Problems of space gastroenterology and microenvironment

Numerous studies have revealed changes in gastrointestinal secretion, motility, evacuation, and absorption in humans and animals after actual space missions and under hypokinesia of various duration as well. It is found that short-term space missions produce transient changes in the activity of digestive enzymes, instability of bifido- and lactoflora peculiar to stress reaction, and an enhanced evacuation of the stomach. Extended space missions result in more pronounced but transient changes which characterize mainly two states: development of a hypersecretory syndrome of the stomach and decrease in the functional capacity of the pancreas. As a rule, the changes of membranous enzymes are of compensatory-and-adaptive character. Concurrent with this, there occur disbiotic changes of various degree in the intestinal microflora.