Camilleri, M

Summary Esophageal high-resolution manometry (HRM) is the gold standard for evaluating esophageal motility disorders but can be limited by patient intolerance. With increasing use of glucagon-like peptide-1 receptor agonists (GLP-1RAs) for obesity and type 2 diabetes, delayed gastric emptying raises concerns for HRM feasibility and safety. This study assessed HRM tolerability in patients on GLP-1RAs. We conducted a retrospective case–control study of adult patients who underwent HRM at our tertiary care center between January 2014 and November 2024. Patients actively taking GLP-1RAs during HRM were identified as cases, while an equal number of consecutive eligible patients not on GLP-1RAs served as controls. Patients with established gastrointestinal dysmotility, prior foregut surgery, esophageal mechanical obstruction, large hiatal hernias, malignancy, or recent opioid use were excluded. From a prospective database of 7194 HRM attempts, 83 cases and 83 matched controls were identified. Among 166 patients, 15 (9.0%) had incomplete HRM due to intolerance, with similar rates between GLP-1RA users and controls (10.84% vs. 7.2%, P = 0.59). Predictors of incomplete HRM included younger age (44.9 ± 17.4 vs. 60.4 ± 13.7 years, P < 0.01), globus (P = 0.02), dyspepsia (P = 0.02), and depression (P = 0.04). No aspiration or adverse events occurred in either group. Duration of HRM before abortion was similar between cases and controls. GLP-1RA use was not associated with increased risk of HRM abortion or adverse events, suggesting these medications do not significantly impact HRM feasibility or safety.

ABSTRACT Background Microbial overgrowth (MO) in the small intestine can cause gastrointestinal symptoms and may arise from stasis, such as dysmotility. Microtypes of MO include small intestinal bacterial overgrowth (SIBO) and intestinal methanogen overgrowth (IMO). Dyssynergic defecation (DD) is associated with constipation and slow colonic transit (STC). Our aim was to assess the relationship between DD and MO. Methods We retrospectively identified patients who underwent both anorectal manometry (ARM) and balloon expulsion testing (BET) for DD, and MO testing using either small intestinal aspirate culture or breath testing. SIBO was analyzed using two culture thresholds: ≥ 10 5 CFU/mL and ≥ 10 3 CFU/mL. Chi‐square tests compared positive vs. negative results. Key Results 436 patients underwent culture of SB aspirates. At the ≥ 10 5 CFU/mL threshold, 41.7% were diagnosed with SIBO, and 87.4% at ≥ 10 3 CFU/mL. At ≥ 10 5 CFU/mL, percent anal relaxation was significantly lower in SIBO‐positive patients. SIBO patients were more likely to have reduced anal relaxation ( p = 0.032), but no other ARM parameters or BET > 60 s. At ≥ 10 3 CFU/mL, a more negative recto‐anal pressure differential (RAPD) was observed, along with a combination of RAPD < −45 mmHg and resting anal pressure > 90 mmHg. 637 patients underwent breath testing for MO, with 174 positive results, predominantly showing IMO (73%). In this group, BET was significantly longer, and anal relaxation was significantly lower. SIBO at ≥ 10 3 CFU/mL was more prevalent in DD than STC (85.5% vs. 64.7%, p = 0.002). IMO was more common in DD than STC ( p = 0.021). Conclusion/Inferences DD may be a risk factor for MO, often with evidence of methanogenesis.

ABSTRACT Background Bile acid diarrhoea, a common cause of diarrhoea‐predominant irritable bowel syndrome, has a similar prevalence to coeliac disease and inflammatory bowel diseases. The mainstay of treatment is bile acid sequestrants (BAS). The effectiveness of using bile acid‐targeted therapies remains unclear. Aim To compare BAS with placebo for bile acid diarrhoea. Methods We conducted a systematic review and meta‐analysis of randomised controlled trials comparing BAS to placebo using a comprehensive search of databases from inception to 8/1/2023. Inclusion required unequivocal diagnosis using serum or faecal biochemical parameters, or 75 SeHCAT. Co‐primary endpoints were ≥ 30% improvement in bowel movement consistency and frequency averaged over 7 days. Adverse effects were also summarised. Results Database search resulted in 1152 citations; 1 additional study was added. Ultimately, 6 trials (5 parallel arm, 1 crossover) involving 182 participants evaluated the effectiveness of BAS over 1–8 weeks. Participants were between the third and seventh decades of life and mostly female. The risk of bias was low except in one parallel and one crossover trial. Meta‐analysis of parallel‐design trials of sequestrants only showed a clinically significant reduction in stool consistency and frequency with pooled relative risks of 1.50 (95% CI: 1.14–1.96) and 2.80 (95% CI: 1.68–4.67), respectively. There was no observable heterogeneity ( I 2 = 0%), and the certainty of evidence was moderate. There was no statistically significant difference in adverse effects. Conclusions This study quantifies the significant and rapid improvement in both stool consistency and frequency with BAS in patients with objective diagnosis of bile acid diarrhoea. Sequestrants also appear well tolerated.

ABSTRACTIntroductionUpper and lower gastrointestinal (GI) dysfunctions frequently coexist, potentially mediated by gastrocolonic or cologastric neural reflexes. This study aims to assess the prevalence of impaired gastric accommodation (GA) and delayed gastric emptying (GE) among patients with slow colonic transit (CT), dyssynergic defecation (DD), and to evaluate relationships between CT or DD with impaired GA and delayed GE.MethodsWe reviewed records of 178 adult patients at Mayo Clinic (2005–2025) with documented slow CT or DD (respectively based on scintigraphy and high‐resolution anorectal manometry [ARM] and balloon expulsion [BE]) who underwent 99mTc‐SPECT measurement of GA and scintigraphic GE of 320‐kcal, 30% fat egg meal. Slow CT was defined by geometric center (GC) at 48 h < 2.1 for males and < 1.9 for females. Abnormal GA ratio was assessed as reduced < 2.62 or increased > 3.85, and delayed GE % < 75% at 4 h. Correlations were assessed using Spearman rank test.ResultsReduced GA was found in 23.7% with DD and 26.7% with slow CT, while increased GA was observed in 30.1% and 24.4%, respectively. Delayed GE was present in 20.5% DD patients and 35.6% slow CT patients. GC 48 h and 24 h were positively correlated with GE% 4 h (Rs = 0.279, and Rs = 0.294 respectively, both p < 0.001) suggesting slow CT retards GE. GC 48 h was moderately correlated with resting anal pressure (Rs = 0.259, p < 0.001) and negatively with the rectoanal pressure gradient (Rs = −0.166, p = 0.027). No significant correlations were observed between CT and GA.ConclusionSlow CT is associated with slower GE, suggesting cologastric reflex inhibition, but not with GA. There is a high prevalence of impaired GA and delayed GE in slow CT and DD.

ABSTRACT Background Several genetic syndromes that affect nerve development and functioning may involve the enteric nervous system and present clinically as dysmotility syndromes, typically in childhood. Aim To review the enteric neuromuscular manifestations, predominantly observed in adults, of neurofibromatosis type I at a tertiary referral center. Methods We conducted a medical records review at the Mayo Clinic and documented clinical manifestations and findings on radiology, pathology, and specialized motility tests of the esophagus, stomach, colon, and rectal evacuatory functions. The tests included scintigraphic gastrointestinal and colonic transit measurements, intraluminal esophageal, gastrointestinal, colonic, and anorectal manometry, and balloon expulsion test. Results Among 2406 with documented NF1, the gastrointestinal manifestations were obstruction or dysmotility, seen in 2% of the cohort. Thirteen patients had small bowel or colonic obstructions: 4 gastrointestinal stromal tumors, 3 malignant peripheral nerve sheath tumors, 3 neurofibromas, 1 diffuse ganglioneuromatosis, 1 schwannoma, and 1 inflammatory fibroid polyp. In addition, 38 patients had abnormal gut motility, including esophageal achalasia or spasm, delayed gastric emptying, slow colonic transit, and dyssynergic defecation. Gastric, small bowel, and colonic manometry were characterized by normal amplitude incoordinated contractions suggestive of neuropathy. In the few resected specimens, myenteric plexus proliferation or diffuse ganglioneuromatosis was identified histologically. Conclusions In addition to mechanical obstruction, typically due to benign tumors affecting smooth muscle or components of nerve (sheath or nerve fiber), patients with NF1 may present with dysmotility syndromes such as gastroparesis, slow colonic transit, or global dysmotility. Neuropathic dysmotility in NF1 can be identified by manometry and by histological evidence of myenteric plexus proliferation or diffuse ganglioneuromatosis.

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.

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 &gt;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.

AbstractIntroductionThe American Neurogastroenterology and Motility Society Gastroparesis Cardinal Symptom Index‐Daily Diary (ANMS GCSI‐DD) is a patient‐reported outcome (PRO) instrument for gastroparesis. This study evaluated the psychometric properties of the ANMS GCSI‐DD and determined a meaningful change threshold using the data from a phase 2b trial in adults with moderate‐to‐severe idiopathic or diabetic gastroparesis (DG).MethodsThe psychometric properties of ANMS GCSI‐DD were analyzed using other clinician‐ and patient‐reported outcomes from 242 patients during the 12‐week trial. Trial exit interviews were conducted in a cohort of 32 patients to capture their perspectives on meaningful change from the trial.ResultsANMS GCSI‐DD demonstrated good performance: unidimensionality scores exhibited good fit; internal consistency reliability was >0.70; test–retest reliability was above 0.90, and convergent validity showed strong correlations (0.70–0.90) with overall severity rating and moderate correlations (0.30–0.70) with other outcomes. ANMS GCSI‐DD scores discriminated among groups with varying severity of gastroparesis symptoms in known‐groups validity (p < 0.001) and were responsive to symptom improvement. Triangulation of the quantitative anchor‐based estimates of 0.9–1.4 category points as a meaningful change in the ANMS GCSI‐DD composite score, and the qualitative exit interview findings of 0.5–1.5 as meaningful change, supports a one‐point change on a five‐point scale (0–4) as the meaningful change threshold.ConclusionThe ANMS GCSI‐DD is a reliable and valid PRO instrument to employ in clinical development for patients with moderate‐to‐severe idiopathic or DG, and a one‐point score change in the ANMS GCSI‐DD composite score is recommended as a meaningful change threshold of symptom change.

Abstract Satiation is the physiologic process that regulates meal size and termination, and it is quantified by the calories consumed to reach satiation. Given its role in energy intake, changes in satiation contribute to obesity's pathogenesis. Our study employed a protocolized approach to study the components of food intake regulation including a standardized breakfast, a gastric emptying study, appetite sensation testing, and a satiation measurement by an ad libitummeal test. These studies revealed that satiation is highly variable among individuals, and while baseline characteristics, anthropometrics, body composition and hormones, contribute to this variability, these factors do not fully account for it. To address this gap, we explored the role of a germline polygenic risk score, which demonstrated a robust association with satiation. Furthermore, we developed a machine-learning-assisted gene risk score to predict satiation and leveraged this prediction to anticipate responses to anti-obesity medications. Our findings underscore the significance of satiation, its inherent variability, and the potential of a genetic risk score to forecast it, ultimately allowing us to predict responses to different anti-obesity interventions.