Effects of Spaceflight on the Human Gastrointestinal Tract Microbiome

Space travel has been shown to affect various physiological and psychological processes in humans including the composition and function of the gut microbiome. In addition to the unique conditions of space, space travel is associated with changes in diet, circadian and diurnal rhythms, and physical activity, all of which can impact the gut microbiome. Additionally, the microgravity and radiation exposure encountered during space travel may have direct effects on gut microbiome composition and function. In this short review, we summarize the current state of knowledge on the effect of space travel on the human gut microbiome, including research designs that include animals (rodents), humans, and novel simulations. Experiments were conducted under conditions of spaceflight, ground-based, and analogous flight simulation.