Scientists at UPenn believe they’ve discovered the REAL cause of long Covid

Scientists think they may have finally discovered the real cause of long Covid.

Researchers from the University of Pennsylvania found patients with the lingering condition have two things in common.

They have remnants of the virus in their gut and lower levels of the ‘feel good’ hormone serotonin.

While serotonin is often thought of in the context of the brain, 95 percent of the body’s serotonin is actually produced in the gut.

And other than mood, it plays a crucial role in sleep, digestion, nausea, wound healing, bone health, blood clotting and libido – all of which have been affected in one way or another in long Covid patients.

Researchers from the University of Pennsylvania based their new explanation on their previous findings that serotonin levels were lower in people with the complex condition

The scientists studied the blood of 58 patients suffering from long Covid for up to 22 months after their infection.

They compared this to the blood of 30 people who had no symptoms after their infection and 60 people in the early, most severe stage of Covid.

Maayan Levy, one of the study’s lead authors, told the New York Times that the amount of serotonin and other substances in the body changed right after infection with Covid, which also happens straight after other viral infections.

In the long Covid group, serotonin was the only important molecule that did not return to pre-infection levels.

The researchers also examined stool samples from some of the long Covid patients and discovered they contained remaining particles of the virus.

Viral ‘leftovers’ trigger the immune system to release infection-fighting proteins known as interferons.

These cause inflammation that lowers the body’s ability to take in tryptophan, an amino acid that helps generate serotonin in the gut.

In addition, blood clots can form after a coronavirus infection, which might hinder how well the body can circulate serotonin.

Below-normal serotonin levels play havoc with the vagus nerve system, which sends signals between the brain and body.

Serotonin also plays a part in short-term memory, so the researchers hypothesized that diminished serotonin could cause memory problems that are experienced with long Covid. 

The study was published Monday in the journal Cell.

Long Covid is defined by the World Health Organization as the development of new virus-related symptoms three months after the initial Covid infection. 

These symptoms can last from months to years, with doctors often puzzled over what is causing them.

The condition includes a wide range of symptoms, such as shortness of breath, brain fog and fatigue, and depression.

The Centers for Disease Control and Prevention (CDC) estimates that one in 13 US adults, or 7.5 percent, have long Covid.

But there is still serious debate about the true scale and severity of it. Several studies indicate that most people who develop the condition would suffer the common symptoms regardless of whether they had Covid.