Intraintestinal Delivery of Tastants Using a Naso-Duodenal-Ileal Catheter Does Not Influence Food Intake or Satiety

Intraduodenal activity of taste receptors reduces food intake. Taste receptors are expressed throughout the entire gastrointestinal tract. Currently, there are no data available on the effects of distal taste receptor activation. In this study, we investigate the effect of intraduodenal and/or intraileal activation of taste receptors on food intake and satiety. In a single-blind randomized crossover trial, fourteen participants were intubated with a naso-duodenal-ileal catheter and received four infusion regimens: duodenal placebo and ileal placebo (DPIP), duodenal tastants and ileal placebo (DTIP), duodenal placebo and ileal tastants (DPIT), duodenal tastants and ileal tastants (DTIT). Fifteen minutes after cessation of infusion, subjects received an ad libitum meal to measure food intake. Visual analog scale scores for satiety feelings were collected at regular intervals. No differences in food intake were observed between the various interventions (DPIP: 786.6 ± 79.2 Kcal, DTIP: 803.3 ± 69.0 Kcal, DPIT: 814.7 ± 77.3 Kcal, DTIT: 834.8 ± 59.2 Kcal, p = 0.59). No differences in satiety feelings were observed. Intestinal infusion of tastants using a naso-duodenal-ileal catheter did not influence food intake or satiety feelings. Possibly, the burden of the four-day naso-duodenal-ileal intubation masked a small effect that tastants might have on food intake and satiety

The potential role for impaired mucosal integrity in the generation of esophageal pain using capsaicin in humans: an explorative study

OBJECTIVES: Esophageal pain is mediated by sensory nerves, most importantly via the activation of the Transient Receptor Potential Vanilloid 1 (TRPV1) capsaicin receptor. TRPV1 is activated and sensitized by a broad range of pungent compounds, as well as inflammatory mediators and tissue irritants. Luminal stressors are suggested to impair the barrier function, which results in consequent activation of these sensory nerve terminals and pain. Here we investigated the effect of the perfusion of capsaicin, a TRPV1 agonist, on mucosal impedance and pain in asymptomatic volunteers. METHODS: Thirteen asymptomatic volunteers completed a single blind, saline-controlled, randomized crossover study. Capsaicin or saline was perfused for 30 min in the distal oesophagus. Visual Analogue Scale (VAS) pain intensity scores and intraluminal impedance indicating mucosal integrity were determined. Distal and proximal biopsies were obtained 10 min later to measure TRPV1 mRNA and Trpv1 immunopositivity, as well as the intercellular space area. RESULTS: Capsaicin perfusion resulted in significantly greater pain intensity (P=0.047) and impaired recovery of the mucosal impedance compared to saline-treated controls (P=0.027). Pain response was significantly associated with decreased mucosal impedance. Similar dynamics were seen in the proximal esophagus, but mucosal impedance recovered entirely to the pre-infusion values there. There was a significant association between mucosal impedance and intercellular space width in the distal esophagus. TRPV1 transcription and expression were not significantly altered within this observation period. DISCUSSION: Esophageal capsaicin perfusion results in pain, which is likely to be explained by impaired mucosal impedance and defective restoration capacity in the distal esophagus

The potential role for impaired mucosal integrity in the generation of esophageal pain using capsaicin in humans:an explorative study

INTRODUCTION: Esophageal pain is mediated by sensory nerves, most importantly by the activation of the transient receptor potential vanilloid 1 (TRPV1) capsaicin receptor. TRPV1 is activated and sensitized by a broad range of pungent compounds, as well as inflammatory mediators and tissue irritants. Luminal stressors are suggested to impair the barrier function, which results in consequent activation of these sensory nerve terminals and pain. In this study, we investigated the effect of the perfusion of capsaicin, a TRPV1 agonist, on mucosal impedance and pain in asymptomatic volunteers. METHODS: Thirteen asymptomatic volunteers completed a single-blind, saline-controlled, randomized crossover study. Capsaicin or saline was perfused for 30 minutes in the distal esophagus. Visual analog scale pain intensity scores and intraluminal impedance indicating mucosal integrity were determined. Distal and proximal biopsies were obtained 10 minutes later to measure TRPV1 messenger RNA and TRPV1 immunopositivity, as well as the intercellular space area. RESULTS: Capsaicin perfusion resulted in significantly greater pain intensity (P = 0.047) and impaired recovery of the mucosal impedance compared with saline-treated controls (P = 0.027). Pain response was significantly associated with decreased mucosal impedance. Similar dynamics were seen in the proximal esophagus, but mucosal impedance recovered entirely to the preinfusion values there. There was a significant association between mucosal impedance and intercellular space width in the distal esophagus. TRPV1 transcription and expression were not significantly altered within this observation period. DISCUSSION: Esophageal capsaicin perfusion results in pain, which is likely to be explained by impaired mucosal impedance and defective restoration capacity in the distal esophagus

The Effect of an Encapsulated Nutrient Mixture on Food Intake and Satiety: A Double-Blind Randomized Cross-Over Proof of Concept Study

Activation of the intestinal brake by infusing nutrients into the distal small intestine with catheters inhibits food intake and enhances satiety. Encapsulation of macronutrients, which protects against digestion in the proximal gastrointestinal tract, can be a non-invasive alternative to activate this brake. In this study, we investigate the effect of oral ingestion of an encapsulated casein and sucrose mixture (active) targeting the distal small intestine versus a control product designed to be released in the stomach on food intake, satiety, and plasma glucose concentrations. Fifty-nine volunteers received the active and control product on two separate test days. Food intake was determined during an ad libitum meal 90 min after ingestion of the test product. Visual analogue scale scores for satiety and blood samples for glucose analysis were collected at regular intervals. Ingestion of the active product decreased food intake compared to the control product (655 kcal compared with 699 kcal, respectively, p < 0.05). The area under the curve (AUC) for hunger was decreased (p < 0.05) and AUC for satiety was increased (p < 0.01) after ingestion of the active product compared to the control product. Ingestion of an encapsulated protein-carbohydrate mixture resulted in inhibition of food intake compared to a non-encapsulated control product

Effect of Vagus nerve integrity on short and long-term efficacy of antireflux surgery

OBJECTIVES:Vagus nerve injury is a feared complication of antireflux surgery (ARS) that may negatively affect reflux control. The aim of the present prospective study was to evaluate short-term and long-term impact of vagus nerve injury, evaluated by pancreatic polypeptide response to insulin-induced hypoglycemia (PP-IH), on the outcome of ARS.METHODS:In the period from 1990 until 2000, 125 patients with gastroesophageal reflux disease (GERD) underwent ARS at a single center. Before and 6 months after surgery, vagus nerve integrity testing (PP-IH), 24-h pH-monitoring, gastric emptying, and reflux-associated symptoms were evaluated. In 2014, 14-25 years after surgery, 110 patients were contacted again for evaluation of long-term symptomatic outcome using two validated questionnaires (Gastrointestinal Symptom Rating Scale (GSRS) and GERD-Health Related Quality of Life (HRQL)).RESULTS:Short-term follow-up: vagus nerve injury (PP peak ≤47 pmol/l) was observed in 23 patients (18%) 6 months after fundoplication. In both groups, a comparable decrease in reflux parameters and symptoms was observed at 6-month follow-up. Postoperative gastric emptying was significantly delayed in the vagus nerve injury group compared with the vagus nerve intact group. Long-term follow-up: patients with vagus nerve injury showed significantly less effective reflux control and a higher re-operation rate.CONCLUSIONS:Vagus nerve injury occurs in up to 20% of patients after ARS. Reflux control 6 months after surgery was not affected by vagus nerve injury. However, long-term follow-up showed a negative effect on reflux symptom control and re-operation rate in patients with vagus nerve injury

Effect of Vagus nerve integrity on short and long-term efficacy of antireflux surgery

OBJECTIVES:Vagus nerve injury is a feared complication of antireflux surgery (ARS) that may negatively affect reflux control. The aim of the present prospective study was to evaluate short-term and long-term impact of vagus nerve injury, evaluated by pancreatic polypeptide response to insulin-induced hypoglycemia (PP-IH), on the outcome of ARS.METHODS:In the period from 1990 until 2000, 125 patients with gastroesophageal reflux disease (GERD) underwent ARS at a single center. Before and 6 months after surgery, vagus nerve integrity testing (PP-IH), 24-h pH-monitoring, gastric emptying, and reflux-associated symptoms were evaluated. In 2014, 14-25 years after surgery, 110 patients were contacted again for evaluation of long-term symptomatic outcome using two validated questionnaires (Gastrointestinal Symptom Rating Scale (GSRS) and GERD-Health Related Quality of Life (HRQL)).RESULTS:Short-term follow-up: vagus nerve injury (PP peak ≤47 pmol/l) was observed in 23 patients (18%) 6 months after fundoplication. In both groups, a comparable decrease in reflux parameters and symptoms was observed at 6-month follow-up. Postoperative gastric emptying was significantly delayed in the vagus nerve injury group compared with the vagus nerve intact group. Long-term follow-up: patients with vagus nerve injury showed significantly less effective reflux control and a higher re-operation rate.CONCLUSIONS:Vagus nerve injury occurs in up to 20% of patients after ARS. Reflux control 6 months after surgery was not affected by vagus nerve injury. However, long-term follow-up showed a negative effect on reflux symptom control and re-operation rate in patients with vagus nerve injury