Impacts of microgravity on amino acid metabolism during spaceflight

Spaceflight exerts an extreme and unique influence on human physiology as astronauts are subjected to long-term or short-term exposure to microgravity. During spaceflight, a multitude of physiological changes, including the loss of skeletal muscle mass, bone resorption, oxidative stress, and impaired blood flow, occur, which can affect astronaut health and the likelihood of mission success. In vivo and in vitro metabolite studies suggest that amino acids are among the most affected nutrients and metabolites by microgravity (a weightless condition due to very weak gravitational forces). Moreover, exposure to microgravity alters gut microbial composition, immune function, musculoskeletal health, and consequently amino acid metabolism. Appropriate knowledge of daily protein consumption, with a focus on specific functional amino acids, may offer insight into potential combative and/or therapeutic effects of amino acid consumption in astronauts and space travelers. This will further aid in the successful development of long-term manned space mission and permanent space habitats.

Automated summary

Spaceflight has significant impacts on human physiology, particularly in terms of skeletal muscle loss, bone resorption, oxidative stress, impaired blood flow, and altered gut microbial composition. Amino acids, as fundamental nutrients and metabolites, are highly affected by microgravity. By understanding the importance of daily protein consumption and specific functional amino acids, potential combative and therapeutic effects of amino acid intake can be explored, leading to the successful development of long-term manned space missions and permanent space habitats.