The effect of space flight on the health of astronauts’ cardiovascular system

Weightlessness in space alters the structure of the heart and the size of its chambers. In addition, exposure to radiation in space can accelerate the onset of Arteriosclerosis (hardening of the arteries) and even cause vascular calcification. Therefore candidates for space travel are required to undergo comprehensive medical examinations of their cardiovascular system. This is an area in which we have already gained experience.

Innovative molecular technologies enable us to identify various states of health in the human body. By thorough examination of biological samples (blood, saliva, urine and stool), we have discovered that a large percentage of the biological materials (metabolites) in the blood stream are the product of bacteria from the microbiome (the total population of bacteria in the human digestive system). The microbiome changes due to being in space and nutritional changes in space. As a result, we expect that the metabolites in the blood of the astronauts flying to space are going to change.

In recent years we have created one of the largest databases in the world comparing cardiac patients with healthy people. Through mathematical models and machine learning, we have characterized metabolic pathways mediated by the gut bacteria, and which are related to the cardiovascular system, which so far have not been known. In the study we are about to conduct in Beilinson Hospital, together with the Weizmann Institute, we will be studying on the astronauts these metabolic pathways we have discovered in “regular” people who are not flying to space. Our research plan is to construct a precise personal metabolic map for each astronaut, based on the microbiome and metabolites from biological samples we will be collecting from the astronauts at various points in time before and after the flight. This metabolic map is going to enable us to assess the change in cardiovascular risk for each astronaut following space flight, and thereby to gain a more comprehensive, precise understanding of the effect of the stay in space on the cardiovascular system.
This is a groundbreaking study and we are grateful for the opportunity we've been given to collaborate with the Rakia project and Eytan Stibbe, the second Israeli in space.