Effects of Lactulose on Gut Microbiota and Metabolism in Diabetic Constipated Patients

Launched by PEKING UNION MEDICAL COLLEGE HOSPITAL · Jul 4, 2025

Keywords

ClinConnect Summary

This clinical trial is studying how a medicine called lactulose affects the gut bacteria and digestion in people with type 2 diabetes who also have chronic constipation (difficulty having regular bowel movements). Constipation is common in people with diabetes, and researchers want to understand whether lactulose, which is a gentle laxative that also helps feed good gut bacteria, can improve bowel habits and change the balance of bacteria and metabolic activity in the gut. The study will also look at whether combining lactulose with certain probiotics (live beneficial bacteria) has additional benefits.

Adults between 18 and 70 years old who have type 2 diabetes and meet specific criteria for ongoing constipation may be eligible to join. Participants should have stable blood sugar control and avoid certain foods and supplements during the study to keep the results clear. Those with other serious health issues or recent use of antibiotics, laxatives, or probiotics won’t qualify. If you join, you can expect to take lactulose alone or with probiotics, and the researchers will collect stool samples to study changes in gut bacteria and metabolism. This trial aims to better understand how lactulose works in diabetic constipation and may help improve treatment options in the future.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • Age: 18-70 years
• * Type 2 Diabetes Diagnosis (per 2017 ADA criteria), meeting ≥1 of:
• • 1. Fasting plasma glucose (FPG) ≥7.0 mmol/L
• • 2. hour plasma glucose ≥11.1 mmol/L during 75g anhydrous oral glucose tolerance test (OGTT)
• • 3. Random plasma glucose ≥11.1 mmol/L with hyperglycemia symptoms or hyperglycemic crisis
• * Functional Constipation (Rome IV criteria), requiring:
• • 1. ≥2 of the following
• • 1. occurring in ≥25% of defecations
• • 2. Straining
• • 3. Lumpy/hard stools (Bristol Stool Scale 1-2)
• • 4. Sensation of incomplete evacuation
• • 5. Anorectal obstruction/blockage
• • 6. Manual maneuvers required
• • 7. \<3 spontaneous bowel movements/week
• • 2. No loose stools without laxatives
• • 3. Exclusion of IBS diagnosis. Symptom duration \>6 months, with active symptoms meeting criteria for last 3 months.
• • Stable Glycemic Control: No anticipated antidiabetic medication adjustments during study
• • Dietary Stability: Maintain consistent diet; avoid yogurt, fermented foods, prebiotic-containing processed foods, or other items that may confound results
• Exclusion Criteria:
• • Secondary Constipation due to organic diseases or medication effects.
• • Constipation-predominant Irritable Bowel Syndrome (IBS-C).
• • Concurrent gastrointestinal disorders (e.g., inflammatory bowel disease, colorectal cancer).
• • Type 1 Diabetes Mellitus.
• * Severe chronic comorbidities, including:
• • 1. Cardiopulmonary insufficiency
• • 2. Cerebrovascular diseases
• • 3. Psychiatric disorders
• * Recent use (within 1 month) of confounding medications:
• • 1. Probiotics/prebiotics
• • 2. Antibiotics
• • 3. Laxatives (e.g., osmotic/stimulant agents)
• • 4. Prokinetics