Gastrointestinal Motility, Part 1: Esophageal Transit and Gastric Emptying

Computer modeling of digestive processes in the alimentary tract and their physiological regulation mechanisms: closing the gap between digestion models and in vivo behavior

Introduction

A model has been developed for in silico simulation of digestion and its physiological feedback mechanisms.

Methods

The model is based on known physiology described in the literature and is able to describe the complexity of many simultaneous processes related to food digestion.

Results

Despite the early stage of development of the model, it already encompasses a large number of processes that occur simultaneously, enabling the prediction of a large number of post-prandial physiological markers, which can be highly functional in combination with in vitro, organ-on-a-chip and digital twin models purposed to measure the physiological properties of organs and to predict the effect of adjusted food composition in normal and diseased states.

Discussion

Input from and collaboration between science fileds is needed to further develop and refine the model and to connect with in vitro, in vivo, and ex vivo (organ-on-a-chip) models.

The role of gastric emptying in glucose homeostasis and defense against hypoglycemia: Innocent bystander or partner in crime?

Maintenance of plasma glucose (PG) homeostasis is due to a complex network system. Even a minor fall in PG activates multiple neuroendocrine actions promoting hormonal, metabolic and behavioral responses, which prevent and ultimately recover hypoglycemia, primarily neuroglycopenia. Among these responses, gastric emptying (GE) plays an important role by coordinated mechanisms which regulate transit and absorption of nutrients through the small intestine. A bidirectional relationship between GE and glycemia has been established: GE may explain the up to 30-40 % variance in glycemic response following a carbohydrate-rich meal. In addition, acute and chronic hyperglycemia induce deceleration of GE after meals. Hypoglycemia accelerates GE, but its role in counterregulation has been poorly investigated. The role of GE as a counterregulatory mechanism has been confirmed in pathophysiological conditions, such as gastroparesis or following recurrent hypoglycemia. Therefore, it could represent an "ancestral" mechanism, highly conservative and effective in all individuals, conditions and clinical contexts. Recent guidelines recommend GLP-1 receptor agonists (GLP-1RAs) either as the first injectable therapy for type 2 diabetes mellitus or in combination with insulin. Considering the potential impact on GE, it would be important to study subjects on GLP-1 RAs during hypoglycemia, to establish whether a possible deceleration of GE impairs glucose counterregulation.

The Effect of Gut-Training and Feeding-Challenge on Markers of Gastrointestinal Status in Response to Endurance Exercise: A Systematic Literature Review

BACKGROUND

Nutrition during exercise is vital in sustaining prolonged activity and enhancing athletic performance; however, exercise-induced gastrointestinal syndrome (EIGS) and exercise-associated gastrointestinal symptoms (Ex-GIS) are common issues among endurance athletes. Despite this, there has been no systematic assessment of existing trials that examine the impact of repetitive exposure of the gastrointestinal tract to nutrients before and/or during exercise on gastrointestinal integrity, function, and/or symptoms.

OBJECTIVE

This systematic literature review aimed to identify and synthesize research that has investigated the impact of 'gut-training' or 'feeding-challenge' before and/or during exercise on markers of gastrointestinal integrity, function, and symptoms.

METHODS

Five databases (Ovid MEDLINE, EMBASE, CINAHL Plus, Web of Science Core Collection, and SPORTDiscus) were searched for literature that focused on gut-training or feeding-challenge before and/or during exercise that included EIGS and Ex-GIS variables. Quality assessment was conducted in duplicate and independently using the Cochrane Collaboration's risk-of-bias (RoB 2) tool.

RESULTS

Overall, 304 studies were identified, and eight studies were included after screening. Gut-training or feeding-challenge interventions included provision of carbohydrates only (n = 7) in various forms (e.g., gels or liquid solutions) during cycling or running, or carbohydrate with protein (n = 1) during intermittent exercise, over a varied duration (4-28 days). Gut discomfort decreased by an average of 47% and 26% with a 2-week repetitive carbohydrate feeding protocol (n = 2) and through repeated fluid ingestion over five trials (n = 1), respectively. Repetitive carbohydrate feeding during exercise for 2 weeks resulted in the reduction of carbohydrate malabsorption by 45-54% (n = 2), but also led to no significant change (n = 1). The effect of gut-training and feeding-challenges on the incidence and severity of Ex-GIS were assessed using different tools (n = 6). Significant improvements in total, upper, and lower gastrointestinal symptoms were observed (n = 2), as well as unclear results (n = 4). No significant changes in gastric emptying rate (n = 2), or markers of intestinal injury and permeability were found (n = 3). Inconclusive results were found in studies that investigated plasma inflammatory cytokine concentration in response to exercise with increased carbohydrate feeding (n = 2).

CONCLUSIONS

Overall, gut-training or feeding-challenge around exercise may provide advantages in reducing gut discomfort, and potentially improve carbohydrate malabsorption and Ex-GIS, which may have exercise performance implications.

Bridging the Gap between Food Effects under Clinical Trial Conditions and Real Life: Modeling Delayed Gastric Emptying of Drug Substances and Gastric Content Volume Based on Meal Characteristics

Delayed gastric emptying is known to have a major impact on drug absorption. While the test meal recommended by the FDA and EMA to study food effects represents a worst-case scenario, it does not reflect the reality of the patients. Physiologically based pharmacokinetic (PBPK) models could bridge the gap between clinical settings of food effect studies and the diverse nonclinical situations by simulating the effect of meals with different compositions and volumes. A mathematical equation based on a stretched exponential function was reparameterized to describe the gastric emptying process of mixed solid meals. The model was fitted to literature data including the gastric emptying data of 23 meals from 15 studies. Using a multiple linear regression model, we were able to predict the two function parameters from the meal characteristics caloric content and the percentage of calories derived from fat. After implementation into the PBPK software PK-Sim, the model, together with a separate compartment for liquid gastric contents, was compared to commercially available software. The model is able to simulate the gastric emptying of mixed solid meals containing drugs based on specific meal characteristics. A second compartment allows for distribution between liquid and solid components and rapid gastric emptying along the Magenstrasse.

When you are living and dying at the same time: A qualitative exploration of living with gastrointestinal motility disorders

BACKGROUND

An expanding base of evidence indicates that chronic gastrointestinal disorders not only impact physical wellbeing, but also affect many psychosocial aspects of life. However, less is known about gastrointestinal motility disorders. The present study aimed to explore how individuals experience gastrointestinal motility disorders and their impact on daily living.

METHODS

Eleven people with a gastrointestinal motility disorder participated in semi-structured interviews face-to-face or via telephone. The interviews explored how participants came to be diagnosed, their experiences with health professionals, as well as the impact of dysmotility on enjoyment of food, socialising, eating out and quality of life (QoL). Interviews were tape-recorded, transcribed and analysed using an inductive thematic analysis approach.

RESULTS

Analysis revealed an overarching theme of frustration that stemmed from three subthemes: (1) feeling misunderstood, judged and dismissed by health professionals leading to delayed diagnosis, misdiagnosis and multiple diagnoses; (2) severity and unpredictability of undesirable gastrointestinal symptoms; and (3) reduced QoL because of physical and social limitations, impairing their ability to have normal life experiences, including education, work and social activities.

CONCLUSIONS

Dysmotility is a complex illness that impacts almost all aspects of a person's life. In addition to managing reported physical symptoms, the social and psychological burden associated with dysmotility needs to be addressed to improve outcomes and QoL.

Time Courses of Gastric Volume and Content after Different Types of Casein Ingestion in Healthy Men: A Randomized Crossover Study

BACKGROUND

Few studies have evaluated differences in the curd-forming ability of casein on gastric volume and content directly after ingestion in humans.

OBJECTIVES

This study evaluated the time course of gastric volume and curd conditions in the stomach after protein ingestion.

METHODS

This was an open-labeled, randomized crossover trial. Ten healthy men [age: 33.4 ± 7.3 y; BMI (kg/m²): 21.9 ± 0.9] received 350 g of 3 isonitrogenous and isocaloric protein drinks containing 30 g micellar casein (MCN), sodium caseinate (SCN), or whey protein concentrate (WPC). The gastric antrum cross-sectional area (CSA) and curd in the stomach were measured using ultrasonography within 5 h after ingestion. The differences between test foods were tested using the MIXED model and post hoc tests using Fisher's protected least significant difference.

RESULTS

The incremental AUC of the gastric antrum CSA after MCN ingestion was 1.3-fold and 1.5-fold higher than that after the ingestion of SCN and WPC, respectively (both P < 0.05), but not different between SCN and WPC. The number of participants with curds ≥20 mm with a high echogenicity clot observed in the stomach within 5 h after MCN ingestion was significantly greater than that after the ingestion of other proteins (n = 9 for MCN, n = 2 for SCN, and n = 0 for WPC; bothP < 0.01). The regression line slopes on total plasma amino acid concentration and gastric antrum CSA were significantly different between the participants with and without curds.

CONCLUSIONS

In contrast to SCN and WPC, MCN ingestion resulted in slow kinetics of gastric antrum CSA. Differences in curd formation of casein in the stomach affect gastric emptying and plasma amino acid absorption kinetics after ingestion in healthy men. This trial was registered at University Hospital Medical Information Network Clinical Trials Registry as UMIN000038388 (https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000043746).

Early steps of an alternative test meal for gastric emptying scintigraphy

Background/Aim. Gastric emptying (GE) scintigraphy provides a physiologic and noninvasive measurement of GE. Although GE scintigraphy has been standardized, preparing a meal is still complex and not practical in daily routine. The aim of the study was to prepare a simple, practical, and easily standardizable semisolid meal and investigate its role in estimating the GE function in of rabbits. Methods. In the first part of the study (basal condition), the mixture of the macroaggregated albumin (MAA) labeled with 37 MBq (1 mCi) of technetium-99m (99mTc) and 40 g of barium sulfate (1g/mL) was applied to animals via a nasogastric catheter. A series of images (frame/min, 60 min) in the anterior and posterior projections were dynamically acquired, and the motion was corrected after the radiopharmaceutical application. A few days later, the same rabbits were scanned under the same protocol after a 1 mg atropine injection to simulate gastroparesis condition. Eleven rabbits were included according to inclusion and exclusion criteria, and a total of twenty-two imaging data sets were analyzed for quantification. Results. In the basal study, total counts of the mixture decreased from 87,800.83 ? 12,622.76 to 42,733.14 ? 6,591.53 at 30 min and to 13,684.19 ? 1,774.90 at 60 min, and these decreases were statistically significant (p = 0.003). Emptying percentages were 51.39 ? 0.78% at 30 min and 84.32 ? 1.56 at 60 min and were statistically significant (p = 0.003). After intravascular atropine sulfate injection, total counts of the mixture decreased from 84,508.78 ? 11,871.48 to 64,995.18 ? 9,298 at 30 min and to 53,507.17 ? 7,258.98 at 60 min, and these decreases were statistically significant (p = 0.003). Emptying percentages were 23.10 ? 1.11% at 30 min and 36.63 ? 1.42 at 60 min and were statistically significant (p = 0.003). The difference between basal and post-atropine sulfate gastric emptying percentage at 30th (p = 0.003) and 60th (p = 0.003) min was statistically significant. Conclusion. The meal, used in this study, is non-nutrient, fatty-free, and semisolid and is easy to prepare and administer. Due to its semisolid nature, it offers a chance to evaluate the quantification of regional and total GE as well as the separate roles of the fundus and antrum.

Alcohol Metabolism Enriches Squamous Cell Carcinoma Cancer Stem Cells That Survive Oxidative Stress via Autophagy

BACKGROUND

Alcohol (ethanol) consumption is a major risk factor for head and neck and esophageal squamous cell carcinomas (SCCs). However, how ethanol (EtOH) affects SCC homeostasis is incompletely understood.

METHODS

We utilized three-dimensional (3D) organoids and xenograft tumor transplantation models to investigate how EtOH exposure influences intratumoral SCC cell populations including putative cancer stem cells defined by high CD44 expression (CD44H cells).

RESULTS

Using 3D organoids generated from SCC cell lines, patient-derived xenograft tumors, and patient biopsies, we found that EtOH is metabolized via alcohol dehydrogenases to induce oxidative stress associated with mitochondrial superoxide generation and mitochondrial depolarization, resulting in apoptosis of the majority of SCC cells within organoids. However, CD44H cells underwent autophagy to negate EtOH-induced mitochondrial dysfunction and apoptosis and were subsequently enriched in organoids and xenograft tumors when exposed to EtOH. Importantly, inhibition of autophagy increased EtOH-mediated apoptosis and reduced CD44H cell enrichment, xenograft tumor growth, and organoid formation rate.

CONCLUSIONS

This study provides mechanistic insights into how EtOH may influence SCC cells and establishes autophagy as a potential therapeutic target for the treatment of EtOH-associated SCC.

Esophageal dysmotility and lung disease in patients with systemic sclerosis: is there a possible association or correlation? A retrospective chart review

OBJECTIVE

Our aim was to evaluate the relationship between esophageal dysmotility and lung disease by correlating the results of Echocardiogram and Pulmonary Function Test (PFT) with Esophageal Transit Study (ETT).

METHODS

Charts of Systemic Sclerosis (SSc) patients fulfilling 2013 ACR/EULAR classification criteria seen in Rheumatology clinics were reviewed and their demographics, ETT result, PFT, and echocardiogram data were collected at baseline, years 1, 3, 5, and 10. Patients were divided based on their ETT status and were compared with respect to each variable using a two-sided two-sample t test for continuous variables and a Fisher's exact test for categorical variables.

RESULTS

130 patients were identified with either limited cutaneous SSc (109) or diffuse cutaneous SSc (21) with a mean age of 52.65 years. The mean DLCO was statistically worse in abnormal ETT patients [p value = 0.0004] as were the progression rates per year for DLCO at - 2.25 (p value = 0.019). Progression rate of FVC per year was statistically significant in the abnormal ETT group, although the mean value was not. The number of patients with abnormal PASP was not statistically different between the two groups (p values 0.104, 0.178, 0.653 at baseline, years 3 and 5, respectively).

CONCLUSION

The presence of esophageal dysmotility was associated with increased pulmonary involvement in the form of abnormal DLCO with worsening progression rates per year. There was no statistically significant difference in PASP and FVC between the two groups; however, the progression rate for FVC was worse in adjusted models.

Prevalence and Clinical Characteristics of Dyssynergic Defecation and Slow Transit Constipation in Patients with Chronic Constipation

Patients with chronic constipation who do not respond to initial treatments often need further evaluation for dyssynergic defecation (DD) and slow transit constipation (STC). The aims of this study are to characterize the prevalence of DD and STC in patients referred to a motility center with chronic constipation and correlate diagnoses of DD and STC to patient demographics, medical history, and symptoms. High-resolution ARM (HR-ARM), balloon expulsion testing (BET) and whole gut transit scintigraphy (WGTS) of consecutive patients with chronic constipation were reviewed. Patients completed questionnaires describing their medical history and symptoms at the time of testing. A total of 230 patients completed HR-ARM, BET, and WGTS. Fifty (22%) patients had DD, and 127 (55%) patients had STC. Thirty patients (13%) had both DD and STC. There were no symptoms that were suggestive of STC vs. DD; however, patients with STC and DD reported more severe constipation than patients with normal transit and anorectal function. Patients with chronic constipation often need evaluation for both DD and STC to better understand their pathophysiology of symptoms and help direct treatment.

Severe gastroparesis is associated with an increased incidence of slow-transit constipation as measured by wireless motility capsule

BACKGROUND

Dysmotility in one region of the gastrointestinal tract has been found to predispose patients to developing motility disorders in other gastrointestinal segments. However, few studies have evaluated the relationship between gastroparesis and constipation.

METHODS

Retrospective review of 224 patients who completed 4-hour, solid-phase gastric emptying scintigraphy (GES), and wireless motility capsule (WMC) testing to evaluate for gastroparesis and slow-transit constipation, respectively. When available, anorectal manometry data were reviewed to evaluate for dyssynergic defecation. Patients were divided into two groups based on the results of the GES: 101 patients with normal gastric emptying and 123 patients with gastroparesis (stratified by severity). Differences in constipation rates were compared between the groups.

KEY RESULTS

Slow-transit constipation was more common in the gastroparesis group, but statistical significance was not reached (42.3% vs 34.7%, p = 0.304). Univariate logistical regression analysis found no association between slow-transit constipation and gastroparesis (OR 1.38, 95% CI 0.80-2.38, p = 0.245) nor dyssynergic defecation and gastroparesis (OR 0.88, 95% CI 0.29-2.70, p = 0.822). However, when stratifying gastroparesis based on severity, slow-transit constipation was found to be associated with severe gastroparesis (OR 2.45, 95% CI 1.20-5.00, p = 0.014). This association was strengthened with the exclusion of patients with diabetes mellitus (OR 3.5, 95% CI 1.39-8.83, p = 0.008) - a potential confounder.

CONCLUSIONS & INFERENCES

Patients with severe gastroparesis (>35% gastric retention at the 4-hour mark on solid-phase GES) have an increased likelihood of having underlying slow-transit constipation. Dyssynergic defecation does not appear to be associated with gastroparesis (of any severity).

68Ga-NOTA PET imaging for gastric emptying assessment in mice

BACKGROUND

Positron emission tomography (PET) has the potential for visualization and quantification of gastric emptying (GE). The traditional Chinese medicine (TCM) has been recognized promising for constipation. This study aimed to establish a PET imaging method for noninvasive GE measurement and to evaluate the efficacy of a TCM on delayed GE caused by constipation using PET imaging.

METHODS

[⁶⁸Ga]Ga-NOTA was synthesized as the tracer and sesame paste with different viscosity were selected as test meals. The dynamic PET scans were performed after [⁶⁸Ga]Ga-NOTA mixed with test meals were administered to normal mice. Two methods were utilized for the quantification of PET imaging. A constipation mouse model was treated with maren chengqi decoction (MCD), and the established PET imaging scans were performed after the treatment.

RESULTS

[⁶⁸Ga]Ga-NOTA was synthesized within 20 min, and its radiochemical purity was > 95%. PET images showed the dynamic process of GE. %ID/g, volume, and total activity correlated well with each other. Among which, the half of GE time derived from %ID/g for 4 test meals were 3.92 ± 0.87 min, 13.1 ± 1.25 min, 17.8 ± 1.31 min, and 59.7 ± 3.11 min, respectively. Constipation mice treated with MCD showed improved body weight and fecal conditions as well as ameliorated GE measured by [⁶⁸Ga]Ga-NOTA PET.

CONCLUSIONS

A PET imaging method for noninvasive GE measurement was established with stable radiotracer, high image quality, and reliable quantification methods. The efficacy of MCD on delayed GE was demonstrated using PET.

Effect of Paraplegia on the Time Course of Exogenous Fatty Acid Incorporation Into the Plasma Triacylglycerol Pool in the Postprandial State

Spinal cord injury (SCI) results in disordered fat metabolism. Autonomic decentralization might contribute to dyslipidemia in SCI, in part by influencing the uptake of dietary fats through the gut-lymph complex. However, the neurogenic contributions to dietary fat metabolism are unknown in this population. We present a subset of results from an ongoing registered clinical trial (NCT03691532) related to dietary fat absorption. We fed a standardized (20 kcal⋅kgFFM^–1) liquid meal tolerance test (50% carb, 35% fat, and 15% protein) that contained stable isotope lipid tracer (5 mg⋅kgFFM^–1 [U-¹³C]palmitate) to persons with and without motor complete thoracic SCI. Blood samples were collected at six postprandial time points over 400 min. Changes in dietary fatty acid incorporated into the triacylglycerol (TAG) pool (“exogenous TAG”) were used as a marker of dietary fat absorption. This biomarker showed that those with paraplegia had a lower amplitude than non-injured participants at Post₂₄₀ (52.4 ± 11.0 vs. 77.5 ± 16.0 μM), although this failed to reach statistical significance (p = 0.328). However, group differences in the time course of absorption were notable. The injury level was also strongly correlated with time-to-peak exogenous TAG concentration (r = −0.806, p = 0.012), with higher injuries resulting in a slower rise in exogenous TAG. This time course documenting exogenous TAG change is the first to show a potential neurogenic alteration in SCI dietary fat absorption.

Autophagy mitigates ethanol-induced mitochondrial dysfunction and oxidative stress in esophageal keratinocytes

During alcohol consumption, the esophageal mucosa is directly exposed to high concentrations of ethanol (EtOH). We therefore investigated the response of normal human esophageal epithelial cell lines EPC1, EPC2 and EPC3 to acute EtOH exposure. While these cells were able to tolerate 2% EtOH for 8 h in both three-dimensional organoids and monolayer culture conditions, RNA sequencing suggested that EtOH induced mitochondrial dysfunction. With EtOH treatment, EPC1 and EPC2 cells also demonstrated decreased mitochondrial ATPB protein expression by immunofluorescence and swollen mitochondria lacking intact cristae by transmission electron microscopy. Mitochondrial membrane potential (ΔΨm) was decreased in a subset of EPC1 and EPC2 cells stained with ΔΨm–sensitive dye MitoTracker Deep Red. In EPC2, EtOH decreased ATP level while impairing mitochondrial respiration and electron transportation chain functions, as determined by ATP fluorometric assay, respirometry, and liquid chromatography-mass spectrometry. Additionally, EPC2 cells demonstrated enhanced oxidative stress by flow cytometry for mitochondrial superoxide (MitoSOX), which was antagonized by the mitochondria-specific antioxidant MitoCP. Concurrently, EPC1 and EPC2 cells underwent autophagy following EtOH exposure, as evidenced by flow cytometry for Cyto-ID, which detects autophagic vesicles, and immunoblots demonstrating induction of the lipidated and cleaved form of LC3B and downregulation of SQSTM1/p62. In EPC1 and EPC2, pharmacological inhibition of autophagy flux by chloroquine increased mitochondrial oxidative stress while decreasing cell viability. In EPC2, autophagy induction was coupled with phosphorylation of AMP activated protein kinase (AMPK), a cellular energy sensor responding to low ATP levels, and dephosphorylation of downstream substrates of mechanistic Target of Rapamycin Complex (mTORC)-1 signaling. Pharmacological AMPK activation by AICAR decreased EtOH-induced reduction of ΔΨm and ATP in EPC2. Taken together, acute EtOH exposure leads to mitochondrial dysfunction and oxidative stress in esophageal keratinocytes, where the AMPK-mTORC1 axis may serve as a regulatory mechanism to activate autophagy to provide cytoprotection against EtOH-induced cell injury.

In-house-Prepared Semisolid Bolus for Esophageal Transit Scintigraphy in Normal Volunteers and its Comparison with Liquid Bolus

Background/Aims:

Esophageal transit scintigraphy (ETS) is a useful tool for evaluating esophageal motility disorders, although conflicting results are seen due to lack of ideal bolus. Semisolid/solid boluses have shown superiority over liquid boluses, and the present study aims to establish the utility of in-house-prepared bolus in normal volunteers and its comparison with liquid bolus.

Materials and Methods:

Thirty-three healthy volunteers were selected for ETS with in-house-prepared semisolid bolus jelly containing ^99mTc-sulfur colloid. Dynamic studies were acquired in anterior projection with single swallow for both supine and sitting positions. T90% esophageal emptying time (EET) was calculated for whole and three equally divided segments of esophagus and also done with liquid bolus on different day.

Results:

The median value of EET for semisolid bolus for whole esophagus in sitting and supine positions was 11.7 s (interquartile range [IQR]: 8.0–16.7) and 17.7 s (IQR: 12.0–33.0). EET of liquid bolus for whole esophagus in sitting and supine positions was 9.3 s (IQR: 8.0–13.3) and 13.0 s (IQR: 9.7–25.0), respectively. Significantly different EET for whole esophagus and lower one-third esophagus between sitting and supine positions was seen for semisolid (whole esophagus;P = 0.003, lower one-third esophagus; P = 0.025) and liquid boluses (whole esophagus; P = 0.032, lower one-third esophagus; P = 0.016). Comparing EET using semisolid and liquid boluses, only lower one-third esophagus in supine position showed significant difference (P = 0.033).

Conclusions:

In-house-prepared semisolid radiolabeled jelly is inexpensive, easy to prepare with good radiolabeling. Condensed dynamic images from semisolid bolus were better, sharper, and reproducible in comparison to liquid bolus without fragmentation. This study standardized semisolid bolus and verified its suitability for clinical use.

Sleeve gastrectomy for treatment of delayed gastric emptying-indications, technique, and results

INTRODUCTION

Delayed gastric emptying (DGE) can be caused by gastric motility disorders such as gastroparesis with idiopathic background, diabetic neuropathy, or postsurgical nerve damage. Currently, a variety of endoscopic and surgical treatment options are available. We noted clinical improvement of gastric emptying with reduction of the gastric fundus following both fundoplication and fundectomy. As a consequence, we explored the effect of sleeve gastrectomy on gastric emptying. The focus of this paper is to investigate the role of laparoscopic sleeve gastrectomy (LSG) in the treatment of gastroparesis.

METHODS

Patients with symptoms suggestive of gastroparesis received diagnostic work-up (gastric emptying scintigraphy and/or Radiographic Barium-Sandwich Emptying studies). Patients with fundic emptying problems and moderate gastric dilation were selected for a LSG. All perioperative parameters were documented regarding patients characteristics, complications, and outcomes expressed as symptoms and quality of life (GIQLI gastrointestinal quality of life index). Assessment of DGE: Barium Emptying Radigraphy Index (BERI) 0-5.

RESULTS

From 122 patients with gastroparesis, 19 patients were selected for LSG (mean age 54 years (23-68); 10 males/9 females. Morbidity 2/19; no mortality; follow-up mean 24 months (12-60); preop/postop: BERI: 2, 31/1, 27 (p < 0.01); we noted significant improvement of the quality of life (preoperative GIQLI 78 (44-89)) to postoperative values of 114 (range 87-120) (p < 0.0001). Preoperative median BMI of these 19 patients was 24 [1-10], which was not significantly changed in the 15 patients at > 1 year follow-up with 23 [1-8]. Postoperative recurrence of DGE occurred in 3 patients who were reoperated after >1 year follow-up.

CONCLUSION

LSG is a potential surgical treatment option for selected patients with gastroparesis and fundic emptying problems.

Esophageal transit scintigraphy in children: a user's guide and pictorial review

Technical and clinical aspects of esophageal transit scintigraphy in pediatric patients are reviewed via several illustrative cases that highlight its utility in evaluating primary and secondary esophageal motility disorders.

Gastrointestinal Transit Time, Glucose Homeostasis and Metabolic Health: Modulation by Dietary Fibers

Gastrointestinal transit time may be an important determinant of glucose homeostasis and metabolic health through effects on nutrient absorption and microbial composition, among other mechanisms. Modulation of gastrointestinal transit may be one of the mechanisms underlying the beneficial health effects of dietary fibers. These effects include improved glucose homeostasis and a reduced risk of developing metabolic diseases such as obesity and type 2 diabetes mellitus. In this review, we first discuss the regulation of gastric emptying rate, small intestinal transit and colonic transit as well as their relation to glucose homeostasis and metabolic health. Subsequently, we briefly address the reported health effects of different dietary fibers and discuss to what extent the fiber-induced health benefits may be mediated through modulation of gastrointestinal transit.

The predictive value of hunger score on gastric evacuation after oral intake of carbohydrate solution

BACKGROUND

Surgical patients are asked to fast for a sufficient duration to ensure that the amount of residual liquid in the stomach is within the safe range, thereby reducing the risk of gastric reflux perioperatively. The authors hypothesized that subjective hunger numerical rating scale (NRS) score could also help assess the process of gastric emptying and determine the amount of fluid remaining in the stomach.

METHODS

The current study consisted of healthy volunteers recruited by advertisement and mutual introduction. Participants were asked to rate their subjective hunger feeling every 30 min after oral administration of 8 mL/kg carbohydrate nutrient solution that contained 10% maltodextrin and 2.5% sucrose. Consecutively, the gastric residual fluid was measured by magnetic resonance imagining (MRI). The Spearman's correlation coefficient, the ROC curves and the stepwise regression were used to analyze the predictive value of NRS for the gastric emptying process.

RESULTS

The cohort consisted of 29 healthy volunteers enrolled in this study. The area under ROC curves estimated by the NRS score for the gastric residual volume of 2 mL/kg, 1 mL/kg, and 0.5 mL/kg were AUC2.0 = 0.78, AUC1.0 = 0.76, and AUC0.5 = 0.72, respectively. The correlation coefficient between the NRS score and the residual liquid in the stomach was -0.57 (P < 0.01). The correlation coefficient between the increase of the NRS score and the decrease of gastric liquid residual volume was 0.46 (P < 0.01). The standardized estimate of NRS score for the residual volume was -0.18 (P < 0.01) and the standardized estimate of fasting time was -0.73 (P < 0.01).

CONCLUSIONS

The subjective hunger NRS score can not accurately predict the gastric residual volume, but it can provide a reference for clinicians to judge the gastric emptying process and it should be used as a second check after oral intake of clear fluids before surgery according to the new fasting protocol.

Bidirectional Relationship between Gastric Emptying and Plasma Glucose Control in Normoglycemic Individuals and Diabetic Patients

Gastric emptying and glycemic control pathways are closely interrelated processes. Gastric chyme is transferred into the duodenum with velocities depending on its solid or liquid state, as well as on its caloric and nutritional composition. Once nutrients enter the intestine, the secretion of incretins (hormonal products of intestinal cells) is stimulated. Among incretins, glucagon-like peptide-1 (GLP-1) has multiple glycemic-regulatory effects that include delayed gastric emptying, thus triggering a feedback loop lowering postprandial serum glucose levels. Glycemic values also influence gastric emptying; hyperglycemia slows it down, and hypoglycemia accelerates it, both limiting glycemic fluctuations. Disordered gastric emptying in diabetes mellitus is understood today as a complex pathophysiological condition, with both irreversible and reversible components and high intra- and interindividual variability of time span and clinical features. While limited delays may be useful for reducing postprandial hyperglycemias, severely hindered gastric emptying may be associated with higher glycemic variability and worsened long-term glycemic control. Therapeutic approaches for both gastric emptying and glycemic control include dietary modifications of meal structure or content and drugs acting as GLP-1 receptor agonists. In the foreseeable future, we will probably witness a wider range of dietary interventions and more incretin-based medications used for restoring both gastric emptying and glycemic levels to nearly physiological levels.

Impaired vagal activity to meal in patients with functional dyspepsia and delayed gastric emptying

Objective This study was performed to investigate impaired vagal activity to meal in patients with functional dyspepsia (FD) with delayed gastric emptying (GE). Methods Eighty-five patients were studied. GE parameters, including those in the overall and proximal stomach, were measured by GE functional tests at the Department of Nuclear Medicine. Autonomic nervous function was tested by spectral analysis of heart rate variability (HRV). The vagal activity and sympathetic activity were analyzed by recording the power in the high-frequency component (HF), low-frequency component (LF), and LF/HF ratio. Results Overall and proximal GE were delayed in 47.2% and 50.9% of the patients, respectively. Spectral analysis of HRV showed that the HF in patients with delayed proximal GE was significantly lower and that the LF/HF ratio was significantly higher than those in patients with normal proximal GE after a meal. Conclusion Delayed proximal GE might be caused by disrupted sympathovagal balance as a result of decreased vagal activity after a meal. Improvement in vagal activity may constitute an effective treatment method for patients with FD.

Esophageal transit scintigraphy in systemic sclerosis

Systemic sclerosis is a rare connective tissue disease, distinctive features of which are fibrosis and microangiopathy. The esophagus is one of the most commonly involved internal organs. Most patients experience dysphagia, difficulties in swallowing and gastro-esophageal reflux. However, in up to one third of cases, the initial onset of esophageal disease may be clinically silent. There are several diagnostic modalities available for assessing both morphological and functional abnormalities of the esophagus. If structural abnormalities are suspected, endoscopy is the method of choice. Functional evaluation is best achieved with manometry. Both endoscopy and manometry are invasive techniques, with low patient acceptance. Barium-contrast study is well tolerated, but qualitative assessment of functional abnormalities is imprecise. Esophageal scintigraphy is an easy, non-invasive, sensitive and specific diagnostic modality. It can detect esophageal dysfunction even in asymptomatic patients. In patients already diagnosed with systemic sclerosis, scintigraphy is useful in evaluating severity and progression of the disease.