Figure 1.

Possible mechanism of action of glutamine on cognition and mood. Hypoxia from high altitude, through inflammation, can affect neurotransmitters activity in the brain, worsening mood and cognition. Moreover, hypoxia can negatively affect the gut–brain axis by dysregulation of gut microbiota and or immune cells in the gut. The increase in the glutamine–glutamate ratio favors excitatory activity, which may improve mood and cognition. Moreover, glutamine could improve the intestinal barrier by immune cells and balance the gut microbiota.