Stress and brain functional changes in patients with Crohn's disease: A functional magnetic resonance imaging study.

BACKGROUND: In Crohn's disease (CD) patients, stress is believed to influence symptoms generation. Stress may act via central nervous system pathways to affect visceral sensitivity and motility thus exacerbating gastrointestinal symptoms. The neural substrate underpinning these mechanisms needs to be investigated in CD. We conducted an explorative functional magnetic resonance imaging (fMRI) study in order to investigate potential differences in the brain stress response in CD patients compared to controls. METHODS: 17 CD patients and 17 healthy controls underwent a fMRI scan while performing a stressful task consisting in a Stroop color-word interference task designed to induce mental stress in the fMRI environment. KEY RESULTS: Compared to controls, in CD patients the stress task elicited greater blood oxygen level dependent (BOLD) signals in the midcingulate cortex (MCC). CONCLUSIONS & INFERENCES: The MCC integrate "high" emotional processes with afferent sensory information ascending from the gut. In light of these integrative functions, the stress-evoked MCC hyperactivity in CD patients might represent a plausible neural substrate for the association between stress and symptomatic disease. The MCC dysfunction might be involved in mechanisms of central disinhibition of nociceptive inputs leading to amplify the visceral sensitivity. Finally, the stress-evoked MCC hyperactivity might affect the regulation of intestinal motility resulting in exacerbation of disease symptoms and the autonomic and neuroendocrine regulation of inflammation resulting in enhanced inflammatory activity.

Risk of permanent stoma in extensive Crohn's colitis: the impact of biological drugs.

AIM: The overall risk of permanent stoma was determined in patients with extensive Crohn's colitis. An attempt was made to analyse whether biological drugs have modified the surgical approach in patients with anorectal involvement. METHOD: In all, 233 patients with Crohn's disease colitis operated on between 1995 and 2010 were reviewed retrospectively. Fifty-one were treated before 2002 (prebiological era) and 182 after 2002 (biological era). The relationship was determined between the use of immunosuppressors, biological drugs, the presence of perianal disease and anorectal stenosis and the rate of permanent stoma formation. RESULTS: In the prebiological era 23 (45.1%) patients without anorectal involvement underwent colectomy and ileorectal anastomosis, 17 (33.3%) with severe anorectal disease had proctocolectomy and 11 (21.6%) with anorectal involvement had abdominal colectomy with permanent ileostomy. In the biological era 73 (40.1%) patients without anorectal involvement underwent colectomy and ileorectal anastomosis, nine (5%) with severe anorectal involvement had proctocolectomy and 100 (54.9%) with anorectal involvement had colectomy with terminal ileostomy. Of these 100, 75 have subsequently been treated with biological drugs with full regression of anorectal lesions in 81.3%. Rates of permanent stoma in the prebiological and biological era were 60.8% and 19.2% (P < 0.001). Univariate and multivariate analysis showed that only the use of biological drugs was significantly associated with an increased rate of rectal preservation (P < 0.05). CONCLUSION: The risk of a permanent stoma in patients with Crohn's colitis and anorectal involvement is significantly reduced with combined surgical and biological treatment.

New insights into the brain involvement in patients with Crohn's disease: a voxel-based morphometry study.

BACKGROUND: Crohn's disease (CD) is a chronic intestinal disorder characterized by overproduction of inflammatory cytokines and recurrent abdominal pain. Recently, brain morphological abnormalities in the pain matrix were found in patients with chronic pain disorders including irritable bowel syndrome. To investigate potential structural brain changes associated with CD, we used magnetic resonance imaging (MRI). Furthermore, we tested whether in patients gray matter (GM) volumes correlated with disease duration. METHODS: Eighteen CD patients in remission and 18 healthy controls underwent structural MRI. Voxel-based morphometry (VBM) is a fully automated technique allowing identification of regional differences in the amount of GM enabling an objective analysis of the whole brain between groups of subjects. VBM was used for comparisons and correlation analysis. KEY RESULTS: With respect to controls, CD patients exhibited decreased GM volumes in portion of the frontal cortex and in the anterior midcingulate cortex. Disease duration was negatively correlated with GM volumes of several brain regions including neocortical and limbic areas. CONCLUSIONS & INFERENCES: Crohn's disease is associated with brain morphological changes in cortical and subcortical structures involved in nociception, emotional, and cognitive processes. Our findings provide new insight into the brain involvement in chronic inflammatory bowel disorders.

Randomized controlled trials in pouchitis.

Pouchitis is the most common complication of Proctocolectomy with ileal pouch-anal anastomosis (IPAA) in patients with ulcerative colitis (UC). The diagnosis of pouchitis requires the presence of symptoms, together with characteristic endoscopic and histological abnormalities. The exact cause of pouchitis is not known. Whereas 'acute' pouchitis can be treated rapidly and successfully in the majority of patients, "refractory" and 'chronic pouchitis' remain therapeutic challenges to patients and physicians. Metronidazole and Ciprofloxacin budesonide enemas and oral probiotic therapy with VSL#3 all appear to be effective therapies for acute and/or chronic pouchitis. The medical therapy of pouchitis remains largely empiric, and additional multicenter, randomized, double-blind, placebo-con- trolled, dose-ranging trials are needed. In future trials, treatment indications such as active acute or chronic pouchitis and maintenance of remission for acute or chronic pouchitis should be clearly defined.

Distinct proteomic profiles characterise non-erosive from erosive reflux disease.

BACKGROUND: Erosive reflux disease (ERD) and non-erosive reflux disease (NERD) are often regarded as part of the spectrum of the same disease. AIM: To elucidate molecular features that characterise NERD and ERD at the protein level. METHODS: A total of 56 consecutive subjects were enrolled: 10 healthy subjects, 24 with NERD and 22 with ERD. Eight specimens were taken from macroscopically normal mucosa at 5 cm of gastro-oesophageal junction. Four were processed for the proteins extraction and four for evaluation using haematoxylin-eosin and immunohistochemistry. We used shotgun proteomics to identify tentative disease molecular features for ERD or NERD. Candidate distinctive proteins were verified using immunohistochemistry. RESULTS: Shotgun proteomics analysis revealed 33 differentially expressed proteins in NERD vs. ERD samples, involved in cellular proliferation, keratinisation, stress responses and sugar metabolism. Based on a gene ontology meta-analysis, seven of them were further analysed using Western blotting (WB) and four also using immunohistochemistry. We identified novel candidate disease molecular features for GERD and few distinctive proteins to discriminate NERD and ERD. In particular, Transitional Endoplasmic Reticulum ATPase (TER ATPase), GAPDH, Alpha 1 Acid Glycoprotein 1, Annexin A1, Calmodulin and 14-3-3 proteins were confirmed at WB analysis. CONCLUSIONS: Non-erosive reflux disease and ERD are distinct disease entities at the protein level. This study proposes an array of candidate biomarkers possibly useful to discriminate between NERD and ERD.

Selective cyclooxygenase-2 silencing mediated by engineered E. coli and RNA interference induces anti-tumour effects in human colon cancer cells.

BACKGROUND: Cyclooxygenase-2 (COX-2) overexpression is strongly associated with colorectal tumourigenesis. It has been demonstrated that the chronic use of non-steroidal anti-inflammatory drugs (COX inhibitors) partially protects patients from colorectal cancer (CRC) development and progression but induces severe cardiovascular side effects. New strategies for selective COX-2 blockade are required. METHODS: We developed an improved technique, based on RNA interference (RNAi), to gain a selective COX-2 silencing in CRC cells by a tumour-dependent expression of anti-COX-2 short-hairpin RNA (shCOX-2). Anti-COX-2 shRNA-expressing vectors were delivered in CRC cells (in vitro) and in colon tissues (ex vivo) using engineered Escherichia coli strains, capable of invading tumour cells (InvColi). RESULTS: A highly tumour-dependent shCOX-2 expression and a significant COX-2 silencing were observed in CRC cells following InvColi strain infection. Cyclooxygenase-2 silencing was associated with a strong reduction in both proliferative and invasive behaviour of tumour cells. We also demonstrated a pivotal role of COX-2 overexpression for the survival of CRC cells after bacterial infection. Moreover, COX-2 silencing was achieved ex vivo by infecting colon tissue samples with InvColi strains, leading to anti-inflammatory and anti-tumour effects. CONCLUSION: Our RNAi/InvColi-mediated approach offers a promising tool for a highly selective COX-2 blockade in vitro and in vivo.

Potential role of the cannabinoid receptor CB in the pathogenesis of erosive and non-erosive gastro-oesophageal reflux disease.

BACKGROUND: Cannabinoid (CB) receptors have been located in brain areas involved in the triggering of TLESRs as well as in the nodose ganglion from which vagal afferents emanate. The distribution of CB(1) receptors has been investigated in the human gastrointestinal mucosa, as expression of inflammatory process. AIM: To evaluate the CB(1) expression in oesophageal mucosa. METHODS: A total of 87 consecutive subjects were enrolled: 10 controls, 39 NERD and 38 erosive oesophagitis. Eight specimens were taken from macroscopically normal mucosa. Five were processed by haematoxylin-eosin, MIB1/CB(1) evaluation and three for the RNA and proteins extraction. RESULTS: The mean MIB1-LI value was 31% and 22% in NERD and ERD patients, respectively, compared to 68% in the healthy subjects. Mean CB(1)mRNA/GUSB mRNA value of the controls was 0.66, while in GERD patients, it was 0.28. In NERD and ERD, the mean values of CB(1)/GUSB were 0.38 and 0.17, respectively, with highly significant differences between the NERD vs. ERD groups. Semi-quantitative analysis of CB(1) expression, performed with WB, shows in NERD patients a higher CB(1) receptor expression than ERD patients. CONCLUSIONS: With this study, we showed for the first time the presence of CB(1) receptors in the human oesophageal epithelium.

Clinical trial: ulcerative colitis maintenance treatment with 5-ASA: a 1-year, randomized multicentre study comparing MMX with Asacol.

BACKGROUND: 5-ASA-MMX (1.2 g/tablet) is a 5-aminosalicylic acid formulation, designed for once-daily dosing in the treatment of ulcerative colitis. AIM: To evaluate the efficacy and safety of 5-ASA-MMX (2.4 g/day, once daily), compared with Asacol (2.4 g/day, twice daily) in the maintenance of left-sided UC, through a double-blind, double-dummy, parallel-group, randomized, comparator study. METHODS: In all, 331 patients with UC were randomized to receive either 5-ASA-MMX 2.4 g/day, once daily, or Asacol 2.4 g/day, twice daily, for 12 months. All patients were in remission for >or=1 month prior to the trial, with >or=1 documented relapse in the previous year. The co-primary endpoints of this study were the proportion of patients in clinical, and clinical and endoscopic remission following 12 months' treatment. RESULTS: In the intent-to-treat population, excluding those with major protocol deviations, 68.0 and 65.9% patients in the 5-ASA-MMX and Asacol groups, respectively, were in clinical remission (P = 0.69), and 60.9 and 61.7% of patients, respectively, were in clinical and endoscopic remission (P = 0.89). Diary card data revealed statistically significant treatment differences favouring 5-ASA-MMX. Both treatments were similarly tolerated. CONCLUSIONS: Once-daily 5-ASA-MMX is similarly effective with a comparable safety profile to Asacol administered twice daily, for the maintenance treatment of ulcerative colitis.

Medical treatment and management of severe ulcerative colitis.

Severe colitis is a life-threatening complication of ulcerative colitis. Early recognition of the severity of the colitis and intensive treatment and monitoring have all contributed to improved outcome. Since their introduction in the 1950s, corticosteroids are the first line therapy for severe active ulcerative colitis (UC). Several prognostic parameters (such as stools movement per day, C-reactive protein, increased amount of intestinal gas or small bowel dilation, hypoalbuminemia, fever, etc.) help the physician to quickly introduce infliximab or cyclosporine or to refer the patient to the surgeon. This decision requires a careful evaluation of the patient and a medical/surgical team.

Interaction of probiotic Lactobacillus and Bifidobacterium strains with human intestinal epithelial cells: adhesion properties, competition against enteropathogens and modulation of IL-8 production.

The human intestinal microbiota plays a pivotal role in human nutrition and health by promoting the supply of nutrients, preventing pathogen colonization and shaping and maintaining normal mucosal immunity. The depletion of the individual microbiota can result in a higher susceptibility to enteropathogenic bacteria infection. In order to reduce this risk, the use of food supplements containing probiotic bacteria has been recently addressed. In this paper, we investigate the protective role toward enteropathogen infection of probiotic strains belonging to Lactobacillus and Bifidobacterium. According to our experimental data, Lactobacillus acidophilus Bar13, L. plantarum Bar10, Bifidobacterium longum Bar33 and B. lactis Bar30 were effective in displacing the enteropathogens Salmonella typhimurium and Escherichia coli H10407 from a Caco-2 cell layer. Moreover, L. acidophilus Bar13 and B. longum Bar33 have been assessed for their immunomodulatory activity on IL-8 production by HT29 cells. Both strains showed the potential to protect enterocytes from an acute inflammatory response. These probiotic strains are potential candidates for the development of new functional foods helpful in counteracting enteropathogen infections.

Short-term treatment with infliximab in chronic refractory pouchitis and ileitis.

BACKGROUND: Chronic refractory pouchitis is a long-term complication after ileal pouch-anal anastomosis and it may be associated with ileal inflammation. AIM: To determine the efficacy of infliximab in treatment of chronic refractory pouchitis complicated by ileitis, using a wireless capsule endoscopy. METHODS: Sixteen patients with chronic refractory pouchitis complicated by ileitis were enrolled. Pouchitis was diagnosed by clinical, endoscopic and histological criteria. Ileitis was documented using wireless capsule endoscopy. Duodenum-jejunum and proximal-middle ileum were evaluated and the presence of small lesions and large lesions were noted. Crohn's disease, intestinal infections were excluded in all patients. Patients were treated with infliximab and clinical response was recorded. Wireless capsule endoscopy was repeated at week 10 and Pouchitis Disease Activity Index score was determined. RESULTS: Ten patients were enrolled and completed the study. Clinical remission was achieved in nine patients. At wireless capsule endoscopy and pouch endoscopy, a complete recovery of lesions was observed in eight patients. One patient presented four small lesions of the ileum at the 6 weeks of treatment and one patient did not show any modification. Clinical and endoscopic remission was maintained in these eight patients at least 6 months. CONCLUSION: These preliminary results indicate that infliximab may be recommended for the treatment of chronic refractory pouchitis complicated by ileitis.

Controlled study using wireless capsule endoscopy for the evaluation of the small intestine in chronic refractory pouchitis.

BACKGROUND: Pouchitis is a common long-term complication after ileal pouch anal anastomosis for ulcerative colitis. Chronic refractory pouchitis is a treatment-resistant condition that affects 5-15% of patients. AIM: To test the hypothesis of a small bowel involvement using wireless capsule endoscopy. MATERIAL AND METHODS: This is a single-blind, prospective, cohort study. Twenty-four patients: 16 were patients with chronic refractory pouchitis and eight, with a macroscopically and histologically normal ileal pouch, were considered as control subjects. Diagnosis of pouchitis was confirmed using the pouchitis disease activity index. All subjects were submitted to wireless capsule endoscopy procedure. Within 2 weeks before wireless capsule endoscopy, patients underwent a pouch endoscopy and a small bowel follow-through. Re-examination of the colonic surgical and histological specimens was also performed. RESULTS: One patient with chronic pouchitis was excluded because of incomplete bowel cleaning. At small bowel follow-through of 16 patients, two subjects (13%) showed only a focal ectasia of the middle ileum and a substenosis of the pouch. At wireless capsule endoscopy all the 15 evaluable patients with chronic pouchitis (100%) showed diffuse lesions from duodenum to ileum consisting of aphthae, erosions, erythema, atrophy, cobblestone, deep/fissural ulcers. CONCLUSIONS: This enteropathy needs further research, and wireless capsule endoscopy could be useful to show involvement of small bowel in patients with chronic pouchitis.

Oral budesonide in the treatment of chronic refractory pouchitis.

BACKGROUND: Pouchitis is the major long-term complication after ileal-pouch nal anastomosis for ulcerative colitis. Ten to 15% of patients develop a chronic pouchitis, either treatment responsive or treatment refractory. AIM: To evaluate the efficacy of oral budesonide in inducing remission and improving quality of life in patients with chronic refractory pouchitis. METHODS: Twenty consecutive patients with active pouchitis, not responding after 1 month of antibiotic treatment were treated with budesonide controlled ileal release 9 mg/day for 8 weeks. Symptomatic, endoscopic and histological evaluations were undertaken before and after treatment according to Pouchitis Disease Activity Index. Remission was defined as a combination of Pouchitis Disease Activity Index clinical score of < or = 2, endoscopic score of < or = 1 and total Pouchitis Disease Activity Index score of < or = 4. The quality of life was assessed with the Inflammatory Bowel Disease Questionnaire. RESULTS: Fifteen of 20 patients (75%) achieved remission. The median total Pouchitis Disease Activity Index scores before and after therapy were, respectively, 14 (range 9-16) and 3 (range 2-10) (P < 0.001). The median Inflammatory Bowel Disease Questionnaire score also significantly improved from 105 (range 77-175) to 180 (range 85-220) (P < 0.001). CONCLUSION: Eight-week treatment with oral budesonide appears effective in inducing remission in patients with active pouchitis refractory to antibiotic treatment in this open-label study.

Beclomethasone dipropionate versus mesalazine in distal ulcerative colitis: a multicenter, randomized, double-blind study.

BACKGROUND: Topical beclomethasone diproprionate has shown efficacy in ulcerative colitis. AIM: To assess, in a multicenter, randomized, double-blind study, the tolerability and safety of topical beclomethasone diproprionate (3mg) enema and foam versus mesalazine (2g) enema and foam in mild-moderate distal ulcerative colitis. PATIENTS: In 15 referral gastrointestinal units, 99 patients with distal ulcerative colitis were enrolled. This number was lower than planned according to the statistical analysis, due to a low recruitment rate. METHODS: Patients were randomly assigned to random preparations (beclomethasone diproprionate enema, beclomethasone diproprionate foam, mesalazine enema, mesalazine foam) once nightly for 8 weeks, with clinical and endoscopical assessment (Disease Activity Index score) at baseline (T0), 4 (T4) and 8 weeks (T8). Results were expressed as median and range (95% confidence interval). The efficacy was assessed by comparing the Disease Activity Index value at T4 and T8 by using the Student's t-test or the Wilcoxon-Mann-Whitney test. RESULTS: Efficacy was comparable in the beclomethasone diproprionate or mesalazine groups at both T4 and T8 (response at T4: beclomethasone diproprionate 78% [95% confidence interval 0.6-0.8] versus mesalazine 79% [95% confidence interval 0.6-0.8]; T8: beclomethasone diproprionate 84% [95% confidence interval 0.7-0.9] versus mesalazine 90% [95% confidence interval 0.7-1.0]; p=n.s.; remission at T4: beclomethasone diproprionate 24% [95% confidence interval 0.1-0.3] versus mesalazine 28% [95% confidence interval 0.1-0.3]; remission at T8: beclomethasone diproprionate 36% [95% confidence interval 0.2-0.5] versus mesalazine 52% [95% confidence interval 0.3-0.6]; p=n.s.). The Disease Activity Index lowered at T4 and T8 versus T0 in the four groups (T4 versus T0: beclomethasone diproprionate foam Disease Activity Index 2 versus 6 p<0.0001; beclomethasone diproprionate enema 4 versus 6, mesalazine enema 3 versus 6, mesalazine foam 3.5 versus 7, p<0.001 for all three groups; T8 versus T0: p<0.01). The Disease Activity Index lowered at T8 versus T4 in the beclomethasone diproprionate enema and foam (Disease Activity Index: 2 versus 4 and 1 versus 4, respectively; p<0.05) and in the mesalazine enema (Disease Activity Index: 1.5, range 0-4 versus 3, range 0-12; p<0.01), but not in the mesalazine foam group (Disease Activity Index: 1, range 0-9 versus 3.5, range 0-8; p=n.s.). The safety profile was favourable for all groups. CONCLUSIONS: Beclomethasone diproprionate and mesalazine enema and foam show a comparable tolerability and efficacy in mild active distal ulcerative colitis.

Review article: aminosalicylates for distal colitis.

About two-thirds of patients with ulcerative colitis have an inflammatory involvement distal to the splenic flexure and therefore may be effectively treated with topical treatment. This allows the delivery of the active drug directly to the site of inflammation, limiting the systemic absorption and the potential side effects. Topical aminosalicylate therapy is the most effective approach, provided that the formulation reaches the upper extent of the disease. Suppositories should be considered the treatment of choice for proctitis and distal sigmoiditis. A 1 g Pentasa-suppository once daily induces a quicker clinical and endoscopic remission and was better tolerated than a 500-mg suppository twice daily. Enemas, foams and gel, thanks to their proximal spread, should be the treatment of choice for proctosigmoiditis and left-sided colitis. Oral aminosalicylates are less effective than topical therapies for patients with active disease; however, a combination of oral and topical aminosalicylates can be successfully tried in refractory patients. Topical aminosalicylates also play an important role in the maintenance of remission, and the combination of oral plus rectal 5-aminosalicylate is superior to the single agent. Patients who prefer not to continue on long-term rectal therapy can be treated with oral aminosalicylates.

CT-guided percutaneous pelvic abscess drainage in Crohn's disease.

BACKGROUND: Percutaneous abscess drainage (PAD) is the current therapy for abdominal or pelvic collections. PAD has poorer curative rate for abscesses in Crohn's disease (CD), commonly complicated by wide fistulas and multiloculations. METHODS: We retrospectively evaluated abscess cure rate, complications and final outcome in 87 CD patients, 70 with spontaneous and 17 with postoperative pelvic abscesses, all treated with CT-guided PAD during the last 7 years. RESULTS: A 77% primary success rate and an 84.3% secondary success rate were obtained without major complications. The higher success rate for PAD was for postoperative (88.2%) rather than spontaneous abscesses (74.2%). Seventy-two percent of treated patients did not develop recurrent abscesses and underwent elective surgery up to 40 months later. CONCLUSION: PAD in pelvic abscess complicating CD is an effective alternative to early surgery with satisfactory curative success rates. In unsuccessful cases, due to wide fistulas or postoperative anastomotic dehiscence, PAD helped in planning elective surgery, reducing surgical complications.

Antibiotic treatment of Crohn's disease: results of a multicentre, double blind, randomized, placebo-controlled trial with rifaximin.

BACKGROUND: Clinicians often employ antibiotics in Crohn's disease. Rifaximin is active against bacteria frequently found in the intestinal mucosa of Crohn's disease patients. AIM: To evaluate the difference in efficacy between once and twice/daily oral administration of rifaximin and placebo in the treatment of active Crohn's disease. METHODS: We enrolled 83 patients with mild-to-moderate Crohn's disease and randomized to three treatments for 12 weeks: Group A (rifaximin 800 mg o.d. + placebo), Group B (rifaximin 800 mg b.d.) and Group C (placebo b.d.). RESULTS: Clinical remission was achieved by 52% of Group B, 32% (A) and 33% (C). Clinical response was seen in 67% (B), 48% (A) and 41% (C), without reaching a statistically significant difference. Treatment failures were: 4% (B), 12% (A) and 33% (C), (P = 0.010). Remission and response rates of rifaximin 800 mg b.d. were significantly higher than those of placebo and rifaximin 800 mg o.d. in patients with elevated C reactive protein values (P < 0.05). CONCLUSIONS: Rifaximin 800 mg b.d. was superior to placebo in inducing clinical remission of active Crohn's disease. Although this difference was not statistically significant, the number of the failures in the placebo group was significantly higher than those who received rifaximin 800 mg b.d.

Bacterial and fungal microbiota in relation to probiotic therapy (VSL#3) in pouchitis.

BACKGROUND: The intestinal microbiota plays a critical role in the pathophysiology of pouchitis, a major complication after ileal pouch anal anastomosis in patients with ulcerative colitis. Recently, controlled trials have demonstrated that probiotics are effective in maintenance of remission in pouchitis patients. However, the mechanism by which therapy with probiotics works remains elusive. This study explores the role of the bacterial and fungal flora in a controlled trial for maintenance of remission in pouchitis patients with the probiotic VSL#3 compound. METHODS: The mucosa associated pouch microbiota was investigated before and after therapy with VSL#3 by analysis of endoscopic biopsies using ribosomal DNA/RNA based community fingerprint analysis, clone libraries, real time polymerase chain reaction (PCR), and fluorescence in situ hybridisation. Patients were recruited from a placebo controlled remission maintenance trial with VSL#3. RESULTS: Patients who developed pouchitis while treated with placebo had low bacterial and high fungal diversity. Bacterial diversity was increased and fungal diversity was reduced in patients in remission maintained with VSL#3 (p = 0.001). Real time PCR experiments demonstrated that VSL#3 increased the total number of bacterial cells (p = 0.002) and modified the spectrum of bacteria towards anaerobic species. Taxa specific clone libraries for Lactobacilli and Bifidobacteria showed that the richness and spectrum of these bacteria were altered under probiotic therapy. CONCLUSIONS: Probiotic therapy with VSL#3 increases the total number of intestinal bacterial cells as well as the richness and diversity of the bacterial microbiota, especially the anaerobic flora. The diversity of the fungal flora is repressed. Restoration of the integrity of a "protective" intestinal mucosa related microbiota could therefore be a potential mechanism of probiotic bacteria in inflammatory barrier diseases of the lower gastrointestinal tract.

Probiotics and barrier function in colitis.

Probiotic administration may exert a protective effect in colitis by preventing mucosal barrier disruption and influencing the extent of mucosal injury.