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Scientists offer a new explanation for long COVID

In some patients, remnants of the coronavirus in the gut may stifle production of serotonin, an important neurotransmitter, researchers suggest.
Scientists offer a new explanation for long COVID
Posted at 5:59 PM, Oct 17, 2023

Researchers from the University of Pennsylvania have found that COVID-19 virus particles can stay in the intestinal tract long after infection for some people. The virus induces an inflammatory response, and that inflammatory response leads to reduced levels of serotonin.

"One thing to know about serotonin, even in the peripheral system, is it has widespread effects on many different organ systems," said Dr. Benjamin Abramoff, the Post-COVID Assessment and Recovery Clinic director at the University of Pennsylvania.

Serotonin is a chemical messenger between the brain and body. It impacts functions like blood clots and body temperature regulation, mood, sleep and memory.

"It may have an impact on things like autonomic dysfunction, when people have either they're feeling like their heart is racing or they have trouble going from laying down to standing up," said Abramoff. 

"The next steps would be, of course, to get a better, deeper mechanistic understanding of what exactly is going on in between the gut and the brain and the other symptoms," said Maayan Levy, an assistant professor of microbiology at the University of Pennsylvania.

UPenn researchers say they will also look to study Prozac, part of a class of drugs called SSRIs that raise serotonin levels in the brain.

"Long COVID seems to come in a variety of forms. There are the people who have lost their taste and smell. There are the brain fog folks. Then there are aches and pains and disruption of function of the lungs and maybe other organ systems," said Dr. William Schaffner, an infectious disease physician at Vanderbilt University. 

Long COVID, also known as post-COVID remains something doctors diagnose by ruling out other illnesses. There is no cure, but they can treat the symptoms.

This summer, an international research initiative identified 73 genes associated with long COVID development. And in late September, scientists from Mount Sinai and Yale announced they had Identified biomarkers in the blood and found clear differences in immune and hormone function in long haul patients. 

SEE MORE: Long COVID is a thing. What about long colds?

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