Gastric Myoelectrical Activity Research Articles

The impact of heat treatment of bovine milk on gastric emptying and nutrient appearance in peripheral circulation in healthy females: a randomized controlled trial comparing pasteurized and ultra-high temperature milk

BackgroundHeat treatments of dairy, including pasteurization and ultra-high temperature (UHT) processing, alter milk macromolecular structures, and ultimately affect digestion. In vitro, animal, and human studies show faster nutrient release or circulating appearance after consuming UHT milk (UHT-M) compared with pasteurized milk (PAST-M), with a faster gastric emptying (GE) rate proposed as a possible mechanism. ObjectivesTo investigate the impact of milk heat treatment on GE as a mechanism of faster nutrient appearance in blood. We hypothesized that GE and circulating nutrient delivery following consumption would be faster for UHT-M than PAST-M. MethodsIn this double-blind randomized controlled cross-over trial, healthy female (n = 20; 27.3 ± 1.4 y, mean ± SD) habitual dairy consumers, consumed 500 mL of either homogenized bovine UHT-M or PAST-M (1340 compared with 1320 kJ). Gastric content volume (GCV) emptying half-time (T50) was assessed over 3 h by magnetic resonance imaging subjective digestive symptoms, plasma amino acid, lipid and B vitamin concentrations, and gastric myoelectrical activity were measured over 5 h. ResultsAlthough GCV T50 did not differ (102 ± 7 min compared with 89 ± 8 min, mean ± SEM, UHT-M and PAST-M, respectively; P = 0.051), GCV time to emptying 25% of the volume was 31% longer following UHT-M compared with PAST-M (42 ± 2 compared with 32 ± 4 min, P = 0.004). Although GCV remained larger for a longer duration following UHT-M (treatment × time interaction, P = 0.002), plasma essential amino acid AUC was greater following UHT-M than PAST-M (55,324 ± 3809 compared with 36,598 ± 5673 μmol·min·L-1, P = 0.006). Heat treatment did not impact gastric myoelectrical activity, plasma appetite hormone markers or subjective appetite scores. ConclusionsContrary to expectations, GE was slower with UHT-M, yet, as anticipated, aminoacidemia was greater. The larger GCV following UHT-M suggests that gastric volume may poorly predict circulating nutrient appearance from complex food matrices. Dairy heat treatment may be an effective tool to modify nutrient release by impacting digestion kinetics. Clinical Trial Registrywww.anzctr.org.au (ACTRN12620000172909).

Effects of corticotropin-releasing hormone on gastric electrical activity and sensorimotor function in healthy volunteers: a double-blinded crossover study.

Biopsychosocial factors are associated with disorders of gut-brain interaction (DGBI) and exacerbate gastrointestinal symptoms. The mechanisms underlying pathophysiological alterations of stress remain unclear. Corticotropin-releasing hormone (CRH) is a central regulator of the hormonal stress response and has diverse impact on different organ systems. The aim of the present study was to investigate the effects of peripheral CRH infusion on meal-related gastrointestinal symptoms, gastric electrical activity, and gastric sensorimotor function in healthy volunteers (HVs). In a randomized, double-blinded, placebo-controlled, crossover study, we evaluated the effects of CRH on gastric motility and sensitivity. HVs were randomized to receive either peripheral-administered CRH (100 µg bolus + 1 µg/kg/h) or placebo (saline), followed by at least a 7-day washout period and assignment to the opposite treatment. Tests encompassed saliva samples, gastric-emptying (GE) testing, body surface gastric mapping (BSGM, Gastric Alimetry; Alimetry) to assess gastric myoelectrical activity with real-time symptom profiling, and a gastric barostat study to assess gastric sensitivity to distention and accommodation. Twenty HVs [13 women, mean age 29.2 ± 5.3 yr, body mass index (BMI) 23.3 ± 3.8 kg/m2] completed GE tests, of which 18 also underwent BSGM measurements during the GE tests. The GE half-time decreased significantly after CRH exposure (65.2 ± 17.4 vs. 78.8 ± 24.5 min, P = 0.02) with significantly increased gastric amplitude [49.7 (34.7-55.6) vs. 31.7 (25.7-51.0) µV, P < 0.01], saliva cortisol levels, and postprandial symptom severity. Eleven HVs also underwent gastric barostat studies on a separate day. However, the thresholds for discomfort during isobaric distensions, gastric compliance, and accommodation did not differ between CRH and placebo.NEW & NOTEWORTHY In healthy volunteers, peripheral corticotropin-releasing hormone (CRH) infusion accelerates gastric-emptying rate and increases postprandial gastric response, accompanied by a rise in symptoms, but does not alter gastric sensitivity or meal-induced accommodation. These findings underscore a significant link between stress and dyspeptic symptoms, with CRH playing a pivotal role in mediating these effects.

Isoflurane anesthesia suppresses gastric myoelectric power in the ferret.

Gastric myoelectric signals have been the focus of extensive research; although it is unclear how general anesthesia affects these signals, and studies have often been conducted under general anesthesia. Here, we explore this issue directly by recording gastric myoelectric signals during awake and anesthetized states in the ferret and explore the contribution of behavioral movement to observed changes in signal power. Ferrets were surgically implanted with electrodes to record gastric myoelectric activity from the serosal surface of the stomach, and, following recovery, were tested in awake and isoflurane-anesthetized conditions. Video recordings were also analyzed during awake experiments to compare myoelectric activity during behavioral movement and rest. A significant decrease in gastric myoelectric signal power was detected under isoflurane anesthesia compared to the awake condition. Moreover, a detailed analysis of the awake recordings indicates that behavioral movement is associated with increased signal power compared to rest. These results suggest that both general anesthesia and behavioral movement can affect the signal power of gastric myoelectric recordings. In summary, caution should be taken in studying myoelectric data collected under anesthesia. Further, behavioral movement could have an important modulatory role on these signals, affecting their interpretation in clinical settings.

The impact of heat-set milk protein gel textures modified by pH on circulating amino acid appearance and gastric function in healthy female adults: a randomised controlled trial.

Modification of dairy proteins during processing impacts structural assemblies, influencing textural and nutritional properties of dairy products, and release and availability of amino acids during digestion. By modifying only pH, acid heat-set bovine dairy gels with divergent textural properties were developed to alter protein digestion. In vitro assay confirmed faster digestion of protein from a firm gel (pH 5.65) versus a soft gel (pH 6.55). We hypothesised that firm gel (FIRM-G; pH 5.6) would result in greater indispensable amino acid (IAA) appearance in circulation over 5 h and corresponding differences in gastric myoelectrical activity relative to soft gel (SOFT-G; pH 6.2). In a randomised, single-blind cross-over trial, healthy females (n = 20) consumed 150 g of each gel; plasma amino acid appearance was assessed over 5 hours. Iso-nitrogenous, iso-caloric gels were prepared from identical mixtures of bovine milk and whey protein concentrates; providing 17.7 g (FIRM-G) and 18.9 g (SOFT-G) of protein per serving. Secondary outcomes included gastric myoelectrical activity measured by body surface gastric mapping, glycaemic, triglyceridaemic, and subjective appetite and digestive responses. Overall plasma IAA (area under the curve) did not differ between gels. However, plasma IAA concentrations were higher, and increased more rapidly over time after SOFT-G compared with FIRM-G (1455 ± 53 versus 1350 ± 62 μmol L-1 at 30 min, p = 0.024). Similarly, total, branched-chain and dispensable amino acids were higher at 30 min with SOFT-G than FIRM-G (total: 3939 ± 97 versus 3702 ± 127 μmol L-1, p = 0.014; branched-chain: 677 ± 30 versus 619 ± 34 μmol L-1, p = 0.047; dispensable: 2334 ± 53 versus 2210 ± 76 μmol L-1, p = 0.032). All other measured parameters were similar between gels. Peak postprandial aminoacidaemia was higher and faster following ingestion of SOFT-G. Customised plasma amino acid appearance from dairy is achievable by altering gel coagulum structure using pH during processing and may have minimal influence on related postprandial responses, with implications for targeting food design for optimal health. The Clinical Trial Registry number is ACTRN12622001418763 (https://www.anzctr.org.au) registered November 7, 2022.

Gastric emptying and myoelectrical activity testing in children with esophageal atresia: A pilot study.

Abnormalities of gastric function in children with esophageal atresia (EA) could potentially contribute to gastrointestinal symptoms and reduced quality of life (QOL). Therefore, we aimed to determine the feasibility and clinical usefulness of gastric function testing in children with EA. The validated PedsQL Gastrointestinal Symptoms Questionnaire (PedsQL-GI) was completed to assess gastrointestinal symptoms and symptom-related QOL. Gastric emptying and gastric myoelectrical activity were studied using 13C-gastric emptying octanoic acid breath test (13C-GEBT) and surface electrogastrography (EGG). Correlations between 13C-GEBT and EGG parameters and PedsQL-GI scores were investigated. Fifteen patients (four males) were included (median age: 6 [3.0-8.5] years). Mean PedsQL-GI scores as reported by the children were comparable to the healthy population. However, parents reported a diminished QOL. Gastric function tests (gastric emptying and/or surface EGG) showed abnormalities in 12 patients (80%). Patients with abnormal slow waves showed abnormal gastric emptying coefficientmore often. There was no significant association between 13C-GEBT nor EGG results and PedsQL-GI scores. 13C-GEBT and EGG can be used to evaluate gastric function in patients with EA. Abnormal gastric function tests were present in 80% of our cohort. However, abnormal gastric function did not significantly correlate with reported gastrointestinal symptom-related QOL.

Are dietary intakes linked to interoception and gastric myoelectric activity in women with binge eating disorder and bulimia nervosa?

Are dietary intakes linked to interoception and gastric myoelectric activity in women with binge eating disorder and bulimia nervosa?

Quantifying the effects of vagus nerve stimulation on gastric myoelectric activity in ferrets using an interpretable machine learning approach.

Vagus nerve stimulation (VNS) is a potential treatment option for gastrointestinal (GI) diseases. The present study aimed to understand the physiological effects of VNS on gastrointestinal (GI) function, which is crucial for developing more effective adaptive closed-loop VNS therapies for GI diseases. Electrogastrography (EGG), which measures gastric electrical activities (GEAs) as a proxy to quantify GI functions, was employed in our investigation. We introduced a recording schema that allowed us to simultaneously induce electrical VNS and record EGG. While this setup created a unique model for studying the effects of VNS on the GI function and provided an excellent testbed for designing advanced neuromodulation therapies, the resulting data was noisy, heterogeneous, and required specialized analysis tools. The current study aimed at formulating a systematic and interpretable approach to quantify the physiological effects of electrical VNS on GEAs in ferrets by using signal processing and machine learning techniques. Our analysis pipeline included pre-processing steps, feature extraction from both time and frequency domains, a voting algorithm for selecting features, and model training and validation. Our results indicated that the electrophysiological changes induced by VNS were optimally characterized by a distinct set of features for each classification scenario. Additionally, our findings demonstrated that the process of feature selection enhanced classification performance and facilitated representation learning.

Association of gastric myoelectric activity and body composition in women with binge eating disorder and bulimia nervo-sa

Association of gastric myoelectric activity and body composition in women with binge eating disorder and bulimia nervo-sa

Prediction of gastroesophageal reflux episodes by smooth muscle electromyography: A translational study in rats and adolescents

AimsOur aim was to measure the myoelectric modifications during gastric acid secretion along with the gastric pH in a rat model and to detect the gastrointestinal (GI) myoelectric changes in adolescents suffering from gastroesophageal reflux disease (GERD) along with the esophageal pH measurement. Main methodsIn anesthetized rats, gastric acid secretion was initiated with intragastric histamine (50 mg/kg), and gastric pH, GI myoelectric activity and mechanical GI contractions were measured with intragastric pH electrode, subcutaneously implanted smooth muscle electromyography (SMEMG) electrodes and organ implanted strain gauges, respectively. In the clinical study, esophageal pH and GI myoelectric activity were measured in adolescents suffering from GERD with intraesophageal pH electrode and SMEMG electrodes placed on the abdominal surface, respectively. The SMEMG records were analyzed by fast Fourier transformation (FFT) and power spectrum density maximum (PsDmax) values were calculated for the GI segments. Key findingsIn rats, histamine initiated an immediate increase in gastric PsDmax, which preceded the significant reduction in gastric pH by 75 min. The myoelectric change was independent of mechanical GI contractions. In adolescents, the GERD episodes were preceded by a significant increase in gastric PsDmax 45 min earlier. These changes were independent of motion or meals. SignificanceIncreased gastric myoelectric activity during histamine stimulation or GERD might be linked to the enhanced activity of the gastric proton pump, indicating a link between gastric acid secretion and GERD episodes. It is supposed that SMEMG might be a tool for predicting forthcoming reflux episodes in GERD.

Gastric Myoelectric Activity and Body Composition in Women with Binge Eating Disorder and Bulimia Nervosa: A Preliminary Trial Study.

Women with eating disorders (EDs) often complain of abnormal gastric responses, which may impact their eating patterns and, consequently, their body composition. Binge eating disorder (BED) and bulimia nervosa (BN) have been shown to affect gastric myoelectric activity (GMA), which may provide a basis for the gastric response in this disease population. This study aimed to examine GMA and body composition in patients with an ED compared to age-body mass index (BMI) matched controls. This case-control study included 18 adults diagnosed with BED or BN compared to 19 age-gender-BMI-matched controls. The electrogastrography with water load test was used to measure GMA during fasting and after water loading to satiety. Body composition was measured using a bioelectric impedance analyzer. The results showed that the ED group had a significantly higher water load than the control group and increased percentages of tachygastria times. Comparing the BED and BN subgroups showed differences in body composition status between the subgroups in the form of less fat mass, muscle mass, and total body water in the BN subgroup. In the BN subgroup, fat mass was associated with the average dominant frequency in the EGG. Thus, measuring GMA may be a promising approach to understanding gastric abnormalities in patients with EDs. Therapies targeting improving body composition in women with BED and BN are recommended in future ED management strategies.

Placebo effects on nausea and motion sickness are resistant to experimentally-induced stress

Nausea often occurs in stressful situations, such as chemotherapy or surgery. Clinically relevant placebo effects in nausea have been demonstrated, but it remains unclear whether stress has an impact on these effects. The aim of this experimental study was to investigate the interplay between acute stress and placebo effects in nausea. 80 healthy female volunteers susceptible to motion sickness were randomly assigned to either the Maastricht Acute Stress Test or a non-stress control condition, and to either placebo treatment or no treatment. Nausea was induced by a virtual vection drum and behavioral, psychophysiological as well as humoral parameters were repeatedly assessed. Manipulation checks confirmed increased cortisol levels and negative emotions in the stressed groups. In the non-stressed groups, the placebo intervention improved nausea, symptoms of motion sickness, and gastric myoelectrical activity (normo-to-tachy (NTT) ratio). In the stressed groups, the beneficial effects of the placebo intervention on nausea and motion sickness remained unchanged, whereas no improvement of the gastric NTT ratio was observed. Results suggest that placebo effects on symptoms of nausea and motion sickness are resistant to experimentally-induced stress. Stress most likely interfered with the validity of the gastric NTT ratio to measure nausea and thus the gastric placebo effect.

Postprandial effect of gastrointestinal hormones and gastric activity in patients with irritable bowel syndrome

Altered gut regulation, including motor and secretory mechanisms, is characteristic of irritable bowel syndrome (IBS). The severity of postprandial symptoms in IBS patients is associated with discomfort and pain; gas-related symptoms such as bloating and abdominal distension; and abnormal colonic motility. The aim of this study was to assess the postprandial response, i.e., gut peptide secretion and gastric myoelectric activity, in patients with constipation-predominant IBS. The study was conducted on 42 IBS patients (14 males, 28 females, mean age 45.1 ± 15.3 years) and 42 healthy participants (16 males, 26 females, mean age 41.1 ± 8.7 years). The study assessed plasma gut peptide levels (gastrin, CCK—Cholecystokinin, VIP—Vasoactive Intestinal Peptide, ghrelin, insulin) and gastric myoelectric activity obtained from electrogastrography (EGG) in the preprandial and postprandial period (meal–oral nutritional supplement 300 kcal/300 ml). Mean preprandial gastrin and insulin levels were significantly elevated in IBS patients compared to the control group (gastrin: 72.27 ± 26.89 vs. 12.27 ± 4.91 pg/ml; p < 0.00001 and insulin: 15.31 ± 12.92 vs. 8.04 ± 3.21 IU/ml; p = 0.0001), while VIP and ghrelin levels were decreased in IBS patients (VIP: 6.69 ± 4.68 vs. 27.26 ± 21.51 ng/ml; p = 0.0001 and ghrelin: 176.01 ± 88.47 vs. 250.24 ± 84.55 pg/ml; p < 0.0001). A nonsignificant change in the CCK level was observed. IBS patients showed significant changes in postprandial hormone levels compared to the preprandial state—specifically, there were increases in gastrin (p = 0.000), CCK (p < 0.0001), VIP (p < 0.0001), ghrelin (p = 0.000) and insulin (p < 0.0001). Patients with IBS showed reduced preprandial and postprandial normogastria (59.8 ± 22.0 vs. 66.3 ± 20.2%) compared to control values (83.19 ± 16.7%; p < 0.0001 vs. 86.1 ± 9.4%; p < 0.0001). In response to the meal, we did not observe an increase in the percentage of normogastria or the average percentage slow-wave coupling (APSWC) in IBS patients. The postprandial to preprandial power ratio (PR) indicates alterations in gastric contractions; in controls, PR = 2.7, whereas in IBS patients, PR = 1.7, which was significantly lower (p = 0.00009). This ratio reflects a decrease in gastric contractility. Disturbances in the postprandial concentration of gut peptides (gastrin, insulin and ghrelin) in plasma may contribute to abnormal gastric function and consequently intestinal motility, which are manifested in the intensification of clinical symptoms, such as visceral hypersensitivity or irregular bowel movements in IBS patients.

The effect of single and repeated doses of rivastigmine on gastric myoelectric activity in experimental pigs.

Rivastigmine is a pseudo-irreversible cholinesterase inhibitor used for therapy of Alzheimer's disease and non-Alzheimer dementia syndromes. In humans, rivastigmine can cause significant gastrointestinal side effects that can limit its clinical use. The aim of this study was to assess the impact of rivastigmine on gastric motor function by means of electrogastrography (EGG) in experimental pigs. Six experimental adult female pigs (Sus scrofa f. domestica, hybrids of Czech White and Landrace breeds; 3-month-old; mean weight 30.7 ± 1.2 kg) were enrolled into the study twice and created two experimental groups. In group A, a single intragastric dose of 6 mg rivastigmine hydrogen tartate was administered in the morning to fasting pigs before EGG recording. In group B, rivastigmine was administered to overnight fasting animals in a dietary bolus in the morning for 7 days (6 mg per day). On day 8, an intragastric dose of 12 mg rivastigmine was given in the morning to fasting pigs before EGG. EGG recording was accomplished by means of an EGG standalone system. Recordings from both groups were evaluated in dominant frequency and EGG power (areas of amplitudes). In total, 1,980 one-minute EGG intervals were evaluated. In group A, basal EGG power (median 1290.5; interquartile range 736.5-2330 μV2) was significantly higher in comparison with the power of intervals T6 (882; 577-1375; p = 0.001) and T10 (992.5; 385-2859; p = 0.032). In group B, the dominant frequency increased significantly from basal values (1.97 ± 1.57 cycles per minute) to intervals T9 (3.26 ± 2.16; p < 0.001) and T10 (2.14 ± 1.16; p = 0.012), respectively. In group B, basal EGG power (median 1030.5; interquartile range 549-5093) was significantly higher in comparison with the power of intervals T7 (692.5; 434-1476; p = 0.002) and T8 (799; 435-1463 μV2; p = 0.004). Both single as well as repeated intragastric administration of rivastigmine hydrogen tartrate caused a significant decrease of EGG power (areas of amplitudes) in experimental pigs. EGG power may serve as an indirect indicator of gastric motor competence. These findings might provide a possible explanation of rivastigmine-associated dyspepsia in humans.

Efficacy and safety of the herbal formula Naesohwajung-tang for functional dyspepsia: a randomized, double-blind, placebo-controlled, multi-center trial.

Background: Current treatment and management options for functional dyspepsia (FD) often fail to alleviate symptoms. Naesohwajung-tang (NHT) is a herbal formula frequently used to treat functional dyspepsia in traditional Korean medicine. However, few animal and case reports on the use of Naesohwajung-tang for functional dyspepsia treatment exist, and the clinical evidence remains deficient. Objectives: This study aimed to evaluate the efficacy of Naesohwajung-tang in patients with functional dyspepsia. Methods: We enrolled 116 patients with functional dyspepsia at two study sites in this 4weeks, randomized, double-blind, placebo-controlled trial and randomly assigned them to either the Naesohwajung-tang or placebo group. To evaluate the efficacy of Naesohwajung-tang, the primary endpoint was a score on the total dyspepsia symptom (TDS) scale after treatment. The overall treatment effect (OTE), single dyspepsia symptom (SDS) scale, food retention questionnaire (FRQ), Damum questionnaire (DQ), functional dyspepsia-related quality of life (FD-QoL) questionnaire, and gastric myoelectrical activity measured using electrogastrography were evaluated as secondary outcomes. Laboratory tests were performed to confirm the safety of the intervention. Results: The 4weeks administration of Naesohwajung-tang granules demonstrated a significantly higher reduction in the total dyspepsia symptom (p < 0.05) and a higher degree of improvement in the total dyspepsia symptom (p < 0.01) than the placebo group. Patients who underwent Naesohwajung-tang had a significantly higher overall treatment effect and a greater increase in the degree of improvement in scores such as epigastric burning, postprandial fullness, early satiation, functional dyspepsia-related quality of life, and Damum questionnaire (p < 0.05). Additionally, the Naesohwajung-tang group showed a greater effect in preventing a decrease in the percentage of normal gastric slow waves after meals than the placebo group. As a result of subgroup analyses using the degree of improvement in total dyspepsia symptom, Naesohwajung-tang was found to be more effective than placebo in female, younger patients (<65years), with a high body-mass index (≥22), overlap type, food retention type, and Dampness and heat in the spleen and stomach systems pattern. There was no significant difference in the incidence of adverse events between the two groups. Conclusion: This is the first randomized clinical trial to verify that Naesohwajung-tang leads on symptom relief in patients with functional dyspepsia. Clinical Trial Registration: https://cris.nih.go.kr/cris/search/detailSearch.do/17613, identifier KCT0003405.

Gastric Myoelectric Activity and Body Composition Changes during Weight Loss via Sleeve Gastrectomy and Lifestyle Modification: Prospective Cohort Study.

The capability of bariatric surgery (BS) and lifestyle intervention (LSI) in ameliorating obesity-associated altered gastric myoelectric activity (GMA) in relation to body composition is underinvestigated. This work studied GMA during weight loss via sleeve gastrectomy and multimodal lifestyle intervention. Seventy-nine participants with morbid obesity were assigned into three groups: bariatric surgery (BS group, n = 27), in which laparoscopic sleeve gastrectomy was performed; lifestyle intervention (LS group, n = 22), in which a calorie-deficit balanced diet with gradual physical activity and personalized behavioral modification were carried out; and waitlist control (C group, n = 30). For all participants, multichannel electrogastrography (EGG) with water-load testing and bioelectric impedance body composition analysis were done at baseline, after three months, and at six months. In the BS group, the water-load volume was decreased but without improvement in the bradygastria. In the LS group, preprandial bradygastria were reduced and some postprandial normogastria were increased throughout the study period. Except for fat-free mass and total body water, the parameters of body composition changes were superior in the BS group. In the LS group, the amount of fat-mass loss was negatively correlated with bradygastria times and positively correlated with preprandial and the early postprandial average dominant frequency (ADF). In addition, in the BS group, fat-mass loss was positively correlated with the ADF at late postprandial times. In conclusion, compared to BS, LS produced moderate normalization of GMA with the preservation of fat-free mass. The GMA changes were significantly associated with the amount of fat loss, regardless of the method of obesity management.

Effects of water ingestion on autonomic activity and gastric motility in patients with celiac disease.

The pathogenesis of celiac disease is associated with an autoimmune process. The disease causes chronic inflammation of the small intestinal mucosa, which may affect the brain-gut axis. The activation of visceral receptors (gastrointestinal mechanoreceptor and osmoreceptor) in response to stomach distension caused by water ingestion has not been studied before. Our results showed reduced responsiveness of the autonomic nervous system to water ingestion in patients with celiac disease, which may lead to disturbances of gastric myoelectrical activity and depends on baseline autonomic activity. Water intake can induce gastric distension and motility response, without changes in gastrointestinal hormones. It can also increase the activity of the autonomic nervous system. On the other hand, inflammation in celiac disease (CeD) can alter visceral perception (increase sensitization), leading to autonomic dysfunction. We aimed to investigate the effect of water ingestion on autonomic activity measured as heart rate variability (HRV) and gastric myoelectrical activity measured by electrogastrography (EGG) in patients with CeD. The study included 53 patients with CeD and 50 healthy controls: mean (SD) age, 43.4 (14.8) years and 44.1 (9.2) years, respectively. Electrocardiography with HRV analysis and simultaneous 4-channel EGG was performed before and after the water load test (WLT) ingestion 500-ml water over 5 minutes. We found that compared with controls, at fasting, patients with CeD showed a reduced percentage of normogastria (P=0.045) and an average percentage of slow wave coupling (P<0.01) with increased dominant power (DP) (P<0.001). Moreover, water ingestion in CeD patients reduced the percentage of gastric arrhythmia (P<0.01) and increased the percentage of normogastria (P<0.01) and DP (P<0.01). Finally, in the CeD group, water ingestion increased HRV indices: low frequency by 116.9% (P<0.001), high frequency by 125.3% (P<0.01), but they did not reach the values of the control group. Patients with CeD showed a smaller increase in parasympathetic autonomic activity after the WLT than controls. Altered autonomic responsiveness may contribute to the disturbances of gastric myoelectrical activity and depends on baseline autonomic activity.

Principles and clinical methods of body surface gastric mapping: Technical review.

Chronic gastric symptoms are common, however differentiating specific contributing mechanisms in individual patients remains challenging. Abnormal gastric motility is present in a significant subgroup, but reliable methods for assessing gastric motor function in clinical practice are lacking. Body surface gastric mapping (BSGM) is a new diagnostic aid, employs multi-electrode arrays to measure and map gastric myoelectrical activity non-invasively in high resolution. Clinical adoption of BSGM is currently expanding following studies demonstrating the ability to achieve specific patient subgrouping, and subsequent regulatory clearances. An international working group was formed in order to standardize clinical BSGM methods, encompassing a technical group developing BSGM methods and a clinical advisory group. The working group performed a technical literature review and synthesis focusing on the rationale, principles, methods, and clinical applications of BSGM, with secondary review by the clinical group. The principles and validation of BSGM were evaluated, including key advances achieved over legacy electrogastrography (EGG). Methods for BSGM were reviewed, including device design considerations, patient preparation, test conduct, and data processing steps. Recent advances in BSGM test metrics and reference intervals are discussed, including four novel metrics, being the 'principal gastric frequency', BMI-adjusted amplitude, Gastric Alimetry Rhythm Index™, and fed: fasted amplitude ratio. An additional essential element of BSGM has been the introduction of validated digital tools for standardized symptom profiling, performed simultaneously during testing. Specific phenotypes identifiable by BSGM and the associated symptom profiles were codified with reference to pathophysiology. Finally, knowledge gaps and priority areas for future BSGM research were also identified by the working group.

Diagnostic Methods for Evaluation of Gastric Motility-A Mini Review.

Gastric motility abnormalities are common in patients with disorders of gut-brain interaction, such as functional dyspepsia and gastroparesis. Accurate assessment of the gastric motility in these common disorders can help understand the underlying pathophysiology and guide effective treatment. A variety of clinically applicable diagnostic methods have been developed to objectively evaluate the presence of gastric dysmotility, including tests of gastric accommodation, antroduodenal motility, gastric emptying, and gastric myoelectrical activity. The aim of this mini review is to summarize the advances in clinically available diagnostic methods for evaluation of gastric motility and describe the advantages and disadvantages of each test.

Endoscopic mucosal electrodes: New directions for recording and regulating gastric myoelectric activity.

With the gradual deepening of the study of gastric motility disorders, people increasingly realize that gastric myoelectric activity plays an important role in coordinating gastric function. This article introduces the advantages of endoscopic mucosal electrodes compared with traditional electrodes. Several different types of mucosal electrodes and how to fix the electrodes by endoscope are introduced. Endoscopic mucosal electrodes can record and regulate gastric myoelectric activity, which has great value in the study of gastric motility. Endoscopic mucosal electrode technique refers to the fixation of the electrode in the designated part of the gastric mucosa by endoscope. Through endoscopic mucosal electrodes, on the one hand, we can record gastric myoelectric activity, on the other hand, we can carry out gastric electrical stimulation to interfere with gastric rhythm. Endoscopic mucosal electrodes have higher accuracy than traditional cutaneous electrodes, less trauma and lower cost than serosal electrodes. Endoscopic mucosal electrodes have a good application prospect for diseases such as gastroparesis and obesity.

Does exertional heat stress impact gastrointestinal function and symptoms?

Exertional-heat stress generates a thermoregulatory strain that exacerbates splanchnic hypoperfusion and sympathetic drive, but the effects on gastrointestinal function are poorly defined. The study aimed to determine the effects of exertional-heat stress on gastric myoelectrical activity, orocecal transit time (OCTT), and gastrointestinal symptoms (GIS). Randomised cross-over study. Endurance runners (n = 16) completed 2 h of running at 60 % V̇O2max in 35 °C (HOT) and 22 °C (TEMP) ambient conditions. Surface electrogastrography (cEGG) was recorded pre- and post-exercise to determine gastric myoelectrical activity, a lactulose challenge was used to determine OCTT, and GIS were recorded using a modified visual analogue scale tool. Post-exercise Tre [HOT:38.8(38.5 to 39.0)°C and TEMP:38.1(37.8 to 38.4)°C] and Δ Tre [HOT:2.2(2.0 to 2.4)°C and TEMP:1.5(1.2 to 1.8)°C] was higher on HOT compared to TEMP (p < 0.001). Normal gastric myoelectrical cycle frequency reduced (p = 0.010) on HOT [-11.7(-20.8 to -2.6)%], but this decrease did not differ (p = 0.058) from TEMP [-2.7(-8.3 to 3.0)%]. Bradygastria increased post-exercise on both trials (HOT:11.3(2.3 to 20.4)%, p = 0.030; and TEMP:7.4(2.1 to 12.6)%, p = 0.009). OCTT did not differ between trials (p = 0.864) with transit response classified as very slow on both HOT (99(68 to 131)min) and TEMP (98(74 to 121)min). GIS incidence was higher on HOT (88 %) compared to TEMP (81 %), in accordance with greater total-GIS and upper-GIS severity (p = 0.005 and p = 0.033, respectively). Running for 2 h at 60 % V̇O2max in either hot or temperate ambient conditions instigates perturbations in myoelectrical activity and OCTT, with GIS incidence and severity greater in hot conditions.