Stimulation of small intestinal burst activity in the postprandial state differentially affects lipid and glucose absorption in healthy adult humans

Abstract

Small intestinal motor activity is important for the optimal digestion and absorption of nutrients. These motor responses to feeding are frequently abnormal during critical illness, with the persistence of migrating bursts of contractions during enteral feeding. Whether this disturbance influences nutrient absorption is not known. In this study, the effects of small intestinal burst activity on lipid and glucose absorption were evaluated in 10 healthy human adults (6 males, 4 females, 19–47 yr). Upper gastrointestinal manometry was recorded for 6 h during and shortly after a 20-min intravenous infusion of either erythromycin (1 mg/kg), to stimulate burst activity, or saline (0.9%) in a double-blind randomized fashion. Simultaneously with the start of the intravenous infusion, 60 ml liquid feed mixed with 200 μl 13C-triolein and 2 g 3- O-methylglucose (3-OMG) was infused intraduodenally for 30 min. Absorption of lipid and glucose was assessed using the [13C]triolein breath test and plasma concentrations of 3-OMG, respectively. Infusion of erythromycin was followed by a more rapid onset of burst activity following commencement of the duodenal infusion compared with saline (30 ± 6.1 vs. 58 ± 10.7 min; P < 0.05). Erythromycin was associated with a slower recovery of 13CO2 ( P < 0.01). A positive correlation existed between the time to onset of burst activity and 13CO2 recovery ( P < 0.001). Erythromycin had no effect on 3-OMG absorption. In conclusion, stimulation of small intestinal burst activity reduces the rate of lipid absorption but not glucose absorption in healthy human adults.

Relationship between altered small intestinal motility and absorption after abdominal aortic aneurysm repair

“…Individual SI pressure waves were defined as a rise C6 mmHg from baseline of between 0.8 and 7 s duration [12]. A burst was defined as C10 pressure waves per minute for at least 2 min, migrating sequentially over C4 channels [12]. Changes in pressure due to physical strains were excluded.…”

“…Small intestinal lipid and glucose absorption were assessed by 13 C-triolein breath test [12,21] and 3-O-methylglucose (3-OMG) concentrations [12,21], respectively. The test meal was 60 ml Ensure Ò (21% fat, 20% protein, 59% carbohydrate with 1 kcal/ml; Abbott Australia, Kurnell, Australia) mixed with 200 ll [1,1,1-13 C3] triolein (99%, 200 mg; Cambridge Isotope Laboratories, USA) and 3 g 3-OMG (98%; Sigma-Aldrich, St Louis, MO, USA) [12,21].…”

“…The test meal was 60 ml Ensure Ò (21% fat, 20% protein, 59% carbohydrate with 1 kcal/ml; Abbott Australia, Kurnell, Australia) mixed with 200 ll [1,1,1-13 C3] triolein (99%, 200 mg; Cambridge Isotope Laboratories, USA) and 3 g 3-OMG (98%; Sigma-Aldrich, St Louis, MO, USA) [12,21].…”

“…After an overnight fast, the recording assembly was passed via an anaesthetised nostril into the stomach and hence intestine by peristalsis. A saline-filled 18-gauge intravenous cannula was inserted subcutaneously in a forearm for measurement of trans-mucosal potential difference (TPMD) [12,22]. Duodenal placement was confirmed by a TPMD reading C-15 mV at the most proximal manometric side-hole [17,22], ensuring the recording segment was [20 cm distal to the pylorus.…”

“…Both the number and length of pressure waves are important in transit [7][8][9] and absorption [10,11]. In healthy volunteers, artificially inducing phase III-like burst activity [12] accelerates transit [13] and impairs lipid, but not glucose, absorption [12].…”