Overgrowth of the indigenous gut microbiome and irritable bowel syndrome.

Culture-independent molecular techniques have demonstrated that the majority of the gut microbiota is uncultivable. Application of these molecular techniques to more accurately identify the indigenous gut microbiome has moved with great pace over recent years, leading to a substantial increase in understanding of gut microbial communities in both health and a number of disorders, including irritable bowel syndrome (IBS). Use of culture-independent molecular techniques already employed to characterise faecal and, to a lesser extent, colonic mucosal microbial populations in IBS, without reliance on insensitive, traditional microbiological culture techniques, has the potential to more accurately determine microbial composition in the small intestine of patients with this disorder, at least that occurring proximally and within reach of sampling. Current data concerning culture-based and culture-independent analyses of the small intestinal microbiome in IBS are considered here.

Wind -- problems with intestinal gas.

BACKGROUND: Problems with intestinal gas and its transit through the gut are common, although the mechanisms causing the most common problems of belching (eructation), bloating, and passing flatus from the anus are reasonably complex. OBJECTIVE: This article outlines the role of intestinal gas in the genesis of the common symptoms of wind, the importance of gas transit, and considers new information about our understanding of small bowel motility. DISCUSSION: Healthcare providers often underestimate the severity of a patient's symptoms relating to the oesophagus, stomach, small bowel, and colon, especially the loose relationship between bloating and abdominal distension. Medications and diet modification play a key role in management, particularly in terms of fibre, resistant starch and fat intake.

Malabsorption may contribute to malnutrition in the elderly.

Malnutrition, either actually malnourished or at risk, is present in 80% of the elderly population presenting to hospital for admission. Although many factors contribute to this situation, one yet to be explored is malabsorption. We therefore aimed to assess nutritional status as well as the prevalence of altered mucosal permeability and celiac disease among a group of elderly patients presenting for rehabilitation. Forty-eight subjects were recruited (16 females) with a mean age of 83.7 (SD 6.1), body mass index 21.8 kg/m(2) (SD 3.9), mini-nutritional assessment (MNA) 19.5 (SD 3.4). They had no current gastrointestinal symptoms and undertook an assessment of mucosal permeability using the dual sugar absorption test of lactulose (7.5 g) and rhamnose (1 g). Ten of the 48 subjects had increased mucosal permeability with an L:R ration ranging from 0.0860 to 7.706 (N 0.01-0.08). These subjects were all at risk or malnourished according to the MNA score and they had a significantly lower mean MNA score of 17.2 (SD 3.5) compared to normal absorbers with a mean of 19.5 (SD 3.4). Two of the subjects had positive tissue trans-glutaminase antibodies. The higher risk of potential malabsorption in this elderly population has significant implications both for nutritional supplementation and for drug absorption as well as being a possible major contributor to malnutrition.

Appendicectomy as a therapy for ulcerative proctitis.

OBJECTIVES: Available data regarding whether appendicectomy performed after the onset of ulcerative colitis can modulate its clinical course are currently limited. This study aimed at addressing this issue. METHODS: In this study, we report a prospective case series of 30 adult patients (median age 35 years, range 17-70 years; male/female: 11/19) with ulcerative proctitis (median duration of symptoms 5 years, range 8 months to 30 years; median Simple Clinical Colitis Activity Index score 9, range 7-12), who underwent appendicectomy in the absence of any history suggestive of previous appendicitis. Patients were subsequently followed up clinically with the assessment of the Simple Clinical Colitis Activity Index for a median of 14 months (range 9-32 months). RESULTS: After appendicectomy, the clinical activity index improved significantly to a median score of 2 (range 0-12) (P<0.0005). The improvement in the clinical activity index occurred in 27 of 30 (90%) patients, whereas the index remained unchanged in the remaining 3 of 30 (10%) patients. Furthermore, 12 of 30 (40%) patients experienced a complete resolution of symptoms (clinical activity index score of 0) by 12 months, such that all pharmacological treatments could be withdrawn, and have remained in remission off all previous treatments for a median 9 months (range 6-25 months). The time required for a complete resolution of symptoms post appendicectomy ranged from 1 to 12 months (median 3 months) (Kaplan-Meier analysis). None of the clinical or histological factors analyzed were significantly associated with post-appendicectomy outcome. CONCLUSIONS: This case series, the largest reported so far, provides rationale for controlled trials to properly evaluate the possible role of appendicectomy in the treatment of ulcerative proctitis.

IBS or intolerance?

BACKGROUND: The contribution of specific foods to the genesis of symptoms in irritable bowel syndrome (IBS) has been increasingly recognised in recent years. OBJECTIVE: This article discusses the dietary triggers for IBS and the role of diagnostic testing in patients with IBS. DISCUSSION: In addition to the long standing implication of lactose in lactase deficient patients, fermentable dietary oligosaccharides, disaccharides, monosaccharides and polyols, together with very low carbohydrate diets, have been increasingly recognised as important in the causation and treatment of irritable bowel syndrome. Understanding their role and utilising the services of a practising dietician have become additional important tools for general practitioners managing this common complaint.

Does subclinical malabsorption of carbohydrates prevent colorectal cancer? A hypothesis.

The incidence of colorectal cancer (CRC) is high in the western world and low in Asia and Africa. Fibre and starch are thought to be important protective factors, with a strong inverse relationship between starch consumption and CRC incidence. Whether this is true in Asia, particularly, and Africa is debatable. Because rice is the most easily absorbed of carbohydrates, a mechanism whereby there is an increased starch load in the colon in the Asian population needs to be identified. One possible cause is subclinical malabsorption. This is linked to increased mucosal permeability and low gross domestic product (GDP) per capita, which reflects poor sanitation and water supplies with increased risk for small bowel bacterial overgrowth leading to mucosal cell damage. A potential cause of the dramatic rise in CRC incidence in Japan may relate to its equally dramatic increase in GDP per capita of 600% over 50 years. This correlation appears to be stronger than with other dietary factors including fruit, vegetables and meat. Worldwide, a close correlation exists among low GDP per capita, low CRC incidence and presumed subclinical malabsorption. All these factors combine to maintain a low incidence of CRC in poorly developed countries.

Irritable bowel syndrome.

BACKGROUND: Irritable bowel syndrome (IBS) a common worldwide problem, particularly women, and presents from the teenage years onward. OBJECTIVE: This article discusses the causes, diagnosis and management of IBS. DISCUSSION: Disturbed motility and sensory function underlie much of the disturbance in function that, not infrequently, begins following an episode of gastroenteritis. There is an intimate role for the brain-gut axis in modulating symptoms relating to underlying causes of small bowel bacterial overgrowth, food intolerance and sensitivity, and abnormalities of corticotropin releasing factors. Management requires long term involvement with the patient as there is no single therapeutic strategy that is predictably effective. However, diet, bulking agents, antispasmodics and a variety of alternative therapies including herbs, probiotics, and psychological intervention are important in individual patients.

Effect of oral sucralfate on late rectal injury associated with radiotherapy for prostate cancer: A double-blind, randomized trial.

PURPOSE: To assess whether oral sucralfate is effective in preventing late rectal injury in prostate cancer patients treated with radiotherapy. METHODS AND MATERIALS: A double-blind, placebo-controlled, randomized trial was conducted across four institutions in Australia. Patients receiving definitive radiotherapy for prostate cancer were randomized to receive either 3 g of oral sucralfate suspension or placebo twice daily. Data on patients' symptoms were collected for 2 years, and flexible sigmoidoscopy was scheduled at 12 months after treatment. RESULTS: A total of 338 patients were randomized, of whom 298 had adequate follow-up data available for an analysis of late symptoms. Of the 298 patients, 143 were randomized to receive sucralfate and 155 placebo. The cumulative incidence of Radiation Therapy Oncology Group Grade 2 or worse late rectal toxicity at 2 years was 28% for placebo and 22% for the sucralfate arm (p = 0.23; 95% confidence interval for the difference -3% to 16%). Seventeen percent of patients in the sucralfate group had significant bleeding (Grade 2 or worse) compared with 23% in the placebo group (p = 0.18, 95% confidence interval -15% to 3%). No statistically significant difference was found between the two groups with respect to bowel frequency (p = 0.99), mucus discharge (p = 0.64), or fecal incontinence (p = 0.90). Sigmoidoscopy findings showed a nonstatistically significant reduction in Grade 2 or worse rectal changes from 32% with placebo to 27% in the sucralfate group (p = 0.25). CONCLUSION: This trial demonstrated no statistically significant reduction in the incidence of late rectal toxicity in patients randomized to receive sucralfate. However, this result was considered inconclusive, because the trial was unable to exclude clinically important differences in the late toxicity rates.