Reduced biliary sterol output with no change in total faecal excretion in mice expressing a human apolipoprotein A-I variant.

BACKGROUND/AIMS: Apolipoprotein (apo)A-I(M) (ilano), is a molecular variant of apoA-I(wild-type), associated with dramatically low HDL-cholesterol levels, but no increased risk for cardiovascular disease. In view of the present uncertainties on the role of apoA-I in liver cholesterol removal by way of bile acids and neutral sterols, and of the greater capacity of apoA-I(M) (ilano) to remove arterial cholesterol, biliary sterol metabolism was evaluated in transgenic mice expressing apoA-I(M) (ilano). METHODS: ApoA-I(M) (ilano) mice were fed a high-cholesterol/high-fat diet, and compared with human apoA-I(wild-type) mice. Plasma lipid levels, hepatic bile flow and composition, hepatic and intestinal cholesterol and bile acid content, and faecal sterol content were measured. Moreover, the expression of hepatic ABCA1, SR-B1 and that of hepatic and intestinal genes involved in bile acid metabolism were evaluated. RESULTS: The dietary treatment led to a strong elevation in HDL-cholesterol levels in A-I(M) (ilano) mice, associated with an increased expression of hepatic ABCA1. ApoA-I(M) (ilano) mice showed lower cholesterol output from the liver compared with apoA-I(wild-type) mice, in the absence of liver sterol accumulation. Faecal excretion of neutral sterols and bile acids was similar in the two mouse lines. CONCLUSIONS: In spite of a different response to the dietary challenge, with an increased ABCA1 expression and a lower hepatic cholesterol output in apoA-I(M) (ilano) mice, the net sterol excretion is comparable in the two transgenic lines.

A new model for portal protein profile analysis in course of ileal intraluminal bile acid infusion using an in situ perfused rat intestine.

Due to the importance of intestinal transport in pharmacological studies and the emerging role of intestinal signaling activity in the gut-liver axis, we have developed a new method to investigate intestinal transport and liver signaling using cell and serum free mesenteric perfusion system in the rat. The method regarding bile acid active absorption was validated, then, the portal venous content was examined for fibroblast growth factor 15(FGF15), a putative signaling protein produced by the ileal enterocytes following bile acid absorption. After isolation and cannulation of the relevant vessels (abdominal aorta and portal vein), the abdominal aorta and the terminal ileum were infused with respectively Krebs-Ringer solution and tauroursodeoxycholate (TUDCA) and the absorption was assessed by its recovery in the portal vein. After immunoblot, liquid chromatography and mass spectrometry analysis were performed both on gel bands digestion products and on portal outflow samples in order to evaluate if negligible amounts of FGF15 were present in the portal circulation. TUDCA absorption was efficient, intestinal morphology and oxygen consumption were normal. Despite accurate analysis, we could not find FGF15. Our method proved to be reliable for studying the active bile acid absorption. It is also suitable to identify molecules produced by enterocytes and transferred to the portal circulation in response to absorption of different substances such as nutrients or drugs. Since FGF15 was not recovered we suggest the possibilities that this protein is produced in very little amounts, poorly transferred outside the cell, or that it is extremely unstable and rapidly degraded.

Ribavirin for chronic hepatitis C: and the mystery goes on.

Twenty years ago, ribavirin was first used in the treatment for chronic hepatitis C. After few years, ribavirin, in combination with interferon-alpha, showed a dramatic synergistic efficacy against hepatitis C virus infection, leading to viral clearance in about 50% of patients. Recent discovery of potent inhibitors of hepatitis C virus proteases did not replace ribavirin as the mainstay of combination therapy for chronic hepatitis C. Despite this fundamental role of ribavirin, many aspects of the mechanism of action and of the optimal dose and duration of therapy remain to be discovered or settled. In the present review, the authors recall the milestones in the history of ribavirin and try to shed light on the more relevant features of ribavirin action and utilization, and on the clinical problems encountered in managing and optimizing treatment for chronic hepatitis C. Finally, some potential off-label use of this drug in most difficult-to-treat subjects is pointed out. In conclusion, even if a sort of mystery surrounds ribavirin, its efficacy against hepatitis C virus infection fortunately remains lasting and stable.

Intestinal epithelial cells in inflammatory bowel diseases.

The pathogenesis of inflammatory bowel diseases (IBDs) seems to involve a primary defect in one or more of the elements responsible for the maintenance of intestinal homeostasis and oral tolerance. The most important element is represented by the intestinal barrier, a complex system formed mostly by intestinal epithelial cells (IECs). IECs have an active role in producing mucus and regulating its composition; they provide a physical barrier capable of controlling antigen traffic through the intestinal mucosa. At the same time, they are able to play the role of non-professional antigen presenting cells, by processing and presenting antigens directly to the cells of the intestinal immune system. On the other hand, immune cells regulate epithelial growth and differentiation, producing a continuous bi-directional cross-talk within the barrier. Several alterations of the barrier function have been identified in IBD, starting from mucus features up to its components, from epithelial junctions up to the Toll-like receptors, and altered immune responses. It remains to be understood whether these defects are primary causes of epithelial damage or secondary effects. We review the possible role of the epithelial barrier and particularly describe the role of IECs in the pathogenesis of IBD.

ESWL for difficult bile duct stones: a 15-year single centre experience.

AIM: To evaluate the efficacy of extracorporeal shock wave lithotripsy (ESWL) for the management of refractory bile duct cholelithiasis in a third level referral centre. METHODS: The clinical records of all patients treated with a second generation electromagnetic lithotripter (Lithostar Plus, SIEMENS) from October 1990 to April 2005 were evaluated. All patients were monitored during the procedure and antibiotics were administered in case of cholangitis. The chi(2) test and logistic regression analysis were performed as appropriate. RESULTS: Two hundred and fourteen patients (102 males, 112 females; mean age 74.8 +/- 0.84 years--single stone 97, multiple stones 117) underwent ESWL. The mean number of sessions and shock waves were 3.5 +/- 0.13 and 3477.06 +/- 66.17, respectively. The maximum stone size was 5 cm. Complete stone clearance was achieved in 192 (89.7%) patients. Of the remaining patients 15 required surgery, 2 a palliative stent and in 5 patients stone fragmentation led to effective bile drainage with clinical resolution despite incomplete clearance. Age, sex and stone characteristics were not related to treatment outcome. Major complications occurred in two patients (haemobilia and rectal bleeding) and minor complications in 25 (3 vomiting, 22 arrhythmias). No procedure-related deaths occurred. CONCLUSION: ESWL is a safe and effective technique for clearance of refractory bile duct stones.

Natural history of gallstone disease: Expectant management or active treatment? Results from a population-based cohort study.

BACKGROUND AND AIMS: The knowledge of natural history is essential for disease management. We evaluated the natural history (e.g. frequency and characteristics of symptoms and clinical outcome) of gallstones (GS) in a population-based cohort study. METHODS: A total of 11 229 subjects (6610 men, 4619 women, age-range: 29-69 years, mean age: 48 years) were studied. At ultrasonography, GS were present in 856 subjects (338 men, 455 women) (7.1%). GS were followed by means of a questionnaire inquiring about the characteristics of specific biliary symptoms. RESULTS: At enrollment, 580 (73.1%) patients were asymptomatic, 94 (11.8%) had mild symptoms and 119 (15.1%) had severe symptoms. GS patients were followed up for a mean period of 8.7 years; 63 subjects (7.3%) were lost to follow up. At the end of the follow up, of the asymptomatic subjects, 453 (78.1%) remained asymptomatic; 61 (10.5%) developed mild symptoms and 66 (11.4%) developed severe symptoms. In subjects with mild symptoms, the symptoms disappeared in 55 (58.5%), became severe in 23 (24.5%), remained stable in 16 (17%); in subjects with severe symptoms, the symptoms disappeared in 62 (52.1%), became mild in 20 (16.8%) and remained stable in 37 (31.1%). A total of 189 cholecystectomies were performed: 41.3% on asymptomatic patients, 17.4% on patients with mild symptoms and 41.3% on patients with severe symptoms. CONCLUSIONS: This study indicates that: (i) asymptomatic and symptomatic GS patients have a benign natural history; (ii) the majority of GS patients with severe or mild symptoms will no longer experience biliary pain; and (iii) a significant proportion of cholecystectomies are performed in asymptomatic patients. Expectant management still represents a valid therapeutic approach in the majority of patients.

G-CSF in Peg-IFN induced neutropenia in liver transplanted patients with HCV recurrence.

AIM: To evaluate the efficacy of granulocyte colony stimulating factors (G-CSF) in liver transplanted patients with hepatitis C (HCV) recurrence and Pegylated-IFN alpha-2b induced neutropenia, and to evaluate the impact of G-CSF administration on virological response. METHODS: Sixty-eight patients undergoing antiviral treatment for post-liver transplantation (OLT) HCV recurrence were enrolled. All patients developing neutropenia received G-CSF. RESULTS: Twenty three (34%) received G-CSF. Mean neutrophil count at the onset of neutropenia was 700/mmc (range 400-750/mmc); after 1 mo of G-CSF it increased to 1210/mmc (range 300-5590/mmc) (P < 0.0001). Three patients did not respond to G-CSF. Treatment duration was similar in neutropenic and non-neutropenic patients. No differences in the rate of discontinuation, infections or virological response were observed between the two groups. G-CSF was protective for the onset of de novo autoimmune hepatitis (P < 0.003). CONCLUSION: G-CSF administration is effective in the case of Peg-IFN induced neutropenia increasing neutrophil count, prolonging treatment and leading to sustained virological response (SVR) rates comparable to non-neutropenic patients. It prevents the occurrence of de novo autoimmune hepatitis.

Isolation of stem cell populations with trophic and immunoregulatory functions from human intestinal tissues: potential for cell therapy in inflammatory bowel disease.

BACKGROUND AIMS: Bone marrow (BM)- and adipose tissue (AT)-derived mesenchymal stromal cells (MSC) are currently under evaluation in phase III clinical trials for inflammatory bowel disease and other intestinal disease manifestations. The therapeutic efficacy of these treatments may derive from a combination of the differentiation, trophic and immunomodulatory abilities of the transplanted cells. We investigated intestinal tissues as sources of MSC: such cells may support tissue-specific functions and hold advantages for engraftment and contribution in the gastrointestinal environment. METHODS: Intestinal specimens were collected, and the mucosa and submucosa mechanically separated and enzymatically digested. Mesenchymal stromal populations were isolated, expanded and characterized under conditions commonly used for MSC. The differentiation potential, trophic effect and immunomodulatory ability were investigated. Results We successfully isolated and extensively expanded populations showing the typical MSC profile: CD29+, CD44+, CD73+, CD105+ and CD166+, and CD14(-), CD34(-) and CD45(-). Intestinal mucosal (IM) MSC were also CD117+, while submucosal cultures (ISM MSC) showed CD34+ subsets. The cells differentiated toward osteogenic, adipogenic and angiogenic commitments. Intestinal-derived MSC were able to induce differentiation and organization of intestinal epithelial cells (Caco-2) in three-dimensional collagen cultures. Immunomodulatory activity was evidenced in co-cultures with normal heterologous phytohemagglutinin-stimulated peripheral blood mononuclear cells. Conclusions Multipotent MSC can be isolated from intestinal mucosal and submucosal tissues. IM MSC and ISM MSC are able to perform trophic and immunomodulatory functions. These findings could open a pathway for novel approaches to intestinal disease treatment.

Incidence of gallstone disease in Italy: results from a multicenter, population-based Italian study (the MICOL project).

AIM: To evaluate gallstone incidence and risk factors in a large population-based study. METHODS: Gallstone incidence and risk factors, were evaluated by structured questionnaire and physical examination, respectively, in 9611 of 11 109 (86.5%) subjects who were gallstone-free at the cross-sectional study. RESULTS: Six centers throughout Italy enrolled 9611 subjects (5477 males, 4134 females, aged 30-79 years), 9517 of whom were included into analysis: 424 subjects (4.4%) had gallstones and 61 (0.6%) had been cholecystectomized yielding a cumulative incidence of 0.67% per year (0.66% in males, 0.81% in females). Increasing age, a high body mass index (BMI), a history of diabetes, peptic ulcer and angina, and low cholesterol and high triglyceride levels were identified as risk factors in men while, in females, the only risk factors were increasing age and a high BMI. Increasing age and pain in the right hypocondrium in men and increasing age in females were identified as predictors of gallstones. Pain in the epigastrium/right hypocondrium was the only symptom related to gallstones; furthermore, some characteristics of pain (forcing to rest, not relieved by bowel movements) were significantly associated with gallstones. No correlation was found between gallstone characteristics and clinical manifestations, while increasing age in men and increasing age and BMI in females were predictors of pain. CONCLUSION: Increasing age and BMI represent true risk factors for gallstone disease (GD); pain in the right hypocondrium and/or epigastrium is confirmed as the only symptom related to gallstones.

Inflammatory bowel disease: Moving toward a stem cell-based therapy.

The incidence and prevalence of Crohn's disease (CD) and ulcerative colitis (UC), the two major forms of inflammatory bowel diseases (IBD), are rising in western countries. The modern hygienic lifestyle is probably at the root of a disease where, in genetically susceptible hosts, the intestinal commensal flora triggers dysregulated immune and inflammatory responses. Current therapies ranging from anti-inflammatory drugs to immunosuppressive regimens, remain inadequate. Advances in our understanding of the cell populations involved in the pathogenetic processes and recent findings on the regenerative, trophic and immunoregulatory potential of stem cells open new paths in IBD therapy. Hematopoietic and mesenchymal stem cells are catalyzing the attention of IBD investigators. This review highlights the pivotal findings for stem cell-based approaches to IBD therapy and collects the encouraging results coming in from clinical trials.

Development and validation of a HPLC-ESI-MS/MS method for the determination of 5-aminosalicylic acid and its major metabolite N-acetyl-5-aminosalicylic acid in human plasma.

A new HPLC method for the determination of 5-aminosalicylic acid (5-ASA) and N-acetyl-5-aminosalicylic acid (N-Ac-5-ASA) in human plasma was developed and validated. Plasma samples were analyzed after protein precipitation with methanol and the two analytes were separated using a C18 column with a mobile phase composed of 17.5 mmol/L acetic acid (pH 3.3):acetonitrile=85:15 (v/v) at 0.2 mL/min flow rate. 4-ASA and N-Ac-4-ASA were used as internal standards. Selective detection was performed by tandem mass spectrometry with electrospray source, operating in negative ionization mode and in multiple reaction monitoring acquisition (m/z 152-->108 for 5-ASA; m/z 194-->150 and 194-->107 for N-Ac-5-ASA). The limit of quantification (LOQ) was 50 ng/mL for both analytes (0.2 ng injected) and matrix-matched standard curves showed linearity up to 4000 ng/mL. In the entire analytical range the within- and between-batch precision (R.S.D.%) values were respectively < or = 6.3% and < or = 11% for 5-ASA and < or = 8.0% and < or = 10% for N-Ac-5-ASA. For both analytes the within- and between-batch accuracy (bias%) values ranged respectively from -8.4% to 7.9% and from -7.9% to 8.0%. The overall recoveries (n=6) at three tested concentration levels (i.e. 100, 1000 and 4000 ng/mL) were respectively >90% for 5-ASA and >95% for N-Ac-5-ASA (R.S.D.% < or = 10%). The method was applied to evaluate the pharmacokinetic of 5-ASA after a single oral dose administration of this compound (1200 mg) to 24 healthy volunteers. The mean maximum concentration levels were 680 ng/mL for 5-ASA and 1240 ng/mL for N-Ac-5-ASA and the kinetic profiles were in agreement with previous studies.

Efficacy of esomeprazole (20 mg once daily) for reducing the risk of gastroduodenal ulcers associated with continuous use of low-dose aspirin.

OBJECTIVES: Low-dose aspirin is standard treatment for prevention of cardiovascular events in at-risk patients. However, long-term administration of low-dose aspirin is associated with a greater risk of adverse events, including gastroduodenal ulcers. This study determined the efficacy of esomeprazole for reducing the risk of gastric and/or duodenal ulcers and dyspeptic symptoms in patients receiving continuous, low-dose aspirin therapy. METHODS: Patients aged > or =60 yr, without baseline gastroduodenal ulcer at endoscopy, who were receiving aspirin 75-325 mg once daily, were randomized to esomeprazole 20 mg once daily or placebo for 26 wk. The presence of endoscopic gastric and/or duodenal ulcers and esophageal lesions was assessed at weeks 8 and 26. Upper gastrointestinal symptoms were assessed at weeks 8, 16, and 26. RESULTS: The intention-to-treat population comprised 991 patients (esomeprazole, N = 493; placebo, N = 498). Twenty-seven patients (5.4%) in the placebo group developed a gastric or duodenal ulcer during 26 weeks' treatment compared with eight patients (1.6%) in the esomeprazole group (life-table estimates: 6.2%vs 1.8%; P= 0.0007). At 26 wk, the cumulative proportion of patients with erosive esophagitis was significantly lower for esomeprazole versus placebo (4.4% and 18.3%, respectively; P < 0.0001). At 26 wk, esomeprazole-treated patients were more likely to experience resolution of heartburn, acid regurgitation, and epigastric pain (P < 0.05). CONCLUSIONS: Esomeprazole 20 mg once daily reduces the risk of developing gastric and/or duodenal ulcers and symptoms associated with the continuous use of low-dose aspirin in patients aged > or =60 yr without preexisting gastroduodenal ulcers.

Proton pump inhibitors in cirrhosis: tradition or evidence based practice?

Proton pump inhibitors (PPI) are very effective in inhibiting acid secretion and are extensively used in many acid related diseases. They are also often used in patients with cirrhosis sometimes in the absence of a specific acid related disease, with the aim of preventing peptic complications in patients with variceal or hypertensive gastropathic bleeding receiving multidrug treatment. Contradicting reports support their use in cirrhosis and evidence of their efficacy in this condition is poor. Moreover there are convincing papers suggesting that acid secretion is reduced in patients with liver cirrhosis. With regard to Helicobacter pylori (H pylori) infection, its prevalence in patients with cirrhosis is largely variable among different studies, and it seems that H pylori eradication does not prevent gastro-duodenal ulcer formation and bleeding. With regard to the prevention and treatment of oesophageal complications after banding or sclerotherapy of oesophageal varices, there is little evidence for a protective role of PPI. Moreover, due to liver metabolism of PPI, the dose of most available PPIs should be reduced in cirrhotics. In conclusion, the use of this class of drugs seems more habit related than evidence-based eventually leading to an increase in health costs.

Serum protein profiling in patients with inflammatory bowel diseases using selective solid-phase bulk extraction, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and chemometric data analysis.

The identification of new biomarkers or a disease-related protein fingerprint for inflammatory bowel diseases (IBDs) represents a major task in the diagnosis, prognosis and pharmacological therapy. To address these issues, a simple and rapid analytical proteomic method for serum protein profiling based on selective beads-based solid-phase bulk extraction, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and chemometric data analysis was developed. Serum proteins from healthy subjects (22) and patients with Crohn's disease (15) and ulcerative colitis (26) were selectively extracted according to reversed-phase (C18), strong anion-exchange (SAX) and metal ion affinity (IDA-Cu(II)) principles. This approach allowed enrichment of serum proteins/peptides due to the high interaction surface between analytes and the solid phase and high recovery due to the elution step performed directly on the MALDI-target plate. The MALDI-TOF MS serum protein profiles were acquired and, after a data pre-processing step, analyzed by linear discriminant analysis (LDA), a chemometric classification technique, in order to classify serum samples among healthy subjects and patients with inflammatory bowel diseases (IBDs). Since the high number of variables in the MALDI spectra (more than 16000 m/z values) prevents the use of LDA, the variables were reduced to 10-20 by features selection, thus allowing the evaluation of a pattern of m/z values with high discriminant power. Serum protein profiles obtained by reversed-phase extraction and the selection of 20 m/z values gave the best overall prediction ability (96.9%). The recognition of these m/z values may allow the identification of protein biomarkers involved in IBDs.

Results of endoscopic retrograde cholangiopancreatography in the treatment of biliary tract complications after orthotopic liver transplantation: our experience.

BACKGROUND/AIMS: Biliary tract complications are a common cause of morbidity and mortality after orthotopic liver transplantation. We report our experience in the use of ERCP in the treatment of post liver transplantation biliary complications. METHODOLOGY: Retrospectively we evaluated 34 patients who had undergone ERCP out of 460 who received a liver transplantation between January 1999 and December 2004. Eighteen patients presented biliary strictures, anastomotic in 12 cases and hilar in 6 cases; seven patients presented a biliary fistula and fifteen presented biliary stones in 8 cases associated to stricture and in 1 case to a fistula. Finally three patients underwent ERCP do to jaundice. The 18 patients with biliary strictures underwent sphincterotomy, dilation and stenting; the seven cases with fistulas were treated with a plastic biliary stent without sphincterotomy and the patients with biliary stones underwent sphincterotomy and endoscopic toilette of the common bile duct. RESULTS: An ERCP success rate of 97.7% was achieved without any significant complications. We obtained the resolution of all the biliary anastomotic strictures; resolution of hilar strictures was obtained in 66.6%. Biliary leak healed in 85.7% of patients. Complete endoscopic toilette was achieved in all the patients with biliary stones. CONCLUSIONS: In our experience ERCP has proved to be safe and effective in the treatment of post liver transplant biliary complications.

A new iron free treatment with oral fish cartilage polysaccharide for iron deficiency chronic anemia in inflammatory bowel diseases: a pilot study.

AIM: To investigate the effect of a new oral preparation, highly concentrated in fish cartilage, in a group of inflammatory bowel diseases (IBD) patients with chronic iron deficient anemia. METHODS: In an open label pilot study, we supple-mented a group of 25 patients (11 with Crohn's disease and 14 with ulcerative colitis) in stable clinical conditions and chronic anemia with a food supplement which does not contain iron but contains a standardized fraction of fish cartilage glycosaminoglycans and a mixture of antioxidants (Captafer Medestea, Turin, Italy). Patients received 500 mg, twice a day during meals, for at least 4 mo. Patients were suggested to maintain their alimentary habit. At time 0 and after 2 and 4 mo, emocrome, sideremia and ferritin were examined. Paired data were analyzed with Student's t test. RESULTS: Three patients relapsed during the study (2 in the 3rd mo, 1 in the 4th mo), two patients were lost to follow up and two patients dropped out (1 for orticaria, 1 for gastric burning). Of the remaining 18 patients, levels of serum iron started to rapidly increase within the 2nd mo of treatment, P < 0.05), whereas serum ferritin and hemoglobin needed a longer period to significantly improve their serum levels (mo 4) P < 0.05. The product was safe, easy to administer and well tolerated by patients. CONCLUSION: These data suggest a potential new treatment for IBD patients with iron deficiency chronic anemia and warrant further larger controlled studies.

A new oral formulation for the release of sodium butyrate in the ileo-cecal region and colon.

AIM: To develop a new formulation with hydroxy propyl methyl cellulose and Shellac coating for extended and selective delivery of butyrate in the ileo-caecal region and colon. METHODS: One-gram sodium butyrate coated tablets containing 13C-butyrate were orally administered to 12 healthy subjects and 12 Crohn's disease patients and the rate of 13C-butyrate absorption was evaluated by 13CO2 breath test analysis for eight hours. Tauroursodeoxycholic acid (500 mg) was co-administered as a biomarker of oro-ileal transit time to determine also the site of release and absorption of butyrate by the time of its serum maximum concentration. RESULTS: The coated formulation delayed the 13C-butyrate release by 2-3 h with respect to the uncoated tablets. Sodium butyrate was delivered in the intestine of all subjects and a more variable transit time was found in Crohn's disease patients than in healthy subjects. The variability of the peak 13CO2 in the kinetic release of butyrate was explained by the inter-subject variability in transit time. However, the coating chosen ensured an efficient release of the active compound even in patients with a short transit time. CONCLUSION: Simultaneous evaluation of breath 13CO2 and tauroursodeoxycholic acid concentration-time curves has shown that the new oral formulation consistently releases sodium butyrate in the ileo-cecal region and colon both in healthy subjects and Crohn's disease patients with variable intestinal transit time. This formulation may be of therapeutic value in inflammatory bowel disease patients due to the appropriate release of the active compound.

Efficacy of long term cyclic administration of the poorly absorbed antibiotic Rifaximin in symptomatic, uncomplicated colonic diverticular disease.

AIM: To comparatively evaluate the long term efficacy of Rifaximin and dietary fibers in reducing symptoms and/or complication frequency in symptomatic, uncomplicated diverticular disease. METHODS: 307 patients (118 males, 189 females, age range: 40-80 years) were enrolled in the study and randomly assigned to: Rifaximin (400 mg bid for 7 d every month) plus dietary fiber supplementation (at least 20 gr/d) or dietary fiber supplementation alone. The study duration was 24 mo; both clinical examination and symptoms' questionnaire were performed every two months. RESULTS: Both treatments reduced symptom frequency, but Rifaximin at a greater extent, when compared to basal values. Symptomatic score declined during both treatments, but a greater reduction was evident in the Rifaximin group (6.4 +/- 2.8 and 6.2 +/- 2.6 at enrollment, P = NS, 1.0 +/- 0.7 and 2.4 +/- 1.7 after 24 mo, P < 0.001, respectively). Probability of symptom reduction was higher and complication frequency lower (Kaplan-Meyer method) in the Rifaximin group (P < 0.0001 and 0.028, respectively). CONCLUSION: In patients with symptomatic, uncomplicated diverticular disease, cyclic administration of Rifaximin plus dietary fiber supplementation is more effective in reducing both symptom and complication frequency than simple dietary fiber supplementation. Long term administration of the poorly absorbed antibiotic Rifaximin is safe and well tolerated by the patients, confirming the usefulness of this therapeutic strategy in the overall management of diverticular disease.