Use of the Analysis of the Volatile Faecal Metabolome in Screening for Colorectal Cancer.

Diagnosis of colorectal cancer is an invasive and expensive colonoscopy, which is usually carried out after a positive screening test. Unfortunately, existing screening tests lack specificity and sensitivity, hence many unnecessary colonoscopies are performed. Here we report on a potential new screening test for colorectal cancer based on the analysis of volatile organic compounds (VOCs) in the headspace of faecal samples.

Analysis of volatile organic compounds of bacterial origin in chronic gastrointestinal diseases.

Background: The aim of this study was to determine whether volatile organic compounds (VOCs) present in the headspace of feces could be used to diagnose or distinguish between chronic diseases of the gastrointestinal tract and apparently healthy volunteers.

Methods: A total of 87 people were recruited, divided between 4 categories: healthy volunteers (n = 19), Crohn's disease (n = 22), ulcerative colitis (n = 20), and irritable bowel syndrome (n = 26). They each supplied fecal samples before, and except for the healthy volunteers, after treatment.

Diversity and distribution of sulphate-reducing bacteria in human faeces from healthy subjects and patients with inflammatory bowel disease.

The relative abundance of different groups of sulphate-reducing bacteria (SRB) in faecal DNA collected before and after therapy from patients suffering from Crohn's disease (CD), irritable bowel syndrome (IBS) or ulcerative colitis (UC) has been compared with that from healthy controls. Growth tests revealed that SRB were not more abundant in samples from patients with CD before treatment than in the healthy control group. For most of the 128 samples available, these preliminary results were confirmed using degenerate PCR primers that amplify the dsrAB gene.

Is the abundance of Faecalibacterium prausnitzii relevant to Crohn's disease?

Reports that bacteria within the Firmicutes phylum, especially the species Faecalibacterium prausnitzii, are less abundant in Crohn's disease (CD) patients and supernatants from cultures of this bacterium are anti-inflammatory prompted the investigation of the possible correlations between the abundance of F. prausnitzii and the response to treatment in patients with gut diseases and healthy controls. In a randomized, double-blind trial, faeces were collected from healthy volunteers, and from patients with active CD, ulcerative colitis (UC) and irritable bowel syndrome before and after treatment.

Symptom classification in irritable bowel syndrome as a guide to treatment.

Objective: The treatment of irritable bowel syndrome (IBS) remains unsatisfactory. There are no objective markers for diagnosis, and classification (currently based on symptoms) provides little insight into potential causes or optimal therapy. The aim of this study was to determine whether a Swedish classification of IBS based on cluster analysis of patients' symptoms might provide a guide to successful treatment.

Interferon beta-1a for the maintenance of remission in patients with Crohn's disease: results of a phase II dose-finding study.

Background: Crohn's disease (CD) and multiple sclerosis (MS) share common pathogenic processes. Interferon (IFN) beta-1a is effective and generally well tolerated in patients with MS and has been shown to down-regulate the expression of interleukin-12, a cytokine that is thought to be involved in mucosal degeneration in CD. IFN beta-1a therefore offers promise as a treatment for CD.

Do interventions which reduce colonic bacterial fermentation improve symptoms of irritable bowel syndrome?

Abnormal fermentation may be an important factor in irritable bowel syndrome (IBS). Gastroenteritis or antibiotic therapy may damage the colonic microflora, leading to increased fermentation and the accumulation of gas. Gas excretion may be measured by whole-body calorimetry but there has only been one such study on IBS to date.

Effect of probiotics on preventing disruption of the intestinal microflora following antibiotic therapy: a double-blind, placebo-controlled pilot study.

In this pilot-scale, double-blind, placebo-controlled trial, 30 patients with Helicobacter pylori infection were randomised into three groups prior to their 7 days eradication therapy, to study the effects of probiotic supplement comprising Lactobacillus acidophilus and Bifidobacterium bifidum on the intestinal microflora in response to antibiotic therapy. Group I received the placebo product from day 1 to day 15, Group II received placebo from day 1 to day 7 and probiotics from day 8 to day 15 and Group III received probiotics from day 1 to day 15. Patients provided stool samples for analysis on days 1, 7, 12, 17 and 27.

Immunoglobulin coating of faecal bacteria in inflammatory bowel disease.

Objective: An inappropriate mucosal immune response to the commensal bacterial flora may play a role in the pathogenesis of inflammatory bowel disease (IBD). In this study we determined the percentage of immunoglobulin-coated bacteria in the stools of patients and controls.

Methods: Faecal samples were obtained from 18 patients with IBD (one sample during exacerbation and one shortly after remission was achieved), 15 healthy volunteers, eight infectious colitis patients, and 13 IBD patients in long-term remission.

Derivation and identification of questions that act as predictors of abdominal pain of musculoskeletal origin.

Objective: Although most causes of abdominal pain have a visceral origin, the musculoskeletal system must be considered when the cause is not obvious. This prospective study aimed to identify questions that would aid the diagnosis of patients with abdominal pain of musculoskeletal origin.

Design: Assessment of consecutive patients with abdominal pain recruited from gastroenterological outpatient clinics to develop diagnostic pointers to identify abdominal pain arising from musculoskeletal disorders.

Evaluation of hydrogen excretion after lactulose administration as a screening test for causes of irritable bowel syndrome.

Objective: To determine whether it is possible to separate cases of irritable bowel syndrome associated with excess total hydrogen production (as a surrogate of colonic fermentation; these patients may be offered an exclusion diet as treatment) from other causes of irritable bowel syndrome by determining the amount of hydrogen excreted on patients' breath after oral administration of lactulose.

Design: Comparison of 24-hour hydrogen excretion and breath hydrogen following lactulose in untreated patients fulfilling the Rome criteria for irritable bowel syndrome, normal controls and irritable bowel syndrome patients who had previously failed to improve on an exclusion diet.

Methods: Colonic fermentation was measured by indirect calorimetry over 24 h.