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Journal of Food Science Jul 2024Food digestion is important for human health. Advances have been made using in vitro models to study food digestion, but there is considerable potential for numerical... (Review)
Review
Food digestion is important for human health. Advances have been made using in vitro models to study food digestion, but there is considerable potential for numerical approaches in stomach modeling, as they can provide a comprehensive understanding of the complex flow and chemistry in the stomach. The focus of this study is to provide a concise review of the developed numerical stomach models over the past two decades. The gastric physiological parameters that are required for a computational model to represent the human gastric digestion process are discussed, including the stomach geometry, gastric motility, gastric emptying, and gastric secretions. Computational methods used to model gastric digestion are introduced and compared, including different computational fluid dynamics as well as solid mechanics methods. The challenges and limitations of current studies are discussed, as well as the areas for future research that need to be addressed. There has been progress in simulating gastric fluid flow with stomach wall motion, but much work remains to be done. The complex food breakdown mechanisms and a comprehensive chemical digestion process have not been implemented in any developed models. Numerical method that was once computationally expensive will be revolutionized as computing power continues to improve. Ultimately, the advancement of modeling of gastric food digestion will allow for additional hypothesis testing to streamline the development of food products that are beneficial to human health.
Topics: Digestion; Humans; Stomach; Models, Biological; Gastric Emptying; Computer Simulation; Hydrodynamics
PubMed: 38865250
DOI: 10.1111/1750-3841.17157 -
Annals of Internal Medicine Nov 2023
Topics: Humans; Gastric Emptying; Glucagon-Like Peptide-1 Receptor; Glucagon; Insulin; Blood Glucose; Peptide Fragments
PubMed: 37931267
DOI: 10.7326/M23-2019 -
Journal of Clinical Gastroenterology Apr 2020Gastrointestinal (GI) disturbances are common during training and competition, especially among endurance athletes. Historically, little attention has been paid to the... (Review)
Review
Gastrointestinal (GI) disturbances are common during training and competition, especially among endurance athletes. Historically, little attention has been paid to the psychobiological etiology of GI problems in sport. The aim of this review is to: (1) provide a physiological overview of how psychological stress and anxiety impact GI system function; (2) review the literature that has examined the role of stress and anxiety in GI distress in athletes; and (3) provide suggestions for future research. Animal and human studies have documented that psychological stressors reduce gastric motility and delay stomach emptying while simultaneously increasing large intestine motility. These functional changes are likely mediated through the secretion of corticotropin-releasing factor and subsequent alterations in autonomic nervous system activity, which act to reduce splanchnic blood flow and increase GI permeability. In addition, chronic stress and anxiety may worsen GI discomfort by increasing visceral hypersensitization. Still, only a couple of studies have found modest associations between stress, anxiety, and the occurrence/severity of GI distress in active populations. As such, future work should attempt to confirm that experimentally inducing psychological stress results in the aforementioned GI problems during exercise. Furthermore, studies are needed to determine how psychological stress impacts the tolerance to nutritional fueling and whether it worsens the GI permeability that normally occurs with exercise.
Topics: Animals; Dyspepsia; Gastric Emptying; Gastrointestinal Diseases; Gastrointestinal Motility; Humans; Stress, Psychological
PubMed: 31851100
DOI: 10.1097/MCG.0000000000001308 -
The Quarterly Journal of Nuclear... Mar 2024Pediatric gastrointestinal imaging plays a crucial role in evaluating and managing digestive system disorders in children. This comprehensive review dives into the... (Review)
Review
Pediatric gastrointestinal imaging plays a crucial role in evaluating and managing digestive system disorders in children. This comprehensive review dives into the nuances of pediatric gastrointestinal imaging techniques, focusing on three specific modalities: gastric emptying scintigraphy (GES), intestinal transit scintigraphy (ITS), and gastrointestinal bleeding scintigraphy. GES involves real-time monitoring of stomach emptying using radiotracers and gamma camera technology. While challenges exist in standardizing protocols due to age-specific meal compositions, GES remains pivotal in diagnosing motility disorders, gastroesophageal reflux, and abdominal pain in children. ITS, utilizing [Ga], provides insights into gastrointestinal motility disorders such as Hirschsprung disease. It aids in whole-gut transit evaluation, guiding surgical interventions and improving long-term clinical outcomes. Gastrointestinal bleeding scintigraphy, employing [mTc], assists in diagnosing conditions like Meckel's diverticulum and occult bleeding, offering continuous monitoring to pinpoint the bleeding site along the entire gastrointestinal tract. SPECT-CT improves the accuracy and the standards of care. Each technique's protocol details, clinical indications, and diagnostic capabilities are thoroughly discussed, highlighting the importance of these non-invasive, functional imaging modalities in pediatric gastroenterology.
Topics: Humans; Child; Radionuclide Imaging; Gastric Emptying; Radioisotopes; Gastrointestinal Hemorrhage
PubMed: 38587360
DOI: 10.23736/S1824-4785.24.03548-9 -
Life Sciences Feb 2021Cisplatin treatment induces an autonomic dysfunction and gastrointestinal and cardiovascular disorders. Physical exercise as well as pyridostigmine treatment induces...
Cisplatin treatment induces an autonomic dysfunction and gastrointestinal and cardiovascular disorders. Physical exercise as well as pyridostigmine treatment induces improves in the autonomic nervous system. In the current study, we investigated the effect of physical exercise and pyridostigmine treatment on gastrointestinal and cardiovascular changes in cisplatin-treated rats. Rats were divided into groups: Saline (S), Cisplatin (Cis), Exercise (Ex), Cisplatin+Exercise (Cis+Ex), Pyridostigmine (Pyr), and Cisplatin+Pyridostigmine (Cis+Pyr). We induced gastrointestinal dysmotility by administering 3 mg kg of cisplatin once week for 5 weeks. The Ex was swimming (1 h per day/5 days per week for 5 weeks with 5% b.w.). GE was evaluated through the colorimetric method of fractional red phenol recovery 10 min after feeding. Pyr groups received 1.5 mg kg, p.o. or concomitant Cis treatment. Moreover, gastric contraction in vitro and hemodynamic parameters such as MAP, HR, and evoked baroreflex sensitivity were assessed, as well as sympathetic and parasympathetic tone and intrinsic heart rate (IHR). Cis decrease GE vs. saline (p<0.05). Cis+Ex or Cis+Pyr prevented (p<0.05) decrease in GE vs. Cis rats. Cis decreased (p<0.05) gastric responsiveness in vitro vs. saline. Cis+Ex or Cis+Pyr prevented this phenomenon. Cis treatment increase MAP and decrease in HR (p<0.05) vs saline. Cis+Ex or Cis+Pyr attenuated (p<0.05) both alterations. Cis increased sympathetic tone and decreased vagal tone and IHR (p<0.05) vs. the saline. Cis+Ex or Cis+Pyr prevented those effects vs. the Cis group. In conclusion, physical exercise and pyridostigmine treatment improves autonomic dysfunction and prevented GE delay and changes in hemodynamic parameters, baroreflex sensitivity, and cardiac autonomic control in cisplatin-treated rats.
Topics: Animals; Autonomic Nervous System; Baroreflex; Blood Pressure; Cardiovascular System; Cisplatin; Gastric Emptying; Heart; Heart Rate; Male; Myocardial Infarction; Physical Conditioning, Animal; Pyridostigmine Bromide; Rats; Rats, Wistar; Vagus Nerve
PubMed: 33383052
DOI: 10.1016/j.lfs.2020.118972 -
European Journal of Obstetrics,... Oct 2023The effect of pregnancy on gastric emptying has not been established, although the predominant clinical assumption is that gastric emptying is delayed during pregnancy....
BACKGROUND/AIMS
The effect of pregnancy on gastric emptying has not been established, although the predominant clinical assumption is that gastric emptying is delayed during pregnancy. We hypothesized that the rate of emptying of nutrients during pregnancy is not delayed, but is actually more rapid when compared to the non-pregnant state. The rate of gastric emptying is a major determinant of postprandial glucose elevations.
MATERIALS AND METHODS
24 female and 4 male Spague-Dawley rats were used. Female rats were randomly divided into two groups: eight rats for the control group and sixteen rats for the pregnant group. Using physiologic, non-traumatic nuclear medicine scintigraphy imaging methodology, the authors studied gastric emptying of a liquid mixed meal in pregnant rats and non-pregnant controls. Body weights, daily food ingestion, and the rate of nutrient gastric emptying were recorded in both groups at pre-pregnancy, early pregnancy, and late pregnancy.
RESULTS
The authors found that pregnancy in this rat model is associated with a 37-43% increased rate of nutrient gastric emptying from the stomach in late pregnancy as compared to non-pregnant control rats and pre-pregnancy rats.
CONCLUSION
These findings contradict the current clinical assumption that gastric emptying is delayed in pregnancy. If further studies confirm a more rapid gastric emptying rate during human pregnancy, new therapies aimed at slowing the rate of nutrient absorption should be considered for the prevention and treatment of pregnancy-associated nausea, gestational diabetes, and other insulin-resistant pregnancy-associated states such as pre-eclampsia.
Topics: Humans; Animals; Rats; Female; Male; Pregnancy; Gastric Emptying; Body Weight; Cystography; Diabetes, Gestational; Glucose; Morning Sickness
PubMed: 37639818
DOI: 10.1016/j.ejogrb.2023.08.370 -
Neurogastroenterology and Motility Aug 2020The proximal and distal regions of the stomach are thought to have different roles during gastric accommodation and emptying; however, regional changes in gastric...
BACKGROUND
The proximal and distal regions of the stomach are thought to have different roles during gastric accommodation and emptying; however, regional changes in gastric structure and function during and after a meal have not been described in detail. This study applied non-invasive imaging to study changes in regional gastric volume and morphology during accommodation and emptying of a liquid nutrient meal.
METHOD
MRI studies were performed on 16 healthy volunteers. Three-dimensional (3D) gastric morphology was reconstructed by validated image processing technology. The 3D models were segmented into seven regions. The relative contribution of each region to gastric accommodation and emptying was assessed. Changes in morphology were documented by tracking movements of four distinct gastric landmarks.
KEY RESULTS
The initial 100 mL liquid nutrient increases distal stomach volume more than that of other gastric regions (∆V7 = 28 ± 6% ∆TGV; P ≤ .05). Subsequent volume is accommodated mainly in the proximal stomach (∆V1 = 42 ± 10% ∆TGV; P ≤ .05). Early-phase emptying occurs from distal stomach with proximal stomach volume remaining stable. Subsequently, distal stomach volume remains stable while proximal stomach volume decreases progressively. During gastric filling, the stomach elongates and expands anteriorly and inferiorly (15.2 ± 7.4 mm and 32.3 ± 8.4 mm, respectively, for the incisural midpoint) with torsion indicated by ~70° difference in the movements of proximal and distal gastric landmarks.
CONCLUSIONS AND INFERENCES
Non-invasive MRI describes volume change and distribution of a liquid meal within proximal and distal stomach during gastric accommodation and emptying. Additionally, novel observations of changes to 3D gastric morphology within the abdomen are documented.
Topics: Adult; Female; Gastric Emptying; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Organ Size; Stomach; Young Adult
PubMed: 32390262
DOI: 10.1111/nmo.13865 -
Obesity Surgery Aug 2021Sleeve gastrectomy (SG) results in significant anatomical and physiological alterations of the esophagus and stomach, including food tolerance. Currently, there is no...
PURPOSE
Sleeve gastrectomy (SG) results in significant anatomical and physiological alterations of the esophagus and stomach, including food tolerance. Currently, there is no consensus on the parameters of abnormal esophageal transit and gastric emptying in this population. We describe standardized esophageal transit and gastric emptying protocols, and define expected values following an uncomplicated SG.
MATERIALS AND METHODS
In 43 asymptomatic post-SG patients with optimal weight loss, a standardized liquid and semi-solid (oatmeal) esophageal transit study, plus a 90-min semi-solid gastric emptying study with dynamic 5-s image acquisition to assess gastroesophageal reflux, was performed. Gastric emptying half-time and retention rate was calculated. Esophageal transit and reflux were graded by visual inspection of images.
RESULTS
Thirty-one female and 12 male patients participated: mean age 49.0±10.7 years, pre-operative BMI 47.6±7.0 kg/m, excess weight loss 58.8±26.0% at median follow-up of 7.4 months. The standardized semi-solid meal and liquid preparations were well tolerated. Delays in esophageal transit of liquid and semi-solid boluses were infrequent (7.0% and 16.3% respectively). Deglutitive reflux of both semi-solids and liquids was common (48.8% and 32.6%). The median semi-solid gastric emptying half-time was 21.0 min. A large proportion of substrate transited into the small bowel on initial image acquisition (median 39.1%). Reflux events during gastric emptying were common (median 5.0 events, 12.7% of image acquisition time).
CONCLUSIONS
Rapid gastric emptying with asymptomatic deglutitive and post-prandial gastroesophageal reflux events are common following SG. We have defined the expected values of standardized esophageal transit and gastric emptying scintigraphy specifically tailored to SG patients.
Topics: Adult; Esophagus; Female; Gastrectomy; Gastric Emptying; Humans; Male; Middle Aged; Obesity, Morbid; Radionuclide Imaging
PubMed: 34091832
DOI: 10.1007/s11695-021-05487-7 -
Neurogastroenterology and Motility Nov 2023Early-life events impact maturation of the gut microbiome, enteric nervous system, and gastrointestinal motility. We examined three regions of gastric tissue to...
BACKGROUND
Early-life events impact maturation of the gut microbiome, enteric nervous system, and gastrointestinal motility. We examined three regions of gastric tissue to determine how maternal separation and gut microbes influence the structure and motor function of specific regions of the neonatal mouse stomach.
METHODS
Germ-free and conventionally housed C57BL/6J mouse pups underwent timed maternal separation (TmSep) or nursed uninterrupted (controls) until 14 days of life. We assessed gastric emptying by quantifying the progression of gavaged fluorescein isothiocyanate (FITC)-dextran. With isolated rings of forestomach, corpus, and antrum, we measured tone and contractility by force transduction, gastric wall thickness by light microscopy, and myenteric plexus neurochemistry by whole-mount immunostaining.
KEY RESULTS
Regional gastric sampling revealed site-specific differences in contractile patterns and myenteric plexus structure. In neonatal mice, TmSep prolonged gastric emptying. In the forestomach, TmSep increased contractile responses to carbachol, decreased muscularis externa and mucosa thickness, and increased the relative proportion of myenteric plexus nNOS+ neurons. Germ-free conditions did not appreciably alter the structure or function of the neonatal mouse stomach and did not impact the changes caused by TmSep.
CONCLUSIONS AND INFERENCES
A regional sampling approach facilitates site-specific investigations of murine gastric motor physiology and histology to identify site-specific alterations that may impact gastrointestinal function. Delayed gastric emptying in TmSep is associated with a thinner muscle wall, exaggerated cholinergic contractile responses, and increased proportions of inhibitory myenteric plexus nNOS+ neurons in the forestomach. Gut microbes do not profoundly affect the development of the neonatal mouse stomach or the gastric pathophysiology that results from TmSep.
Topics: Mice; Animals; Animals, Newborn; Gastroparesis; Maternal Deprivation; Mice, Inbred C57BL; Stomach; Myenteric Plexus; Disease Models, Animal; Gastric Emptying
PubMed: 37772676
DOI: 10.1111/nmo.14676 -
Gastroenterology Clinics of North... Sep 2020This article reviews the latest enhancements in standards and technology for performing gastric emptying and associated small bowel and colon transit scintigraphic... (Review)
Review
This article reviews the latest enhancements in standards and technology for performing gastric emptying and associated small bowel and colon transit scintigraphic studies. It discusses how developments in appropriate use criteria, American Medical Association Current Procedural Terminology coding, and advanced commercial software permit clinicians to obtain more comprehensive physiologic studies of gastric, small bowel, and colon gastrointestinal motility disorders. It shows how gastrointestinal scintigraphy has expanded to permit assessments of global and regional (fundic and antral) gastric motility and how it permits a single study (whole-gut transit scintigraphy), including measurement of solid and liquid gastric emptying and small bowel and colon transit.
Topics: Colon; Dyspepsia; Gastric Emptying; Gastrointestinal Motility; Humans; Image Enhancement; Intestine, Small; Radionuclide Imaging; Software; Stomach
PubMed: 32718567
DOI: 10.1016/j.gtc.2020.04.006