Genetic Carbohydrate Maldigestion as a Model to Study Food Hypersensitivity

Summary

Irritable bowel syndrome (IBS) affects one in seven people with gastrointestinal (GI) symptoms. IBS strongly impacts quality of life, is a leading cause of work absenteeism, and consumes 0.5% of the healthcare annual budget. It manifests in women more than men with symptoms including abdominal pain, bloating, constipation (IBS-C), diarrhoea (IBS-D), and mixed presentations (IBS-M) (1). The development of therapeutic options is hampered by the poor understanding of the underlying cause of symptoms.

Many patients find that certain foods (particularly carbohydrates) trigger their symptoms, and avoiding such foods has been shown effective in IBS, like in the low-FODMAP (fermentable oligo-, di-, mono-saccharides and polyols) exclusion diet.

This has suggested that the food-symptom relation may involve malabsorption of carbohydrates due to inefficient digestion. However only a percentage of patients respond to this diet. Recently it has been reported that a subset of IBS carries hypomorphic (defective) gene variant of the sucrase isomaltase (SI), the enzyme that normally digests carbohydrates, sucrose and starch. This carbohydrate maldigestion (the breakdown of complex carbohydrates by a person's small bowel enzymes) is characterized by diarrhoea, abdominal pain and bloating, which are also features of IBS. This possibly occurs via accumulation of undigested carbohydrates in the large bowel, where they cause symptoms due to gas production following bacterial fermentation. Similar mechanisms may be acting at the level of other enzymes involved in the digestion, breakdown and absorption of carbohydrates (carb digestion genes -CDGs). Aim of the study is to study the prevalence of this genetic alteration in a large number of IBS patients as compared to asymptomatic controls.

Conditions

• Irritable Bowel Syndrome (IBS)
• Sucrase Isomaltase Deficiency

Interventions

OTHER

Stool and saliva sample collection

Stool and saliva samples collection

OTHER

Questionnaire completion

Questionnaire on; * demographic, ethnicity, IBS subtype, post-infection onset, previous surgeries * IBS severity score for adults * Hospital Anxiety and Depression scores for adults * Somatization score for adults * Total glucose and fructose and excess fructose, lactose, sorbitol, mannitol, oligosaccharides (Fructans and GOS) as measured by CNAQ questionnaire for adults and children * Quality of Life as measured by the PedsQL™ GI Symptoms Module * GI symptoms as measured by the PedsQL™ GI Symptoms Module * Anxiety, Depression as measured by the Pediatric PROMIS®

Sponsors & Collaborators

• CICbioGUNE

  collaborator UNKNOWN

• Christian-Albrechts-University of Kiel

  collaborator UNKNOWN

• University of Veterinary Medicine Hannover

  collaborator UNKNOWN

• Nottingham University Hospitals NHS Trust

  lead OTHER

Eligibility

Min Age

5 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-07-23

Primary Completion

2025-09-30

Completion

2026-03-31

Countries

• United Kingdom

Study Locations