Magnus Simren

Magnus Simren
University of Gothenburg | GU · Department of Internal Medicine & Clinical Nutrition

MD, PhD; Professor

About

627
Publications
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Publications

Publications (627)
Article
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LINKED CONTENT This article is linked to Lövdahl et al papers. To view these articles, visit https://doi.org/10.1111/apt.16934 and https://doi.org/10.1111/apt.16947
Article
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Background Gut‐directed hypnotherapy improves symptoms for patients with irritable bowel syndrome (IBS). Group hypnotherapy, as well as hypnotherapy administered by nurses, can increase treatment availability, but there are few comparisons between individual and group‐based hypnotherapy. Aim We aimed to evaluate and compare the effectiveness of nu...
Article
Irritable bowel syndrome with diarrhoea (IBS‐D) and functional diarrhoea (FDr) are the two major functional bowel disorders characterized by diarrhoea. In spite of their high prevalence, IBS‐D and FDr are associated with major uncertainties, especially regarding their optimal diagnostic work‐up and management. A Delphi consensus was performed with...
Article
The majority of patients with irritable bowel syndrome (IBS) experiences food‐related symptoms, which are associated with high symptom burden, reduced quality of life, increased healthcare consumption and reduced intake of certain nutrients. In this review we aimed to describe a clinically useful approach for physicians, by presenting the latest pr...
Article
There has been a dramatic increase in clinical studies examining the relationship between disorders of gut-brain interactions (DGBI) and symptoms evoked by food ingestion in the upper and lower GI tract, but study design is challenging to verify valid endpoints. Consequently, mechanistic studies demonstrating biological relevance, biomarkers and no...
Article
Gastroesophageal reflux disease (GERD) often requires lifelong treatment to return to and maintain a normal quality of life. Proton pump inhibitors (PPIs) offer effective medical treatment and can be used for a long time with good safety margins. The diagnostic criteria for GERD must be strictly based on current guidelines and the need for maintain...
Article
Background Irritable Bowel Syndrome (IBS) negatively influences mental and physical quality of life (QoL), but factors that explain this impact are still unclear. Increasing evidence has associated IBS severity, psychological distress, somatic symptoms, and gastrointestinal (GI)-specific anxiety with QoL in IBS. The aim of this study is to further...
Article
Background: Alteration of the host-microbiota cross talk at the intestinal barrier may participate in the pathophysiology of irritable bowel syndrome (IBS). Therefore, we aimed to determine effects of fecal luminal factors from IBS patients on the colonic epithelium using colonoids. Methods: Colon-derived organoid monolayers, colonoids, generate...
Article
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Background Irritable Bowel Syndrome (IBS) is a highly prevalent functional gastrointestinal disorder. Earlier studies have shown that IBS can limit the ability to perform at work and lead to absenteeism. However, few studies focus on work life experiences based on patients’ narratives. The purpose of this study was to construct a theory for how per...
Article
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Background Patients with disorders of gut-brain interaction (DGBI) report meal intake to be associated with symptoms. DGBI patients with meal-related symptoms may have more severe symptoms overall and worse health outcomes, but this subgroup has not been well characterized. We aimed to describe the global prevalence of meal-related abdominal pain a...
Article
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Introduction Ulcerative colitis (UC) contributes to impaired health-related quality of life (HRQoL). Although disease activity is the most important factor, reduced HRQoL has been reported even in quiescent UC. We aimed to determine HRQoL, and identify predictors thereof, in patients with long-standing UC in remission. Methods In total, 66 patient...
Article
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(1) Background: Predictors of dietary treatment response in irritable bowel syndrome (IBS) remain understudied. We aimed to investigate predictors of symptom improvement during the low FODMAP and the traditional IBS diet for four weeks. (2) Methods: Baseline measures included faecal Dysbiosis Index, food diaries with daily energy and FODMAP intake,...
Article
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Gut dysmotility is associated with constipation, diarrhea, and functional gastrointestinal disorders like irritable bowel syndrome (IBS), although its molecular underpinnings are poorly characterized. We studied stool frequency (defined by the number of bowel movements per day, based on questionnaire data) as a proxy for gut motility in a GWAS meta...
Article
Disorders of gastric motor and sensory function affect 10%-20% of the world's population and adversely impact nutrition, quality of life, work productivity, and health care costs. Classifying these disorders can be challenging given the heterogeneity of symptom presentation, the presence of symptoms unexplained by endoscopic, radiographic and/or la...
Article
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Somatization, defined as the presence of multiple somatic symptoms, frequently occurs in irritable bowel syndrome (IBS) and may constitute the clinical manifestation of a neurobiological sensitization process. Brain imaging data was acquired with T1 weighted 3 tesla MRI, and gray matter morphometry were analyzed using FreeSurfer. We investigated di...
Article
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Introduction: Gastrointestinal (GI) symptoms in coronavirus-19 disease (COVID-19) have been reported with great variability and without standardization. In hospitalized patients, we aimed to evaluate the prevalence of GI symptoms, factors associated with their occurrence, and variation at 1 month. Methods: The GI-COVID-19 is a prospective, multi...
Conference Paper
Introduction Individuals with coeliac disease (CD) can experience persisting gastrointestinal symptoms despite adhering to a gluten-free diet (GFD). This may be due to functional gastrointestinal disorders (FGIDs), although there is little data on its prevalence and associated factors. Methods An online health questionnaire was completed by adult...
Article
Background and aims Rumination syndrome is a Disorder of Gut-Brain Interaction (DGBI) of unknown etiology. We aimed to assess its global prevalence and potential associations with other medical conditions. Methods Data were collected via the Internet in 26 countries. Subjects were evenly distributed by country, sex and age groups and were invited...
Article
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Background: Human milk oligosaccharide supplementation safely modulates fecal bifidobacteria abundance and holds the potential to manage symptoms in irritable bowel syndrome (IBS). Here, we aimed to determine the role of a 4:1 mix of 2'-O-fucosyllactose and lacto-N-neotetraose (2'FL/LNnT) on the modulation of the gut microbiota composition and hos...
Article
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Background: Irritable bowel syndrome (IBS) is a multi-faceted gastrointestinal disorder where food intake often triggers symptoms. Metabolomics may provide mechanistical insights to why responses to dietary modifications are diverse. Objective: This study aimed to identify metabolite patterns related to dietary intake in patients with IBS, and t...
Article
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Background: Aloe barbadensis Mill. (Aloe) extract was found to be well-tolerated, safe and showed beneficial effects in subsets of irritable bowel syndrome (IBS) patients in two randomized, double-blind, controlled studies. However, the individual studies were underpowered to perform subgroup analyses. We therefore determined the effect of Aloe ex...
Article
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Background Irritable bowel syndrome (IBS) is highly prevalent worldwide but mechanisms for healthcare seeking behaviours in this patient group are poorly understood. Objective To describe healthcare utilization and identify factors associated with seeking healthcare amongst IBS subjects in the general population. Methods An internet survey was co...
Article
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Background Studies on allergy-related diseases in relation to abdominal pain-related functional gastrointestinal disorders (AP-FGIDs) in children are few and results are contradictory. We examined the associations between childhood allergy-related diseases and adolescent AP-FGIDs in general and irritable bowel syndrome (IBS) in particular. Method...
Article
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Background and aims Wheat contains several components, including gluten and fructan, that may be associated with gastrointestinal symptoms (GI) in irritable bowel syndrome (IBS). The aims of the study were to determine the average daily intake of gluten, investigate the association of gluten and GI symptoms, as well as the association between fruct...
Article
Background & Aims Individuals with celiac disease (CD) can experience persisting gastrointestinal symptoms despite adhering to a gluten-free diet (GFD). This may be due to functional gastrointestinal disorders (FGIDs), although there is little data on its prevalence and associated factors. Methods An online health questionnaire was completed by ad...
Article
Background & aims: Neither food intake, nor the clinical characteristics of irritable bowel syndrome (IBS) patients with severe food avoidance and restriction have been investigated. The aim of our study was to identify those patients and to characterize their symptoms, quality of life, and nutrient intake. Methods: IBS patients who completed th...
Article
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Background: Although it is widely acknowledged that food intake can worsen symptoms in patients with irritable bowel syndrome (IBS), there is a lack of efficient treatments that can apply to all patients and subtypes of IBS. As IBS can manifest in different ways, it is likely that the most successful treatment option will differ among patients; th...
Preprint
BACKGROUND Although it is widely acknowledged that food intake can worsen symptoms in patients with irritable bowel syndrome (IBS), there is a lack of efficient treatments that can apply to all patients and subtypes of IBS. As IBS can manifest in different ways, it is likely that the most successful treatment option will differ among patients; ther...
Article
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Patients with irritable bowel syndrome (IBS) are suggested to have an altered intestinal microenvironment. We therefore aimed to determine the intestinal microenvironment profile, based on faecal microbiota and metabolites, and the potential link to symptoms in IBS patients. The faecal microbiota was evaluated by the GA-mapTM dysbiosis test, and ta...
Article
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Irritable bowel syndrome (IBS) is a gut‐brain disorder in which symptoms are shaped by serotonin acting centrally and peripherally. The serotonin transporter gene SLC6A4 has been implicated in IBS pathophysiology, but the underlying genetic mechanisms remain unclear. We sequenced the alternative P2 promoter driving intestinal SLC6A4 expression and...
Article
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Background: Due to important biases, conventional end-of-day and end-of-week assessment methods of gastrointestinal symptoms in functional dyspepsia (FD) are considered suboptimal. Real-time symptom assessment based on the experience sampling method (ESM) could be a more accurate measurement method. This study aimed to evaluate validity and reliab...
Article
Background and aims Conditions such as irritable bowel syndrome (IBS), functional dyspepsia and functional constipation are among the prevalent gastrointestinal disorders classified as disorders of gut brain interaction (DGBI), which can adversely affect the lives of sufferers. This study aimed to assess the degree and consequences of overlapping D...
Article
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Patients with ulcerative colitis (UC) have an altered gut microbiota composition, but the microbial relationship to disease activity needs to be further elucidated. Therefore, temporal dynamics of the fecal microbial community during remission and flare was determined. Fecal samples were collected at 2–6 time-points from UC patients during establis...
Article
Background Central sensitization has been suggested as an explanation of the wide range of gastrointestinal and extraintestinal symptoms commonly seen in irritable bowel syndrome (IBS). In this study, the presence and level of central sensitization, and its association to gastrointestinal (GI) symptoms were explored in IBS in comparison with contro...
Article
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Background While several studies have documented associations between dietary habits and microbiota composition and function in healthy individuals, no study explored these associations in patients with irritable bowel syndrome (IBS), and especially with symptoms. Methods Here, we used a novel approach that combined data from a 4-day food diary, i...
Article
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Although incompletely understood, microbiota-host interactions are assumed to be altered in irritable bowel syndrome (IBS). We, therefore, aimed to develop a novel analysis pipeline tailored for the integrative analysis of microbiota-host interactions and association to symptoms and prove its utility in a pilot cohort. A multilayer stepwise integra...
Article
Background Clinical trials in irritable bowel syndrome are associated with high placebo response rates. We aimed to identify the magnitude of the placebo response and the contributing factors to this occurrence. Methods We did a systematic review and meta-analysis with a search of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Tr...
Article
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Background Postprandial symptoms presumably related to intestinal gas production are common in patients with irritable bowel syndrome (IBS). The aim of the study was to assess if oral α‐galactosidase is superior to placebo in reducing gastrointestinal (GI) symptoms and intestinal gas production after ingestion of carbohydrate‐rich meals in adult pa...
Article
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Background Chronic constipation is a prevalent disorder that affects quality of life of patients and consumes resources in healthcare systems worldwide. In clinical practice, it is still considered a challenge as clinicians frequently are unsure as to which treatments to use and when. Over a decade ago, a Neurogastroenterology and Motility journal...
Article
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Restricting intake of FODMAPs (Fermentable Oligo-, Di-, Monosaccharides and Polyols) is used as treatment for irritable bowel syndrome (IBS). However, whether habitual FODMAP consumption correlates to symptom severity, and if this relationship differs among IBS subtypes, is unclear. The aim was to study the relationship between habitual FODMAP inta...
Preprint
Full-text available
Patients with ulcerative colitis (UC) have an altered gut microbiota composition, but the microbial relationship to disease activity needs to be further elucidated. Therefore, temporal dynamics of the fecal microbial community during remission and flare was determined. Fecal samples were collected at 2–6 time-points from UC patients during establis...
Article
Introduction: Treatment options for irritable bowel syndrome (IBS) are limited, causing many patients to remain symptomatic. This study assessed the potential of human milk oligosaccharides (HMOs) to normalize bowel habits. Secondary outcomes included IBS severity and health-related quality of life. Methods: This multicenter, open-label trial re...
Article
Full-text available
BACKGROUND Chronic constipation is a prevalent disorder that affects patients' quality of life and consumes resources in healthcare systems worldwide. In clinical practice, it is still considered a challenge as clinicians frequently are unsure as to which treatments to use and when. Over a decade ago, a Neurogastroenterology & Motility journal supp...
Article
Full-text available
Objective The incidence of IBS increases following enteric infections, suggesting a causative role for microbial imbalance. However, analyses of faecal microbiota have not demonstrated consistent alterations. Here, we used metaproteomics to investigate potential associations between mucus-resident microbiota and IBS symptoms. Design Mucus samples...
Article
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Background Enhanced perception of visceral stimuli is an important feature of Irritable Bowel Syndrome (IBS), but it is not known whether visceral sensitivity is associated with regional structural brain properties in IBS. Methods Structural brain magnetic resonance imaging data from 216 women with IBS and 138 healthy women were parcellated with F...