Thoracoabdominal Wall Motion-Guided Biofeedback Treatment of Abdominal Distension: A Randomized Placebo-Controlled Trial.

BACKGROUND & AIMS: Abdominal distention results from abdominophrenic dyssynergia (ie, diaphragmatic contraction and abdominal wall relaxation) in patients with disorders of gut-brain interaction. This study aimed to validate a simple biofeedback procedure, guided by abdominothoracic wall motion, for treating abdominal distension. METHODS: In this randomized, parallel, placebo-controlled trial, 42 consecutive patients (36 women and 6 men; ages 17-64 years) with meal-triggered visible abdominal distension were recruited. Recordings of abdominal and thoracic wall motion were obtained using inductance plethysmography via adaptable belts. The signal was shown to patients in the biofeedback group, who were taught to mobilize the diaphragm. In contrast, the signal was not shown to the patients in the placebo group, who were given a placebo capsule. Three sessions were performed over a 4-week intervention period, with instructions to perform exercises (biofeedback group) or to take placebo 3 times per day (control group) at home. Outcomes were assessed through response to an offending meal (changes in abdominothoracic electromyographic activity and girth) and clinical symptoms measured using daily scales for 7 days. RESULTS: Patients in the biofeedback group (n = 19) learned to correct abdominophrenic dyssynergia triggered by the offending meal (intercostal activity decreased by a mean ± SE of 82% ± 10%, anterior wall activity increased by a mean ± SE of 97% ± 6%, and increase in girth was a mean ± SE of 108% ± 4% smaller) and experienced improved clinical symptoms (abdominal distension scores decreased by a mean ± SE of 66% ± 5%). These effects were not observed in the placebo group (all, P < .002). CONCLUSIONS: Abdominothoracic wall movements serve as an effective biofeedback signal for correcting abdominophrenic dyssynergia and abdominal distention in patients with disorders of gut-brain interaction. ClincialTrials.gov, Number: NCT04043208.

External kinesiology tape for improvement in fecal incontinence symptom bother in women: a pilot study.

INTRODUCTION AND HYPOTHESIS: Fecal incontinence is a debilitating condition with a devastating impact on quality of life. Using a commercially available kinesiology band we developed an anal tape to be applied to the anus with the aim to determine its impact on symptom bother and quality of life. METHODS: Four-week prospective, self-controlled, pilot study of patients with FI. The primary outcome was improvement in any of the four domains (lifestyle, coping/behavior, depression/self-perception, embarrassment) evaluated by the "Fecal Incontinence Quality of Life Scale." Secondary outcomes included improvement in frequency of incontinence events and safety. Days 0-14 served as control period and days 15-28 as study period. Patients were asked to rate their satisfaction and willingness to use the device in the future using a 10-cm continuous visual analog scale. RESULTS: Twenty patients completed the study. Median age was 64 years; all patients were females. Significant improvements were observed in all domains of the Fecal Incontinence Quality of Life Scale from baseline to day 28 (p < 0.001 for all) and in three of four domains between day 15 and 28 (p < 0.04) but not between days 1 and 14. Five patients (25%) had a ≥ 50% improvement in incontinence events. Patients reported satisfaction and willingness to use the anal tape in the future. Other than mild difficulty to remove the anal tape, no adverse events were reported. CONCLUSIONS: In this small pilot study, the use of the anal tape was safe and effective. The primary outcome of significant improvement in quality of life was achieved ( ClinicalTrials.gov ID:NCT02989545). PUBLIC TRIAL REGISTRY: ClinicalTrials.gov identifier NCT02989545. https://clinicaltrials.gov/ct2/show/NCT02989545.

Detection of elusive polyps using a large-scale artificial intelligence system (with videos).

BACKGROUND AND AIMS: Colorectal cancer is a leading cause of death. Colonoscopy is the criterion standard for detection and removal of precancerous lesions and has been shown to reduce mortality. The polyp miss rate during colonoscopies is 22% to 28%. DEEP DEtection of Elusive Polyps (DEEP2) is a new polyp detection system based on deep learning that alerts the operator in real time to the presence and location of polyps. The primary outcome was the performance of DEEP2 on the detection of elusive polyps. METHODS: The DEEP2 system was trained on 3611 hours of colonoscopy videos derived from 2 sources and was validated on a set comprising 1393 hours from a third unrelated source. Ground truth labeling was provided by offline gastroenterologist annotators who were able to watch the video in slow motion and pause and rewind as required. To assess applicability, stability, and user experience and to obtain some preliminary data on performance in a real-life scenario, a preliminary prospective clinical validation study was performed comprising 100 procedures. RESULTS: DEEP2 achieved a sensitivity of 97.1% at 4.6 false alarms per video for all polyps and of 88.5% and 84.9% for polyps in the field of view for less than 5 and 2 seconds, respectively. DEEP2 was able to detect polyps not seen by live real-time endoscopists or offline annotators in an average of .22 polyps per sequence. In the clinical validation study, the system detected an average of .89 additional polyps per procedure. No adverse events occurred. CONCLUSIONS: DEEP2 has a high sensitivity for polyp detection and was effective in increasing the detection of polyps both in colonoscopy videos and in real procedures with a low number of false alarms. (Clinical trial registration number: NCT04693078.).

Nonalcoholic fatty liver disease and the risk of post-endoscopic retrograde cholangiopancreatography pancreatitis: the hidden danger.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) has been identified as risk factor for several diseases; however, its association with post endoscopic retrograde cholangiopancreatography pancreatitis (PEP) has not been studied. AIMS: To assess whether NAFLD is a risk factor for the development of PEP. METHODS: We performed a retrospective multicenter study. All patients who underwent ERCP during 2013-2016 at either the Shaare Zedek Medical Center in Jerusalem or EMMS Nazareth hospital and who had a diagnosis of NAFLD by abdominal imaging were eligible for inclusion. Four hundred and one patients were included, among them, 38 (9.5%) were diagnosed with PEP according to clinical, laboratory and radiological criteria. RESULTS: In univariate analysis, the following risk factors were associated with increased risk for PEP; Fatty liver (OR 2.363, p = .01), elevated levels of aspartate transaminase (OR 1.008, p = .04), ALT (OR 0.979, p = .0007), alkaline phosphatase (OR 1.008, p = .01), gamma-glutamyl transferase (OR 1.014, p = .0005) and total bilirubin (OR 1.141, p = .005). In multivariate logistic regression analysis, only NAFLD showed statistically significant association with PEP (OR 3.224, 95% CI 1.548-6.713, p = .001) with receiver operator characteristics (ROC) area under the curve (AUC) of 0.8156. CONCLUSION: NAFLD was shown to be a risk factor for PEP. Therefore, we suggest considering prophylactic pancreatic stenting and/or NSAID's suppositories among these patients.

The severity of anemia does not correlate with the risk of gastrointestinal cancer in subsequent evaluation.

Introduction: Iron deficiency anemia (IDA) is a risk factor for gastrointestinal (GI) malignancies. Little is known regarding the correlation between the depth of anemia and the risk for GI malignancy. The aim of this study was to test the hypothesis that very low hemoglobin levels pose an additional risk compared to low hemoglobin levels.Methods: Patients 40-70 years old, presenting to the ER with IDA during years 2016-2017 were retrospectively analyzed. Comparison was performed between two groups, one with a very low hemoglobin level (below 8 g/dL) and the other a low hemoglobin level (between 8-10 g/dL).Results: 1020 patients were analyzed, and 107 fulfilled the inclusion criteria. Seventy-five patients (70%) were in the very low hemoglobin group and 21 patients (19.6%) were diagnosed with a new GI malignancy. Mean age was 56, 49 (45%) were females, and 68 (63%) underwent esophagogastroduodenoscopy (EGD) or/and colonoscopy during the index hospitalization. The median hemoglobin and MCV were 7.3 G/dL, and 73 fL, respectively. New malignancies were found in 15/75 (20%) and 6/32 (19%) of patients with very low and low hemoglobin levels, respectively (p = .88). GI malignancies were more commonly found in females compared to males, 14 (29%) vs. 7 (12%), p = .032, respectively. The right colon was the most common site for malignancy. Active GI bleeding was not a risk factor for GI malignancy.Conclusions: Very low hemoglobin levels and overt GI bleeding do not pose an additional risk factor for GI malignancy, compared to low hemoglobin levels and no overt GI bleeding.

A prospective study of fecal calprotectin and lactoferrin as predictors of small bowel Crohn's disease in patients undergoing capsule endoscopy.

BACKGROUND: Capsule endoscopy (CE) is often used to investigate small bowel Crohn's disease (CD). AIM: The aim of this study is to prospectively assess the value of fecal calprotectin and lactoferrin to predict CE findings. PATIENTS AND METHODS: Sixty-eight consecutive patients that were referred for CE were included. Stool samples for calprotectin and lactoferrin and blood samples were collected for relevant parameters. Correlation between fecal markers and CE findings was assessed and receiver operating characteristic (ROC) curves were built to determine the predictive values of fecal markers for the diagnosis of CD. RESULTS: Fecal calprotectin data was available for all the patients and lactoferrin data for 38. CE findings compatible with CD were found in 23 (33%) patients and 45 (67%) were negative for CD. The average age of the CD group was 34 compared to 46 in the non-CD group (p = .048). Median calprotectin and lactoferrin in the CD group and in the control group were 169 mg/kg vs. 40 (p = .004) and 6.6 mg/kg vs. 1 (p = .051), respectively. The area under the ROC curve was 0.767 for calprotectin and 0.70 for lactoferrin. A fecal calprotectin concentration of 95 mg/kg and fecal lactoferrin of 1.05 mg/kg had a sensitivity, specificity, positive predictive value and negative predictive value of 77 and 73%, 60 and 65%, 50 and 50%, and 84 and 84% in predicting CE findings compatible with CD. CONCLUSIONS: Fecal markers are simple and noninvasive surrogates for predicting CE findings compatible with CD. Fecal markers can help determine which patients should be referred for CE. ClinicalTrials.gov Identifier: NCT01266629.

The Importance of Intestinal Eotaxin-1 in Inflammatory Bowel Disease: New Insights and Possible Therapeutic Implications.

BACKGROUND: Involvement of eotaxin-1 in inflammatory bowel disease has been previously suggested and increased levels of eotaxin-1 have been described in both ulcerative colitis and in Crohn's disease. The association between serum levels of eotaxin-1 and that within the colonic mucosa has not been well defined, as is the potential therapeutic value of targeting eotaxin-1. AIMS: To characterize serum and intestinal wall eotaxin-1 levels in various inflammatory bowel disease patients and to explore the effect of targeting eotaxin-1 by specific antibodies in dextran sodium sulfate-induced colitis model. METHODS: Eotaxin-1 levels were measured in colonic biopsies and in the sera of 60 ulcerative colitis patients, Crohn's disease patients and healthy controls. We also followed in experimental colitis the effect of targeting eotaxin-1 by a monoclonal antibody. RESULTS: Colon eotaxin-1 levels were significantly increased in active but not in quiescent ulcerative colitis and Crohn's disease patients compared to healthy controls. Levels of eotaxin-1 in the colon were correlated with eosinophilia only in tissues from active Crohn's disease patients. Our results did not show any statistically significant change in serum eotaxin-1 levels among ulcerative colitis, Crohn's disease and healthy controls. Moreover, we demonstrate that in dextran sodium sulfate-induced colitis, targeting of eotaxin-1 with 2 injections of anti eotaxin-1 monoclonal antibody ameliorates disease activity along with decreasing colon weight and improving histologic inflammation. CONCLUSION: Eotaxin-1 is increasingly recognized as a major mediator of intestinal inflammation. Our preliminary human and animal results further emphasize the value of targeting eotaxin-1 in inflammatory bowel disease.

Gastric Polyp Growth during Endoscopic Surveillance for Esophageal Varices or Barrett's Esophagus.

BACKGROUND: We recently observed patients with chronic liver disease (CLD) or chronic reflux symptoms (CRS) who developed gastric polyps (GPs) while undergoing surveillance gastroscopies for the detection of esophageal varices or Barrett's esophagus, respectively. OBJECTIVES: To identify risk factors for GP growth and estimate its growth rate. METHODS: GP growth rate was defined as the number of days since the first gastroscopy (without polyps) in the surveillance program, until the gastroscopy when a GP was discovered. RESULTS: Gastric polyp growth rates in CLD and CRS patients were similar. However, hyperplastic gastric polyps (HGPs) were detected more often (87.5% vs. 60.5%, P = 0.051) and at a higher number (2.57 ± 1.33 vs. 1.65 ± 0.93, P = 0.021) in the CLD patients. Subgroup analysis revealed the following findings only in CLD patients with HGPs: (i) a positive correlation between the GP growth rate and the patient's age; the older the patient, the higher the GP growth rate (r = 0.7, P = 0.004). (ii) A negative correlation between the patient's age and the Ki-67 proliferation index value; the older the patient, the lower the Ki-67 value (r = -0.64, P = 0.02). No correlation was detected between Ki-67 values of HGPs in CLD patients and the presence of portal hypertension, infection with Helicobacter pylori, or proton pump inhibitor use. CONCLUSIONS: In comparison with CRS patients, CLD patients developed HGPs more often and at a greater number. Young CLD patients may have a tendency to develop HGPs at a faster rate than elderly CLD patients.

A Retrospective Comparison of Fecal Microbial Transplantation Methods for Recurrent Clostridium Difficile Infection.

BACKGROUND: Antibiotic treatment of Clostridium difficile infection (CDI) has a high failure rate. Fecal microbiota transplantation (FMT) has proven very effective in treating these recurrences. OBJECTIVES: To determine which method of fecal microbiota transplantation (upper or lower gastrointestinal) and which type of donor (a relative or unrelated) is superior. METHODS: This is a retrospective analysis of treatment protocols and outcomes in 22 patients with refractory or recurrent CDI who underwent FMT at two Israeli facilities. Each center used a different donor type, stool preparation and method of delivery. The Tel Aviv Sourasky Medical Center used unrelated fecal donors and frozen stool samples and delivered them primarily (92%) via the lower gastrointestinal (GI) tract. Shaare Zedek Medical Center used fresh donor stool of relatives and delivered them primarily (90%) via the upper GI tract. RESULTS: FMT had an overall 2 month cure rate of 89%. Patients treated with FMT that was executed through the lower GI tract recovered faster from the infection (1.6 ± 1.08 vs. 2.4 ± 1 days for the upper tract, P = 0.03). The results also showed that patients who received lower GI tract FMTs were more likely to be cured of CDI (100% vs. 75% for upper tract FMTs, P = 0.16). Five patients (22%) died of CDI/FMT-unrelated causes and two (10%) died of CDI/FMT-related causes during the study period. CONCLUSIONS: Lower GI tract FMT is a safe and effective treatment for refractory and recurrent CDI, and yields quicker results than upper GI tract FMT.

Intracardiac mass as initial cardiac manifestation of Behçet's disease: think before you cut.

Behçet's disease (BD) is a chronic multisystemic inflammatory disorder. Cardiac abnormalities including intracardiac thrombi have been described in up to 16% of cases. The clinical presentation of cardiac complications in BD may include fever, dyspnea, chest pain, hemoptysis, and edema. We present 2 cases of patients who underwent surgical excision of intracardiac masses thought to be intracardiac malignancies. Further pathological and clinical evaluation established intracardiac inflammatory masses due to BD as the final diagnosis. As intracardiac masses may be the presenting manifestation of BD, it is crucial for echocardiographers to consider BD in the differential diagnosis. A careful history and physical exam looking for signs and symptoms of BD is critical before considering surgical excision of unexplained intracardiac masses. If the final diagnosis is BD anti-inflammatory therapy should be considered the basis of treatment.

Conditioning by a Previous Experience Impairs the Rewarding Value of a Comfort Meal.

BACKGROUND: Meal ingestion induces a postprandial experience that involves homeostatic and hedonic sensations. Our aim was to determine the effect of aversive conditioning on the postprandial reward of a comfort meal. METHODS: A sham-controlled, randomised, parallel, single-blind study was performed on 12 healthy women (6 per group). A comfort meal was tested before and after coupling the meal with an aversive sensation (conditioning intervention), induced by infusion of lipids via a thin naso-duodenal catheter; in the pre- and post-conditioning tests and in the control group, a sham infusion was performed. Participants were instructed that two recipes of a tasty humus would be tested; however, the same meal was administered with a colour additive in the conditioning and post-conditioning tests. Digestive well-being (primary outcome) was measured every 10 min before and 60 min after ingestion using graded scales. RESULTS: In the aversive conditioning group, the comfort meal in the pre-conditioning test induced a pleasant postprandial experience, which was significantly lower in the post-conditioning test; the effect of aversive conditioning (change from pre- to post-conditioning) was significant as compared to sham conditioning in the control group, which showed no differences between study days. CONCLUSION: The hedonic postprandial response to a comfort meal in healthy women is impaired by aversive conditioning. CLINICALTRIALS: gov ID: NCT04938934.

Reversal of Conditioned Food Aversion Using a Cognitive Intervention: A Sham-Controlled, Randomized, Parallel Study.

BACKGROUND: Aversive conditioning weakens the gratifying value of a comfort meal. The aim was to determine the effect of a cognitive intervention to reverse aversive conditioning and restore hedonic postprandial response. METHODS: This was a randomized, sham-controlled, single-blind, parallel study that was conducted on 12 healthy women (n = 6 in each group). The reward value of a comfort meal was measured on different days: at initial exposure, after aversive conditioning (administration of the same meal with a masked fat overload on the previous day) and after a cognitive intervention (disclosing the aversive conditioning paradigm in the test group vs. no explanation in the control group). The primary outcome, digestive wellbeing, was determined using graded scales at regular intervals before and after ingestion. RESULTS: At initial exposure, the comfort meal produced a rewarding experience that was impaired using aversive conditioning; upon re-exposure to the original meal, the cognitive intervention increased meal wanting and liking; improved digestive wellbeing and mood; tended to reduce postprandial satiety, bloating/fullness; and abolished discomfort/pain, thereby restoring the hedonic value of the comfort meal. By contrast, sham intervention had no effects, and the postprandial sensations remained like the responses to the offending meal. CONCLUSION: In this proof-of-concept study, we demonstrate that in healthy women, a mild, short-term acquired aversion to a comfort meal can be reversed using a cognitive intervention. CLINICALTRIALS: gov ID: NCT05897411.

Evaluation of abdominal gas by plain abdominal radiographs.

BACKGROUND: Our aim was to determine the reliability of plain abdominal radiographs for the evaluation of abdominal gas content in patients with functional digestive symptoms. METHODS: Abdominal CT scan scout views, mimicking a conventional plain abdominal radiograph, were obtained from 30 patients both during episodes of abdominal distension and basal conditions. Physicians (n = 50) were instructed to rate the estimated volume of gas in the 60 images presented in random sequence using a scale graded from 0 to ≥600 ml. KEY RESULTS: The gas volumes estimated in the scout views differed from those measured by CT by a median of 90 (95% CI 70-102) ml, and the misestimation was not related to the absolute volume in the image. The accuracy of the observers, measured by their mean misestimation, was not related to their specialty or the training status (misestimation by 96 (95% CI 85-104) ml in staff vs 78 (70-106) ml in residents; p = 0.297). The accuracy was independent of the order of presentation of the images. Gas volume measured by CT in the images obtained during episodes of abdominal distension differed by a median of 39 (95% CI 29-66) ml from those during basal conditions, and this difference was misestimated by a median of 107 (95% CI 94-119) ml. The accuracy of these estimations was not related to the absolute gas volumes (R = -0.352; p < 0.001) or the magnitude of the differences. CONCLUSIONS & INFERENCES: Plain abdominal radiographs have limited value for the evaluation of abdominal gas volume in patients with functional gut disorders.

Effect of colonic distension on small bowel motility measured by jejunal high-resolution manometry.

BACKGROUND: Abnormal motility patterns in the jejunum can be detected in patients with prominent colonic content, and these abnormalities may be due to either a primary jejunal dysfunction or a reflex distortion. The objective of the present study was to determine the effect of colonic distension on small bowel postprandial motility using high-resolution manometry. METHODS: Single center, controlled, parallel, randomized, single blind study in healthy subjects testing the effect of colonic filling vs sham infusion on the responses to a meal in 16 healthy subjects. Nutrients were continuously infused in the proximal jejunum (2 Kcal/min) during the 2-h study period to induce a steady-state postprandial motor pattern. Jejunal motility was measured by water-perfused, high-resolution manometry. After 1 h postprandial recording (basal period), gas was infused during 7.5 min via a rectal tube (720 mL or sham infusion), and jejunal motility was recorded for another hour. KEY RESULTS: Jejunal postprandial motility during the basal period was characterized by two overlapping components: a) continuous segmental activity (non-propagated or shortly propagated) and b) intercurrent propagated fronts (3.8 ± 1.1 fronts of 2-5 clustered contractions/h >10 cm propagation). As compared to sham infusion, colonic gas filling: a) inhibited continuous segmental contractile activity (by 17 ± 4%; p = 0.044 vs control group) and b) stimulated intermittent propagated fronts (up to 9.0 ± 2.2 fronts/h; p = 0.017 vs control group). CONCLUSIONS AND INFERENCES: Long retrograde reflexes induced by colonic distension distort the balance between segmental and propagated activity, and may affect the normal response of the jejunum to food ingestion. Jejunal manometry in patients may be artifacted by colonic overload.

Gastrointestinal Contributions to the Postprandial Experience.

Food ingestion induces homeostatic sensations (satiety, fullness) with a hedonic dimension (satisfaction, changes in mood) that characterize the postprandial experience. Both types of sensation are secondary to intraluminal stimuli produced by the food itself, as well as to the activity of the digestive tract. Postprandial sensations also depend on the nutrient composition of the meal and on colonic fermentation of non-absorbed residues. Gastrointestinal function and the sensitivity of the digestive tract, i.e., perception of gut stimuli, are determined by inherent individual factors, e.g., sex, and can be modulated by different conditioning mechanisms. This narrative review examines the factors that determine perception of digestive stimuli and the postprandial experience.

Abdominothoracic Postural Tone Influences the Sensations Induced by Meal Ingestion.

Postprandial objective abdominal distention is frequently associated with a subjective sensation of abdominal bloating, but the relation between both complaints is unknown. While the bloating sensation has a visceral origin, abdominal distention is a behavioral somatic response, involving contraction and descent of the diaphragm with protrusion of the anterior abdominal wall. Our aim was to determine whether abdominal distention influences digestive sensations. In 16 healthy women we investigated the effect of intentional abdominal distention on experimentally induced bloating sensation (by a meal overload). Participants were first taught to produce diaphragmatic contraction and visible abdominal distention. After a meal overload, sensations of bloating (0 to 10) and digestive well-being (-5 to + 5) were measured during 30-s. maneuvers alternating diaphragmatic contraction and diaphragmatic relaxation. Compared to diaphragmatic relaxation, diaphragmatic contraction was associated with diaphragmatic descent (by 21 + 3 mm; p < 0.001), objective abdominal distension (32 + 5 mm girth increase; p = 0.001), more intense sensation of bloating (7.3 + 0.4 vs. 8.0 + 0.4 score; p = 0.010) and lower digestive well-being (-0.9 + 0.5 vs. -1.9 + 0.5 score; p = 0.028). These results indicate that somatic postural tone underlying abdominal distention worsens the perception of visceral sensations (ClinicalTrials.gov ID: NCT04691882).

Beta-glycoglycosphingolipid-induced alterations of the STAT signaling pathways are dependent on CD1d and the lipid raft protein flotillin-2.

Beta-glucosylceramide has been shown to affect natural killer T cell function in models of inflammation. We, therefore, investigated the effects of different beta-glycosphingolipids, including beta-glucosylceramide, on STAT (signal transducers and activators of transcription) signaling pathways and determined whether these effects were mediated by lipid raft microdomains and/or CD1d molecules. The effects of alpha- and beta-structured ligands on the lipid raft protein flotillin-2 were studied in both natural killer T hybridoma cells and leptin-deficient mice. To determine whether CD1d was involved in the effects of the beta-glycosphingolipids, an anti-CD1d blocking antibody was used in a cell proliferation assay system. The downstream effects on the protein phosphorylation levels of STAT1, STAT3, and STAT6 were examined in both immune-mediated hepatitis and hepatoma models. The effects of beta-glycosphingolipids on the STAT signaling pathways were found to be dependent on CD1d. Lipid rafts were affected by both the dose and ratio of the beta-glycosphingolipids and the acyl chain length, and these effects were followed by downstream effects on STAT proteins. Our results show that beta-glycosphingolipids have beneficial effects in natural killer T cell-dependent immune-mediated metabolic and malignant animal models in vivo.

Food, Eating, and the Gastrointestinal Tract.

Food ingestion induces a metered response of the digestive system. Initially, the upper digestive system reacts to process and extract meal substrates. Later, meal residues not absorbed in the small bowel, pass into the colon and activate the metabolism of resident microbiota. Food consumption also induces sensations that arise before ingestion (e.g., anticipatory reward), during ingestion (e.g., gustation), and most importantly, after the meal (i.e., the postprandial experience). The postprandial experience involves homeostatic sensations (satiety, fullness) with a hedonic dimension (digestive well-being, mood). The factors that determine the postprandial experience are poorly understood, despite their potential role in personalized diets and healthy eating habits. Current data suggest that the characteristics of the meal (amount, palatability, composition), the activity of the digestive system (suited processing), and the receptivity of the eater (influenced by multiple conditioning factors) may be important in this context.

Sex Differences and Commonalities in the Impact of a Palatable Meal on Thalamic and Insular Connectivity.

The neural mechanisms underlying subjective responses to meal ingestion remain incompletely understood. We previously showed in healthy men an increase in thalamocortical, and a decrease in insular-cortical connectivity in response to a palatable meal. As sex is increasingly recognized as an important biological variable, we aimed to evaluate sex differences and commonalities in the impact of a well-liked meal on thalamic and anterior insular connectivity in healthy individuals. Participants (20 women and 20 age-matched men) underwent resting-state magnetic resonance imaging (rsMRI) before and after ingesting a palatable meal. In general, the insula showed extensive postprandial reductions in connectivity with sensorimotor and prefrontal cortices, while the thalamus showed increases in connectivity with insular, frontal, and occipital cortices, in both women and men. However, reductions in insular connectivity were more prominent in men, and were related to changes in meal-related sensations (satiety and digestive well-being) in men only. In contrast, increases in thalamic connectivity were more prominent in women, and were related to changes in satiety and digestive well-being in women only. These results suggest that brain imaging may provide objective and sex-specific biomarkers of the subjective feelings associated with meal ingestion.