Glutamate and GABA (gamma-aminobutyric acid) are important neurotransmitters in the body. Neurotransmitters are chemical messengers that pass on electric impulses from one cell to another. Most neurotransmitters of the body are amino acids.
Neurotransmitters can either be excitatory or inhibitory based on the type of signals they transmit. A balanced firing of excitatory and inhibitory impulses is required for the brain to function appropriately. Glutamate controls the excitatory impulses, while GABA regulates the inhibitory impulses.
Role of Glutamate In the Gut-Brain Axis
Research has demonstrated a connection between the digestive tract and the brain, referred to as the gut-brain axis. This axis helps to coordinate and maintain gut functions while simultaneously modulating brain functions. Glutamate particularly plays an essential role in this axis.
Glutamate is present in the gut as a product of the digestion of dietary proteins, and food additives such as Monosodium Glu as well as seafood. However, dietary glutamate does not normally get absorbed into the brain. The functions of glutamate in the gut are as follows:
- Glutamate from diet partakes in the production of essential amino acids such as Proline, Arginine, Citrulline, and Glutathione.
- Glutamate is also needed for transmitting taste signals.
- In the esophagus and stomach, and intestine, Glutamate affects motility and the secretion of digestive juices.
Glutamate enhances gastric motility and could be used in conditions with gut dysmotility. However, glutamate has been implicated in worsening symptoms of irritable bowel disease and inflammatory bowel syndrome.
In the brain, glutamate helps in crucial functions such as learning, memory, behavior, and cognition. Ironically, it is toxic to nerve cells when present in the extracellular fluid, a phenomenon known as ‘excitotoxicity’.
As such, it is constantly being taken away from the ECF as soon as it is released by cells, and it plays a role in the pathogenesis of neurodegenerative diseases like motor neuron disease, Huntington’s disease, and Parkinson’s disease.
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