Clinical Trial: Multi‐Strain Probiotic Improves Bile Acid Profile, Microbiome, and Metabolomic Parameters in Patients With History of Bile Acid Malabsorption—A Randomized, Controlled Trial
ABSTRACT Background Bile acid (BA) malabsorption (BAM) is a common cause of chronic diarrhoea and may occur in some patients due to abnormalities of the gut microbiota. Effects of probiotics on faecal secretory BAs, particularly the primary BA, chenodeoxycholic acid, are unclear. Aim/Methods We conducted a randomized, double‐blind, placebo‐controlled trial of the De Simone formulation 8‐strain probiotic in 24 patients previously diagnosed with BAM. Patients were randomized to 3 weeks of the probiotic (900 billion bacteria) or placebo (maltose), both administered three times daily. Symptoms, serum 7 α C4, faecal primary BAs, intestinal permeability by 13 C‐mannitol‐lactulose test (0.1 and 1 g of the sugars respectively) over 24 h, faecal short chain fatty acids (SCFA), microbiome, and metabolome were assessed at baseline and post‐intervention. Results Data from 22 patients were included. Probiotic supplementation was associated with a significant decrease in % faecal primary BAs (chenodeoxycholic acid and cholic acid) with median change from baseline −5.7 [IQR −10.3, 0.9]% compared to 9.8 [IQR 0.2, 20.6]% on placebo ( p = 0.012). The faecal microbiome was significantly different in the probiotic group after intervention, driven by probiotic‐specific species. There were no significant differences in symptoms, intestinal permeability, or SCFA. However, there was a numerical difference in the changes from baseline in 0‐2 h 13 C‐mannitol excretion −1.9 [−13.9, 4.2] mg for the probiotic and 1.0 (−0.5, 12.7) mg for placebo ( p = 0.084). Conclusions The De Simone formulation probiotic induced significant microbiome and metabolome changes in patients with BAM, ultimately leading to a decrease in % faecal primary BAs and possible reduction in intestinal permeability. Clinical Trials.gov registration NCT #06609148, January 2, 2025.
A Pilot Validation Study of Plant‐Based and Allergy‐Friendly Alternative for Testing Gastric Emptying: A Randomized Trial in Healthy Participants
ABSTRACT Background Gastric emptying (GE) scintigraphy with 4‐h imaging and a radiolabeled chicken egg‐based meal (320 kcal, 30% fat) is the standard test for gastroparesis at Mayo Clinic, with an intraindividual coefficient of variation (COV intra ) of 23.8% for GE half emptying time (T 1/2 ). Alternative meals for patients with dietary restrictions, including egg allergies or vegan diets, are lacking, limiting test accessibility. The study aimed to establish a vegan, lactose‐, nut‐, and gluten‐free meal with similar caloric and fat content to the egg meal and to assess its performance in GE studies. Methods In Vitro: 99m Tc binding to egg meal over 4 h was compared to a calorically and nutritionally similar vegan alternative, JUST Egg, using a validated in vitro model simulating gastric conditions of pH, pepsin, and stirring. In Vivo: 10 healthy participants underwent randomized crossover GE scintigraphy with standard and vegan meals, spaced ≥ 3 days apart to measure GE% at 2 h, 4 h, and GE T 1/2 . Group comparisons and variance analysis included Rank Sum tests and Bland–Altman plots. Key Results In Vitro: A strong correlation ( R = 0.975, p ‐value < 0.01) between 99m Tc binding in the egg and vegan egg models was observed. Minimal variance (< 10%) was recorded at all time points. In Vivo: GE at 4 h and GE T 1/2 showed non‐statistically significant mean differences, < 2% and < 10 min respectively, between both meals. The intra‐individual variability was 18.8%. Conclusions and Inferences The vegan meal demonstrated in vitro stability, in vivo performance comparable to the egg meal, and a COV intra of 18.8%, which was lower than the 23.8% reported in repeat egg meal GE studies. Trial Registration ClinicalTrials.gov number NCT06991036 ( https://clinicaltrials.gov/study/NCT06991036?term=NCT06991036&rank=1 )
A pilot, randomized, placebo-controlled trial of rimegepant on visceral sensation and symptoms in nonconstipation IBS pain
This pilot, randomized, double-blind trial in a relatively small sample of patients with IBS-related pain shows rimegepant significantly reduced sensations of gas, urgency, and pain during rectal distention and decreased rectal compliance. Decrease in compliance implies that changes in physical properties or distensibility of rectum did not contribute to alterations in rectal sensation. Same dose of rimegepant did not significantly impact daily abdominal pain, BM frequency, or colonic transit. There were no serious adverse events.
Indomethacin Fails to Increase Intestinal Permeability in Healthy Volunteers
INTRODUCTION: Indomethacin is often used experimentally to induce intestinal hyperpermeability, enabling evaluation of interventions targeting barrier function. METHODS: We conducted a randomized, double-blind, placebo-controlled study (NCT05538247) in healthy volunteers to assess whether a supplement could mitigate indomethacin-induced hyperpermeability. Participants received 150 mg/d of indomethacin for 6 days, either before or during placebo/supplement administration. Permeability was measured using 13 C-mannitol and lactulose urinary excretion. RESULTS: Contrary to expectations, indomethacin failed to increase 13 C-mannitol excretion in either group. No meaningful elevations in serum (zonulin, claudins) or fecal (calprotectin) biomarkers were observed. DISCUSSION: Our findings suggest that the expected increase in intestinal permeability after indomethacin administration may not be consistently observed in healthy volunteers. These results highlight the need to carefully consider the reproducibility and sensitivity of this model in future clinical studies aiming to investigate gut barrier function.
Effects of Ricinoleic Acid (Castor Oil) on Gut Permeability in Healthy Participants: Provocative Test for Treatments Aimed at Restoring Barrier Function
INTRODUCTION: Altered intestinal permeability (IP) is implicated in multiple gastrointestinal and systemic disease conditions; an experimental model of perturbed IP in healthy subjects is needed. Traditional approaches to perturbing IP include use of nonsteroidal anti-inflammatory drugs. METHODS: We conducted a single-center, randomized, placebo-controlled pilot study of dose-related effects of castor oil (CO) (and its ingredient ricinoleic acid) at 750, 1,500, or 3,000 mg daily doses on IP. Permeability was assessed using validated 13 C-mannitol and lactulose urine excretion at 0–2, 8–24, and 0–24 hours after oral administration. RESULTS: Permeability analysis across all groups demonstrated significant difference among the groups for 0–2 hours 13 C-mannitol, 0–24 hours 13 C-mannitol, and borderline significant difference for 2–8 hours 13 C-mannitol ( P = 0.060) and 0–24 hours lactulose ( P = 0.056). Direct comparison of 3,000 mg CO vs placebo ( t test) demonstrated higher excretion of 13 C-mannitol and lactulose at 0–2, and 0–24 hours, and lactulose at 2–8 hours. DISCUSSION: CO may perturb small intestinal and colonic permeability in healthy adults.
Intestinal Permeability In Vivo in Patients With Inflammatory Bowel Disease: Comparison of Active Disease and Remission
Abstract Background and Aims Inflammatory bowel disease (IBD) is associated with altered mucus and increased intestinal permeability (IP). Prior reports on permeability in IBD typically used lactulose-to-mannitol ratio (LMR). Food contamination with 12C-mannitol is a significant potential confounder in IP assessment. We aimed to compare small intestinal (SI) and colonic (COL) permeability in IBD, both active (ACT) and in remission (REM), to normal healthy volunteers (NHV). Methods Inflammatory bowel disease activity was based on Simple Endoscopic Score for Crohn’s Disease (SES-CD) and Mayo endoscopy score for ulcerative colitis (UC). We performed 24-hour IP test using 100 mg 13C-mannitol and 1000 mg lactulose with urine collected during 0-2, 2-8, and 8-24 hours. The primary endpoint was mg excretion of 13C-mannitol and lactulose during 2-24 hours reflecting SI and COL permeability. Results Among 17 CD patients, 7 were ACT (SES-CD >6), and 10 REM (SES-CD 0-2). Among 20 UC patients, 10 had ACT (Mayo score 2-3), and 10 REM (Mayo score 0-1). Urinary excretions over 2-24 hours were higher for IBD than NHV: 13C-mannitol (13.8 [IQR 8.8, 18.7] NHV; 18.4 [15.6, 29.9] REM; 19.7 [13.8, 23.6] ACT, P = .003) and lactulose (1.8 [1.3, 3.1] NHV; 3.6 [2.0, 5.0] REM; 3.5 [2.0, 6.6] ACT, P = .006). There was no difference between ACT and REM for any timed urine collection. LMR at 2-24 hours (or 2-8 and 8-24 hours) were not statistically significant between the 3 groups (0.014 [0.010, 0.021] NHV; 0.016 [0.010, 0.023] REM; 0.016 [0.012, 0.038] ACT, P = .237). Conclusions Intestinal permeability is increased in IBD using validated in vivo assay relative to NHV; increased IP in IBD persists during remission.
S801 Dose-Related Effects of Ricinoleic Acid (Castor Oil) on Gut Permeability in Healthy Participants: Provocative Test for Treatments Aimed at Restoring Barrier Function
Objective Symptoms in gastroparesis (Gp) and functional dyspepsia (FD) overlap; using egg protein substitute to measure gastric emptying of solids (GES), ~40% of patients are reclassified from Gp to FD, and vice versa. Our aim was to assess inter-individual and intra-individual coefficients of variation (COV) in GES in symptomatic patients with Gp or FD with documented slow or normal GES, respectively. Design Scintigraphic GES (T1/2 and GE% at 2 and 4 hours) using a 320 kcal real egg meal (30% fat) was tested in the following: single measurements in 20 patients with diabetes mellitus (10 each type 1 and type 2); repeat GES to estimate COVintra measured: 3 days apart in 9 Gp, 4 weeks apart in 21 Gp and 18 with FD with normal GE assigned to placebo and in 70 patients at 94.3 weeks (median) apart. Results COVinter for GE% at 4 hours and GE T1/2 were respectively 14.2% and 23.5% in FD and 27.5% and 33% in Gp; COVintra for GE% at 4 hours and GE T1/2 up to 4 weeks apart were 23.4% and 37.9% in FD and 20.1% and 33% in Gp. GE% at 2 hours showed less consistent results. However, >85% retained original diagnosis as normal or delayed. From clinical GES to baseline research for Gp group, repeat GES (after treatment) showed the COVintra for GE% at 4 hours was 37.3% at median 94.3 weeks, with 26/70 changed diagnoses. Conclusion The 320 kcal (30% fat) GES scintigraphic test provides consistent diagnosis in >85% and should be the standard test for suspected gastric emptying disorders.
Comparison of gastric emptying T‐half estimates using linear interpolation based on two, four, or nine data points
Abstract Objective This study aimed to determine the effects of a long‐acting glucagon‐like peptide‐1 (GLP‐1) receptor agonist, liraglutide, and placebo subcutaneously over 16 weeks on weight and gastric functions and to evaluate associations of single‐nucleotide polymorphisms in GLP1R (rs6923761) and TCF7L2 (rs7903146) with effects of liraglutide. Methods The study conducted a randomized, parallel‐group, placebo‐controlled, 16‐week trial of liraglutide, escalated to 3 mg subcutaneously daily in 136 otherwise healthy adults with obesity. Weight, gastric emptying of solids (GES), gastric volumes, satiation, and body composition measured at baseline and after treatment were compared in two treatment groups using analysis of covariance. Results Liraglutide ( n = 59) and placebo ( n = 65) groups completed treatment. Relative to placebo, liraglutide increased weight loss at 5 and 16 weeks (both p < 0.05), slowed time to half GES (T 1/2 ) at 5 and 16 weeks (both p < 0.001), and increased fasting gastric volume ( p = 0.01) and satiation ( p < 0.01) at 16 weeks. GES T 1/2 was positively correlated with weight loss on liraglutide (both p < 0.001). After 16 weeks of liraglutide, GLP1R rs6923761 (AG/AA vs. GG) was associated with reduced percent body fat ( p = 0.062), and TCF7L2 rs7903146 (CC vs. CT/TT) was associated with lower body weight ( p = 0.015). Conclusions Liraglutide, 3 mg, induces weight loss with delay in GES T 1/2 and reduces calorie intake. Slowing GES and variations in GLP1R and TCF7L2 are associated with liraglutide effects in obesity.