Meal Effects on Gastric Bioelectrical Activity Utilizing Body Surface Gastric Mapping in Healthy Subjects

Background Gastric sensorimotor disorders are prevalent. While gastric emptying measurements are commonly used, they may not fully capture the underlying pathophysiology. Body surface gastric mapping (BSGM) recently emerged to assess gastric sensorimotor dysfunction. This study assessed varying meal size on BSGM responses to inform test use in a wider variety of contexts. Methods Data from multiple healthy cohorts receiving BSGM were pooled, using four different test meals. A standard BSGM protocol was employed: 30-min fasting, 4-hr post-prandial, using Gastric Alimetry® (Alimetry, New Zealand). Meals comprised: i) nutrient drink + oatmeal bar (482 kcal; ’standard meal’); ii) oatmeal bar alone; egg and toast meal, and pancake (all ∼250 kcal). Gastric Alimetry metrics included BMI-adjusted Amplitude, Principal Gastric Frequency, Gastric Alimetry Rhythm Index (GA-RI) and Fed:Fasted Amplitude Ratio (ff-AR). Key Results 238 participants (59.2% female) were included. All meals significantly increased amplitude and frequency during the first post-prandial hour (p<0.05). There were no differences in postprandial frequency across meals (p>0.05). The amplitude and GA-RI of the standard meal (n=110) were significantly higher than the energy bar alone (n=45) and egg meal (n=65) (all p<0.05). All BSGM metrics were comparable across the 3 smaller meals (p>0.05). A higher symptom burden was found in the oatmeal bar group vs the standard meal and pancake meal (p=0.01, 0.003, respectively). Conclusions & Inferences The consumption of lower calorie meals elicited different post-prandial responses, when compared to the standard Gastric Alimetry meal. These data will guide interpretations of BSGM when applied with lower calorie meals. ### Competing Interest Statement GOG, and AG hold intellectual property and grants in gastric electrophysiology and are Directors of University of Auckland spin-out companies (GOG: Alimetry, Insides Company; AG: Alimetry); SC, GS and CNA are members of Alimetry. The remaining authors have no relevant conflicts of interest to declare. ### Funding Statement New Zealand Health Research Council ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethical approval references: Auckland Health Research Ethics Committee (AHREC) - AH1130, Conjoint Health Research Ethics Board (CHREB) - REB19-1925, The Ethics Committee Research UZ Leuven S65541, University of Louisville Institutional Review Board - 723369, and Western Sydney University Human Research Ethics Committee - H13541 I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors