Francesc Casellas

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Our knowledge of species and functional composition of the human gut microbiome is rapidly increasing, but it is still based on very few cohorts and little is known about variation across the world. By combining 22 newly sequenced faecal metagenomes of individuals from four countries with previously published data sets, here we identify three robust(More)
IBD—ulcerative colitis and Crohn's disease—is emerging as a worldwide epidemic. An association between the increased incidence of IBD and environmental factors linked to socioeconomic development has been persistently detected in different parts of the world. The lifestyle in developed countries might impair the natural patterns of microbial colonization of(More)
BACKGROUND Inflammatory bowel disease impairs patients' perception of health and has a negative impact on health-related quality of life (HRQOL). Most studies include patients from a single hospital. This may bias limit results through the use of small patient samples and/or samples within a restricted disease spectrum. METHODS HRQOL was measured in(More)
Most current approaches for analyzing metagenomic data rely on comparisons to reference genomes, but the microbial diversity of many environments extends far beyond what is covered by reference databases. De novo segregation of complex metagenomic data into specific biological entities, such as particular bacterial strains or viruses, remains a largely(More)
BACKGROUND Increased numbers of mast cells and mast cell activation in distal gut segments are associated with symptom onset and severity in irritable bowel syndrome (IBS). Although upper gut symptoms are common, mast cells have not been thoroughly evaluated in proximal gut in IBS patients. METHODS Jejunal biopsies obtained by Watson's capsule, aspiration(More)
BACKGROUND & AIMS Scarce data suggest that cholecystectomy may alter bowel habit. The aim of this study was to determine whether cholecystectomy modifies gut transit. METHODS Five experimental groups were studied: 29 patients with uncomplicated gallstones before and 1 month after elective cholecystectomy, 22 patients 4 years after elective(More)
The objective of this study is to validate the Spanish translation of the Inflammatory Bowel Disease Questionnaire (SIBDQ) on ulcerative colitis and Crohn's disease by assessing its convergence validity, discriminatory power, reliability and sensitivity to change. For that purpose, 211 patients with inflammatory bowel disease (116 with ulcerative colitis(More)
BACKGROUND Inulin and oligofructose promote selective growth of saccharolytic bacteria with low inflammatory potential. OBJECTIVE To test the effect of oligofructose-enriched inulin in patients with active ulcerative colitis. DESIGN Prospective, randomized, placebo controlled pilot trial. Eligible patients had been previously in remission with(More)
Using a disease specific instrument to measure the health related quality of life (HRQOL) of patients with inflammatory bowel disease (IBD), it has been shown that their perceived HRQOL worsens during active disease. The precise factors involved in HRQOL changes reported by these patients are largely unknown. Our aim was to elucidate which socio-demographic(More)
BACKGROUND:Crohn's disease (CD) has a negative impact on patients' perception of health. Several factors, such as disease activity, influence HRQOL impairment. However, the effect of the phenotypic CD characteristics recognized in the Vienna classification on health-related quality of life (HRQoL) remains unknown.METHODS:HRQOL was measured in CD patients(More)