Is there any place for alimentary probiotics, prebiotics or synbiotics, for patients with inflammatory bowel disease?

The pathogenesis of inflammatory bowel disease (IBD) involves an interaction between genetically determined host susceptibility, dysregulated immune response, and the enteric microbiota. Ecological treatments including probiotics, prebiotics, and synbiotics are actively studied in Crohn's disease (CD), ulcerative colitis (UC) and pouchitis. We review herein the literature on the rational use of probiotics in IBD considering efficacy (as evaluated in randomized controlled trials), mechanisms of action and safety issues. A probiotic effect is strictly restricted to one defined strain and cannot be generalized from one to another. There is evidence of efficacy of some probiotic drugs in pouchitis (VSL#3), and in the prevention of recurrence of UC (Escherichia coli Nissle 1917). However, the evidence for efficacy of probiotic drugs in CD is still low as well as that of dietary ecological treatments. Despite an ecological (hopefully nutritional) treatment of IBD is promising, many questions remain unanswered and further clinical and fundamental studies are needed.

Risk factors associated with small bowel adenocarcinoma in Crohn's disease: a case-control study

BACKGROUND AND AIMS

It is well established that Crohn's disease (CD) is associated with an increased risk of small bowel adenocarcinoma (SBA). The data concerning SBA risk factors in CD are scanty. The aim of this study was to identify them.

METHODS

In 11 French centers affiliated with the GETAID (Groupe d'Etude Thérapeutique des Affections Inflammatoires du Tube Digestif), we identified 29 patients with CD and SBA. Eighty-seven CD controls without SBA recruited in a single center were matched to the cases for sex, age, duration, and CD site. A conditional logistic regression, taking into account the matching between cases and controls, was performed.

RESULTS

In univariate analysis, the cases had had significantly less small bowel resection and received prolonged treatment with salicylates (more than 2 yr), less often than the controls (odds ratio, OR [95% confidence interval, CI] 0.07 [0.01-0.32] and 0.29 [0.10-0.82], respectively). In multivariate analysis, both associations remained significant (OR 0.04 [0.01-0.28], P= 0.001; OR 0.16 [0.03-0.79], P= 0.02, respectively).

CONCLUSION

This study suggests that small bowel resection and prolonged salicylates use may protect against SBA in CD patients.

Predictive factors of response to cyclosporine in steroid-refractory ulcerative colitis

OBJECTIVES

Cyclosporine is an effective rescue therapy in steroid-refractory ulcerative colitis (UC) and may avoid immediate colectomy. However, the individual's response to cyclosporine is poorly predictable. The aim of this study was to identify predictive factors of the response to cyclosporine in steroid-refractory UC.

METHODS

One hundred thirty-five patients with steroid-refractory UC, admitted consecutively between 1992 and 2004, were included. Data were collected on the first day of the cyclosporine therapy. Colonoscopy was performed within 2 days preceding or following the cyclosporine treatment in 118 patients for assessing the presence of severe endoscopic lesions.

RESULTS

The actuarial rate of colectomy was 0.45 at 6 months. Cox analysis in the whole population selected three predictive criteria of colectomy: body temperature >37.5 degrees C (adjusted hazard ratio = 1.94, 95% confidence interval 1.51-2.49), heart rate >90 bpm (1.86, 1.45-2.38), and C-reactive protein (CRP) >45 mg/L (1.70, 1.34-2.16). In the 118 patients who underwent colonoscopy, the presence of severe endoscopic lesions was an independent predictive factor of colectomy (2.38, 1.80-3.14). Colonoscopy was decisive and changed the therapeutic decision in patients with one or two criteria: 71% of the patients with severe endoscopic lesions were colectomized versus 17% of the patients without severe endoscopic lesions (P < 0.001). Finally, the clinical, biological, and endoscopic criteria allowed the classification of the patients into two different groups (80%vs 20% colectomy at 6 months).

CONCLUSION

In patients with steroid-refractory UC, the combination of simple criteria is useful to predict the response to cyclosporine. Colonoscopy is crucial in patients with intermediate clinical and biological severity.

A double blind randomized controlled trial of a probiotic combination in 100 patients with irritable bowel syndrome

OBJECTIVES

The purpose of this study was to evaluate the effects of a probiotic combination on symptoms in patients with irritable bowel syndrome (IBS).

METHODS

We investigated the efficiency of a probiotic dietary supplement, containing four strains of lactic acid bacteria, on symptoms of IBS. One hundred and sixteen patients with IBS fulfilling the Rome II criteria were randomized in a parallel group, double-blind study to receive a placebo or a probiotic combination (1 x 10(10) cfu once daily) for four weeks. The symptoms that were monitored weekly included discomfort, abdominal pain, and stool frequency and quality. Quality of life was assessed before and at the end of the treatment using the SF36 and FDD-quality-of-life questionnaires.

RESULTS

One hundred subjects completed the study (48 probiotic combination, 52 placebo). The probiotic combination was not superior to the placebo in relieving symptoms of IBS (42.6 versus 42.3% improvement). However, the decrease of abdominal pain between the first and the fourth week of treatment was significantly higher in probiotic treated patients (-41.9 versus -24.2%, P=0.048). Interesting findings from the IBS sub-groups were also observed such as a lower pain score at end point in patients with alternating bowel habits (P=0.023) and an increase of stool frequency in the constipated sub-group from the first week of probiotic treatment (P=0.043).

CONCLUSIONS

The probiotic combination was not significantly superior to the placebo in relieving symptoms of IBS. Despite the apparent high placebo response, interesting findings from IBS sub-groups were observed in the field of abdominal pain and stool frequency.

Nodular regenerative hyperplasia in patients with inflammatory bowel disease treated with azathioprine

AIM

To assess the characteristics and clinical course of nodular regenerative hyperplasia (NRH) in patients with inflammatory bowel disease treated with azathioprine, so as to estimate the frequency of this complication and search for risk factors.

METHODS

Cases were identified through a systematic survey of patients followed at 11 centres. At one centre, the cumulative risk of NRH was estimated and a case-control study was undertaken to identify risk factors.

RESULTS

37 cases of NRH (30 male, 7 female) were identified between 1994 and 2005. The median dose of azathioprine was 2 mg/kg/d (range 1.5 to 3.0). The median time between the start of azathioprine and the diagnosis of NRH was 48 months (range 6 to 187). After a median follow up period of 16 months (range 1 to 138), 14 patients developed complications of portal hypertension. Using multivariate analysis, male sex and stricturing behaviour were the two risk factors associated with NRH in patients treated with azathioprine. The cumulative risk calculated from the database (one centre) was 0.5% at 5 years (95% confidence interval, 0.11 to 0.89) and 1.25% at 10 years (0.29 to 2.21).

CONCLUSIONS

NRH is a rare but potentially severe complication of azathioprine in patients with inflammatory bowel disease. Clinicians should be aware of this complication, and should monitor liver function tests and platelet counts closely in their patients.

Patchy distribution of mucosal lesions in ileal Crohn's disease is not linked to differences in the dominant mucosa-associated bacteria: a study using fluorescence in situ hybridization and temporal temperature gradient gel electrophoresis

BACKGROUND

The mucosa-associated bacteria (MAB) are suspected of being involved in the pathogenesis of Crohn's disease. We analyzed and compared the MAB in noninflamed and inflamed ileal mucosa of Crohn's disease patients (n = 22).

METHODS

Tissue samples from the inflamed ileal mucosa and from the adjacent noninflamed ileal mucosa were taken from surgical resection specimens. The MAB were investigated using fluorescence in situ hybridization with 7 group-specific probes and temporal temperature gradient gel electrophoresis (TTGE).

RESULTS

Samples from both noninflamed and inflamed mucosa were obtained from 15 patients. The distribution of the bacterial populations was not different between noninflamed and inflamed mucosa. The Bacteroidetes phylum was dominant and accounted for 29% of MAB (0%-74%) in noninflamed tissues and 32% (0%-70%) in inflamed areas. The gamma Proteobacteria represented 12% (0%-70%) of MAB both in noninflamed and inflamed areas. The Clostridium coccoides group (Firmicutes phylum) represented 15% of MAB in noninflamed tissues versus 7% in inflamed areas. For most of the patients the similarity index between TTGE paired profiles was very high.

CONCLUSION

The dominant MAB do not differ between noninflamed and inflamed ileal mucosa in Crohn's disease. This argues against a localized dysbiosis to explain the patchy distribution of mucosal lesions.

Nutritional advantages of probiotics and prebiotics

The potential ‘nutritional advantages’ of probiotics and prebiotics consist of preventive, and sometimes curative, effects against certain diseases. The evidence supporting such advantages, which requires randomised controlled trials and consistency of results from study to study, is rapidly increasing. This article summarizes the effects against diseases of intestinal origin. There is a high level of evidence for positive effects of some prebiotics to alleviate constipation and treat hepatic encephalopathy. Interesting aspects, but with a lower level of evidence at the present time, include prevention of colon cancer, intestinal infection, and recurrence of inflammatory bowel disease. There is a high level of evidence for positive effects of some probiotics in the alleviation of lactose intolerance, antibiotic-associated intestinal disorders and gastroenteritis. Evidence is rapidly growing regarding the prevention of recurrence of inflammatory bowel diseases. Positive trials have suggested preventive effects against intestinal colonization with specific gut pathogens includingClostridium difficileandHelicobacter pylori.

Antioxidant effects of metronidazole in colonic tissue

Reactive oxygen species, primarily generated in the mitochondria, contribute to tissue injury in inflammatory bowel diseases. The efficacy of metronidazole (MTZ) in some situations of inflammatory bowel disease may result not only from its antibiotic effect, but also from an antioxidant effect. We evaluated, under physiologic conditions, the antioxidant potential of MTZ on the biomarkers of oxidative damage to proteins (protein carbonyls), lipids (malondialdehyde), and the levels of antioxidant defense (glutathione) in the small bowel, large bowel, and liver of control and MTZ-treated rats. Basal levels of protein carbonyls and malondialdehyde were significantly higher in the colon compared with those in the small intestine, whereas glutathione levels were quite similar along the bowel. MTZ reduced significantly the colonic oxidative damage to proteins without any side effect in the liver. This is the first evidence of an antioxidant effect of MTZ on oxidative protein damage in the colon under physiologic conditions.