Ulcerative colitis: factors affecting difficulties of life and psychological well being of patients in remission

BACKGROUND

Ulcerative colitis is a chronic disease of unknown aetiology characterized by alternating periods of remission and relapses. The difficulties in the patients with ulcerative colitis daily life mostly arise from symptoms associated with bowel inflammation but there are many patients who have difficulties despite being in the remission phase. This study was conducted to elucidate factors that influence perception of difficulties of life and psychological well being of patients with ulcerative colitis in remission.

METHODS

A questionnaire survey was carried out in 72 outpatients with ulcerative colitis in remission. The perception of difficulties of life was assessed using the scale developed by Tanaka et al. Psychological well being was assessed using the Japanese version of the 'profile of mood states'. Physical condition, demographic attributes and psychosociological states were also investigated as related factors.

RESULTS

There was no outstanding aspect of psychological well being, but a relatively large number of patients perceived a 'decline of vitality or vigour' despite being in the remission phase. In the presence of irritable bowel syndrome-like symptoms, the scores for 'difficulties of life in society' or 'difficulties concerned with bowel movements' were high. Scores for 'decline of vitality or vigour' were high when the emotive coping scores were high, social support was lower, disease durations were short and relapses occurred more than once. When the emotive coping scores were high, psychological well being was not fine.

RELEVANCE TO CLINICAL PRACTICE

Strategies need to be developed to allow patients to recover and maintain their strength in the remission phase. Further, the strategies should take the above factors into consideration.

Lyprinol (stabilised lipid extract of New Zealand green-lipped mussel): a potential preventative treatment modality for inflammatory bowel disease

BACKGROUND

Lyprinol (Pharmalink International), the stabilised lipid extract of the New Zealand green-lipped mussel, is currently used to relieve symptoms of arthritis. We investigated the effect of pretreatment with Lyprinol (LYP) on experimentally induced inflammatory bowel disease (IBD) in mice.

METHODS

Male C57BL/6 mice (aged 6 weeks) were gavaged daily for 13 days with (150 microl) olive oil (OO; n = 7), fish oil (FO; n = 8), or LYP (n = 8). Mice consumed 2% dextran sulfate sodium (DSS) for 6 days, starting on day 7. Body weight and disease activity index (DAI) scores were recorded daily. Colonic damage was determined by histopathology. Colonic inflammation was quantified by myeloperoxidase (MPO) activity.

RESULTS

LYP treatment significantly (P < 0.05) reduced body weight loss, DAI scores, crypt area losses, and cecum and colon weights, compared with FO treatment. MPO activity was not significantly affected by any treatment.

CONCLUSIONS

These findings provide preliminary evidence that Lyprinol may be potentially useful in ameliorating symptoms of IBD. The benefit, however, is unlikely to be due to the omega-3 fatty acid content. Dose-response evaluation of Lyprinol in experimental IBD is warranted.

The effect of dietary glutathione and coenzyme Q10 on the prevention and treatment of inflammatory bowel disease in mice

Because reactive oxygen species have been implicated as mediators of inflammatory bowel disease (IBD), we evaluated the potential preventive and therapeutic effects of two dietary antioxidants, glutathione (GSH) and coenzyme Q10 (CoQ10) on dextran sulfate sodium (DSS)-induced colitis in mice. Fifty female 8-wk old Swiss-Webster mice were randomly assigned to 4 groups for a pre-treatment "prevention" study: (1) GSH (1% of diet); (2) CoQ10 (200 mg/kg/d); (3) DSS only (3% of drinking water); (4) control (no treatment). The mice in groups 1 and 2 were fed with GSH or CoQ10 for 21 wks, and the mice in groups 1, 2 and 3 were provided DSS from wk 7 for 4 cycles (1 cycle = 1 wk DSS followed by 2-wk water). Another 50 mice were randomly assigned to 4 groups for a 21-wk "treatment" study where the mice in groups 1, 2, and 3 were administered DSS for 6 cycles (18 wks) to induce colitis. GSH and CoQ10 were added from wk 7 until the completion of the protocol. Loose stools and hemocult positivity were modestly but significantly reduced with GSH or CoQ10 at several periods during the intervention in both the prevention and treatment studies. In contrast, histological evaluation revealed increases in colonic dysplasia and ulceration with GSH or CoQ10. Thus, in this mouse model, GSH and CoQ10 appear to have a beneficial effect on acute signs of IBD, but may have an adverse impact on the chronic pathophysiology of the disease. Further studies using additional animal models are required to determine whether GSH or CoQ10 provide a favorable or unfavorable benefit:risk ratio in the prevention or treatment of IBD.

Dietary risk factors for inflammatory bowel disease: a multicenter case-control study in Japan

To evaluate the role of dietary factors in the etiology of inflammatory bowel disease (IBD), we conducted a multicenter hospital-based case-control study in a Japanese population. Cases were IBD patients aged 15 to 34 years [ulcerative colitis (UC) 111 patients; Crohn's disease (CD) 128 patients] within 3 years after diagnosis in 13 hospitals. One control subject was recruited for each case who was matched for sex, age, and hospital. A semiquantitative food frequency questionnaire was used to estimate preillness intakes of food groups and nutrients. All the available control subjects (n = 219) were pooled, and unconditional logistic models were applied to calculate odds ratios (ORs). In the food groups, a higher consumption of sweets was positively associated with UC risk [OR for the highest versus lowest quartile, 2.86; 95% confidence interval (CI), 1.24 to 6.57], whereas the consumption of sugars and sweeteners (OR, 2.12; 95% CI, 1.08 to 4.17), sweets (OR, 2.83; 95% CI, 1.38 to 5.83), fats and oils (OR, 2.64; 95% CI, 1.29 to 5.39), and fish and shellfish (OR, 2.41; 95% CI, 1.18-4.89) were positively associated with CD risk. In respect to nutrients, the intake of vitamin C (OR, 0.45; 95% CI, 0.21 to 0.99) was negatively related to UC risk, while the intake of total fat (OR, 2.86; 95% CI, 1.39 to 5.90), monounsaturated fatty acids (OR, 2.49; 95% CI, 1.23 to 5.03) and polyunsaturated fatty acids (OR, 2.31; 95% CI, 1.12 to 4.79), vitamin E (OR, 3.23; 95% CI, 1.45 to 7.17), and n-3 (OR, 3.24; 95% CI, 1.52 to 6.88) and n-6 fatty acids (OR, 2.57; 95% CI, 1.24 to 5.32) was positively associated with CD risk. Although this study suffers from the shortcoming of recall bias, which is inherent in most retrospective studies (prospective studies are warranted to confirm the associations between diet and IBD risk), the present findings suggest the importance of dietary factors for IBD prevention.

Cigarette smoking and age at diagnosis of inflammatory bowel disease

OBJECTIVES

The incidence and age of onset of inflammatory bowel disease (IBD) appear to be changing. The aim of this study was to determine whether the prevalence of cigarette smoking differs among patients with Crohn's disease (CD) or ulcerative colitis (UC) at the time of diagnosis compared with the general population and whether smoking history is related to the type and age of IBD onset.

METHODS

Prevalence rates of smoking at the time of IBD diagnosis were compared between patients with CD and UC from the IBD Center at the University of Pittsburgh Medical Center versus age-, gender-, and time period-adjusted rates in the Pennsylvania general population. Analyses also were stratified by gender and diagnoses before and after 40 years of age, i.e., early and late onset.

RESULTS

There were 263 IBD patients (144 UC patients and 119 CD patients) seen in the IBD center between August 2000 and December 2002. The prevalence of active smoking was significantly higher at diagnosis in CD patients compared with the Pennsylvania general population (33% versus 24%, P = 0.04), particularly in those with CD onset at 40 years of age or later (47% versus 27%, P = 0.005). In contrast, smoking prevalence was significantly lower in UC patients than the general population (9% versus 28%, P < 0.0001), particularly among those with UC onset before the age of 40 years (6% versus 27%, P < 0.0001). Smoking cessation was associated with an approximate, but nonsignificant, 3-fold higher likelihood of late-onset UC compared with CD.

CONCLUSIONS

Cigarette smoking is associated with the development of late-onset CD and is protective against developing UC at any age, particularly early onset. Former smoking is associated with a high likelihood of developing late-onset UC, but not CD.

The pharmacological actions of nicotine on the gastrointestinal tract

Increasing use of tobacco and its related health problems are a great concern in the world. Recent epidemiological findings have demonstrated the positive association between cigarette smoking and several gastrointestinal (GI) diseases, including peptic ulcer and cancers. Interestingly, smoking also modifies the disease course of ulcerative colitis (UC). Nicotine, a major component of cigarette smoke, seems to mediate some of the actions of cigarette smoking on the pathogenesis of GI disorders. Nicotine worsens the detrimental effects of aggressive factors and attenuates the protective actions of defensive factors in the processes of development and repair of gastric ulceration. Nicotine also takes part in the initiation and promotion of carcinogenesis in the GI tract. In this regard, nicotine and its metabolites are found to be mutagenic and have the ability to modulate cell proliferation, apoptosis, and angiogenesis during tumoriogenesis through specific receptors and signalling pathways. However, to elucidate this complex pathogenic mechanism, further study at the molecular level is warranted. In contrast, findings of clinical trials give promising results on the use of nicotine as an adjuvant therapy for UC. The beneficial effect of nicotine on UC seems to be mediated through multiple mechanisms. More clinical studies are needed to establish the therapeutic value of nicotine in this disease.

Effect of 5-substituted benzylideneaminosalicylic acid on carrageenan-induced ulcerative colitis

Mesalazine, a drug of choice in the management of ulcerative colitis, was chemically modified as 5-(E)-substituted benzylideneaminosalicylic acid by condensing 5-aminosalicylic acid with selected aryl aldehydes with an intention to improve its pharmacological profile. The tests were performed to study their anti-inflammatory effect on carrageenan-induced ulcerative colitis in albino rats. The histopathological findings, serum transaminase level and lipid peroxide content in the intestine and liver were taken as indices of pharmacological activity. The azomethine derivative formed from salicylaldehyde (5-ASASB3) was found to have maximum activity and it reversed the disease symptoms in experimental animals The azomethine derivative markedly reduces the ulcerative colitis when compared with parent molecule, mesalazine.

Protective effect of lactulose on dextran sulfate sodium-induced colonic inflammation in rats

Promising results have recently been obtained with pre- and probiotic therapy in ulcerative colitis (UC). The prebiotic potential of lactulose is well established, but it has not yet been investigated in experimental colitis models. The purpose of the study was to examine the effect of lactulose on an UC model induced by 3% dextran sulfate sodium (DSS) solution added to drinking water for 7 days in male Wistar rats. Lactulose (300-1000 mg/kg) or 5-aminosalicylic acid (5-ASA; 150 mg/kg) was administered orally twice daily for 6 days. Colonic ulceration area, colon length, body weight changes, diarrhea/bloody feces, colonic mucosal myeloperoxidase activity (MPO), thiobarbituric acid reactive substances (TBARS), and histology were examined. Treatment of animals with DSS for 7 days resulted in severe colonic lesions accompanied by diarrhea, bloody feces, a decrese in body weight, shortening of the colon length, and an increase in MPO activity as well as TBARS, compared to normal rats. Lactulose treatment ameliorated DSS-induced colitis in a dose-dependent manner, and at 1000 mg/kg all of the parameters examined, except TBARS, were shown to improve significantly as compared to controls. Daily administration of 5-ASA also significantly reduced the severity of colonic lesions following DSS treatment. These results demonstrated the protective effect of lactulose in this rat colitis model and suggested that the background of this lactulose effect may be due to alterations of colonic microflora.

Guidelines for immunizations in patients with inflammatory bowel disease

During the past 2 decades, medical therapy for Crohn's disease (CD) and ulcerative colitis (UC) has grown to incorporate a variety of immunesuppressing agents. At the same time, basic insights into the aberrant mucosal immune response underlying inflammatory bowel disease (IBD) have expanded dramatically. The interplay of host susceptibility to infection and the safety and efficacy of immunization for vaccine-preventable diseases has been explored in other immune-mediated disease states but only rarely in IBD. The purpose of this review is to formulate best-practice recommendations for immunization in children and adults with IBD by considering the effects of the IBD disease state and its treatments on both the safety and efficacy of immunization. To do so, we first considered the routine recommendations for immunization of children, adults and distinct populations at increased risk for vaccine-preventable disease. Because it was rarely possible to examine direct data on safety and efficacy of immunization in IBD populations, we relied to a large extent upon extrapolation from similar populations and from knowledge of basic mechanisms. The literature suggests that efficacy of immunization may be diminished in some patients whose immune status is compromised by immune suppression. However, except for live agent vaccines, most immunizations may be safely administered to patients with IBD even when immune compromised. Conversely, protection against vaccine-preventable illness may be of even greater benefit to those at risk for morbid or lethal complications of infections because of an immune compromised state. We conclude that for most patients with IBD, recommendations for immunization do not deviate from recommended schedules for the general population.

Blocking lymphotoxin-beta receptor activation diminishes inflammation via reduced mucosal addressin cell adhesion molecule-1 (MAdCAM-1) expression and leucocyte margination in chronic DSS-induced colitis

The lymphotoxin-beta receptor (LTbetaR) pathway is critical for maintenance of organized lymphoid structures and is involved in the development of colitis. To investigate the mechanisms by which LTbetaR activation contributes to the pathology of chronic inflammation we used a soluble LTbetaR-Ig fusion protein as a competitive inhibitor of LTbetaR activation in the mouse model of chronic colitis induced by oral administration of dextran sulphate sodium. Strong expression of LTbeta which constitutes part of the LTalpha(1)beta(2) ligand complex was detected in colonic tissue of mice with chronic colitis. Treatment with LTbetaR-Ig significantly attenuated the development and histological manifestations of the chronic inflammation and reduced the production of inflammatory cytokines such as TNF, IL-1beta, and IL-6. Moreover, LTbetaR-Ig treatment significantly down-regulated mucosal addressin cell adhesion molecule-1 (MAdCAM-1) expression, leading to reduced leucocyte rolling and sticking in postcapillary and collecting venules and reduced extravasation into the intestinal mucosa as quantified by in vivo fluorescence microscopy. Thus, LTbetaR pathway inhibition ameliorates DSS-induced experimental chronic colitis in mice by MAdCAM-1 down-regulation entailing reduced lymphocyte margination and extravasation into the inflamed mucosa. Therefore, a combined treatment with reagents blocking T cell-mediated perpetuation of chronic inflammation such as LTbetaR-Ig together with direct anti-inflammatory reagents such as TNF inhibitors could constitute a promising treatment strategy for chronic colitis.

Does Appendectomy Reduce the Risk of Ulcerative Colitis?

BACKGROUND

Persons who have had an appendectomy are less prone to develop ulcerative colitis than those who have not. The underlying mechanism and the clinical use of this finding are unknown.

METHODS

Two competing hypotheses were examined: (1) the inverse association between appendectomy and ulcerative colitis is conferred by a mutual determinant such as genes, and (2) the appendix itself has biologic effects that promote the development of ulcerative colitis. We performed a population-based cohort study of all 234,559 persons who had an appendectomy performed in Denmark 1977 through 1999. We used a bidirectional cohort design, calculating the standardized incidence rate of ulcerative colitis both before and after the appendectomy. If the hypothesis of a constant, confounding factor were true, incidence rates of ulcerative colitis would be equal before and after appendectomy. If the incidence of ulcerative colitis were lower after appendectomy than before, it would support the second hypothesis and a true protective effect of the appendectomy. We controlled confounding by age and sex using direct standardization.

RESULTS

Of 234,559 persons who had an appendectomy, 559 developed ulcerative colitis during a mean follow up of 17.5 years. The standardized incidence rate of ulcerative colitis was lower in the postappendectomy period than in the preappendectomy period (incidence rate ratio = 0.74; 95% confidence interval = 0.62-0.88).

CONCLUSIONS

The inverse association between appendectomy and ulcerative colitis is not explained by time-stable factors such as genes. Appendectomy might have a genuine protective effect toward development of ulcerative colitis.

Suppressive activity of a fermented grain food product on dextran sulfate sodium-induced experimental colitis in mice

Oxidative stress has been shown to play pivotal roles in the onset of inflammatory bowel disease. We evaluated the effects of a dietary anti-oxidant, Antioxidant Biofactor (AOB), a processed grain food, on dextran sulfate sodium (DSS)-induced colitis in mice. Female ICR mice were fed a diet containing 0.1% or 1% AOB for 2 weeks, during which they were given 5% DSS in drinking water for the latter 1 week to induce colitis. A diet containing 1% AOB, but not that with 0.1% AOB, attenuated DSS-induced body weight loss and colon shortening (each, P < 0.05), and dramatically improved colitis histologic scores. In addition, DSS-induced increases in colonic mucosal IL-1beta, but not TNF-alpha, protein levels were significantly abrogated in 1% AOB-fed mice (P < 0.05). Further, 1% dietary AOB abolished the expression of IL-1beta mRNA levels in colonic mucosa (P < 0.01). Our results suggest that AOB is effective for the prevention of DSS-induced colitis in mice.

Earlier surveillance colonoscopy programme improves survival in patients with ulcerative colitis associated colorectal cancer: results of a 23-year surveillance programme in the Japanese population

Patients with long-standing ulcerative colitis (UC) are known to have an increased risk for the development of colorectal cancer (CRC). The aim of this study was to clarify the cumulative risk for the development of dysplasia or invasive cancer and the effectiveness of surveillance colonoscopy in the Japanese population. A total of 217 patients received a total of 1027 surveillance colonoscopies between January 1979 and December 2001 at the University of Tokyo hospital. Patients with invasive cancer found in the surveillance group were compared to those referred to our hospital from the other hospitals without surveillance colonoscopy. Surveillance colonoscopy confirmed 15 patients with definite dysplasia. Of these, five were proved to have invasive cancer in the resected specimens. The cumulative risk for the development of invasive cancer at 10, 20, and 30 years was 0.5, 4.1, and 6.1%, respectively, while that for the development of definite dysplasia at 10, 20, and 30 years was 3.1, 10.0, and 15.6%, respectively. All the patients with invasive cancer in the surveillance group remained alive, while three out of four patients in the nonsurveillance group died. Our surveillance programme is useful for detecting UC-associated CRC, and survival may be improved by surveillance colonoscopy.

Effects of dietary folate on ulcerative colitis-associated colorectal carcinogenesis in the interleukin 2- and beta(2)-microglobulin-deficient mice

Folate supplementation may reduce the risk of colorectal dysplasia and cancer in subjects with chronic ulcerative colitis (UC). The interleukin (IL) 2- and beta(2)-microglobulin (beta(2)m)-deficient (IL-2(null) x beta(2)m(null)) mice spontaneously develop colon cancer in the setting of chronic UC. This study investigated the effects of dietary folate on the development of UC-associated colon cancer in the IL-2(null) x beta(2)m(null) mice. Weaning IL-2(null) x beta(2)m(null) mice were randomized to receive 0 (deficient; n = 40), 2 (basal requirement; control; n = 46), or 8 (supplemented; n = 36) mg folate/kg diet for 32 weeks. At necropsy, all macroscopic colonic tumors were identified and histologically classified as dysplasia or adenocarcinoma. The incidence of high-grade lesions (high-grade dysplasia/carcinoma in situ and invasive adenocarcinoma) in the folate-supplemented group was 46% lower than that in the control group (35.3% versus 65.1%, P = 0.009). The incidence of high-grade lesions in the folate-deficient group was also 49% lower than that in the control group (33.3% versus 65.1%, P = 0.007). The higher mortality rate in the folate-deficient group compared with the other two groups (25% versus 6.5% and 5.6%, P < 0.02) partially accounted for the low incidence of high-grade lesions in this group. These data indicate that dietary folate supplementation at 4x the basal dietary requirement significantly suppresses UC-associated colorectal carcinogenesis in the IL-2(null) x beta(2)m(null) mice. These data also suggest that folate deficiency may inhibit colorectal carcinogenesis in chronic UC. However, the high mortality observed in the folate-deficient group precludes a definitive conclusion concerning the effect of folate deficiency on UC-associated colorectal carcinogenesis in this model.

Inhibitory effects of Bifidobacterium longum on experimental ulcerative colitis induced in mice by synthetic dextran sulfate sodium

BACKGROUND/AIMS

The relationship between alterations in intestinal microflora and ulcerative colitis is still not clear. Whether improvement in bacterial populations might be a new strategy for prevention or treatment needs to be tested.

METHODS

Ulcerative colitis was induced in mice by oral administration of synthetic dextran sulfate sodium (molecular weight 54,000). Inhibitory effects of concomitant treatment with Bifidobacterium longum were assessed in terms of total colon length and severity of histological changes. In addition, changes of microflora and short-chain fatty acids were tested in fecal samples and compared before and after treatment.

RESULTS

Administration of B. longum significantly inhibited both shortening of total colon length and the severity of ulcerative colitis compared to controls. It was confirmed that the administered B. longum resided in the gut and blocked the decrease of lactobacilli in fecal samples in mice with dextran sulfate sodium-induced colitis.

CONCLUSIONS

Oral administration of B. longum exerts marked inhibitory effects on ulcerative colitis in mice.

Vanilloid receptor-1 containing primary sensory neurones mediate dextran sulphate sodium induced colitis in rats

BACKGROUND AND AIMS

The role of sensory neurones in colitis was studied by chemical denervation of primary sensory neurones as well as antagonism of the vanilloid receptor-1 (VR-1) in rats prior to administration of dextran sulphate sodium (DSS) to induce colitis.

METHODS

Neonatal rats were chemically denervated by subcutaneous administration of capsaicin; controls received capsaicin vehicle only. When animals reached maturity, colitis was induced by administration of 5% DSS in drinking water for seven days. Additionally, normal adult rats were treated with a VR-1 antagonist capsazepine (CPZ) or vehicle twice daily via an enema from day 0 to day 6 of the DSS regimen. Control rats were treated with an enema infusion of vehicle and 5% DSS, or without either an enema infusion or DSS in drinking water. For both groups of rats, severity of inflammation was quantitated by disease activity index (DAI), myeloperoxidase (MPO) activity, and histological examination.

RESULTS

DSS induced active colitis in all control rats with resultant epithelial ulceration, crypt shortening, and neutrophil infiltration. Both neonatal capsaicinised rats and normal adult rats treated with CPZ enemas exhibited significantly lower levels of DAI, MPO, and histological damage compared with vehicle treated rats (p< 0.05).

CONCLUSIONS

Neonatal capsaicinisation and local administration of CPZ prevents intestinal inflammation in a well established model of colitis indicating that primary sensory neurones possessing VR-1 receptors are required in the propagation of colonic inflammation.

Randomized controlled trial of the effect of bifidobacteria-fermented milk on ulcerative colitis

BACKGROUND

Alterations of intestinal flora, such as reduction in the concentration of bifidobacteria and increase in that of Bacteroides species, are apparently associated with the severity of ulcerative colitis.

OBJECTIVE

We conducted a randomised clinical trial of the use of a bifidobacteria-fermented milk (BFM) supplement as a dietary adjunct in the treatment of ulcerative colitis.

METHODS

The subjects were randomly divided into two groups: a group with BFM supplementation (BFM group, 11 subjects) and a control group (control group, 10 subjects). The BFM group was given 100 mL/day of BFM for one year. Colonoscopies, general blood markers and examinations of intestinal flora including the analysis of fecal organic acids were performed at the commencement of the study and after one year.

RESULTS

Exacerbation of symptoms was seen in 3 out of 11 subjects in the BFM group and in 9 out of 10 in the control group. Log rank statistic analysis of the cumulative exacerbation rates showed a significant reduction in exacerbations for the BFM group (p = 0.0184). The analysis of microflora and the organic acids in the feces showed a significant reduction in the relative proportion of B. vulgatus in Bacteroidaceae and butyrate concentration, respectively, after supplementation with BFM, in comparison with before.

CONCLUSION

Supplementation with the BFM product was successful in maintaining remission and had possible preventive effects on the relapse of ulcerative colitis.

Rationale for probiotic and antibiotic treatment strategies in inflammatory bowel diseases

Inflammatory bowel diseases (IBD), commonly referred to as Crohn's disease and ulcerative colitis are chronic aggressive disorders which share many similarities concerning pathomechanism and clinical course, but have very distinct features. Both entities are mainly located in areas with high bacterial concentrations, such as the terminal ileum and cecum in Crohn's disease and the rectum in ulcerative colitis. In recent years, overwhelming evidence accumulated, supporting the hypothesis that IBD are characterized by a genetically determined, overly aggressive immune response towards ubiquitous luminal antigens, especially commensal bacteria and their products. Trials in both human IBD and experimental colitis have demonstrated that broad-spectrum antibiotics may influence the course of ulcerative colitis and Crohn's disease and antibiotics with narrow activity against the anaerobic fraction of the flora can prevent relapse in Crohn's disease after surgically induced remission. Since relevant antibiotic strategies can be associated with some side effects, the ongoing research recently focused on alternative methods to modify the intestinal flora in patients with IBD. Clinical observations including few controlled trials, basic research, and animal studies have suggested a potential role for probiotic bacteria within the treatment regimens for IBD. However, the mode of action of these organisms is still largely unclear and in vitro studies are inconclusive. This review summarizes recent in vitro and in vivo data regarding the role of the intestinal microflora in the pathogenesis of chronic intestinal inflammation and possible therapeutic mechanisms of probiotic bacteria relevant to IBD. Furthermore, we will review clinical trials examining the efficacy of antibiotic and probiotic treatment strategies in IBD.

Environmental influences on inflammatory bowel disease manifestations. Lessons from epidemiology

Environmental factors play an important role in the disease manifestation, course and prognosis of inflammatory bowel disease. Observations on temporal trends and geographical distribution point at risk factors associated with a Western lifestyle. A large number of studies have been performed on various factors such as diet, smoking, and several infectious agents. Childhood exposures modifying immune responses in later life form a particularly interesting field. However, so far, only smoking in Crohn's disease, and smoking cessation in ulcerative colitis can be considered established as risk factors for the manifestation of the disease. Smoking is also associated with a poor prognosis in Crohn's disease. A strong negative association of appendectomy with ulcerative colitis has been very consistent across many studies; however, the implications of this finding are still obscure.

Protective role of appendicectomy on onset and severity of ulcerative colitis and Crohn's disease

BACKGROUND AND AIMS

Recent studies on appendicectomy rates in ulcerative colitis and Crohn's disease have generally not addressed the effect of appendicectomy on disease characteristics. The aims of this study were to compare appendicectomy rates in Australian inflammatory bowel disease patients and matched controls, and to evaluate the effect of prior appendicectomy on disease characteristics.

METHODS

Patients were ascertained from the Brisbane Inflammatory Bowel Disease database. Controls matched for age and sex were randomly selected from the Australian Twin Registry. Disease characteristics included age at diagnosis, disease site, need for immunosuppression, and intestinal resection.

RESULTS

The study confirmed the significant negative association between appendicectomy and ulcerative colitis (odds ratio (OR) 0.23, 95% confidence interval (CI) 0.14-0.38; p<0.0001) and found a similar result for Crohn's disease once the bias of appendicectomy at diagnosis was addressed (OR 0.34, 95% CI 0.23-0.51; p<0.0001). Prior appendicectomy delayed age of presentation for both diseases and was statistically significant for Crohn's disease (p=0.02). In ulcerative colitis, patients with prior appendicectomy had clinically milder disease with reduced requirement for immunosuppression (OR 0.15, 95% CI 0.02-1.15; p=0.04) and proctocolectomy (p=0.02).

CONCLUSIONS

Compared with patients without prior appendicectomy, appendicectomy before diagnosis delays disease onset in ulcerative colitis and Crohn's disease and gives rise to a milder disease phenotype in ulcerative colitis.

Effects of appendicectomy on the course of ulcerative colitis

BACKGROUND

Appendicectomy reduces the risk of having ulcerative colitis. However, its effect on the natural history of ulcerative colitis remains uncertain.

AIM

To determine whether appendicectomy reduces the overall severity of ulcerative colitis.

PATIENTS AND METHODS

Appendicectomy status and smoking habits were specified by direct interview in 638 patients seen consecutively between 1997 and 2000. Severity of ulcerative colitis was assessed by reviewing therapeutic needs from the onset of colitis. Additionally, the annual incidence of flare up was assessed prospectively between 1997 and 2000 in patients who had not been colectomised.

RESULTS

The 10 year risk of colectomy was 16 (7)% in previously appendicectomised patients (n=49) compared with 33 (2)% in non-appendicectomised patients (n=589, p=0.05). Cox regression showed that previous appendicectomy and current smoking were independent factors protecting against colectomy (adjusted hazard ratio and 95% confidence intervals: 0.40 (0.20-0.78) and 0.60 (0.40-0.95), respectively). The respective proportions of appendicectomised and non-appendicectomised patients who required oral steroids and immunosuppressive therapy were not significantly different (67% v 70% and 27% v 19%, respectively). Between 1997 and 2000, ulcerative colitis was active for 48% of the time in appendicectomised patients (47 of 98 patient years) and for 62% of the time in non-appendicectomised patients (631 of 1024 patient years; p<0.01).

CONCLUSION

Previous appendicectomy is associated with a less severe course of ulcerative colitis. The beneficial effect of appendicectomy on the risk of colectomy is additive to that of current smoking.