Motilin-induced gastric contractions signal hunger in man.

RATIONALE: Hunger is controlled by the brain, which receives input from signals of the GI tract (GIT). During fasting, GIT displays a cyclical motor pattern, the migrating motor complex (MMC), regulated by motilin. OBJECTIVES: To study the relationship between hunger and MMC phases (I-III), focusing on spontaneous and pharmacologically induced phase III and the correlation with plasma motilin and ghrelin levels. The role of phase III was also studied in the return of hunger after a meal in healthy individuals and in patients with loss of appetite. FINDINGS: In fasting healthy volunteers, mean hunger ratings during a gastric (62.5±7.5) but not a duodenal (40.4±5.4) phase III were higher (p<0.0005) than during phase I (27.4±4.7) and phase II (37±4.5). The motilin agonist erythromycin, but not the cholinesterase inhibitor neostigmine, induced a premature gastric phase III, which coincided with an increase in hunger scores from 29.2±7 to 61.7±8. The somatostatin analogue octreotide induced a premature intestinal phase III without a rise in hunger scores. Hunger ratings significantly correlated (ß=0.05; p=0.01) with motilin plasma levels, and this relationship was lost after erythromycin administration. Motilin, but not ghrelin administration, induced a premature gastric phase III and a rise in hunger scores. In contrast to octreotide, postprandial administration of erythromycin induced a premature gastric phase III accompanied by an early rise in hunger ratings. In patients with unexplained loss of appetite, gastric phase III was absent and hunger ratings were lower. CONCLUSIONS: Motilin-induced gastric phase III is a hunger signal from GIT in man.

Effect of baclofen on gastric acid pocket in subjects with gastroesophageal reflux disease symptoms.

Postprandial gastroesophageal reflux (PGER) in the distal esophagus (DE) is associated with a gastric juice 'acid pocket' (AP). Baclofen reduces AP extension into the DE in healthy volunteers, in part through increased lower esophageal sphincter (LES) pressure. We aimed to verify whether baclofen also affects postprandial AP location and extent in gastroesophageal reflux disease (GERD) patients. Thirteen treatment-naive heartburn-prevalent GERD patients underwent two AP studies, after pretreatment with baclofen 40 mg or placebo 30 minutes preprandially. We performed pH-probe stepwise pull-throughs (PT) (1 cm/min, LES -10 to +5 cm) before and every 30 minutes from 30 minutes before up to 150 minutes after a test meal. After the meal, both after placebo and baclofen, gastric pH significantly dropped at 30, 60, 90 minutes postprandially (P: nadir pHs of 3.9 ± 0.6, 2.3 ± 0.6, 2.1 ± 0.4; B: nadir pHs of 2.5 ± 0.4, 2.8 ± 0.4, 2.5 ± 0.3; all P < 0.05). After placebo, LES pressure decreased at 60, 90 and 120 minutes postprandially (32.7 ± 6.1 vs. 24.5 ± 3.1, 27.3 ± 5.9, 27.3 ± 6.0 mmHg; analysis of variance [ANOVA], P = 0.037), but this was prevented by baclofen (25.4 ± 3.4 vs. 29.4 ± 2, 32.2 ± 1.4, 35.5 ± 1.7 mmHg, ANOVA, P = not significant (NS)). Baclofen did not significantly decrease the postprandial AP extent above the LES but prevented the postprandial increase in transient lower esophageal sphincter relaxations (TLESRs) (preprandial vs. postprandial, placebo: 1.1 ± 0.3 vs. 3.7 ± 0.7, P < 0.05; baclofen: 1.4 ± 0.4 vs. 2 ± 0.5, P = NS). In GERD patients, baclofen significantly increases postprandial LES pressure, prevents the increase TLESRs but, unlike in healthy volunteers, does not affect AP extension into the DE.

Effect of baclofen on the acid pocket at the gastroesophageal junction.

Previous studies established that a pocket of highly acidic gastric juice is present postprandially at the gastroesophageal junction in man. The GABA-B agonist baclofen inhibits postprandial reflux events through its effects on the lower esophageal sphincter (LES). The aim of the current study was to investigate whether baclofen would affect the location and the extent of the postprandial acid pocket in healthy volunteers. Twelve healthy volunteers underwent acid pocket studies on two different occasions, at least 1 week apart. LES position was determined preprandially with pull-through manometry. Dual pH electrode and manometry probe stepwise pull-through (1 cm/minute, LES-10 to +5 cm) was performed at 30-minute intervals for 150 minutes, with administration of placebo or baclofen 40 mg after the first and ingestion of a liquid meal after the second pull-through. After placebo, a significant drop in intragastric gastric pH was present at the gastroesophageal junction after the meal, reflecting the acid pocket, and this was associated with a drop in LES pressure. Baclofen did not affect the presence of the acid pocket, but prevented the postprandial drop in LES pressure, and the extent of the acid pocket above the upper margin of the manometrically located LES was significantly decreased by baclofen (1.6 ± 0.7 vs. 0.3 ± 0.4 cm at 60 minutes, 2.2 ± 0.6 vs. 0.2 ± 0.6 at 90 minutes, and 1.5 ± 0.5 vs. 0.7 ± 0.7 cm at 120 minutes, all P < 0.05). Baclofen does not alter the intragastric acid pocket, but limits its extension into the distal esophagus, probably through an increase in postprandial LES pressure.

Office normotensives with a minimal augmentation of intima-media thickness of common carotid arteries: really normotensives?

BACKGROUND AND AIM: Blood pressure is an independent predictor of target organ damage (TOD). Recent data from literature suggest that TOD can be present also in pre-hypertensive subjects, diagnosed with pressure monitoring (PM). Aim of this study is to clarify whether an augmentation of the carotid Intima-Media Thickness (cIMT) in office prehypertensives is a TOD associated to monitoring prehypertension (MP). PATIENTS AND METHODS: We have analyzed our database of individuals  office normotensives showing an increase of cIMT. The ambulatory blood pressure monitoring (ABPM) of these was compared with those of office monitoring normotensives, matched by age and gender, antropometric characteristics, negative for familial hypertension and other risk factors (true normotensives, TN). RESULTS: We have selected 15 presumable prehypetensives (PP) and 8 TN subjects. The ABPM (ambulatory blood pressure monitoring) analysis confirmed that neither the PP nor TN showed systolic (S) and diastolic (D) BP within-day values above their day-night upper reference limits. However the statistical comparison between PP and TN revealed that the first group had a significant elevation of SBP and DBP Daily Mean Level (DML(SBP/DBP): 121 ± 2/81 ± 2 vs 112 ± 2/70 ± 2 mmHg, respectively, p = 0.007 and p = 0.002), confirming the MP diagnosis. CONCLUSIONS: These results demonstrate that cIMT increase in PP fulfill the criteria for MP diagnosis, suggesting that MP should be undertaken in all PP with altered cIMT, but larger prospective studies are needed.

Rifaximin treatment for small intestinal bacterial overgrowth in children with irritable bowel syndrome.

OBJECTIVES: Aims of the study were to assess the effects of rifaximin treatment on small intestinal bacterial overgrowth (SIBO) prevalence and gastrointestinal symptoms. STUDY DESIGN: Fifty (50) irritable bowel syndrome (IBS) children were consecutively enrolled. All subjects underwent lactulose hydrogen/methane breath test (LBT) to assess SIBO before and one month after the treatment with rifaximin 600 mg daily for one week. All IBS patients filled out a Visual Analogic Scale (VAS) to assess and score gastrointestinal symptoms (abdominal pain, constipation, diarrhoea, bloating, flatulence) at baseline and one month after treatment. RESULTS: The prevalence of abnormal LBT in patients with IBS was 66% (33/50). LBT normalization rate was 64% (21/33). Compliance was excellent, and no relevant side-effects were observed during treatment. VAS score was significantly higher in IBS patients with abnormal LBT than SIBO negatives, and strongly improved after successful treatment. CONCLUSIONS: Rifaximin was effective and safe in SIBO treatment and IBS symptoms improvement in childhood. Double blind placebo-controlled interventional studies are warranted to verify the real impact of SIBO on gastrointestinal symptoms in children with IBS.

The role of intestinal microbiota and the immune system.

BACKGROUND: The human gut is an ecosystem consisting of a great number of commensal bacteria living in symbiosis with the host. Several data confirm that gut microbiota is engaged in a dynamic interaction with the intestinal innate and adaptive immune system, affecting different aspects of its development and function. AIM: To review the immunological functions of gut microbiota and improve knowledge of its therapeutic implications for several intestinal and extra-intestinal diseases associated to dysregulation of the immune system. METHODS: Significant articles were identified by literature search and selected based on content, including atopic diseases, inflammatory bowel diseases and treatment of these conditions with probiotics. RESULTS: Accumulating evidence indicates that intestinal microflora has protective, metabolic, trophic and immunological functions and is able to establish a "cross-talk" with the immune component of mucosal immunity, comprising cellular and soluble elements. When one or more steps in this fine interaction fail, autoimmune or auto-inflammatory diseases may occur. Furthermore, it results from the data that probiotics, used for the treatment of the diseases caused by the dysregulation of the immune system, can have a beneficial effect by different mechanisms. CONCLUSIONS: Gut microbiota interacts with both innate and adaptive immune system, playing a pivotal role in maintenance and disruption of gut immune quiescence. A cross talk between the mucosal immune system and endogenous microflora favours a mutual growth, survival and inflammatory control of the intestinal ecosystem. Based on these evidences, probiotics can be used as an ecological therapy in the treatment of immune diseases.  

Obesity and metabolic syndrome: an inflammatory condition.

Obesity causes chronic low-grade inflammation that contributes to systemic metabolic dysfunction associated with obesity-linked disorders that fall under the definition of metabolic syndrome. Adipose tissue is a key endocrine organ as it releases multiple bioactive substances, known as adipose-derived secreted factors or adipokines, that have proinflammatory or anti-inflammatory activities. Dysregulated production or secretion of these adipokines owing to adipose tissue dysfunction can contribute to the pathogenesis of obesity-linked complications. In this emerging context, the gut microbiota-metabolism interactions play an increasingly important role in the understanding and hopefully future treatment of complex metabolic unbalances responsible for insulin resistance and cardiovascular high-risk diseases.

Food allergy: from diagnosis to treatment.

Adverse food reactions, an adverse health effect arising from an immune or nonimmune response that occurs reproducibly on the exposure to a given food, can be divided into toxic and hypersensitivity reactions. When an immunologic mechanism has been shown, hypersensitivity food reactions should be referred to as food allergy that may be IgE- or non-IgE-mediated. Food allergy diagnosis is mainly guided by a correct and accurate history and physical examination, thus leading to prick test and elimination diets. The treatment gold standard is still represented by an elimination diet together with antihistamines and corticosteroid usage in order to reduce the gastrointestinal and potentially life-threatening systemic symptoms. Other treatments are currently under investigation with promising results.

Colitides.

OBJECTIVE: This Review provides an overview of the pathophysiology, epidemiology, histopathology, clinical characteristics of non-IBD forms of colitis over than some preliminary therapeutic evidences. STATE OF THE ART: The term "Colitides" includes a variety of inflammatory diseases of the colon. These forms of colitis occur as either primary conditions or complications of other diseases. The etiopathogenesis of most of them remains obscure and the epidemiological data are rather limited. Clinical presentations include chronic, watery diarrhea, abdominal pain and intermittent rectal bleeding. Endoscopic evaluation and mucosal biopsy are essential to confirm the diagnosis and to exclude IBD-associated colitis. These diseases include microscopic colitis, ischemic colitis, segmental colitis associated with diverticula, radiation colitis, diversion colitis, eosinophilic colitis and Behcet's colitis. TREATMENT: In many cases the treatment is empirical and often the therapy and outcome depend on the severity of the disease.

A case of vomiting in an anorexic achalasic patient.

Wernicke's encephalopathy is a neurological disorder caused by thiamine (vitamin B1) deficiency characterized by vertigo, ataxia, and mental confusion. Wernicke's encephalopathy has a causative association with alcoholism but recently there has been an increased prevalence also in other clinical conditions. In literature potentially fatal Wernicke's encephalopathy onset in an advanced achalasia has been previously reported only once. We describe for the first time an improvement of achalasic symptoms in a young patient affected by end-stage achalasia and anorexia nervosa (coming from ineffective Heller-Dor myotomy) after vitamin B1 supplementation. This case report suggest a potential positive impact of B1 supplementation on end-stage achalasic patients and requires systematic studies to confirm this observation.

The Apparent Asymmetrical Relationship Between Small Bowel Bacterial Overgrowth, Endotoxemia, and Liver Steatosis and Fibrosis in Cirrhotic and Non-Cirrhotic Patients: A Single-Center Pilot Study.

Introduction: Gut microbiota are a complex ecosystem harboring our intestine. They maintain human body equilibrium, while their derangement, namely, "dysbiosis", has been associated with several gastrointestinal diseases, such as liver steatosis (NAFLD) and liver cirrhosis. Small intestinal bacterial overgrowth (SIBO) is an example of dysbiosis of the upper gastrointestinal (GI) tract. Aim: The aim of this study is to evaluate the relationship between SIBO and levels of endotoxemia and grade of liver steatosis (LS) and liver fibrosis (LF) in hepatologic patients. Materials and Methods: Consecutive outpatients referred to our hepatology clinic were tested for SIBO by the lactulose breath test (LBT) and peripheral blood levels of endotoxemia; LS grading and LF were assessed by abdominal ultrasound and transient elastography, respectively. Results: Fifty-two consecutive patients (17 with alcohol abuse (4.5 ± 0.8 alcohol units per day), 4 with HCV and 2 with HBV infection, 24 of metabolic origin, 2 of autoimmune origin, and 3 with cholangiopathies; mean age 54.7 ± 8.3 years, 31 F, BMI 24.1 ± 1.1 Kg/m2) and 14 healthy volunteers (HV) (mean age 50.1 ± 4.3 years, 9 F, BMI 23.3 ± 1.1 Kg/m2) were enrolled. SIBO prevalence was significantly higher in cirrhotic (LC) vs. non-cirrhotic (LNC) patients and vs. HV (all, p < 0.05), with a significant positive trend according to Child-Pugh status (all, p < 0.05). SIBO prevalence was not correlated with LS stages (all, p = NS). Consensually, endotoxin levels were significantly higher in LC vs. LNC and vs. HV (all, p < 0.05) and significantly correlated with LF in patients with LC, according to Child-Pugh status (all, p < 0.05). Conclusion: This study shows that SIBO prevalence and relative endotoxin blood levels seem to be significantly associated with the grade of LF vs. LS in LC. SIBO is also present under pre-cirrhotic conditions, but its prevalence seems to correlate with liver disease irreversible derangement.

Effects of enteral nutrition on patients with pressure lesions: a single center, pilot study.

OBJECTIVE: Protein-energetic malnutrition (PEM) affects prognosis and mortality in elderly patients as an inadequate nutritional status is a risk factor for the development and worsening of pressure sores (PS). We aimed to evaluate the incidence of PEM in outpatients with PS and to study the impact of nutritional support on the stage of PS. PATIENTS AND METHODS: PS patients, divided in a group treated with artificial nutrition (group A) and those fed orally (group B) at home, were consecutively enrolled in the Integrated Home Care program of Ascoli Piceno between June and September 2015. At T0 the patients underwent medical history, nutritional, anthropometric/biochemical parameters assessment, and the staging of the PS. The same assessments and staging of the pressure lesions were performed three months later (T1). RESULTS: Group A (n=25) started from a better nutritional status vs. group B (n=25) at T0, according to MNA assessment. Group A showed a significant improvement of nutritional status correlating with detailed control of nutrients intake and improvement of PS stage (T0 vs. T1, p<0.05). On the other hand, group B showed a significant difference between nutrients intake and nutritional needs that correlated with both malnutrition state increase and worsening of the PS staging (T0 vs. T1, p<0.05). CONCLUSIONS: The present study shows that PEM has a significant prevalence in the elder, in general, and in older people with PS, in particular. A targeted nutritional intake can prevent and help the healing of PS.

Prevalence of small intestinal bacterial overgrowth in children with irritable bowel syndrome: a case-control study.

OBJECTIVE: To assess the prevalence of small intestinal bacterial overgrowth (SIBO) in children affected by irritable bowel syndrome (IBS). STUDY DESIGN: Consecutive children affected by IBS according to Rome II criteria (n = 43) were enrolled at the Gemelli Hospital, Catholic University of Rome. The control population (n = 56) consisted of healthy subjects without IBS symptoms, similar to patients for age, sex, and social background. All subjects underwent lactulose/methane breath test (LBT) to assess small intestinal bacterial overgrowth. RESULTS: The prevalence of abnormal LBT result was significantly higher in patients with IBS (65%, 28/43) with respect to control subjects (7%, 4/56; OR 3.9, 95% CI 7.3-80.1, P < .00001). Patients with abnormal LBT showed a trend toward a worse visual analog scale score with respect to children with IBS without SIBO, but a significant statistical difference was observed only for bloating. CONCLUSIONS: Results from this study suggest a significant epidemiologic association between SIBO and IBS in childhood. Placebo-controlled interventional studies with antibiotics used to treat bacterial overgrowth are warranted to clarify the real impact of the disease on IBS symptoms.

Small bowel bacterial overgrowth and type 1 diabetes.

BACKGROUND: Gastrointestinal motility disorders are often present in diabetic patients (pts). Such motility dysfunctions have been attributed to autonomic neuropathy. Impaired intestinal motility is often associated with small-bowel bacterial overgrowth (SIBO) but only few studies evaluated the relationship between autonomic neuropathy and SIBO in diabetic pts. AIM: To compare the prevalence of SIBO between type 1 diabetic (T1D) pts with and without autonomic neuropathy. PATIENTS AND METHODS: 25 pts (13 males, 12 females; mean age 44.2+/-7) affected by type 1 diabetes with normal cardiovascular autonomic test (group A) and 25 type 1 diabetic pts with abnormal cardiovascular autonomic test (group B) were submitted to hydrogen lactulose breath test. RESULTS: 2 out of 25 (8%) showed SIBO among group A, while 11 out of 25 (44%) showed SIBO among group B (p<0.01). Interestingly, among group B, the daily insulin requirements was significantly higher in SIBO-positive pts compared to SIBO-negative: 0.66+/-0.3 vs. 0.59+/-0.1 UI/kg (p<0.05). CONCLUSIONS: Pts with autonomic neuropathy have a significantly higher prevalence of SIBO, that is also associated with a higher daily insulin requirements.

Antibiotic therapy in small intestinal bacterial overgrowth: rifaximin versus metronidazole.

BACKGROUND AND OBJECTIVES: Few controlled trials on antibiotic therapy for small intestinal bacterial overgrowth are available at present. Aim of the study was to assess efficacy, safety and tolerability of rifaximin with respect to metronidazole for the treatment of small intestinal bacterial overgrowth. MATERIAL AND METHODS: We enrolled 142 consecutive patients with diagnosis of small intestinal bacterial overgrowth. Diagnosis of small intestinal bacterial overgrowth based on the clinical history and the positivity of glucose breath test. Patients were randomised to two 7-day treatment groups: rifaximin 1200 mg/day and metronidazole 750 mg/day. Glucose breath test was reassessed 1 month after. Compliance and side-effect incidence were also evaluated. RESULTS: One drop-out was observed in rifaximin group. Five drops-out occurred in metronidazole group. The glucose breath test normalization rate was significantly higher in the rifaximin with respect to the metronidazole group (63.4% versus 43.7%; p < 0.05; OR 1.50, 95% CI 1.14-4.38). The overall prevalence of adverse events was significantly lower in rifaximin with respect to metronidazole group. DISCUSSION: Rifaximin showed an higher SIBO decontamination rate than metronidazole at the tested doses, both with a significant gain in terms of tolerability. Either the present study or recent evidencies suggest that rifaximin represents a good choice for the management of patients affected by SIBO.

Probiotics: which and when?

There is a natural feeling between our intestinal flora and the gut. These microorganisms, living in the various tracts of human intestine, may affect the host homeostasis. Some of these bacteria can perhaps be a source of infection and sepsis when the bowel barrier is physically or functionally breached. The term 'probiotic' dates from the beginning of the last century and in the last years a market for probiotics worldwide, estimated to be worth billions of pounds, has developed. Although there is persuasive advertising for probiotics and there have been methodological advances in the study of the intestinal microbiota, much remains unproven, e.g. how probiotics work, which strains are effective, what can be expected to be achieved, and what dosage is required for effectiveness. This review of the literature is an evidence-based guide through the developing microbial universe affecting our life.

The effect of arabinoxylooligosaccharides on upper gastroduodenal motility and hunger ratings in humans.

BACKGROUND AND AIMS: Prebiotics such as Arabinoxylooligosaccharides (AXOS) are non-digestible, fermentable food ingredients stimulating growth/activity of colonic bacteria with enhanced carbohydrates fermentation (CF) in humans. The migrating motor complex (MMC) of the gastrointestinal tract has been recently identified as an important hunger signal, but no data are available yet on the role of acute CF on MMC activity and related hunger ratings. Thus, we aimed to study the effect of acute AXOS CF on MMC and hunger in humans. METHODS: A total of 13 healthy volunteers were randomized in a single-blind crossover placebo-controlled study where 9.4 g of AXOS or 10 g of maltodextrin and 1 g of unlabelled lactose ureide (LU) were given 12 hours prior to the study and, in the next morning, together with a pancake containing 500 mg of 13 C-LU. In 10 hours after the meal, 13 CO2 and hydrogen excretion were determined every 15 minutes while hunger/appetite ratings every 2 minutes through a VAS questionnaire. Five hours after the meal, antroduodenal motility was measured using HRM. KEY RESULTS: AXOS significantly increased CF (158 ± 81 vs 840 ± 464 H2 ppm*minute, placebo vs AXOS, P < .05) without affecting the orocecal transit time (OCTT). AXOS had no significant effect on the occurrence, origin, and duration of phase III and on the total number, origin, and duration of phases I and II. Hunger and appetite scores prior and after phase III were not affected by AXOS. CONCLUSIONS: AXOS acutely increases colonic fermentation, but this neither affects OCTT, activity of the MMC, nor interdigestive hunger scores in man.

Impact of patients nutritional status on major surgery outcome.

OBJECTIVE: Surgery is a major stress factor that activates several inflammatory and catabolic pathways in man. An appropriate nutritional status allows the body to react properly to this stressor and recover in a faster and more efficient manner. On the other hand, malnutrition is related to a worse surgery outcome and to a higher prevalence of comorbidities and mortality. The aims of this study were to evaluate the nutritional status of patients undergoing major surgery and investigate the potential correlation between malnutrition and surgical outcomes. PATIENTS AND METHODS: Mini Nutritional Assessment (MNA) and global clinical examination (including biochemical parameters and comorbidities existence) were undertaken in 50 consecutive patients undergoing major surgery. Patients' clinical conditions were re-evaluated at 3 and 6 days after surgery, recording biochemical parameters and systemic and/or wound-related complications. RESULTS: A compromised nutritional status was present in more than half (54%) of patients (malnutrition in 10% and risk of malnutrition in 44% of patients, respectively). Females were slightly more at risk of malnutrition (48% vs. 41%, p=NS, females vs. males) and clearly malnourished (14% vs. 7%, p<0.05, females vs. males). Age was an independent risk factor for malnutrition and within the elders' group (> 80 years old) 16.70% of patients was diagnosed with malnutrition and 58.3% was at risk of malnutrition. Systemic complications were registered in all patients both at 3 and 6 days after surgery. However, well-nourished and at-risk of malnutrition patients had earlier complications that only partially resolved within six days after the operation. Malnourished patients showed fewer complications at the 3rd post-surgery follow-up day but had a worse outcome six days after surgery. CONCLUSIONS: Older age and but not female sex are independent risk factors for malnutrition development in patients undergoing major surgery. More interestingly, more than half of patients with an impaired nutritional status presented a less appropriated stress response to surgery. These data suggest that nutritional status assessment may be important to recognize patients at potential risk of surgical complications and that early nutritional interventions must be promptly arranged.

High dosage rifaximin for the treatment of small intestinal bacterial overgrowth.

BACKGROUND: Rifaximin is a broad spectrum non-absorbable antibiotic used for treatment of small intestinal bacterial overgrowth. Doses of 1200 mg/day showed a decontamination rate of 60% with low side-effects incidence. AIMS: To assess efficacy, safety and tolerability of rifaximin 1600 mg with respect to 1200 mg/day for small intestinal bacterial overgrowth treatment. METHODS: Eighty consecutive small intestinal bacterial overgrowth patients were enrolled. Diagnosis of small intestinal bacterial overgrowth based the clinical history and positivity to H(2)/CH(4) glucose breath test. Patients were randomized in two 7-day treatment groups: rifaximin 1600 mg (group 1); rifaximin 1200 mg (group 2). Glucose breath test was reassessed 1 month after. Compliance and side-effect incidence were also evaluated. RESULTS: One drop-out was observed in group 1 and two in group 2. Glucose breath test normalization rate was significantly higher in group 1 with respect to group 2 both in intention-to-treat (80% vs. 58%; P < 0.05) and per protocol analysis (82% vs. 61%; P < 0.05). No significant differences in patient compliance and incidence of side effects were found between groups. CONCLUSIONS: Rifaximin 1600 mg/day showed a significantly higher efficacy for small intestinal bacterial overgrowth treatment with respect to 1200 mg with similar compliance and side-effect profile.

Effect of methylnaltrexone and naloxone on esophageal motor function in man.

BACKGROUND: Endogenous opioids (EO) acting on µ-opiod receptors in central and enteric nervous system (ENS) control gastrointestinal motility but it is still unclear whether EO in ENS may control esophageal function in man, thus we will study the effects of methylnaltrexone (MNTX), a peripherally selective, and naloxone (NA), a non-selective µ-opiod receptor antagonist, on esophageal motility in healthy subjects. METHODS: Fifteen HV (6 M; 34.1 ± 0.6 years; BMI: 22.1 ± 0.1 kg/m2 ) underwent three esophageal high-resolution manometry impedance (HRiM) studies with 10 saline swallows administered every 30 minutes: drug was administered after 30 minutes (MNTX subcutaneously/NA or saline intravenously), a solid meal after 90 minutes; measurements continued for 120 minutes postprandially. KEY RESULTS: Methylnaltrexone did not significantly decrease the upper esophageal sphincter (UES) percentage of relaxation preprandially (72.5 ± 5 vs 66.9 ± 4.6 and 73 ± 3.8%, ANOVA between placebo, MNTX and NA, P=NS) and postprandially (60 minutes: 68.2 ± 5.6 vs 61 ± 5.5 and 67.1 ± 5.6%; 120 minutes: 68 ± 5.9 vs 59.3 ± 5.2 and 67.7 ± 4.7%; ANOVA between placebo, MNTX and NA, P=NS). MNTX and NA did not significantly alter preprandial and postprandial LES resting pressures and integrated relaxation pressure (ANOVA between placebo, MNTX and NA, all P=NS). Peak front velocity and distal contractile integral were not altered pre- and postprandially by MNTX and NA (ANOVA between placebo, MNTX and NA, P=NS). Transient lower esophageal sphincter relaxations (TLESRs') number was not altered by MNTX and NA (ANOVA between placebo, MNTX and NA, all P=NS). CONCLUSIONS AND INFERENCES: The peripheral selective and non-selective µ-opioid receptor antagonists MNTX and NA, respectively, do not alter TLESRs occurrence and esophageal peristalsis.