Laxative Properties of Microencapsulated Oleic Acid Delivered to the Distal Small Intestine in Patients with Constipation after Bariatric Surgery or Treatment with Glucagon-Like- Peptide 1 Analogues

Background: Constipation is prevalent after bariatric surgery and glucagon-like-peptide 1 (GLP-1) analogues. Increasing fat content in the distal small intestine and colon can enhance colonic peristalsis, potentially alleviating symptoms of constipation. Aim: We investigated whether oleic acid can ameliorate constipation in patients undergoing bariatric surgery or receiving GLP-1 analogues. Methodology: Fourteen adults with chronic constipation according to Rome IV criteria following bariatric surgery or GLP-1 analogues were on stable treatment for constipation for more than 4 weeks. This randomized double-blind crossover trial compared microcapsules containing 21.25 g of oleic acid delivered in the distal small intestine or the stomach. The primary outcome was changed in the number of bowel motions over 24 h. Exploratory endpoints included alterations in straining, diarrhoea, faecal leakage over 24 h and hunger, fullness, nausea and calorie intake for the 3 h after ingesting the microcapsules. Findings: Receiving oleic acid into the distal small intestine increased number of bowel movements per day (2.5 vs 1.1, p = 0.009) and caused softer stool consistency (p = 0.03). 9/14 of the control group passed motions and 13/14 of the intervention group passed motions in 24 h (p = 0.059). No significant differences were observed in straining (p = 0.65), rapid bowel movements (p = 0.08), accidental leakage (p = 0.32), hunger, fullness, nausea or food intake between the groups (all p > 0.05). There were no disparities in safety profile between groups. Conclusion: Microcapsules containing oleic acid delivered to the distal small intestine appear to be a safe and effective relief from chronic constipation in patients undergoing bariatric surgery and/or receiving GLP-1 analogues. Graphical Abstract: (Figure presented.)