Does the appearance of the Magenstrasse depend on the amount of water consumed?

Abstract

The Magenstrasse (stomach road) is a phenomenon describing the rapid evacuation of water drunken after a solid meal from the stomach. So far, its existence has been demonstrated for water volumes of 150 mL or more. The aim of this three-arm, randomised, cross-over, 12-subject study was to investigate whether the Magenstrasse is also present for smaller water volumes. For this purpose, gastric emptying of 50, 100 or 150 mL of water that was administered after a light meal was determined using MR imaging. With each dose of water, a fast-dissolving compression coated tablet containing caffeine and iron oxide as well as a hard capsule containing stable isotope labelled caffeine and medium-chain triglycerides were administered. This made it possible to determine the initial localization of the respective forms in the stomach on MR images as a function of the amount of water drunk, and also to determine the emptying rates of the two caffeine variants using saliva samples that were obtained in the study and quantified using LC-MS/MS. Gastric emptying of the ingested water was rapid and usually completed after approximately 20 min, regardless of the applied volume. In contrast to the consumed water, gastric emptying of natural caffeine and stable isotope labelled caffeine was delayed. The capsule usually floated on liquid and chyme, whereas the compression coated tablet was often embedded in chyme.

Keywords: Capsule; Food effect; Gastric emptying; MRI; Magenstrasse; Saliva; Stomach road; Tablet; Water.

Graphical abstract

Fig. 1

A: Absolute gastric content volume of the three study arms. Dashed line indicates the time point of water ingestion. B: ΔGCV of the three study arms. The dashed black line is indicating a gastric content volume of 0 mL and the dashed red lines indicate the time span used for linear regression to obtain background chyme emptying gastric fluid secretion. C: ΔGWV of the three study arms. The black dashed line is indicating a GWV of 0 mL. D: Fraction of water emptied from the stomach. N = 12, mean ± SD. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 2

A: Baseline corrected salivary caffeine concentration from the compression-coated tablet in the three study arms. B: Baseline corrected salivary ¹³C₃-caffeine concentration from the capsule in the three study arms. N = 12, mean + SD.

Fig. 3

Example images for the localisation of the iron oxide labelled tablet in the HASTE-sequences and the MCT-labelled capsule in the Dixon-VIBE-sequences (fat images). The red (tablet) and yellow (capsule) arrow indicate the location at time point t = 4 min for P01 and P09. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 4

Comparison of the gastric emptying of water observed with MRI, caffeine from a compression-coated tablet and ¹³C₃-caffeine from a hard-gelatine capsule using saliva samples. A: 50 mL. B: 100 mL. C: 150 mL. N = 12, mean + SD.