Serotonin type 3 receptor subunit gene polymorphisms associated with psychosomatic symptoms in irritable bowel syndrome: A multicenter retrospective study

BACKGROUND

Single-nucleotide polymorphisms (SNPs) of the serotonin type 3 receptor subunit (HTR3) genes have been associated with psychosomatic symptoms, but it is not clear whether these associations exist in irritable bowel syndrome (IBS).

AIM

To assess the association of HTR3 polymorphisms with depressive, anxiety, and somatization symptoms in individuals with IBS.

METHODS

In this retrospective study, 623 participants with IBS were recruited from five specialty centers in Germany, Sweden, the United States, the United Kingdom, and Ireland. Depressive, anxiety, and somatization symptoms and sociodemographic characteristics were collected. Four functional SNPs — HTR3A c.-42C>T, HTR3B c.386A>C, HTR3C c.489C>A, and HTR3E c.*76G>A — were genotyped and analyzed using the dominant and recessive models. We also performed separate analyses for sex and IBS subtypes. SNP scores were calculated as the number of minor alleles of the SNPs above. The impact of HTR3C c.489C>A was tested by radioligand-binding and calcium influx assays.

RESULTS

Depressive and anxiety symptoms significantly worsened with increasing numbers of minor HTR3C c.489C>A alleles in the dominant model (F_depressive = 7.475, P_depressive = 0.006; F_anxiety = 6.535, P_anxiety = 0.011). A higher SNP score (range 0-6) was linked to a worsened depressive symptoms score (F = 7.710, P-linear trend = 0.006) in IBS. The potential relevance of the HTR3C SNP was corroborated, showing changes in the expression level of 5-HT₃AC variant receptors.

CONCLUSION

We have provided the first evidence that HTR3C c.489C>A is involved in depressive and anxiety symptoms in individuals with IBS. The SNP score indicated that an increasing number of minor alleles is linked to the worsening of depressive symptoms in IBS.

Rectal Distension Increased the Rectoanal Gradient in Patients with Normal Rectal Sensory Function

BACKGROUND

Frequent observation of abnormal manometric patterns consistent with dyssynergia in healthy volunteers has warranted the need for reassessment of the current methods to enhance the diagnostic value of anorectal manometry in functional defecatory disorders. Whether rectal distention at simulated evacuation will affect anorectal pressure profile and increase rectoanal gradient is not known.

METHODS

One hundred and eight consecutive patients with chronic constipation, 93 females, median age 53 years (interquartile range: 40-65), were studied. Simulated evacuation was performed firstly with empty balloon and subsequently after balloon distention to 50 and 100 ml. Anorectal pressures were compared. We also performed subgroup analysis in relation to outcome of balloon expulsion test (BET). In addition, we studied the effect of rectal distension on the rectoanal pressure gradient with respect to rectal sensory function.

RESULTS

Rectal balloon distension at simulated evacuation improved rectoanal gradient and decreased the rate of dyssynergia during high-resolution anorectal manometry. In subgroup analysis, the increase in rectoanal gradient and correction of dyssynergia with rectal distension was limited to the patients who had normal BET and normal rectal sensory function. Rate of anal relaxation, residual anal pressures, and rectoanal gradient were significantly different between patients with and without normal BET at 50 ml of rectal distension. Rectoanal gradient recorded only after rectal distension, along with BMI and maximum tolerable volumes, could predict BET results independently in patients with chronic constipation.

CONCLUSIONS

Rectal distension during simulated evacuation will affect the anorectal pressure profile. Increase in rectoanal gradient and correction of dyssynergia was only significant in patients with normal rectal sensory function and normal BET.

Small Intestinal Bacterial Overgrowth

The term "small intestinal bacterial overgrowth" (SIBO) has been used to refer to a disorder resulting from the colonization of the small bowel by an increased number of microorganisms or by the presence of bacteria that are not usual constituents of this part of the gastrointestinal tract. Clinical presentations, often in patients with certain risk factors, can range from a full-blown malabsorption syndrome to such "functional" complaints as bloating and flatulence. SIBO is diagnosed by either culture of a small bowel aspirate or one of several breath tests. Treatment of SIBO entails risk factor modification, correction of nutritional deficiencies, and oral antibiotics.

"It ain't over … till it's over!" Risk-mitigation strategies for patients with gastrointestinal diseases in the aftermath of the COVID-19 pandemic

The available COVID-19 literature has focused on specific disease manifestations, infection control, and delivery or prioritization of services for specific patient groups in the setting of the acute COVID-19 pandemic. Local health systems aim to contain the COVID-19 pandemic and hospitals and health-care providers rush to provide the capacity for a surge of COVID-19 patients. However, the short, medium-term, and long-term outcomes of patients with gastrointestinal (GI) diseases without COVID-19 will be affected by the ability to develop locally adapted strategies to meet their service needs in the COVID-19 setting. To mitigate risks for patients with GI diseases, it is useful to differentiate three phases: (i) the acute phase, (ii) the adaptation phase, and (iii) the consolidation phase. During the acute phase, service delivery for patients with GI disease will be curtailed to meet competing health-care needs of COVID-19 patients. During the adaptation phase, GI services are calibrated towards a "new normal," and the consolidation phase is characterized by rapid introduction and ongoing refinement of services. Proactive planning with engagement of relevant stakeholders including consumer representatives is required to be prepared for a variety of scenarios that are dictated by thus far undefined long-term economic and societal impacts of the pandemic. Because substantial changes to the delivery of services are likely to occur, it is important that these changes are embedded into quality and research frameworks to ensure that data are generated that support evidence-based decision-making during the adaptation and consolidation phases.

Overlapping irritable bowel syndrome and inflammatory bowel disease

The pathogenesis of irritable bowel-type symptoms occurring in patients with inflammatory bowel disease who are in apparent remission continues to generate scientific controversy and the interpretation and management of these symptoms, so distressing to the sufferer, represent major challenges for the clinician. On the one hand, these symptoms often satisfy Rome IV criteria for IBS and their occurrence correlates highly with anxiety, a known trigger for IBS. On the other hand, recent studies have shown that many of these patients exhibit subtle inflammatory changes. These observations beg the question: are these symptoms "true" IBS superimposed on IBD, or an active but subclinical form of IBD? While it is certain that earlier studies failed to detect subclinical inflammation, it is also evident that even with the use of sensitive biomarkers for inflammation, such as calprotectin and lactoferrin backed up by pan-endoscopy and biopsy to exclude ongoing inflammatory activity in its most subtle form, the prevalence of IBS-type symptoms remains higher than expected in the IBD patient. Pending further definition of its etiology and pathology, we coined the term irritable inflammatory bowel syndrome (IIBS) to refer to this phenomenon. Here we explore the risk factors for this entity, sift through clues to its pathogenesis and attempt to provide, albeit bereft of a robust evidence base, an approach to its management.

Bifidobacterium breve with α-linolenic acid alters the composition, distribution and transcription factor activity associated with metabolism and absorption of fat

This study focused on the mechanisms that fatty acid conjugating strains - Bifidobacterium breve NCIMB 702258 and Bifidobacterium breve DPC 6330 - influence lipid metabolism when ingested with α-linolenic acid (ALA) enriched diet. Four groups of BALB/c mice received ALA enriched diet (3% (w/w)) either alone or in combination with B. breve NCIMB 702258 or B. breve DPC 6330 (10⁹ CFU/day) or unsupplemented control diet for six weeks. The overall n-3 PUFA score was increased in all groups receiving the ALA enriched diet. Hepatic peroxisomal beta oxidation increased following supplementation of the ALA enriched diet with B. breve (P < 0.05) and so the ability of the strains to produce c9t11 conjugated linoleic acid (CLA) was identified in adipose tissue. Furthermore, a strain specific effect of B. breve NCIMB 702258 was found on the endocannabinoid system (ECS). Liver triglycerides (TAG) were reduced following ALA supplementation, compared with unsupplemented controls (P < 0.01) while intervention with B. breve further reduced liver TAG (P < 0.01), compared with the ALA enriched control. These data indicate that the interactions of the gut microbiota with fatty acid metabolism directly affect host health by modulating n-3 PUFA score and the ECS.

Microbiota-gut-brain signalling in Parkinson's disease: Implications for non-motor symptoms

Parkinson's disease is the second most common neurodegenerative disorder, affecting 1-2% of the population over 65 years of age. The primary neuropathology is the loss of midbrain dopaminergic neurons, resulting in characteristic motor deficits, upon which the clinical diagnosis is based. However, a number of significant non-motor symptoms (NMS) are also evident that appear to have a greater impact on the quality of life of these patients. In recent years, it has become increasingly apparent that neurobiological processes can be modified by the bi-directional communication that occurs along the brain-gut axis. The microbiota plays a key role in this communication throughout different routes in both physiological and pathological conditions. Thus, there has been an increasing interest in investigating how microbiota changes within the gastrointestinal tract may be implicated in health and disease including PD. Interestingly α-synuclein-aggregates, the cardinal neuropathological feature in PD, are present in both the submucosal and myenteric plexuses of the enteric nervous system, prior to their appearance in the brain, indicating a possible gut to brain route of "prion-like" spread. In this review we highlight the potential importance of gut to brain signalling in PD with particular focus on the role of the microbiota as major player in this communication.

The Intestinal Microenvironment and Functional Gastrointestinal Disorders

For decades, interactions between the enteric neuromuscular apparatus and the central nervous system have served as the primary focus of pathophysiological research in the functional gastrointestinal disorders. The accumulation of patient reports, as well as clinical observations, has belatedly led to an interest in the role of various luminal factors and their interactions with each other and the host in functional gastrointestinal disorders. Most prominent among these factors has been the role of food. As a consequence, while not always evidence-based, dietary interventions are enjoying a renaissance in irritable bowel syndrome management. Not surprisingly, given its exploration in many disease states, the gut microbiota has also been studied in functional gastrointestinal disorders; data remain inconclusive. Likewise, there is also a considerable body of experimental and some clinical data to link functional gastrointestinal disorders pathogenesis to disturbances in epithelial barrier integrity, abnormal entero-endocrine signaling and immune activation. These data provide growing evidence supporting the existence of micro-organic changes, particularly in subgroups of patients with functional dyspepsia and IBS. However, their exact role in the complex pathophysiology and symptom generation of functional gastrointestinal disorders needs to be further studied and elucidated particularly with longitudinal and interventional studies.

The Gut Microbiota and Nonalcoholic Fatty Liver Disease

With the recognition of the various metabolic functions of the gut microbiome and of its putative role in obesity, an investigation of the contribution of the bacterial populations of the gastrointestinal tract to the metabolic syndrome and its hepatic manifestation-nonalcoholic liver disease (NAFLD)-became inevitable. Furthermore, the central role of an altered microbiome in the precipitation of infectious and noninfectious complications of liver disease was described decades ago. The contribution of the microbiome to the pathogenesis of NAFLD has been extensively studied in animal models. Convincing evidence for a central role for an altered microbiome (through multiple mechanisms), coupled with such phenomena as impaired gut barrier function and an aberrant host immune response, has been amply demonstrated. The accumulation of a similar level of evidence from human studies has proven more challenging; however, incriminating data accumulate. Although animal studies have demonstrated the benefits of interventions that modulate the microbiome and of probiotics, in particular, in reducing steatosis and preventing progression to steatohepatitis, data in man are scanty and high-quality clinical trials of probiotics and other strategies are needed.

Recruited metastasis suppressor NM23-H2 attenuates expression and activity of peroxisome proliferator-activated receptor δ (PPARδ) in human cholangiocarcinoma

BACKGROUND

Peroxisome proliferator-activated receptor δ (PPARδ) is a versatile regulator of distinct biological processes and overexpression of PPARδ in cancer may be partially related to its suppression of its own co-regulators.

AIMS

To determine whether recruited suppressor proteins bind to and regulate PPARδ expression, activity and PPARδ-dependent cholangiocarcinoma proliferation.

METHODS

Yeast two-hybrid assays were done using murine PPARδ as bait. PPARδ mRNA expression was determined by qPCR. Protein expression was measured by western blot. Immunohistochemistry and fluorescence microscopy were used to determine PPARδ expression and co-localization with NDP Kinase alpha (NM23-H2). Cell proliferation assays were performed to determine cell numbers.

RESULTS

Yeast two-hybrid screening identified NM23-H2 as a PPARδ binding protein and their interaction was confirmed. Overexpressed PPARδ or treatment with the agonist GW501516 resulted in increased cell proliferation. NM23-H2 siRNA activated PPARδ luciferase promoter activity, upregulated PPARδ RNA and protein expression and increased GW501516-stimulated CCA growth. Overexpression of NM23-H2 inhibited PPARδ luciferase promoter activity, downregulated PPARδ expression and AKT phosphorylation and reduced GW501516-stimulated CCA growth.

CONCLUSIONS

We report the novel association of NM23-H2 with PPARδ and the negative regulation of PPARδ expression by NM23-H2 binding to the C-terminal region of PPARδ. These findings provide evidence that the metastasis suppressor NM23-H2 is involved in the regulation of PPARδ-mediated proliferation.

Nonsteroidal anti-inflammatory drugs, proton pump inhibitors, and gastrointestinal injury: contrasting interactions in the stomach and small intestine

Nonsteroidal anti-inflammatory drugs (NSAIDs) and proton pump inhibitors (PPIs) are among the most frequently prescribed groups of drugs worldwide. The use of NSAIDs is associated with a high number of significant adverse effects. Recently, the safety of PPIs has also been challenged. Capsule endoscopy studies reveal that even low-dose NSAIDs are responsible for gut mucosal injury and numerous clinical adverse effects, for example, bleeding and anemia, that might be difficult to diagnose. The frequent use of PPIs can exacerbate NSAID-induced small intestinal injury by altering intestinal microbiota. Thus, the use of PPI is considered to be an independent risk factor associated with NSAID-associated enteropathy. In this review, we discuss this important clinical problem and review relevant aspects of epidemiology, pathophysiology, and management. We also present the hypothesis that even minor and subclinical injury to the intestinal mucosa can result in significant, though delayed, metabolic consequences, which may seriously affect the health of an individual. PubMed was searched using the following key words (each key word alone and in combination): gut microbiota, microbiome, non-steroidal anti inflammatory drugs, proton pump inhibitors, enteropathy, probiotic, antibiotic, mucosal injury, enteroscopy, and capsule endoscopy. Google engine search was also carried out to identify additional relevant articles. Both original and review articles published in English were reviewed.

Disturbance of the gut microbiota in early-life selectively affects visceral pain in adulthood without impacting cognitive or anxiety-related behaviors in male rats

Disruption of bacterial colonization during the early postnatal period is increasingly being linked to adverse health outcomes. Indeed, there is a growing appreciation that the gut microbiota plays a role in neurodevelopment. However, there is a paucity of information on the consequences of early-life manipulations of the gut microbiota on behavior. To this end we administered an antibiotic (vancomycin) from postnatal days 4-13 to male rat pups and assessed behavioral and physiological measures across all aspects of the brain-gut axis. In addition, we sought to confirm and expand the effects of early-life antibiotic treatment using a different antibiotic strategy (a cocktail of pimaricin, bacitracin, neomycin; orally) during the same time period in both female and male rat pups. Vancomycin significantly altered the microbiota, which was restored to control levels by 8 weeks of age. Notably, vancomycin-treated animals displayed visceral hypersensitivity in adulthood without any significant effect on anxiety responses as assessed in the elevated plus maze or open field tests. Moreover, cognitive performance in the Morris water maze was not affected by early-life dysbiosis. Immune and stress-related physiological responses were equally unaffected. The early-life antibiotic-induced visceral hypersensitivity was also observed in male rats given the antibiotic cocktail. Both treatments did not alter visceral pain perception in female rats. Changes in visceral pain perception in males were paralleled by distinct decreases in the transient receptor potential cation channel subfamily V member 1, the α-2A adrenergic receptor and cholecystokinin B receptor. In conclusion, a temporary disruption of the gut microbiota in early-life results in very specific and long-lasting changes in visceral sensitivity in male rats, a hallmark of stress-related functional disorders of the brain-gut axis such as irritable bowel disorder.

Structural changes in the gut microbiome of constipated patients

Previous studies using culture-based methods suggested an association between constipation and altered abundance of certain taxa of the colonic microbiome. We aim to examine the global changes in gut microbial composition of constipated patients. A cross-sectional pilot study using 16S rRNA gene pyrosequencing was performed to compare stool microbial composition of eight constipated patients and 14 nonconstipated controls. Only obese children were enrolled so that the microbiome features associated with constipation would not be obscured by those associated with obesity. The sequencing reads were processed by QIIME for quantitative analysis of the microbial composition at genus and above levels. Dietary intake for all the individuals was assessed by dietary recalls and a food frequency questionnaire. The ecological diversities of fecal microbiome of the constipated patients differed from those of the controls. Significantly decreased abundance in Prevotella and increased representation in several genera of Firmicutes were observed in constipated patients compared with controls. The conventional probiotic genera Lactobacillus and Bifidobacteria were not decreased in the microbiomes of the constipated patients. These alterations in the fecal microbiome of constipated patients suggested that a novel probiotic treatment including certain Prevotella strains may be more effective than conventional probiotic products incorporating Lactobacillus or Bifidobacterium species. While it is possible that the observed changes in the microbiome in constipated subjects are a consequence of a low-fiber diet, these changes also predict a different pattern of bacterial fermentation end-products, such as increased butyrate production, which may contribute to pathogenesis of constipation.

Cytokine imbalance in irritable bowel syndrome: a systematic review and meta-analysis

BACKGROUND

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder of unknown etiology; although infection and inflammation have recently been considered as important etiologic agents. A recent meta-analysis showed correlations between cytokine [interleukin-10 (IL-10) and tumor necrosis factor (TNF)] gene polymorphisms and IBS; however, it is still unknown whether patients with IBS have different cytokine profiles compared to healthy population.

METHODS

To determine the relationships between serum/plasma levels or mucosal expression of IL-10/TNF-α and IBS, we conducted a systematic review and meta-analysis based on case-control studies retrieved from PubMed and EMBASE search through August 2013. Standardized mean difference (SMD) was generated by using the inverse variance method. Heterogeneity was assessed based on I(2) values.

KEY RESULTS

Serum/plasma levels of TNF-α tended to be higher in IBS vs controls (p = 0.09); this reached significance in IBS subtypes vs controls and in female patients with IBS. However, serum/plasma levels of IL-10 were not significantly different in IBS patients vs controls. Further analysis of serum/plasma IL-10 levels in IBS subtypes did not show any difference; however, analysis based on gender showed a significantly lower serum/plasma IL-10 levels in male patients with IBS vs male controls (p = 0.02). Colonic IL-10 mRNA had a significantly lower expression in IBS vs control (p = 0.001).

CONCLUSIONS & INFERENCES

There is an imbalance of proinflammatory TNF-α, and anti-inflammatory IL-10, cytokines in IBS. Stratifying IBS patients based on cytokine profile may represent an opportunity for personalized treatment of this condition.

The gut microbiota and the liver: implications for clinical practice

While a central role for the microbiota in the precipitation of infectious and non-infectious complications of liver disease has been long established, evidence for a more fundamental role in the etiology of several liver diseases continues to accumulate. However, though progress is rapidly occurring in this area, the definitive delineation of the precise relevance of changes in the microbiota to various forms and stages of liver disease is still far from complete. While high quality clinical evidence supports the use of antibiotic therapy, in the management of hepatic encephalopathy, spontaneous bacterial peritonitis and other infectious complications, how these interventions impact on the microbiota and microbiota-host interactions has not been clearly defined. Although probiotics and even, perhaps, fecal transplantation hold promise in the management of liver disease, and the potential impact of probiotics is supported by a considerable amount of laboratory data, high-quality clinical evidence is scanty.

Bifidobacterium breve with α-linolenic acid and linoleic acid alters fatty acid metabolism in the maternal separation model of irritable bowel syndrome

The aim of this study was to compare the impact of dietary supplementation with a Bifidobacterium breve strain together with linoleic acid & α-linolenic acid, for 7 weeks, on colonic sensitivity and fatty acid metabolism in rats. Maternally separated and non-maternally separated Sprague Dawley rats (n = 15) were orally gavaged with either B. breve DPC6330 (10(9) microorganisms/day) alone or in combination with 0.5% (w/w) linoleic acid & 0.5% (w/w) α-linolenic acid, daily for 7 weeks and compared with trehalose and bovine serum albumin. Tissue fatty acid composition was assessed by gas-liquid chromatography and visceral hypersensitivity was assessed by colorectal distension. Significant differences in the fatty acid profiles of the non-separated controls and maternally separated controls were observed for α-linolenic acid and arachidonic acid in the liver, oleic acid and eicosenoic acid (c11) in adipose tissue, and for palmitoleic acid and docosahexaenoic acid in serum (p<0.05). Administration of B. breve DPC6330 to MS rats significantly increased palmitoleic acid, arachidonic acid and docosahexaenoic acid in the liver, eicosenoic acid (c11) in adipose tissue and palmitoleic acid in the prefrontal cortex (p<0.05), whereas feeding B. breve DPC6330 to non separated rats significantly increased eicosapentaenoic acid and docosapentaenoic acid in serum (p<0.05) compared with the NS un-supplemented controls. Administration of B. breve DPC6330 in combination with linoleic acid and α-linolenic acid to maternally separated rats significantly increased docosapentaenoic acid in the serum (p<0.01) and α-linolenic acid in adipose tissue (p<0.001), whereas feeding B. breve DPC6330 with fatty acid supplementation to non-separated rats significantly increased liver and serum docosapentaenoic acid (p<0.05), and α-linolenic acid in adipose tissue (p<0.001). B. breve DPC6330 influenced host fatty acid metabolism. Administration of B. breve DPC6330 to maternally separated rats significantly modified the palmitoleic acid, arachidonic acid and docosahexaenoic acid contents in tissues. The effect was not observed in non-separated animals.

A Distinct Profile of Tryptophan Metabolism along the Kynurenine Pathway Downstream of Toll-Like Receptor Activation in Irritable Bowel Syndrome

Irritable bowel syndrome (IBS), a disorder of the brain-gut axis, is characterised by the absence of reliable biological markers. Tryptophan is an essential amino acid that serves as a precursor to serotonin but which can alternatively be metabolised along the kynurenine pathway leading to the production of other neuroactive agents. We previously reported an increased degradation of tryptophan along this immunoresponsive pathway in IBS. Recently, altered cytokine production following activation of specific members of the toll-like receptor (TLR) family (TLR1-9) has also been demonstrated in IBS. However, the relationship between TLR activation and kynurenine pathway activity in IBS is unknown. In this study, we investigated whether activation of specific TLRs elicits exaggerated kynurenine production in IBS patients compared to controls. Whole blood from IBS patients and healthy controls was cultured with a panel of nine different TLR agonists for 24 h. Cell culture supernatants were then analyzed for both tryptophan and kynurenine concentrations, as were plasma samples from both cohorts. IBS subjects had an elevated plasma kynurenine:tryptophan ratio compared to healthy controls. Furthermore, we demonstrated a differential downstream profile of kynurenine production subsequent to TLR activation in IBS patients compared to healthy controls. This profile included alterations at TLR1/2, TLR2, TLR3, TLR5, TLR7, and TLR8. Our data expands on our previous understanding of altered tryptophan metabolism in IBS and suggests that measurement of tryptophan metabolites downstream of TLR activation may ultimately find utility as components of a biomarker panel to aid gastroenterologists in the diagnosis of IBS. Furthermore, these studies implicate the modulation of TLRs as means through which aberrant tryptophan metabolism along the kynurenine pathway can be controlled, a novel potential therapeutic strategy in this and other disorders.

Contrasting effects of Bifidobacterium breve NCIMB 702258 and Bifidobacterium breve DPC 6330 on the composition of murine brain fatty acids and gut microbiota

BACKGROUND

We previously showed that microbial metabolism in the gut influences the composition of bioactive fatty acids in host adipose tissue.

OBJECTIVE

This study compared the effect of dietary supplementation for 8 wk with human-derived Bifidobacterium breve strains on fat distribution and composition and the composition of the gut microbiota in mice.

METHODS

C57BL/6 mice (n = 8 per group) received B. breve DPC 6330 or B. breve NCIMB 702258 (10(9) microorganisms) daily for 8 wk or no supplement (controls). Tissue fatty acid composition was assessed by gas-liquid chromatography while 16S rRNA pyrosequencing was used to investigate microbiota composition.

RESULTS

Visceral fat mass and brain stearic acid, arachidonic acid, and DHA were higher in mice supplemented with B. breve NCIMB 702258 than in mice in the other 2 groups (P < 0.05). In addition, both B. breve DPC 6330 and B. breve NCIMB 702258 supplementation resulted in higher propionate concentrations in the cecum than did no supplementation (P < 0.05). Compositional sequencing of the gut microbiota showed a tendency for greater proportions of Clostridiaceae (25%, 12%, and 18%; P = 0.08) and lower proportions of Eubacteriaceae (3%, 12%, and 13%; P = 0.06) in mice supplemented with B. breve DPC 6330 than in mice supplemented with B. breve NCIMB 702258 and unsupplemented controls, respectively.

CONCLUSION

The response of fatty acid metabolism to administration of bifidobacteria is strain-dependent, and strain-strain differences are important factors that influence modulation of the gut microbial community by ingested microorganisms.

Selection of symptomatic patients with Crohn's disease for abdominopelvic computed tomography: role of serum C-reactive protein

BACKGROUND

Results of previous studies have shown that repeated abdominopelvic computed tomography (CT) examinations can lead to substantial cumulative diagnostic radiation exposure in patients with Crohn's disease (CD). Improved selection of patients referred for CT will reduce unnecessary radiation exposure. This study examines if serum C-reactive protein (CRP) concentration predicts which symptomatic patients with CD are likely to have significant disease activity or disease complications (such as abscess) detected on abdominopelvic CT.

METHODS

All abdominopelvic CTs performed on patients with CD at a tertiary referral centre during the period June 2003 to June 2008 were identified. CT findings were coded by a pair of independent blinded senior radiologists for (i) small bowel luminal disease, (ii) large bowel luminal disease, (iii) mesenteric inflammatory changes, (iv) penetrating disease (fistulas, abscess, or phlegmon), (v) acute disease complications (obstruction or perforation), and (vi) acute non-CD findings. Imaging findings were correlated with serum CRP checked within 14 days before imaging. The reference range for CRP was defined as 0-5 mg/L.

RESULTS

A total of 147 patients with symptomatic CD had a CRP assay performed within 14 days before undergoing abdominopelvic CT. The median time from CRP assay to imaging was 2 days (interquartile range, 0-6 days). Median CRP before imaging was 24 mg/L (interquartile range, 6-88 mg/L). CT was normal in 34 of 147 case (23.1%). Patients with normal CRP (n = 36) were significantly less likely to have penetrating disease (odds ratio [OR], 0.04 [95% confidence interval {CI}, 0.01-0.7]; P < .001) or large bowel luminal disease (OR, 0.3 [95% CI, 0.1-0.8]; P < .05). Normal CRP excluded penetrating disease with a sensitivity of 1.0 (95% CI, 0.87-1.0). CRP levels did not correlate with the presence of small bowel luminal disease (n = 82), mesenteric inflammatory changes (n = 68), or acute disease complications (n = 10).

CONCLUSION

Symptomatic patients with CD and normal serum CRP are unlikely to have evidence of abscess, fistulating disease, or large bowel luminal disease detected on abdominopelvic CT. However, abdominopelvic CT may demonstrate evidence of clinically significant non-penetrating CD or complications, including perforation and acute obstruction, regardless of serum CRP concentration.

Radiation exposure from diagnostic imaging among patients with gastrointestinal disorders

BACKGROUND & AIMS

There are concerns about levels of radiation exposure among patients who undergo diagnostic imaging for inflammatory bowel disease (IBD), compared with other gastrointestinal (GI) disorders. We quantified imaging studies and estimated the cumulative effective dose (CED) of radiation received by patients with organic and functional GI disorders. We also identified factors and diagnoses associated with high CEDs.

METHODS

We analyzed data from 2590 patients who were diagnosed with GI disorders at a tertiary gastroenterology center from January 1999-January 2009 on the basis of International Statistical Classification of Diseases and Health-related Problems, 10th revision and Rome III criteria. High annual CED and high total CED were defined as figures exceeding the 90th percentile for the population.

RESULTS

Diagnostic imaging was performed on 57% of the patients (1429 of 2509). High annual CEDs (>9.6 millisieverts/annum) were independently associated with Crohn's disease (odds ratio [OR], 5.3; P < .0001), organic small bowel disease (OR, 2.6; P < .005), and functional disorders of childhood and adolescence (OR, 9.8; P < .005). High total CEDs (>30.8 millisieverts) were independently associated with Crohn's disease (OR, 81.9; P < .0001), ulcerative colitis (OR, 19.0; P < .0001), indeterminate colitis (OR, 7.5; P < .0005), and the following non-IBD diagnoses: organic small bowel disorders (OR, 12.5; P < .0001), organic hepatic disorders (OR, 3.6; P < .01), and functional disorders of childhood and adolescence (OR, 13.8; P = .02).

CONCLUSIONS

Higher levels of annual and total diagnostic radiation exposure are associated with IBD and with other organic and functional GI disorders. Evidence-based guidelines for image analysis of patients with organic and functional gastrointestinal disorders, especially those that reduce radiation exposure, are needed.

Review article: probiotics for the treatment of irritable bowel syndrome--focus on lactic acid bacteria

BACKGROUND

Irritable bowel syndrome (IBS) is a poorly understood, yet highly prevalent functional gastrointestinal disorder (FGID). The withdrawal, due to adverse events, of a number of pharmacological agents that were approved for the treatment of IBS has left a therapeutic vacuum for patients suffering from the disorder.

AIM

To review, summarise and critically evaluate current knowledge of lactic acid bacteria (LAB) used to treat IBS.

METHODS

We assessed a comprehensive range of relevant literature from Pubmed, Medline and online sources based on our definition of LAB which included both typical and atypical species, covering Lactobacilli, Bifidobacteria, Enterococci, Streptococci and Bacilli.

RESULTS

Of the 42 trials evaluated examining the efficacy of LAB in IBS, 34 reported beneficial effects in at least one of the endpoints or symptoms examined, albeit with tremendous variation in both the magnitude of effect and the choice of outcome under consideration. However, numerous concerns have been expressed over deficits of trial design and execution relating to strain selection, optimum dosage, mode of action, safety and long-term tolerability in a disorder that can persist throughout the lifetime of affected individuals.

CONCLUSIONS

Progress in the field will require an improved understanding of how the microbiota impacts on health and disease, adequately powered long-term multicentre trials and the embracing of bench to bedside approaches. Recent incremental advances suggest these areas are being addressed and that the future holds much promise for the use of lactic acid bacteria in the treatment of irritable bowel syndrome.

In search of lost opportunities: Marcel Proyce and James Joust discuss doctors, diseases, life and death (a hypothetical conversation between Marcel Proust and James Joyce)

Two of the most influential thinkers of the last century, Marcel Proust (1871-1922) and James Joyce (1882-1941), met in 1922 but had little to say to each other. Had circumstances been different, what might they have said? They had much in common, including an interest in doctors and diseases, but from different perspectives. Although the meeting was a lost opportunity to explore the insights of two great analysts of the human condition, their lives and works provide a record rich in detail and timeless in relevance. From this, we construct what might have been overheard during a conversation between Marcel Proyce and James Joust almost a century ago.

Altered peripheral toll-like receptor responses in the irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a stress-related disorder with disturbed brain-gut communication, gastrointestinal homeostasis and, based on recent evidence, low grade inflammation and an altered microbiota. The immune system is a critical regulator of the brain-gut axis. Toll-like receptors (TLRs) are pattern recognition molecules regulating innate immunity.

AIM

To characterise toll-like receptor activity in IBS.

METHODS

Thirty IBS patients and 30 healthy controls (HC) were recruited. Venous blood was collected, and cultured with a panel of toll-like receptor agonists for 24 h. Cell supernatants were analysed using a multiplex ELISA approach to measure IL1β, IL6, IL8 and TNFα. Plasma was analysed for levels of inflammatory cytokines and cortisol.

RESULTS

Toll-like receptor agonist-induced cytokine (IL1β, IL6, IL8 and TNFα) release was markedly enhanced in stimulated whole blood from IBS (n = 30) patients compared with healthy controls (n = 30). An exaggerated response to the TLR8 agonist for all cytokines investigated was seen in IBS patients. In addition, enhanced TLR2-induced TNFα release, TLR3-induced IL-8 release, TLR4-induced IL1β and TNFα release, TLR5-induced IL1β and TNFα release and TLR7-induced IL-8 release were also observed in IBS patients. No differences in TLR1, TLR6 or TLR9 activity were detected. In addition, plasma levels of cortisol, IL-6 and IL-8 were significantly increased in IBS patients.

CONCLUSION

Taken together, these data demonstrate elevated cytokine levels and toll-like receptor activity in the periphery of patients with the irritable bowel syndrome, indicating some immune dysregulation in these patients.

Recombinant lactobacilli expressing linoleic acid isomerase can modulate the fatty acid composition of host adipose tissue in mice

We have previously demonstrated that oral administration of a metabolically active Bifidobacterium breve strain, with ability to form cis-9, trans-11 conjugated linoleic acid (CLA), resulted in modulation of the fatty acid composition of the host, including significantly elevated concentrations of c9, t11 CLA and omega-3 (n-3) fatty acids in liver and adipose tissue. In this study, we investigated whether a recombinant lactobacillus expressing linoleic acid isomerase (responsible for production of t10, c12 CLA) from Propionibacterium acnes (PAI) could influence the fatty acid composition of different tissues in a mouse model. Linoleic-acid-supplemented diets (2 %, w/w) were fed in combination with either a recombinant t10, c12 CLA-producing Lactobacillus paracasei NFBC 338 (Lb338), or an isogenic (vector-containing) control strain, to BALB/c mice for 8 weeks. A third group of mice received linoleic acid alone (2 %, w/w). Tissue fatty acid composition was assessed by GLC at the end of the trial. Ingestion of the strain expressing linoleic acid isomerase was associated with a 4-fold increase (P<0.001) in t10, c12 CLA in adipose tissues of the mice when compared with mice that received the isogenic non-CLA-producing strain. The livers of the mice that received the recombinant CLA-producing Lb338 also contained a 2.5-fold (albeit not significantly) higher concentration of t10, c12 CLA, compared to the control group. These data demonstrate that a single gene (encoding linoleic acid isomerase) expressed in an intestinal microbe can influence the fatty acid composition of host fat.

Composition and energy harvesting capacity of the gut microbiota: relationship to diet, obesity and time in mouse models

BACKGROUND AND AIMS

Increased efficiency of energy harvest, due to alterations in the gut microbiota (increased Firmicutes and decreased Bacteroidetes), has been implicated in obesity in mice and humans. However, a causal relationship is unproven and contributory variables include diet, genetics and age. Therefore, we explored the effect of a high-fat (HF) diet and genetically determined obesity (ob/ob) for changes in microbiota and energy harvesting capacity over time.

METHODS

Seven-week-old male ob/ob mice were fed a low-fat diet and wild-type mice were fed either a low-fat diet or a HF-diet for 8 weeks (n=8/group). They were assessed at 7, 11 and 15 weeks of age for: fat and lean body mass (by NMR); faecal and caecal short-chain fatty acids (SCFA, by gas chromatography); faecal energy content (by bomb calorimetry) and microbial composition (by metagenomic pyrosequencing).

RESULTS

A progressive increase in Firmicutes was confirmed in both HF-fed and ob/ob mice reaching statistical significance in the former, but this phylum was unchanged over time in the lean controls. Reductions in Bacteroidetes were also found in ob/ob mice. However, changes in the microbiota were dissociated from markers of energy harvest. Thus, although the faecal energy in the ob/ob mice was significantly decreased at 7 weeks, and caecal SCFA increased, these did not persist and faecal acetate diminished over time in both ob/ob and HF-fed mice, but not in lean controls. Furthermore, the proportion of the major phyla did not correlate with energy harvest markers.

CONCLUSION

The relationship between the microbial composition and energy harvesting capacity is more complex than previously considered. While compositional changes in the faecal microbiota were confirmed, this was primarily a feature of high-fat feeding rather than genetically induced obesity. In addition, changes in the proportions of the major phyla were unrelated to markers of energy harvest which changed over time. The possibility of microbial adaptation to diet and time should be considered in future studies.

Irritable bowel syndrome-type symptoms in patients with inflammatory bowel disease: a real association or reflection of occult inflammation?

OBJECTIVES

Do gastrointestinal symptoms in patients with inflammatory bowel disease (IBD) in apparent remission reflect the coexistence of irritable bowel syndrome (IBS) or subclinical inflammation? The aims of this study were as follows: (i) to prospectively determine the prevalence of IBS symptoms in IBD patients in remission; and (ii) to determine whether IBS symptoms correlate with levels of fecal calprotectin.

METHODS

Remission was defined by physician assessment: Crohn's disease (CD) activity index <or=150 and ulcerative colitis disease activity index <or=3, and serum C-reactive protein <10, while off corticosteroids or biologics. Quality of life (QOL) (by inflammatory bowel disease questionnaire), the hospital anxiety and depression scale (HAD), and fecal calprotectin were measured.

RESULTS

Rome II criteria for IBS were fulfilled in 37/62 (59.7%) of CD patients and by 17/44 (38.6%) of those with ulcerative colitis (UC). However, fecal calprotectin was significantly elevated above the upper limit of normal in both IBD patient groups, indicating the presence of occult inflammation. Furthermore, calprotectin levels were significantly higher in CD and UC patients with criteria for IBS than in those without IBS-type symptoms. QOL scores were lower and HAD scores higher among UC patients with IBS symptoms in comparison to those who did not have IBS symptoms.

CONCLUSIONS

IBS-like symptoms are common in patients with IBD who are thought to be in clinical remission, but abnormal calprotectin levels suggest that the mechanism in most cases is likely to be occult inflammation rather than coexistent IBS.

Pharmacological management of constipation

The approach of this review is to give a pragmatic approach to using laxatives, based on a combination of what is known about mechanism of action and the available literature on evidence.

Diagnosis and management of non-erosive reflux disease--the Vevey NERD Consensus Group

BACKGROUND/AIMS

Although considerable information exists regarding gastroesophageal reflux disease with erosions, much less is known of non-erosive reflux disease (NERD), the dominant form of reflux disease in the developed world.

METHODS

An expert international group using the modified Delphi technique examined the quality of evidence and established levels of agreement relating to different aspects of NERD. Discussion focused on clinical presentation, assessment of clinical outcome, pathobiological mechanisms, and clinical strategies for diagnosis and management.

RESULTS

Consensus was reached on 85 specific statements. NERD was defined as a condition with reflux symptoms in the absence of mucosal lesions or breaks detected by conventional endoscopy, and without prior effective acid-suppressive therapy. Evidence supporting this diagnosis included: responsiveness to acid suppression therapy, abnormal reflux monitoring or the identification of specific novel endoscopic and histological findings. Functional heartburn was considered a separate entity not related to acid reflux. Proton pump inhibitors are the definitive therapy for NERD, with efficacy best evaluated by validated quality-of-life instruments. Adjunctive antacids or H(2) receptor antagonists are ineffective, surgery seldom indicated.

CONCLUSIONS

Little is known of the pathobiology of NERD. Further elucidation of the mechanisms of mucosal and visceral hypersensitivity is required to improve NERD management.

Metabolic activity of the enteric microbiota influences the fatty acid composition of murine and porcine liver and adipose tissues

BACKGROUND

Recent reports suggest that the metabolic activity of the gut microbiota may contribute to the pathogenesis of obesity and hepatic steatosis.

OBJECTIVE

The objective was to determine whether the fat composition of host tissues might be influenced by oral administration of commensal bifidobacteria previously shown by us to produce bioactive isomers of conjugated linoleic acid (CLA).

DESIGN

Murine trials were conducted in which linoleic acid-supplemented diets were fed with or without Bifidobacterium breve NCIMB 702258 (daily dose of 10(9) microorganisms) to healthy BALB/c mice and to severe combined immunodeficient mice for 8-10 wk. To ensure that the observations were not peculiar to mice, a similar trial was conducted in weanling pigs over 21 d. Tissue fatty acid composition was assessed by gas-liquid chromatography.

RESULTS

In comparison with controls, there was an increase in cis-9, trans-11 CLA in the livers of the mice and pigs after feeding with linoleic acid in combination with B. breve NCIMB 702258 (P < 0.05). In addition, an altered profile of polyunsaturated fatty acid composition was observed, including higher concentrations of the omega-3 (n-3) fatty acids eicosapentaenoic acid and docosahexaenoic acid in adipose tissue (P < 0.05). These changes were associated with reductions in the proinflammatory cytokines tumor necrosis factor-alpha and interferon-gamma (P < 0.05).

CONCLUSIONS

These results are consistent with the concept that the metabolome is a composite of host and microbe metabolic activity and that the influence of the microbiota on host fatty acid composition can be manipulated by oral administration of CLA-producing microorganisms.

Isolation of lactobacilli with probiotic properties from the human stomach

AIMS

Recent evidence suggests that the human gastric microbiota is much more diverse than previously thought. The aim of this study was to assess the potential for isolating lactobacilli from the human stomach.

METHODS AND RESULTS

Lactobacilli were selectively cultured from gastric biopsies from 12 patients undergoing routine endoscopy. Lactobacilli were present in four of 12 biopsies. We isolated, in total 10 different strains representing five species (Lactobacillus gasseri, L. fermentum, L. vaginalis, L. reuteri and L. salivarius). The 10 isolates varied greatly in their ability to inhibit the growth of two Gram-positive bacteria and two Gram-negative bacteria. Furthermore, the acid and bile resistance profiles of the 10 isolates spanned a wide range.

CONCLUSIONS

Five different Lactobacillus species were cultured from human gastric biopsies for the first time.

SIGNIFICANCE AND IMPACT OF THE STUDY

Diverse Lactobacillus species are more prevalent in the human stomach than previously recognized, representing an untapped source of bacteria with beneficial probiotic and/or biotechnological properties.

Tryptophan degradation in irritable bowel syndrome: evidence of indoleamine 2,3-dioxygenase activation in a male cohort

Background

Irritable bowel syndrome (IBS) is a common disorder that affects 10–15% of the population. Although characterised by a lack of reliable biological markers, the disease state is increasingly viewed as a disorder of the brain-gut axis. In particular, accumulating evidence points to the involvement of both the central and peripheral serotonergic systems in disease symptomatology. Furthermore, altered tryptophan metabolism and indoleamine 2,3-dioxygenase (IDO) activity are hallmarks of many stress-related disorders. The kynurenine pathway of tryptophan degradation may serve to link these findings to the low level immune activation recently described in IBS. In this study, we investigated tryptophan degradation in a male IBS cohort (n = 10) and control subjects (n = 26).

Methods

Plasma samples were obtained from patients and healthy controls. Tryptophan and its metabolites were measured by high performance liquid chromatography (HPLC) and neopterin, a sensitive marker of immune activation, was measured using a commercially available ELISA assay.

Results

Both kynurenine levels and the kynurenine:tryptophan ratio were significantly increased in the IBS cohort compared with healthy controls. Neopterin was also increased in the IBS subjects and the concentration of the neuroprotective metabolite kynurenic acid was decreased, as was the kynurenic acid:kynurenine ratio.

Conclusion

These findings suggest that the activity of IDO, the immunoresponsive enzyme which is responsible for the degradation of tryptophan along this pathway, is enhanced in IBS patients relative to controls. This study provides novel evidence for an immune-mediated degradation of tryptophan in a male IBS population and identifies the kynurenine pathway as a potential source of biomarkers in this debilitating condition.

Medicine in the age of " Ulysses ": James Joyce's portrait of life, medicine, and disease on a Dublin day a century ago

Over time, contemporary writing becomes part of the historical record. In medicine, it is an important learning tool, particularly for understanding the experience and context of disease and illness. Although a century has elapsed since the fictional events on a single day described in James Joyce's Ulysses, the work is still fresh with references and allusions to doctors, illnesses, and the human experience. Ulysses provides perspective on medical and social history and offers a biting commentary of continuing relevance to the doctor-patient relationship.

Gastric motor dysfunction: is eosinophilic mural gastritis a causative factor?

Delayed gastric emptying caused either by gastric motor dysfunction or by gastroparesis is a profoundly debilitating disorder. When unresponsive to medical therapy, patients may undergo radical surgery including near-total gastro-oesophageal, with varied symptomatic improvement. We describe two patients who presented with symptoms consistent with gastro-oesophageal reflux, unresponsive to medical management. After fundoplication both developed symptoms of profound gastric motor dysfunction and subsequently proceeded to near-total gastro-oesophageal with symptomatic improvement. Histological examination of both excised gastric specimens revealed eosinophilic mural gastritis. To our knowledge, these are the first cases to demonstrate the association of mural eosinophilia and symptomatic gastric motor dysfunction. We propose that patients with gastric motor dysfunction, refractory to medical management, progress to laparoscopy and mural biopsy before gastrectomy. This would allow histological analysis of the gastric wall, and in the event of a positive finding of mural eosinophilic gastritis would allow a trial of medical therapy that could include an eosinophilic stabilizer such as the leukotriene D4 receptor antagonist montelukast or intravenous corticosteroid therapy, which may alleviate the symptoms.

Information assimilation and distribution challenges and goals for real and virtual journals

The distribution of biomedical information was transfigured over three centuries ago with the introduction of scientific journals. This enabled the widespread dissemination of data to global audiences and greatly facilitated not only the advance of science but amplified the interaction between investigators despite their different locations. This process continued to expand in a linear fashion prior to the emergence of the Internet. The latter system has prompted a phenomenal augmentation of information accessibility, and its ever-expanding use has resulted in an exponential increase in the demand for digital technology and online resources. This technology has achieved unprecedented acceptance in the scientific domain and enabled publishers to expeditiously produce and distribute journal contents online. Such unparalleled access to information has sparked incendiary debate within the scientific community and among journal publishers in regard to numerous issues. It is thus much debated as to who has the right to "own" or control intellectual property, whether information should be made freely available to the online global community, how to gauge the legitimacy and authenticity of published research, and the need to reexamine the feasibility and profitability of paper journals in consideration of the digital, online formats that continue to gain popularity. To assess the current status of the situation, a meeting of journal editors, research scientists, and publishing executives was held in Constance, Germany, on June 26, 2004, to discuss these issues and formulate strategies and recommendations for the future of biomedical publishing. Herewith we provide a summation (manifesto) of the meeting's proceedings and provide a consensus opinion with the aim of illuminating the subject and also proposing some putative solutions for the major challenges that currently confront the scientific and publishing community.

Small intestinal transplantation

The past few years have witnessed a considerable shift in the clinical status of intestinal transplantation. A great deal of experience has been gained at the most active centers, and results comparable with those reported at a similar stage in the development of other solid-organ graft programs are now being achieved by these highly proficient transplant teams. Rejection and its inevitable associate, sepsis, remain ubiquitous, and new immunosuppressant regimes are urgently needed; some may already be on the near horizon. The recent success of isolated intestinal grafts, together with the mortality and morbidity attendant upon the development of advanced liver disease related to total parenteral nutrition, has prompted the bold proposal that patients at risk for this complication should be identified and should receive isolated small bowel grafts before the onset of end-stage hepatic failure. The very fact that such a suggestion has begun to emerge reflects real progress in this challenging field.

Colorectal cancer screening compliance by medicine residents: perceived and actual

OBJECTIVE

Implementation of colorectal cancer (CRC) screening with widely available techniques can result in a significant reduction in CRC-related mortality. Clinical practice paradigms are often ingrained in physicians during residency. We, therefore, investigated both compliance and perceived obstacles to CRC screening in the practices of physicians-in-training.

METHODS

We conducted a retrospective analysis of medical records of patients who were receiving their primary care in the internal medicine resident clinics at the University of Nebraska Medical Center and were at average risk for CRC. In addition to demographics, data on the use of screening mammography, Pap smear, cholesterol, fecal occult blood testing (FOBT), and flexible sigmoidoscopy (FS) were collected. A questionnaire was also distributed to all internal medicine residents to assess their CRC screening knowledge and perceived screening compliance.

RESULTS

One hundred eight patient charts were reviewed. The percentage of patients appropriately screened for each test was as follows: mammography 66%, Pap smear 65%, cholesterol 53%, FOBT 13%, and FS 16%. Residents dramatically overestimated their perceived FS and FOBT screening rates, 78% and 88%, respectively. Most residents identified barriers to FS screening. Although rudimentary CRC screening knowledge appeared adequate, a number of knowledge-based deficiencies were identified.

CONCLUSIONS

Internal medicine residents at our institution demonstrate poor CRC screening compliance especially when compared with other health care maintenance interventions. This cannot be entirely accounted for by inadequate knowledge; discrepancy between the perceived and actual implementation of CRC screening may be important. Efforts to improve screening compliance should include a focus on physicians-in-training.

Gastric myoelectrical activity and its relationship to the development of nausea and vomiting after intensive chemotherapy and autologous stem cell transplantation

OBJECTIVES

Gastric motor dysfunction may be responsible, in some patients, for the nausea and emesis that occur after high-dose chemotherapy (HDT) and autologous stem cell transplantation (SCT). Because gastric myoelectrical abnormalities may result in nausea and vomiting in other contexts, we sought to define the prevalence of these abnormalities and their relationship to the development of nausea and vomiting in patients undergoing autologous HDT and SCT, and to determine whether electrogastrography (EGG) could serve to detect gastric motor dysfunction in this population.

METHODS

We prospectively studied patients with a variety of malignancies who received standard transplantation doses of chemotherapeutic agents and antiemetics. Gastric emptying scintigraphy was performed before HDT. Gastric myoelectrical activity was assessed before HDT and on days 0, 7, 14, 21, and 28 from SCT using cutaneous EGG electrodes and a portable EGG recorder, and was analyzed by means of a dedicated software program after removal of motion artifact. Symptom assessment was obtained daily from initiation of HDT to 28 days after SCT.

RESULTS

A total of 25 patients were studied: 13 women and 12 men, with a median age of 50 yr (range = 32-65 yr). Before HDT, gastric emptying scintigraphy was normal in all patients (median T(1/2) of 50 min [range = 22-75 min]) and only one patient had mild nausea and anorexia. Nausea, emesis, and anorexia occurred in all patients, peaked in severity at day +7 from SCT and, with the exception of anorexia, had returned toward baseline levels by day +28. Fasting dysrhythmias were present in 63% of the studies at baseline. Serial EGG recordings revealed significant slowing of the dominant frequency with a consequent decrease in tachygastria and increase in normogastria and bradygastria as the symptoms peaked in severity with a subsequent return to baseline values at the study's end. The only clinical variable that was predictive of symptom severity was gender. Women had a higher risk of developing anorexia (score > or = 2) at day +14 compared to men (odds ratio = 11.2; 95% CI = 1.7-76.9; p = 0.01).

CONCLUSIONS

Baseline abnormalities in gastric myoelectrical activity occur frequently in patients who undergo HDT and autologous SCT despite normal gastric emptying scintigraphy and an absence of symptoms. Although slowing of the dominant frequency was seen as symptoms worsened, we failed to identify any EGG parameter at baseline that could predict the severity of nausea, vomiting or anorexia after transplantation.

Non-erosive reflux disease: part of the spectrum of gastro-oesophageal reflux disease, a component of functional dyspepsia, or both?

Over the last several decades, the incidences of gastric cancer and peptic ulcer have declined while the incidences of gastro-oesophageal reflux disease (GORD) and functional dyspepsia have reached virtually epidemic proportions. A similar trend is occurring in oesophageal cancer, with squamous cell carcinoma on the decline and adenocarcinoma on the rise, possibly due to the dramatic increase in GORD. The true clinical spectrum of these disorders, however, is only recently becoming evident: 60% of patients with GORD do not have detectable evidence of oesophagitis; they can be classified as having non-erosive or negative-endoscopy reflux disease (NERD). In this subgroup, a significant proportion will also manifest normal acid exposure on 24-h pH monitoring. Further, patients with NERD appear to be somewhat less responsive to gastric acid suppression with proton pump inhibitors. These differences, combined with the concept of the 'tender' oesophagus and the frequent presence of dyspeptic symptoms in patients with NERD, have important therapeutic implications. Therefore, considering the marked overlap in these disorders, is it realistic or clinically relevant to distinguish the entities of GORD, NERD, and functional dyspepsia? This dilemma has led to general guidelines: should heartburn predominate, treat as GORD; if dyspepsia predominates, treat as functional dyspepsia. In practical terms, each diagnosis requires consideration of the other.

Can symptoms predict esophageal motor function or acid exposure in gastroesophageal reflux disease? A comparison of esophageal manometric and twenty-four-hour pH parameters in typical and extraesophageal gastroesophageal reflux disease

It has been suggested that patterns of esophageal motor function and acid exposure may differ between those patients with gastroesophageal reflux disease (GERD) with classic symptoms and those with extraesophageal manifestations. Our objective was to compare various parameters of esophageal motility and acid exposure between groups of patients who had presented with extraesophageal manifestations of GERD alone, a combination of classic and extraesophageal manifestations, or classic GERD symptoms alone. A retrospective review of consecutive patients undergoing esophageal manometry and 24-hour dual-channel esophageal pH testing was performed. Information on patient demographics, symptoms, and results of various manometric and pH testing parameters was examined. We evaluated 84 patients: 32 with extraesophageal symptoms alone, 24 with both classic and extraesophageal symptoms, and 28 with classic symptoms alone. Apart from a trend toward less supine acid exposure in those with extraesophageal symptoms alone, no significant differences were evident among the three patient groups in any of the other parameters of proximal or distal esophageal acid reflux. With respect to motility parameters, lower esophageal sphincter pressure was lower in those with combined symptoms; otherwise, manometric findings were similar in the three patient groups. Our data do not support the hypothesis that the nature of the clinical presentation of GERD, whether in the form of classic or extraesophageal manifestations, is related to differing patterns of esophageal motor function or esophageal acid exposure.