Bacteria to Assess and Correct Neurotransmitter Imbalances in the Gut? The Future Looks Promising

Today a quick note about a novel and seriously interesting bit of research. As many of you likely know, your gut bacteria are responsible for synthesizing much of your neurotransmitters. For example, 95% of the serotonin in your body is produced in your digestive system. Too much or too little of certain bacteria means too much or too little of these chemicals that are responsible for the normal functioning of the brain. Dysbiosis can, therefore, lead to mental health issues.

Dr. Tae Seok Moon, a professor at Washington University in St. Louis, is working on a fix by genetically engineering bacteria that can – amazingly – monitor chemical production from inside a person and correct any imbalances.[i]  What, you exclaimt?!  That’s not possible!  That’s the stuff of science fiction! But, believe it or not, Dr. Moon has already had a success:  he has engineered bacteria that can sense temperature, pH, oxygen levels, light, pollutants and other toxic chemicals.  “Specific and accurate quantification of chemical concentrations allows for adaptive regulation of enzymatic pathways and temporally precise expression of diagnostic reporters.”[ii]

The upshot of this new paper: Dr. Moon has created Escherichia coli Nissle 1917 (EcN) bacterium, which can discriminate between phenylalanine (Phe) and tyrosine (Tyr), which are two structurally similar molecules that are associated with the disorders (PKU) and type 2 tyrosinemia, respectively.  He is now working on an “actuator” which is a protein that will act based upon what the bacteria senses.  For example, in the case of PKU (a genetic disorder that causes babies to accumulate phenylalanine, as they lack the enzyme necessary to break it down), a sensor bacteria might be able to detect the levels of the amino acid, triggering the actuatory which will break the amino acid down.

This kind of bacteria, by the way, could also be used in the food industry, protecting us against poisons or toxins; in the pharmaceutical industry; or even in fields like the fuel industry. But for now, Dr. Moon is concentrating on humans:  “When this and other neurotransmitters are out of whack, a person can suffer greatly, Moon said. He wants to put an end to this suffering. ‘This is the beginning of our engineering solution.’’”

Well, amen to that.

Anyway, I find this a fascinating concept.  I’ll watch this space for more progress.  Stay tuned.

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[i] https://source.wustl.edu/2021/11/building-bacteria-to-keep-us-well/

[ii] Austin G. Rottinghaus, Chenggang Xi, Matthew B. Amrofell, Hyojeong Yi, Tae Seok Moon. Engineering ligand-specific biosensors for aromatic amino acids and neurochemicals. Cell Systems, 2021; DOI: 10.1016/j.cels.2021.10.006