarks of meat consumption and colorectal cancer risk.
We examine symptom variability in men and women with urological chronic pelvic pain syndrome (UCP... more We examine symptom variability in men and women with urological chronic pelvic pain syndrome (UCPPS). We describe symptom fluctuations as related to early symptom regression and its effect on estimated one-year symptom change. We then describe a method to quantify patient-specific symptom variability. Symptoms were assessed biweekly in 424 UCPPS subjects over one year. Subjects were classified as 'improved', 'no change', or 'worse' according to their rate of change using 1) all data, 2) excluding week 0, and 3) excluding weeks 0 and 2 to evaluate the impact of early symptom regression. Patient-specific time-varying variability was calculated at each interval using a sliding window approach. Patients were classified as high, medium, or low variability at each time and ultimately as high or low variability overall based on their variability for the majority of contacts. Prior to excluding early weeks to adjust for early symptom regression 25-38% and 5-6% of pat...
Background: Irritable Bowel Syndrome (IBS) is a multifactorial functional gastrointestinal disord... more Background: Irritable Bowel Syndrome (IBS) is a multifactorial functional gastrointestinal disorder; however, recent findings have shown a state of immune activation, increased TLR expression and intestinal epithelial diffusion of bacterial molecules to the gut mucosa, at least in a subgroup of patients. Aims: We sought to relate these factors by analyzing the expression of gut homing adhesion molecule (integrin α4β7), intestinal recruiting (CCR5: CC chemokine receptor-5) and activation (CD28) phenotype of T lymphocytes as well as the expression of cytokines and chemokines, when stimulated with Toll-like Receptor (TLR) ligands in IBS patients and controls. Methods: Twenty one IBS-Rome II patients and 19 controls were studied in Mexico. Isolated peripheral blood mononuclear cells (PBMCs) were stimulated with E. coli Lypopolysaccharide (LPS), S. aureus Peptidoglycan (PGN) and unmethylated Cytosine-phosphate-Guanine motifs Hu/MsCpG-C (CpG). The phenotype of T lymphocytes were investigated by flow cytometry after 24 hours of cell culture under TLR stimulation and compared with equally cultured cells without any stimulus. In addition, soluble cytokines and chemokines were measured from the culture supernatant. Results: Cultured T cells from patients with IBS displayed a higher proportion of CD8 cells expressing the α4β7+CCR5+ phenotype after LPS stimulation compared to controls (90.8±0.9 vs. 85.7±1.5%, p=0.006) and CD4 α4β7+CCR5+ after PGN stimulation (65.6±1.6 vs. 61.0±1.6%, p=0.048). In addition, we found lower expression of the co-activation CD28+ molecule in CD4 + α4β7+CCR5+ cells after LPS stimulation in IBS vs. controls (Mean Fluorescence Intensity: 1779±179.2 vs. 2337±47.2, p=0.008). There were no differences in the supernatant concentration of cytokines and chemokines except for lower IL8/CXCL8 in the non-stimulated condition in IBS vs. controls (3.77, 95%CI: 3.59-3.95 vs. 4.18, 95%CI: 3.94-4.42, p=0.006). Conclusions: Peripheral blood T cells expressing gut homing marker in IBS patients showed a co-expression of intestinal recruiting and activation phenotypes in response to TLR-extracellular ligands, while no differences were observed in the nonstimulated cells between the groups. These suggest that there is an interaction between an innate immune predisposition and microbial triggers as a possible underlying or exacerbating mechanism in IBS.
BACKGROUND: Insular cortex is the part of the limbic system that processes and modulates visceral... more BACKGROUND: Insular cortex is the part of the limbic system that processes and modulates visceral sensations. Recent fMRI study in human demonstrates that acid stimulation of the esophagus results in enhanced activation of insular cortex to non-painful esophageal distension. At the molecular level, transgenic overexpression of NMDA receptor subunit NR2B in the mice forebrain exhibits an increase in NMDA receptor-mediated excitatory postsynaptic currents in the insular cortex and behavioral sensitization. AIMS: To determine whether acute esophageal acid exposure in rats results in alteration in NMDA receptor subunits expression in insular cortex. METHODS: Two groups of adult Sprague-Dawley rats (n=4/ group) were used. Animals were anesthetized with sodium pentobarbital (40 mg/kg, ip), and an infusion catheter (PE-10) was inserted into the esophagus through an incision made 2cm below the upper esophageal sphincter. A second catheter (PE-160) was placed 1cm rostral to the incision catheter with the tip directed toward the pharynx to remove accumulated saliva and to prevent aspiration. Rats received 2ml of either 0.1N HCl or saline for 20 min at 0.1ml/min. Four hours later rats were anesthetized again and Evans blue dye (2μl) was administered into the insular region (coordinates A: 1.0 from bregma, L: 4.5 and H:-6 mm from meninges). The brain was removed quickly and 2mm3 region surrounding the dye-injected region was collected and stored under liquid nitrogen till further processing. Tissues were processed for the isolation of membrane proteins. In Westernblots, isolated proteins were evaluated using antibodies against NR1, NR2A and NR2B subunits. The results were expressed as relative intensity of expression against β-actin (mean ±SD). RESULTS: The mean intensity of expression for NR2A subunit in insular cortices from acid-treated rats was significantly higher compared with saline-treated controls (p<0.05). The relative intensity of expression also indicated a significant increase in NR2B subunits in insular cortices in acid-treated group compared with saline-treated controls (p<0.05). No significant difference was observed in the expression of NR1 subunit between acid and saline-treated groups. CONCLUSIONS: Upregulation of modulatory subunits NR2A and NR2B in insular cortex following acute esophageal acid exposure suggests that the acid-induced peripheral insult causes molecular alteration in cortical regions. These molecular changes in insular cortex may contribute to altered neural processing and development of symptoms induced by gastroesophageal acid reflux.
plasma ghrelin levels at 2 h after ICV UCN. UCN induces c-fos mRNA and Fos protein expression in ... more plasma ghrelin levels at 2 h after ICV UCN. UCN induces c-fos mRNA and Fos protein expression in the supraoptic nucleus, paraventricular nucleus of hypothalamus (PVN), locus coeruleus, solitary tract nucleus (NTS), and ventrolateral nucleus of medulla oblongata (VLM), known to influence sympathetic outflow. Fos expression in NTS was markedly suppressed by coadministration of RKT (control 84 ± 28, UCN 352 ± 130, UCN + RKT 48 ± 15; P , 0.05). UCN-induced Fos expression in VLM was also suppressed by RKT (control 35 ± 10, UCN 289 ± 94, UCN + RKT 133 ± 27), but not significant (P=0.08). RKT also suppressed UCN-induced c-fos expression in PVN. In contrast, the dorsal motor nucleus involved in vagal outflow did not show any changes in Fos and fos expression by RKT. Conclusions: These data indicate that a) RKT inhibits the activity of the neuron of NTS suggesting that RKT inhibits vagal input from the periphery to central nerves. b) As the result of inhibiton of vagal input, activity of hypothalamic satiety center, PVN is suppressed resulting in the inhibition of the sympathetic outflow from the central nerve to the periphery. RKT may restore disturbed appetite and ghrelin secretion through the restoration of balance of central autonomic nervous system.
Altered resting-state brain activity, as a measure of functional connectivity, is commonly observ... more Altered resting-state brain activity, as a measure of functional connectivity, is commonly observed in chronic pain. Identifying a reliable signature pattern of altered resting-state activity for chronic pain could provide strong mechanistic insights and serve as a highly beneficial neuroimaging-based diagnostic tool. We collected and analyzed resting-state fMRI data from female patients with urologic chronic pelvic pain syndrome (UCPPS, N = 45) and matched healthy participants (N = 45) as part of a NIDDK funded multicenter project (www.mappnetwork.org). Using dual regression and seed-based analyses, we observed significantly decreased functional connectivity of the default mode network (DMN) to two regions in the posterior medial cortex (PMC): the posterior cingulate cortex (PCC) and left precuneus (TFCE, FWE corrected p<0.05). Further investigation revealed that patients demonstrated increased functional connectivity between the PCC and several brain regions implicated in pain,...
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