Background/Objectives: Our objective was to review published studies of the intestinal barrier and permeability, the deleterious effects of dietary components (particularly fat), the impact of altered intestinal permeability in disease models and human diseases, the role of the microbiome and epigenomics in control of barrier function, and the opportunities to restore normal barrier function with dietary interventions and products of the microbiota. Methods: We conducted a literature review including the following keywords alone or in combination: intestinal barrier, permeability, microbiome, epigenomics, diet, irritable bowel syndrome, inflammatory bowel disease, probiotics. Results: Intestinal permeability is modified by a diet including fat, which increases permeability, and nutrients such as fiber, glutamine, zinc, vitamin D, polyphenols, emulsifiers, and anthocyanins, which decrease permeability. There is significant interaction of the microbiome and barrier function, including the inflammatory of luminal/bacterial antigens, and anti-inflammatory effects of commensals or probiotics and their products, including short-chain fatty acids. Epigenomic modification of barrier functions are best illustrated by effects on junction proteins or inflammation. Detailed documentation of the protective effects of diet, probiotics, prebiotics, and microbiota is provided. Conclusion: intestinal permeability is a critical factor in protection against gastrointestinal diseases and is impacted by nutrients that preserve or heal and repair the barrier and nurture anti-inflammatory effects.

Neurogastroenterology and motility disorders are complex gastrointestinal conditions that are prevalent worldwide, particularly affecting women and younger individuals. These conditions significantly impact the quality of life of people suffering from them. There is increasing evidence linking these disorders to cirrhosis, with a higher prevalence compared to the general population. However, the link between neurogastroenterology and motility disorders and cirrhosis remains unclear due to undefined mechanisms. In addition, managing these conditions in cirrhosis is often limited by the adverse effects of drugs commonly used for these disorders, presenting a significant clinical challenge in the routine management of patients with cirrhosis. This review delves into this connection, exploring potential pathophysiological links and clinical interventions between neurogastroenterology disorders and cirrhosis. Export

INTRODUCTION: To perform a proof-of-concept study to evaluate the performance of individual and combined anorectal manometry and balloon expulsion testing (BET) parameters for diagnosing dyssynergic defecation (DD) using machine learning (ML). METHODS: A single gastrointestinal motility specialist assessed (2008–2018) 307 patients. A ML model was constructed on anorectal manometry/BET data. BET was weight-based in 235 patients and time-based in 72 patients. Missing data were imputed. Data were split 75% train/25% test with preprocessing performed. Five common ML models were trained, and performance was compared using receiver operating characteristic (ROC) area under the curve and accuracy based on 100 bootstrapped samples. The most accurate models were fine-tuned and evaluated on the test set. RESULTS: The median age was 40 years, body mass index 22.2 kg/m ² , and 81% were women. Two-hundred and 22 (72.3%) patients had a clinical diagnosis of DD. Compared with patients without clinical diagnosis of DD, patients with DD had significantly lower rectoanal pressure gradient (RAG) (median −34.7 [IQR −57.1, −13.0] vs −24.6 [IQR −44.5, −2.4] mm Hg, P = 0.009) and more abnormal BET (59.5% vs 11.8%, P < 0.001). Four features were retained in the optimized model as predictors of DD: abnormal BET, greater resting anal pressure (RAP), and more negative RAG. The optimal parameter was abnormal BET ( P = 0.003), but combinations of 2 manometry results (RAP and RAG) yielded positive predictive values (PPVs) >80%. The optimized logistic regression model had an area under the curve of 0.878, with a sensitivity of 75.0% and specificity of 81.8% at a probability threshold of 0.704. DISCUSSION: Abnormal BET, or a combination of 2 manometric parameters (RAP and RAG), provides >80% positive predictive value for diagnosing DD in patients with chronic constipation.