Rao, Archana S.

The glucagon-like peptide 1 (GLP-1) analog ROSE-010 reduced pain during acute exacerbations of irritable bowel syndrome (IBS). Our objective was to assess effects of ROSE-010 on several gastrointestinal (GI) motor and bowel functions in constipation-predominant IBS (IBS-C). In a single-center, randomized, parallel-group, double-blind, placebo-controlled, dose-response study, we evaluated safety, pharmacodynamics, and pharmacokinetics in female patients with IBS-C. ROSE-010 (30, 100, or 300 μg sc) or matching placebo was administered once daily for 3 consecutive days and on 1 day 2–10 days later. We measured GI and colonic transit by validated scintigraphy and gastric volumes by single-photon emission computed tomography. The primary end points were half time of gastric emptying of solids, colonic transit geometric center at 24 h, and gastric accommodation volume. Analysis included intent-to-treat principle, analysis of covariance (with body mass index as covariate), and Dunnett-Hsu test for multiple comparisons. Exposure to ROSE-010 was approximately dose-proportional across the dose range tested. Demographic data in four treatment groups of female IBS-C patients (total 46) were not different. Gastric emptying was significantly retarded by 100 and 300 μg of ROSE-010. There were no significant effects of ROSE-010 on gastric volumes, small bowel or colonic transit at 24 h, or bowel functions. The 30- and 100-μg doses accelerated colonic transit at 48 h. Adverse effects were nausea ( P < 0.001 vs. placebo) and vomiting ( P = 0.008 vs. placebo). Laboratory safety results were not clinically significant. In IBS-C, ROSE-010 delayed gastric emptying of solids but did not retard colonic transit or alter gastric accommodation; the accelerated colonic transit at 48 h with 30 and 100 μg of ROSE-010 suggests potential for relief of constipation in IBS-C.

Mucosal barrier dysfunction contributes to gastrointestinal diseases. Our aims were to validate urine sugar excretion as an in vivo test of small bowel (SB) and colonic permeability and to compare permeability in patients with irritable bowel syndrome-diarrhea (IBS-D) to positive and negative controls. Oral lactulose (L) and mannitol (M) were administered with 99m Tc-oral solution, 111 In-oral delayed-release capsule, or directly into the ascending colon (only in healthy controls). We compared L and M excretion in urine collections at specific times in 12 patients with IBS-D, 12 healthy controls, and 10 patients with inactive or treated ulcerative or microscopic colitis (UC/MC). Sugars were measured by high-performance liquid chromatography-tandem mass spectrometry. Primary endpoints were cumulative 0–2-h, 2–8-h, and 8–24-h urinary sugars. Radioisotopes in the colon at 2 h and 8 h were measured by scintigraphy. Kruskal-Wallis and Wilcoxon tests were used to assess the overall and pairwise associations, respectively, between group and urinary sugars. The liquid in the colon at 2 h and 8 h was as follows: health, 62 ± 9% and 89 ± 3%; IBS-D, 56 ± 11% and 90 ± 3%; and UC/MC, 35 ± 8% and 78 ± 6%, respectively. Liquid formulation was associated with higher M excretion compared with capsule formulation at 0–2 h (health P = 0.049; IBS-D P < 0.001) but not during 8–24 h. UC/MC was associated with increased urine L and M excretion compared with health (but not to IBS-D) at 8–24 h, not at 0–2 h. There were significant differences between IBS-D and health in urine M excretion at 0–2 h and 2–8 h and L excretion at 8–24 h. Urine sugars at 0–2 h and 8–24 h reflect SB and colonic permeability, respectively. IBS-D is associated with increased SB and colonic mucosal permeability.

Daikenchuto (TU-100) is a traditional Japanese (Kampo) medicine used to treat postoperative ileus. TU-100 dose dependently increases gastrointestinal (GI) motility by modulating cholinergic and serotonergic mechanisms in animal studies. The aim of this study was to evaluate the effects of orally administered TU-100 on GI and colonic transit and bowel function in healthy humans. In a randomized, parallel-group, double-blind, placebo-controlled, dose-response study, 60 healthy subjects were randomly assigned to placebo or TU-100 2.5 g or 5 g tid ingested immediately before meals for 5 consecutive days. We measured GI and colonic transit by validated scintigraphy and stool frequency and consistency by daily diaries of bowel function. There were overall treatment effects on colonic filling at 6 h without any significant differences between each dose of TU-100 and placebo. There tended to be overall treatment effects on ascending colon (AC) emptying half-time; the TU-100 (7.5 g/day) treatment significantly accelerated AC emptying compared with placebo. There were numerically higher values of GC24 (which reflect overall colonic transit) with both doses of TU-100, but these changes were not statistically significant. There were no significant overall treatment effects on gastric emptying or stool frequency and consistency. One subject, who received 7.5 g/day of TU-100, had elevated creatine phosphokinase following the study. TU-100 (7.5 g/day) significantly accelerated AC emptying. Further randomized controlled trials in patients with functional constipation or irritable bowel syndrome with constipation are warranted to evaluate the clinical efficacy of TU-100 in these disorders.