Аннотация:The digestive system is the only way of nutrients entry into the body andone of the first to appear evolutionally. At rest, it receives roughly 25 % of the cardiac output. The gastrointestinal tract (GIT) hosts the commensal bacteria, which help to extract or synthesise nutrients, interact with the immune system, and affect diverse physiological functions via their metabolites. Despite plenty of studies of GIT function on the ground, much less is known about GIT adaptation to the conditions of spaceflight.Microgravity and other spaceflight factors exert a complex action on thegastrointestinal system and the mesenteric vasculature, which might lead to gastrointestinal disorders, especially in long-term flights. Interpretation of human data is complicated by heterogeneity of the subjects, diet, and the use of countermeasures, while analysis of gastrointestinal function in space-flown animals is often limited to in vitro tests. Thus, animal studies in the standard laboratory setting are needed to investigate microgravity effects on GIT. Hindlimb unloading is used to simulate microgravity effects in rodents. Here we report the dynamics of functional and morphological changes in the murine intestine over 30-days of hindlimb unloading and 7-day recovery.