Therapeutic Role of Probiotics in Gut-Brain Axis Under Microgravity

Microgravity is a state of free fall which one experiences in space. Human-crewed missions are becoming more sophisticated in the ongoing times. The altered gravitational conditions exert several physiological changes in the astronauts. Among many, one of the significantly affected systems and least discussed so far is the neurological system. Earlier studies have shown that exposure to space condition leads to structural changes in the brain, including distorted neurons and apoptotic astrocytes. Recent studies show the velocity of the action potential is reduced. Hippocampal activity is disrupted leading to cognitive impairment. Neuro ocular change occurs in some astronauts. Probiotics like Bacillus coagulans and Lactobacillus sp. connect gut-brain axis. Several probiotics are effective in treating neurological structural disorders. To sum up, in orbital exploration, astronauts face challenges of cosmic radiation and microgravity, impacting neuronal morphology. Chronic low-dose X-ray exposure delays neurite outgrowth and induces apoptosis. Simulated microgravity intensifies these effects, causing a significant increase in late apoptotic neurons. Astrocytes exposed to microgravity undergo apoptosis, but surviving cells adapt. Microgravity induces cellular senescence in rat cells, mimicking aging. NASA Twin Study reveals cognitive declines post-microgravity. Probiotics show therapeutic potential in neurological disorders, influencing gene expression and apoptotic proteins. They alleviate neurodegeneration and delay senescence, emphasizing their role in neurological well-being. In this review we discuss baseline data in this area since few laboratories has started working on the effect of nanoparticles on probiotics under microgravity. This review would help us and others interested in this field worldwide to work cohesively in future.

Graphical Abstract