6°头低位倾斜卧床试验模拟的微重力增加肠道动力，但未能诱发空间运动病的胃肠道症状。

Microgravity Simulated by the 6° Head-Down Tilt Bed Rest Test Increases Intestinal Motility but Fails to Induce Gastrointestinal Symptoms of Space Motion Sickness.

作者信息

Prakash Meher, Fried Ron, Götze Oliver, May Francisca, Frings-Meuthen Petra, Mulder Edwin, Valentini Judit, Fox Mark, Fried Michael, Schwizer Werner, Misselwitz Benjamin

机构信息

Division of Gastroenterology and Hepatology, University Hospital Zurich and Zurich University, Rämistr. 100, 8091, Zurich, Switzerland.

Division of Hepatology, Department of Medicine II, University Hospital Würzburg, Würzburg, Germany.

出版信息

Dig Dis Sci. 2015 Oct;60(10):3053-61. doi: 10.1007/s10620-015-3738-1. Epub 2015 Jun 9.

DOI:10.1007/s10620-015-3738-1

PMID:26055239

Abstract

BACKGROUND

Space motion sickness (SMS) is the most relevant medical problem during the first days in microgravity. Studies addressing pathophysiology in space face severe technical challenges and microgravity is frequently simulated using the 6° head-down tilt bed rest test (HDT).

AIM

We were aiming to test whether SMS could be simulated by HDT, identify related changes in gastrointestinal physiology and test for beneficial effects of exercise interventions.

METHODS

HDT was performed in ten healthy individuals. Each individual was tested in three study campaigns varying by a 30-min daily exercise intervention of either standing, an upright exercise regimen, or no intervention. Gastrointestinal symptoms, stool characteristics, gastric emptying time, and small intestinal transit were assessed using standardized questionnaires, (13)C octanoate breath test, and H2 lactulose breath test, respectively, before and at day 2 and 5 of HDT.

RESULTS

Individuals described no or minimal gastrointestinal symptoms during HDT. Gastric emptying remained unchanged relative to baseline data collection (BDC). At day 2 of HDT the H₂ peak of the lactulose test appeared earlier (mean ± standard error for BDC-1, HDT2, HDT5: 198 ± 7, 139 ± 18, 183 ± 10 min; p: 0.040), indicating accelerated small intestinal transit. Furthermore, during HDT, stool was softer and stool mass increased (BDC: 47 ± 6, HDT: 91 ± 12, recovery: 53 ± 8 g/day; p: 0.014), indicating accelerated colonic transit. Exercise interventions had no effect.

CONCLUSION

HDT did not induce symptoms of SMS. During HDT, gastric emptying remained unchanged, but small and large intestinal transit was accelerated.

摘要

背景

太空晕动病（SMS）是微重力环境下最初几天最相关的医学问题。研究太空病理生理学面临严峻的技术挑战，微重力环境常通过6°头低位卧床试验（HDT）来模拟。

目的

我们旨在测试HDT是否能模拟SMS，识别胃肠道生理学的相关变化，并测试运动干预的有益效果。

方法

对10名健康个体进行HDT。每个个体在三个研究阶段接受测试，三个阶段的区别在于每天有30分钟的运动干预，分别为站立、直立运动方案或无干预。在HDT前、第2天和第5天，分别使用标准化问卷、（13）C辛酸呼气试验和H2乳果糖呼气试验评估胃肠道症状、粪便特征、胃排空时间和小肠转运情况。

结果

个体在HDT期间未描述有胃肠道症状或仅有轻微症状。胃排空相对于基线数据收集（BDC）保持不变。在HDT第2天，乳果糖试验的H₂峰值出现得更早（BDC - 1、HDT2、HDT5的平均值±标准误：198±7、139±18、183±10分钟；p：0.040），表明小肠转运加快。此外，在HDT期间，粪便更软且粪便量增加（BDC：47±6，HDT：91±12，恢复：53±8克/天；p：0.014），表明结肠转运加快。运动干预没有效果。