[Chronic heart failure: structural and microbiological changes in the colon]

AIM

To study microbiocenosis of the parietal layer of the colon and feces, concentrations of endotoxin and proinflammatory cytokines in patients with chronic heart failure (CHF) of different functional classes vs. healthy subjects of the same age.

MATERIAL AND METHODS

The trial includes 37 patients with ischemic CHF and 13 healthy volunteers. The examination comprised 6-min walking test, echocardiographic evaluation of the left ventricular ejection fraction, clinical state by a special scale, assay for C-reactive protein, endotoxin, fecal seeding, colonoscopy with biopsy and seeding.

RESULTS

Gram-negative flora in the colon and parietal layer occurred in high concentrations correlating with severity of CHF. The examinees with CHF of functional class III-IV had elevated levels of circulating endotoxin and serum C-reactive protein.

[Role of dysbiotic disruption in etiology and pathogenesis of irritable bowel syndrome]

Based on the obtained data, it was established that the development of dysbiotic changes in the large and small intestines after enteric infections is a cause for exacerbation of the irritable bowel syndrome.

Postinfectious irritable bowel syndrome

A small but significant subgroup of patients with irritable bowel syndrome (IBS) report a sudden onset of their IBS symptoms after a bout of gastroenteritis. Population-based surveys show that although a history of neurotic and psychologic disorders, pain-related diseases, and gastroenteritis are all risk factors for developing IBS, gastroenteritis is the most potent. More toxigenic organisms increase the risk 11-fold, as does an initial illness lasting more than 3 weeks. Hypochondriasis and adverse life events double the risk for postinfective (PI)-IBS and may account for the increased proportion of women who develop this syndrome. PI-IBS is associated with modest increases in mucosal T lymphocytes and serotonin-containing enteroendocrine cells. Animal models and some preliminary human data suggest this leads to excessive serotonin release from the mucosa. Both the histologic changes and symptoms in humans may last for many years with only 40% recovering over a 6-year follow-up. Celiac disease, microscopic colitis, lactose intolerance, early stage Crohn's disease, and bile salt malabsorption should be excluded, as should colon cancer in those over the age of 45 years or in those with a positive family history. Treatment with Loperamide, low-fiber diets, and bile salt- binding therapy may help some patients. Serotonin antagonists are logical treatments but have yet to be evaluated.

Infection as a cause of irritable bowel syndrome

The normal response to infection, such as vomiting and diarrhoea, is protective and beneficial. However, in about 10% of patients these protective changes persist and may contribute to the development of post-infective irritable bowel syndrome, which may persist for many years. New insights into the pathogenesis of this condition suggest novel, effective ways of treatment.

Increased rectal mucosal expression of interleukin 1beta in recently acquired post-infectious irritable bowel syndrome

BACKGROUND AND AIMS

Chronic bowel disturbances resembling irritable bowel syndrome (IBS) develop in approximately 25% of patients after an episode of infectious diarrhoea. Although we have previously shown that psychosocial factors operating at the time of, or prior to, the acute illness appear to predict the development of post-infectious IBS (PI-IBS), our finding of an increased inflammatory cell number in the rectum persisting for at least three months after the acute infection suggested that there is also an organic component involved in the development of PI-IBS. To evaluate this further, we measured expressions of interleukin 1beta (IL-1beta) and its receptor antagonist (IL-1ra) in these patients to provide additional evidence that the pathogenesis of PI-IBS is underpinned by an inflammatory process.

METHODS

Sequential rectal biopsy samples were prospectively obtained during and three months after acute gastroenteritis, from eight patients who developed post-infectious IBS (INF-IBS) and seven patients who returned to normal bowel habits after acute gastroenteritis (infection controls, INF-CON). Eighteen healthy volunteers who had not suffered from gastroenteritis in the preceding two years served as normal controls (NOR-CON). IL-1beta and IL-1ra gene expressions were assayed by reverse transcriptase-polymerase chain reaction, and their levels of expression were quantitated by optical densitometry after electrophoresis on agarose gel.

RESULTS

INF-IBS patients exhibited significantly greater expression of IL-1beta mRNA in rectal biopsies than INF-CON patients both during and three months after acute gastroenteritis. Moreover, IL-1beta mRNA expression had increased in biopsies taken from INF-IBS patients at three months after the acute infection but no consistent change was observed in INF-CON patients. IL-1beta mRNA expression of INF-IBS patients at three months post gastroenteritis was significantly greater than NOR-CON whereas that of INF-CON patients was not significantly different from NOR-CON. Despite these differential changes in IL-1beta mRNA expression, no significant changes were observed in IL-1ra mRNA expression among the three groups.

CONCLUSIONS

These findings indicate that those patients who develop IBS post infection exhibit greater IL-1beta mRNA expression, both during and after the infection, compared with individuals who do not develop PI-IBS. We conclude that such patients may be susceptible to inflammatory stimuli, and that inflammation may play a role in the pathogenesis of PI-IBS.

A systematic review of alternative therapies in the irritable bowel syndrome

The irritable bowel syndrome is a common disorder associated with a significant burden of illness, poor quality of life, high rates of absenteeism, and high health care utilization. Management can be difficult and treatment unrewarding; these facts have led physicians and patients toward alternative therapies. We explored a variety of treatments that exist beyond the scope of commonly used therapies for irritable bowel syndrome. Guarded optimism exists for traditional Chinese medicine and psychological therapies, but further well-designed trials are needed. Oral cromolyn sodium may be useful in chronic unexplained diarrhea and appears as effective as and safer than elimination diets. The roles of lactose and fructose intolerance remain poorly understood. Alterations of enteric flora may play a role in irritable bowel syndrome, but supporting evidence for bacterial overgrowth or probiotic therapy is lacking.

Is irritable bowel syndrome more common in patients presenting with bacterial gastroenteritis? A community-based, case-control study

OBJECTIVE

Irritable bowel syndrome (IBS) has been reported to follow infectious diarrhea. Food-borne infections affect 76 million people in the United States and 9.4 million in England per year; of these, only a small percentage of patients see their doctor, and even fewer will have stool culture confirmation. We hypothesized that patients who present to their doctor with gastroenteritis and have positive stool samples may be different from the normal population with regard to their pre-existing bowel symptoms. Our aim was to determine if patients with bacterial gastroenteritis were more likely to have prior IBS, functional dyspepsia, or functional diarrhea, compared with a control population.

METHODS

Between January, 2000 and January, 2001, subjects with stool positive bacterial gastroenteritis and control subjects from the same primary care practice were invited to participate. The main outcome measure was the presence of IBS, functional dyspepsia, or functional diarrhea diagnosed using self-report Rome II modular questionnaires.

RESULTS

A total of 217 people with recent bacterial gastroenteritis and 265 community controls consented to participate in the study. Of these, 89/217 cases and 46/265 controls had one of the functional GI disorders (OR = 3.3; 95% CI = 2.17-5.00). IBS was present in 67 cases (31%) and 26 controls (10%) (OR = 4.1; 95% CI = 2.49-6.72). There was no statistically significant difference in the presence of prior functional dyspepsia or functional diarrhea.

CONCLUSIONS

IBS is more frequent before diagnosis in people with bacterial gastroenteritis presenting to their primary care physician than in community controls. Studies that examine the rate of IBS after bacterial gastroenteritis need to carefully exclude people with prior IBS in a systematic way.

[Post-infectious irritable bowel syndrome. A review based on current evidence]

INTRODUCTION

Pathophysiology of irritable bowel syndrome (IBS) is multifactorial. Recent investigations have associated episodes of infectious gastroenteritis with development of IBS. This condition is named post-infectious IBS (PI-IBS). The role of inflammation-infection in IBS pathogenesis is not well understood.

AIM

To review published scientific evidence on PI-IBS regarding risk factors, causal agents, histopathological changes, and treatment.

MATERIALS AND METHODS

An electronic search in MEDLINE and abstracts presented at national and international GI meetings was performed, looking for information published in the past 50 years including animal studies, cohort studies, case-control studies, and series of cases and case reports, using the key words post-infectious enteritis, post-dysenteric or post-infectious irritable bowel syndrome (PI-IBS), and post-infectious colitis.

RESULTS

Fifty one papers were included. These studies were classified according to pathophysiologic mechanisms, infectious agents involved, animal or human studies, and treatment.

CONCLUSIONS

Current evidence shows a strong association between colonic infection and inflammation with development of IBS. Approximately 25% of patients with IBS have a history of infectious enteritis. Microbial agents related with PI-IBS include bacteria (Campylobacter, Salmonella) and parasites (Trichinella spiralis). Increased number of enteroendocrine cells, CD3 lymphocytes and mast cells within the colonic muscle wall, release of pro-inflammatory substances, and increased number of inflammatory cells with intestinal nervous endings are the most common histopathologic findings. Patients developing PI-IBS have a higher frequency of psychological disorders and stressful events prior to the gastroenteritis episode. Therapeutic interventions with steroids, COX-2 inhibitors, antibiotics and probiotics require further investigation.

Lower frequency of MMC is found in IBS subjects with abnormal lactulose breath test, suggesting bacterial overgrowth

We have recently described an association between irritable bowel syndrome (IBS) and abnormal lactulose breath test, suggesting small intestinal bacterial overgrowth (SIBO). However, the mechanism by which SIBO develops in IBS is unknown. In this case-control study we evaluate the role of small intestinal motility in subjects with IBS and SIBO. Small intestinal motility was studied in consecutive IBS subjects with SIBO on lactulose breath test. After fluoroscopic placement of an eight-channel water-perfused manometry catheter, 4-hr fasting recordings were obtained. Based on this, the number and duration of phase III was compared to 30 control subjects. To test whether there was a relationship between the motility abnormalities seen and the SIBO status of the patient at the time of the motility, subjects with a breath test within 5 days of the antroduodenal manometry were also compared. Sixty-eight subjects with IBS and SIBO were compared to controls. The number of phase III events was 0.7 +/- 0.8 in IBS subjects and 2.2 +/- 1.0 in controls (P < 0.000001). The duration of phase III was 305 +/- 123 sec in IBS subjects and 428 +/- 173 in controls (P < 0.001). Subjects whose SIBO was still present at the time of manometry had less frequent phase III events than subjects with eradicated overgrowth (P < 0.05). In conclusion, phase III is reduced in subjects with IBS and SIBO. Eradication of bacterial overgrowth seems to result in some normalization of motility.

Is lactose intolerance implicated in the development of post-infectious irritable bowel syndrome or functional diarrhoea in previously asymptomatic people?

OBJECTIVE

The relationship between lactose intolerance and post-infectious irritable bowel syndrome (IBS) in adults is uncertain. Bowel symptoms may persist after bacterial gastroenteritis and as post-infectious IBS. Acquired lactose intolerance may follow viral enteric infections in children. We compared the frequency of lactose intolerance after bacterial gastroenteritis in adults with and without symptoms of IBS or functional diarrhoea at 3-6-months' follow-up.

DESIGN

A prospective cohort study was conducted.

METHODS

All subjects with bacterial gastroenteritis confirmed by stool culture from the microbiology laboratory and without prior IBS or functional diarrhoea were eligible to participate. IBS and functional diarrhoea were diagnosed via self-completed Rome II modular questionnaires. Lactose intolerance was determined from a rise in breath hydrogen and plasma glucose and symptoms.

RESULTS

One hundred and twenty-eight subjects with bacterial gastroenteritis were followed prospectively, from which a smaller cohort of 42 subjects took part in this study. The cohort was comprised of 24/25 subjects who developed post-infectious IBS (n = 16) or functional diarrhoea (n = 8) (9 male, 15 female) and 18 random controls (8 male, 10 female) chosen from the group without IBS or functional diarrhoea. The mean age of the subjects was 44.4 years (range 25-76 years). In the group with functional diarrhoea or IBS, four subjects had failure of the plasma glucose to rise but none had abnormal glucose hydrogen breath tests. In the control subjects, one had a positive combined test and six had failure of plasma glucose to rise alone. No subject developed symptoms during the test.

CONCLUSIONS

Bacterial gastroenteritis did not cause persistent lactose intolerance in our study population. Lactose intolerance does not appear to be implicated in the aetiology of post-infectious bowel symptoms, including IBS. Advice to avoid dairy products in patients presenting with post-infectious IBS on the basis that they may have lactose intolerance appears unnecessary in patients from northern England.

The treatment of small intestinal bacterial overgrowth with enteric-coated peppermint oil: a case report

Recent investigations have shown that bacterial overgrowth of the small intestine is associated with a number of functional somatic disorders, including irritable bowel syndrome (IBS), fibromyalgia, and chronic fatigue syndrome. A number of controlled studies have shown that enteric-coated peppermint oil (ECPO) is of benefit in the treatment of IBS. However, despite evidence of strong antimicrobial activity, ECPO has not been specifically investigated for an effect on small intestinal bacterial overgrowth (SIBO). A case report of a patient with SIBO who showed marked subjective improvement in IBS-like symptoms and significant reductions in hydrogen production after treatment with ECPO is presented. While further investigation is necessary, the results in this case suggest one of the mechanisms by which ECPO improves IBS symptoms is antimicrobial activity in the small intestine.

A review of the role of the gut microflora in irritable bowel syndrome and the effects of probiotics

Irritable bowel syndrome (IBS) is a multi-factorial gastrointestinal condition affecting 8-22 % of the population with a higher prevalence in women and accounting for 20-50 % of referrals to gastroenterology clinics. It is characterised by abdominal pain, excessive flatus, variable bowel habit and abdominal bloating for which there is no evidence of detectable organic disease. Suggested aetiologies include gut motility and psychological disorders, psychophysiological phenomena and colonic malfermentation. The faecal microflora in IBS has been shown to be abnormal with higher numbers of facultative organisms and low numbers of lactobacilli and bifidobacteria. Although there is no evidence of food allergy in IBS, food intolerance has been identified and exclusion diets are beneficial to many IBS patients. Food intolerance may be due to abnormal fermentation of food residues in the colon, as a result of disruption of the normal flora. The role of probiotics in IBS has not been clearly defined. Some studies have shown improvements in pain and flatulence in response to probiotic administration, whilst others have shown no symptomatic improvement. It is possible that the future role of probiotics in IBS will lie in prevention, rather than cure.

Evolving concepts in the pathophysiology of functional gastrointestinal disorder

Functional gastrointestinal disorder (FGID) is common and may affect any part of the digestive tract from the esophagus to the rectum. Functional dyspepsia and the irritable bowel syndrome (IBS) are the most commonly recognized and until recently were considered distinct entities. In recent years, however, new observations and studies of the afferent nervous system have extended our concepts of both IBS and dyspepsia and suggest that these conditions may have common triggers and expression from similar pathophysiological processes.

Irritable bowel syndrome: classification and conceptualization

The irritable bowel syndrome is one of a group of functional gastrointestinal disorders within the Rome classification system that is characterized by abdominal discomfort or pain associated with a change in stool habit. It is a multidetermined biopsychosocial disorder in which physiological, psychological, behavioral, and environmental factors may contribute to the clinical expression of the disorder. These can include: (1) early life (e.g., genetic or environmental) factors; (2) physiological factors including increased motor reactivity, visceral hypersensitivity, which may be enabled by postinfectious events, and dysregulation of brain-gut communication (e.g., altered central pain control mechanisms). In addition, psychosocial factors including psychiatric co-morbidity, major trauma (e.g., abuse history), and maladaptive coping may amplify the clinical expression of the disorder and its outcome. Currently, clinical outcome has become understood in terms of global symptom relief and health-related quality of life.

H. pylori infection and visceral hypersensitivity in patients with irritable bowel syndrome

BACKGROUND/AIM

Irritable bowel syndrome (IBS) is characterized by abdominal pain and changes in stool habits. Visceral hypersensitivity (VH) is a key factor in the pathophysiology of IBS. The role of Helicobacter pylori infection in the induction of VH in the upper gastrointestinal tract is controversially discussed. The aim of this study is to evaluate the value of rectal barostat in eliciting abdominal symptoms in patients with IBS in relation to H. pylori infection.

PATIENTS AND METHODS

31 patients (19 female, 12 male, mean age 45.6 +/- 10 years) with normal colonoscopy and clinical signs of IBS were examined by rectal barostat (pressure-controlled balloon distension in the rectum). Induction of typical abdominal discomfort (far from the balloon) defined the examination positive. Level of nonpainful perception (L1), feeling of defecation (L2), and pain or stool urgency (L3) were registered in comparison with a healthy control group (CG; n = 15, 9 female, 6 male). The H. pylori status was defined by (13)C-urea breath test (n = 46).

RESULTS

Typical abdominal discomfort was induced in 9 patients (pain group, PG) by pressure-controlled rectal distension (H. pylori status: 8 positive, 1 negative). Patients not presenting with abdominal pain to rectal distension (nonpain group, NPG) were all H. pylori negative (p < 0.001). L3 as an indicator of VH was reached at a lower pressure threshold in PG than in NPG or CG (p < 0.05). The perception was not different between NPG and CG (p > 0.05).

CONCLUSIONS

The induction of typical abdominal discomfort in patients with IBS by the use of rectal barostat occurred predominantly in H. pylori infected patients and suggests that H. pylori infection may be involved in triggering VH in patients with IBS. Further studies in larger patient groups and after H. pylori eradication therapy are needed to confirm and extend this observation.

Effects of probiotic administration upon the composition and enzymatic activity of human fecal microbiota in patients with irritable bowel syndrome or functional diarrhea

In a clinical trial, 10 patients suffering from irritable bowel syndrome or functional diarrhea were administered the probiotic preparation VSL-3. Preliminary results indicated that administration of VSL-3 improved the clinical picture and changed the composition and biochemistry of fecal microbiota. Titer variations of intestinal bacterial groups were evaluated by culture and PCR techniques. A significant increase in lactobacilli, bifidobacteria and Streptococcus thermophilus was observed as a consequence of probiotic treatment, while enterococci, coliforms, Bacteroides and Clostridium perfringens did not change significantly. The strains Bifidobacterium infantis Y1 and Bifidobacterium breve Y8, included in VSL-3, were specifically detected in feces of patients treated with the probiotic by using strain-specific PCR primers. In addition, fecal beta-galactosidase increased and urease activities decreased as a result of changes in the intestinal microbiota induced by VSL-3 administration.

Relationship of Campylobacter toxigenicity in vitro to the development of postinfectious irritable bowel syndrome

Campylobacter enteritis is associated with a significant risk of developing irritable bowel syndrome, but the mechanism is unknown. This study ascertained bowel symptoms in 93 patients 3 months after Campylobacter jejuni enteritis infection. The infecting organisms were cultured, and the effects of culture supernatants on toxin-sensitive epithelial cell monolayers (HEp-2, Green monkey kidney epithelial [Vero], and CHO-K1) were investigated. In all, 50, 43, and 41 of the isolates showed toxigenic effects on HEp-2, CHO-K1, and Vero cells, respectively. Persistently changed bowel habit was reported by 9 of 50 persons with HEp-2 toxin-positive infections but by only 2 of 43 with isolates negative for toxin (chi2=4.0; P<.05). Toxicity to HEp-2 and Vero cells was associated with significantly increased numbers of days with loose stools 6 months after C. jejuni enteritis infection (both, P<.05). Thus, long-term symptoms that occur Campylobacter infection are significantly associated with bacterial toxicity.

Adaptation of bacteria to the intestinal niche: probiotics and gut disorder

The gastrointestinal tract is a complex ecosystem host to a diverse and highly evolved microbial community composed of hundreds of different microbial species. The interactions that occur between this complex microbial community and the human host have become the focus of scientific research due to increases in the incidence of illnesses associated with deficient or compromised microflora (e.g., gastrointestinal tract infections, inflammatory bowel disease (Crohn's disease and ulcerative colitis), irritable bowel syndrome, antibiotic-induced diarrhea, constipation, food allergies, cardiovascular disease, and certain cancers). Effective multidisciplinary research programs now complement conventional microbiology with molecular ecology techniques to provide culture-independent analysis of the gastrointestinal ecosystem. Furthermore, as we acquire an understanding of gut microflora composition and processes such as intestinal adherence, colonization, translocation, and immunomodulation, we are also elucidating mechanisms by which these can be influenced. This knowledge not only allows scientists to define the activities and interactions of "functional food"-borne beneficial bacteria in the gut, but will also provide the scientific basis for the development of innovative biotechnology-based products tailored to prevent specific diseases and promote overall human gastrointestinal health.

[Irritable bowel syndrome. Survey of definitions, differential diagnosis and pathogenesis]

Abdominal pain/discomfort, bloating, need to rush to the toilet, straining, feeling of incomplete bowel emptying and alternating periods of diarrhea and constipation is the clinical definition of the irritable bowel syndrome. The internationally used syndrome definition is based on expert opinions and answers to patient questionnaires. When symptoms are registered prospectively, abdominal pain starts or worsens after meals and is not relieved by defecation. As in the general population patients with the syndrome define diarrhea as loose stools and constipation as hard stools regardless of stool frequencies. Variation in defecatory symptoms and discrepancies between these symptoms and stool consistency are the hallmarks of the syndrome, and the degree of variation per fortnight is relatively stable in the individual patient. Fermentation of carbohydrates by colonic bacteria, increased sensitivity to bowel distention by gas, gas-producing food, increased secretion of cholecystokinin after fatty meals and/or increased sympathetic nerve tone at stress can give rise to symptoms. Symptoms can start after a single period of bacterial gastroenteritis. Although patients seeking medical care for the syndrome are more often anxious, the syndrome itself is not psychosomatic. Symptoms are possibly mediated through partial degranulation of mast cells in bowel mucosa, but this does not make it an allergic disease. If bowel dysmotility can be measured, early stage or a mild case of intestinal pseudoobstruction should be considered. Hyperreactivity in the enteric nervous system and/or in the brain is the likely main cause of the symptoms. More widespread activity in the brain after exposure to stimuli originating from bowel nerves or less inhibition of this stimulation in the brain are possible mechanisms.

Chlamydia trachomatis infection: is it relevant in irritable bowel syndrome?

BACKGROUND

Irritable bowel syndrome can present with gynaecological symptoms similar to those of chronic pelvic inflammatory disease, which is commonly caused by Chlamydia trachomatis. Infection with this organism might therefore lead to diagnostic and management difficulties in patients, not only as a result of symptom overlap between the two disorders but also because chlamydial infection might exacerbate the symptoms of irritable bowel syndrome. This study was designed to investigate any possible link between chlamydial infection and irritable bowel syndrome.

PATIENTS/METHODS

The prevalence of antibodies to C. trachomatis and abdominal symptomatology was assessed in a group of 100 female patients with irritable bowel syndrome and 100 matched female controls.

RESULTS

25% of patients and 17% of controls were found to have evidence of previous chlamydial infection. This difference was not statistically significant. Within the patient group, no association was found between chlamydial infection and any particular pattern of symptomatology.

CONCLUSIONS

The results of this study indicate that occult chlamydial infection is not a major problem in irritable bowel syndrome and that routine investigation for this organism is unnecessary. They also provide some reassurance that pelvic inflammatory disease and all its potentially serious consequences is not being significantly overlooked in gastroenterological practice.

Helicobacter pylori and dyspepsia: a population-based study of the organism and host

OBJECTIVE

The role of Helicobacter pylori (HP) infection in dyspepsia in the absence of peptic ulcer remains controversial. Specific attributes of the organism or the host response may be important. We aimed to determine whether HP infection overall, CagA status, serum gastrin, or serum pepsinogen levels are associated with dyspepsia in the community.

METHODS

A self-report bowel disease questionnaire was mailed to a random sample of Olmsted County, Minnesota residents, aged 20-50 yr. All respondents who reported symptoms of dyspepsia or irritable bowel syndrome (cases) and all respondents without significant GI symptoms (controls) were invited to participate (n = 260). They were each assessed by a physician and their medical records reviewed. Serum was obtained to measure HP and CagA antibodies, pepsinogen I and II levels, and basal serum gastrin using validated assays.

RESULTS

Of the 148 (57%) subjects who agreed to participate, 36 had dyspepsia (17 had ulcer-like dyspepsia), 35 had irritable bowel syndrome (IBS) without dyspepsia, and 77 were asymptomatic. The proportion who were seropositive for HP were 17% in dyspepsia (24% in ulcer-like dyspepsia), 20% in IBS, and 12% in asymptomatic controls. HP was not associated with dyspepsia, ulcer-like dyspepsia, or IBS after adjusting for age. Pepsinogen levels and serum gastrin were not associated with any of the conditions studied. However, CagA antibody positivity was associated with IBS (p < 0.05), and a borderline statistically significant association with dyspepsia was detected (p = 0.08).

CONCLUSIONS

In this community, HP infection overall does not seem to explain dyspepsia, although the role of CagA-positive HP strains deserve further study.

Alteration of intestinal microflora is associated with reduction in abdominal bloating and pain in patients with irritable bowel syndrome

OBJECTIVE

The influence of the gastrointestinal (GI) microflora in patients with irritable bowel syndrome (IBS) has not been clearly elucidated. This study was undertaken to see if patients with IBS have an imbalance in their normal colonic flora, as some bacterial taxa are more prone to gas production than others. We also wanted to study whether the flora could be altered by exogenous supplementation. In a previous study we have characterized the mucosa-associated lactobacilli in healthy individuals and found some strains with good colonizing ability. Upon colonization, they seemed to reduce gas formation.

METHODS

The study comprised 60 patients with IBS and a normal colonoscopy or barium enema. Patients fulfilling the Rome criteria, without a history of malabsorption, and with normal blood tests underwent a sigmoidoscopy with biopsy. They were randomized into two groups, one receiving 400 ml per day of a rose-hip drink containing 5 x 10(7) cfu/ml of Lactobacillus plantarum (DSM 9843) and 0.009 g/ml oat flour, and the other group receiving a plain rose-hip drink, comparable in color, texture, and taste. The administration lasted for 4 wk. The patients recorded their own GI function, starting 2 wk before the study and continuing throughout the study period. Twelve months after the end of the study all patients were asked to complete the same questionnaire regarding their symptomatology as at the start of the study.

RESULTS

All patients tolerated the products well. The patients receiving Lb. plantarum had these bacteria on rectal biopsies. There were no major changes of Enterobacteriaceae in either group, before or after the study, but the Enterococci increased in the placebo group and remained unchanged in the test group. Flatulence was rapidly and significantly reduced in the test group compared with the placebo group (number of days with abundant gas production, test group 6.5 before, 3.1 after vs 7.4 before and 5.6 after for the placebo group). Abdominal pain was reduced in both groups. At the 12-month follow-up, patients in the test group maintained a better overall GI function than control patients. There was no difference between the groups regarding bloating. Fifty-nine percent of the test group patients had a continuous intake of fermented products, whereas the corresponding figure for the control patients was 73%.

CONCLUSIONS

The results of the study indicate that the administration of Lb. plantarum with known probiotic properties decreased pain and flatulence in patients with IBS. The fiber content of the test solution was minimal and it is unlikely that the fiber content could have had any effect. This type of probiotic therapy warrants further studies in IBS patients.

Bacterial supplementation in the irritable bowel syndrome. A randomised double-blind placebo-controlled crossover study

BACKGROUND

Symptoms of at least a subgroup of patients with irritable bowel syndrome may be associated with an alteration in gut flora. Studies on bacterial based therapy have yielded mixed results.

AIMS

To determine if oral administration of the probiotic Lactobacillus casei strain GG under randomized placebo controlled conditions improves symptoms in irritable bowel syndrome patients with bloating related symptoms.

PATIENTS

A total of 25 patients with clinically confirmed irritable bowel syndrome (Rome criteria) were enrolled in the study.

METHODS

This was a randomised double-blind placebo-controlled crossover trial. Lactobacillus GG was administered as enterocoated tablets constituting a daily dosage of 10(10) colony forming units. Symptoms were assessed by daily symptom diaries and periodic questionnaires.

RESULTS

Twenty-four patients were randomised; 19 (80%) female, mean age 40 years (range 24-60), mean duration of symptoms 4.9 years (range 0.5-18). Nineteen (80%) patients completed the study. No significant differences were found between Lactobacillus casei strain GG and placebo mean symptom scores for pain, urgency or bloating. A trend was noted, however, for a reduction in the number of unformed bowel motions on Lactobacillus casei strain GG treatment for patients with diarrhoea.

CONCLUSIONS

Lactobacillus casei strain GG alone did not significantly improve symptoms in this irritable bowel syndrome subgroup. A "diarrhoea predominant" subgroup may warrant further investigation.

Emerging disease model for functional gastrointestinal disorders

In response to perceived or experienced change that is considered threatening to the individual, the central nervous system mounts a stereotypic response that decreases the sensitivity to pain, modulates the autonomic nervous system outflow, and activates the hypothalamic-pituitary-adrenal (HPA) axis. This response of the "emotional motor system" may or may not be associated with the conscious experience of feelings of fear or anxiety. Alterations in these response systems (either up- or downregulation) may produce symptoms, such as viscero-somatic hypersensitivity, altered bowel habits, or increased anxiety.

Altered gastric emptying in patients with irritable bowel syndrome

Irritable bowel syndrome is the most frequent functional disorder of the digestive system. Patients with irritable bowel syndrome have motor disorders not only in the colon, but also in other parts of the digestive tract such as the oesophagus and small intestine; however, it is not known whether the stomach is also involved. We used a radiolabelled mixed solid-liquid meal (technetium-99m for the solid component, indium-111 for the liquid component) to study gastric emptying of solids (GES), liquids (GEL) and indigestible solids (GER) in 50 patients diagnosed as having irritable bowel syndrome (30 with predominant constipation and 20 with predominant diarrhoea). GER was measured by counting the number of indigestible solids remaining in the stomach 4 h after they were swallowed. In patients with irritable bowel syndrome, GES and GEL were slower than in control subjects (P<0.05). GER was normal in all patients except for two women. Thirty-two patients (64%) showed delayed GES, 29 (58%) delayed GEL, and 2 (4%) delayed GER. Among patients with irritable bowel syndrome, GES was slower in those with predominant constipation than in those with predominant diarrhoea (P<0.05); GEL and GER were similar in both groups. Gastroparesis was found in a large proportion of patients with irritable bowel syndrome, suggesting the presence of a more generalised motor disorder of the gut.

Isolation and evaluation of susceptibility to sulphasalazine of Desulfovibrio desulfuricans strains from the human digestive tract

Various genera of sulphate reducing bacteria (SRB) have been found in the human digestive tract. It is suggested that some of SRB species may be responsible for the development of the clinical symptoms of ulcerative colitis and other disease of large intestine. Sulphasalazine (salicyl-azo-sulphapyridine, SAS) is commonly used to treat patients with ulcerative colitis and Crohn disease. Above 30 samples of faeces or biopsy specimens from 25 patients (age 45 +/- 14 years; M/F, 13/12) suffering from gastrointestinal disorders were used for isolation of Desulfovibrio desulfuricans species. The morphological, physiological and biochemical characteristics of isolated strains and also their susceptibility to SAS was determined. D. desulfuricans isolates were obtained from 5 amongst all patients assayed. Some abnormal, cigar-shaped cells were detected as accompanying the cells represented by rods, curved rods and vibrios. After strains purification, two types of colonies were present on the solid Postgate's medium B (containing lactate as a carbon source and sulphate for energy conservation): the black colonies growing in bulk of agar medium and the transparent, surface-growing mucous colonies. These two types of D. desulfuricans colonies may be a result of different iron availability for bacterial cells. High metabolic activity of strain was not always accompanied by the presence of H2S gas lock in the test tube, although the H2S odor was perceptible. All tested strains multiplied inconsiderably slowly in the presence of SAS at concentrations 10, 20, 40 and 60 mg/cm3. The growing concentrations of SAS did not cause a proportional decrease of the bacterial cells number. Taking into account the positive results of using SAS to treat patients with some colonic diseases and the indicated resistance to SAS of intestinal D. desulfuricans strains, it appears probable, that this SRB species isn't responsible for the development of mentioned diseases.

A multiplex polymerase chain reaction assay for the detection of Mycobacterium paratuberculosis DNA in Crohn's disease tissue

BACKGROUND

Mycobacterium paratuberculosis is implicated as a possible cause of Crohn's disease. However, due to lack of an appropriate diagnostic method, this has been a subject of significant controversy. Our aim was therefore to develop a multiplex polymerase chain reaction (MPCR) for the detection of M. paratuberculosis DNA in Crohn's disease tissue.

METHODS

Biopsy samples were collected by endoscopic forceps from terminal ileum, and genomic DNA was isolated. M. paratuberculosis-specific marker genes were amplified by using the present MPCR method.

RESULTS

Here we report a new MPCR for detection of M. paratuberculosis DNA in Crohn's disease tissue. In this technique two genetic markers, IS900 and a newly described specific marker of MP2, were amplified in a single tube simultaneously. The method was evaluated using biopsy specimens from 10 Crohn's disease patients, 6 ulcerative colitis patients, and 21 irritable bowel syndrome patients. The patients were characterized by using standard clinical and histologic observations. The present MPCR method could not detect M. paratuberculosis DNA in the biopsy specimens. However, the marker genes were amplified from the samples that were spiked with M. paratuberculosis before DNA extraction. The marker genes were also not detected in 10 closely related mycobacterial strains and human genomic DNA.

CONCLUSIONS

The present MPCR method is highly specific and can detect M. paratuberculosis DNA more reliably. These findings do not support an aetiologic role of M. paratuberculosis in Crohn's disease.

Helicobacter pylori seropositivity among Swedish adults with and without abdominal symptoms. A population-based epidemiologic study

BACKGROUND

The role of Helicobacter pylori in functional dyspepsia is unclear. The aim of this population-based study was to determine whether the prevalence of H. pylori infection is higher among people with dyspepsia or irritable bowel syndrome (IBS) than among symptomless persons after control for age, sex, and socioeconomic status.

METHODS

In a postal questionnaire we asked a representative sample (20-79 years; n = 1260) from a Swedish municipality about abdominal symptoms in the preceding 3 months. A randomly selected subsample, 50 with dyspepsia, 50 with IBS, and 50 symptomless, matched with regard to age, sex, and education, were tested for the presence of IgG antibodies to H. pylori, using the HM-CAP immunoassay.

RESULTS

Fifty-five persons (38%) were H. pylori-seropositive. The seroprevalence among dyspeptics (33%) did not exceed that in healthy people (48%) or in those reporting IBS (33%). The prevalence increased with age and with lower social class, but the latter association disappeared when age was taken into account. Neither sex nor symptom intensity predicted Helicobacter seropositivity.

CONCLUSION

Our data are incompatible with an important aetiologic role for H. pylori in functional dyspepsia.

Peptic ulcer disease, irritable bowel syndrome and constipation in two populations in Iran

OBJECTIVE

To determine the prevalence of peptic ulcer disease, irritable bowel syndrome (IBS) and chronic constipation in two Iranian populations (pastoral nomads and industrial labourers) with different life styles, and to evaluate the risk factors associated with these diseases.

SUBJECTS

A total of 455 randomly selected pastoral nomads and 492 industrial labourers (all male) aged between 35-55 years.

METHODS

Demographic and social data were obtained by interviews. An upper gastrointestinal tract endoscopy was performed and biopsy specimens were taken from subjects complaining of abdominal symptoms and randomly selected asymptomatic subjects. A urease test was performed on antral specimens. Serum pepsinogen I concentrations and Helicobacter pylori antibody titres were measured by radioimmunoassay and immunoglobulin (Ig) G enzyme-linked immunosorbent assay tests, respectively.

RESULTS

Serum pepsinogen I concentrations were similar in both nomads and industrial labourers, and the percentage with positive antibody titres for H. pylori was high in both populations (86.3 and 91% in nomads and industrial labourers, respectively). Industrial labourers were twice as likely to have duodenal ulcer (P < 0.05) than nomads. The prevalence of duodenal ulcer disease and gastric ulcer was 4.6 and 0.6% in nomads and 10.3 and 0.4% in industrial labourers, respectively. The prevalence of IBS was similar in nomads (3.1%) and industrial labourers (3.6%). Fewer nomads (1.4%) than industrial labourers (3.3%) had chronic constipation. Logistic regression analysis showed that being an industrial labourer, or smoker and having undergone previous non-gastric surgery were risk factors for duodenal ulcer disease. When the variable 'urease test' was included in the logistic regression analysis, smoking, a positive urease test and the quantity of fruit eaten per week were associated risk factors. The risk factors associated with IBS were the use of analgesics and back pain. The only risk factor associated with chronic constipation was being an industrial labourer.

CONCLUSIONS

Industrial labourers were twice as likely to have duodenal ulcer disease as nomads. The prevalence of IBS and chronic constipation in the two male Iranian populations was lower than that found in western countries. Duodenal ulcer disease was associated with H. pylori colonization but not with a positive serum antibody titre for H. pylori. H. pylori colonization of the antral mucosa and smoking are causative factors for duodenal ulcer disease and fruit intake is possibly an associated factor.

Dyspepsia in healthy blood donors. Pattern of symptoms and association with Helicobacter pylori

Whether Helicobacter pylori is causally linked to dyspepsia remains controversial. The aims of this study were to assess in healthy blood donors the prevalence of dyspepsia and dyspepsia subgroups, determine if H. pylori is associated with different categories of dyspeptic symptoms, and evaluate the association between dyspepsia and nicotine, alcohol, and analgesic use. Consecutive blood donors (N = 180) who had no clinical evidence of organic disease were included. Abdominal symptoms were measured by means of a standardized questionnaire that has been previously validated. Subjects with dyspepsia (defined as pain localized to the upper abdomen) were further subdivided into those with ulcer-like, dysmotility-like, reflux-like, or nonspecific dyspepsia. A total of 65 subjects reported abdominal pain or discomfort during the prior 12 months [36.1%, 95% confidence interval (CI) 29.1-43.1]; 44 subjects (24.4%, 95% CI 18.2-30.7) had dyspepsia. Dysmotility-like, reflux-like, and ulcer-like symptoms were reported by 19.4% (95% CI 13.7-25.2), 17.2% (95% CI 11.7-22.7), and 16.7% (95% CI 11.2-22.1) of subjects with dyspepsia, respectively. Fifty-seven subjects (31.7%, 95% CI 24.9-38.5) were H. pylori positive; 26% of subjects with H. pylori and 24% without H. pylori had dyspepsia (P > 0.50). The seroprevalence of H. pylori was also similar among the different categories of dyspepsia. We conclude that infection with H. pylori is not associated with abdominal complaints in otherwise healthy subjects.

The effect of Hylak drops on symptomatology in persons with irritable bowel syndrome

The authors present an account on the therapeutic effect of Hylak drops of Merckle Co. in patients with irritable bowel syndrome. They assume that in the pathophysiological mechanism of the disease an important part is played by intestinal dysmicrobia. After two weeks' administration Hylak, 3 x 40 drops, they recorded in 20 patients with the exception of one female patient (where ex post lactose intolerance was revealed which is a contraindication of this treatment), partial or complete regression of subjective complaints in particular as regards intestinal discomfort and the number of imperative bowel movements. As to objective indicators, they proved changes in the pH of faeces and qualitative as well as quantitative changes of the microbial spectrum in faeces.

The role of faecal Candida albicans in the pathogenesis of food-intolerant irritable bowel syndrome

Candida albicans was sought in stool samples from 38 patients with irritable bowel syndrome and 20 healthy controls. In only three patients with irritable bowel syndrome was C. albicans discovered and these patients had either recently received antibiotics or the stool sample had been delayed more than 24 hours in transit. C. albicans was isolated from none of the control stool samples. We conclude that C. albicans is not involved in the aetiology of the irritable bowel syndrome.

Intestinal gas production from bacterial fermentation of undigested carbohydrate in irritable bowel syndrome

The relationship between abdominal pain and bowel gas from bacterial fermentation of undigested carbohydrate was investigated in nine patients with irritable bowel syndrome (IBS), six lactose malabsorbers, and 11 asymptomatic controls. All subjects took breath samples and marked analog scales for abdominal pain, bloating, and psychological stress hourly during all waking hours for 7 days. Breath samples were analyzed for hydrogen concentration within 3 days, and the concentration was corrected for storage time. Symptoms of pain and bloating were significantly more common in IBS patients than in lactose malabsorbers or normal controls, and pain was significantly correlated with bloating in IBS patients. Breath hydrogen concentration was similar in all three groups, and breath hydrogen was not correlated with pain ratings in IBS patients. Thus, abdominal pain may be related to bloating from gastrointestinal gas, but bacterial fermentation cannot be the cause of such gas. The most likely source is swallowed air. This study also demonstrates the feasibility of monitoring hydrogen production in the bowel in field studies by having subjects collect hourly breath samples.

The faecal flora of two patients with food-related irritable bowel syndrome during challenge with symptom-provoking foods

The faecal microbial flora of two patients with food-related irritable bowel syndrome was examined while they were on a diet excluding symptom-provoking foods, and then on a diet including such a food. The patients reacted differently to the challenge diet but some changes in faecal output, flora and short chain fatty acid content were seen.

Instability in the faecal flora of a patient suffering from food-related irritable bowel syndrome

The faecal microbial flora of a patient with severe irritable bowel syndrome related to multiple food intolerances was very variable and contained a high proportion of facultative bacteria and an unusual incidence of Clostridium species.

Diagnosis of bacterial overgrowth of the small intestine. Comparison of the 14C-D-xylose breath test and jejunal cultures in 60 patients

Sixty consecutive patients suspected of having bacterial overgrowth of the small intestine (BOG) had aerobic and anaerobic bacterial cultures made of fasting upper jejunal fluid and also a 14C-D-xylose breath test (XBT). Culture-proven BOG was present in 23 patients. In another 15 patients the presence of BOG was ruled out (diagnoses: irritable bowel syndrome, 8; chronic diarrhoea, 6; and lactose malabsorption, 1). These patients were used as controls. The other 22 of the 60 patients could not be placed in either group owing to the presence of factors known to predispose for BOG; none of them had abnormal jejunal cultures, but several had strong clinical suspicion of BOG. An abnormal XBT, defined as values exceeding upper 90% confidence limits (upper range) of the 15 patient control values within a 4-h period, was observed with the following frequencies in the 23 patients with BOG: after 60 min, 35%; after 120 min, 44%; after 180 min, 61%; and after 240 min, 65%. An abnormal XBT was observed in 41% of the 22 patients with normal jejunal cultures but with predisposition for, and clinical suspicion of, BOG. It is concluded that, compared with a relevant control material, the XBT tends to be rather insensitive and that a negative outcome of jejunal cultures is inadequate to exclude the presence of BOG.

Rectal organ culture as a model for the investigation of bacterial adhesion and invasion

A system was developed for the in vitro culture of human rectal mucosa. Its viability was proved by histological appearances and by metabolic studies. Biopsy samples were cultured in the presence of appropriate bacteria isolated from the faeces of patients with ulcerative colitis or with dysenteric illnesses. Attempts to show adhesion of bacteria to the mucosa or invasion of the cultured tissue failed. Problems with the use of this model are discussed.