Although the coronavirus is supposedly a “respiratory” virus, this is clearly not just a lung pathogen as it also affects the gut.

Patients with digestive symptoms and the coronavirus appeared to be tied to worse outcomes. Whereas 60% of patients without digestive symptoms recovered and were discharged, only 34.3% of the patients with digestive symptoms recovered.

The HOW…in the GUT

The virus gets into saliva and gets swallowed or inhaled. It lingers in the throat (pharynx) which explains why the patient often gets a sore throat. From here the virus could either go into the lungs or to the oesophagus. 

The virus somehow gets passed the highly acidic stomach (pH 1.5-3.5) where one of the roles is to kill microbes. The virus binds onto a receptor called angiotensin-converting enzyme 2 (ACE2) receptor.  These ACE2 receptors are specific protein structure that sit on the barrier (epithelial) cells that line the intestine. The virus gets into the intestinal tract and replicates rapidly in the cells of the gut lining. This causes cell damage and loosens the normally impenetrable barrier that keeps bacteria inside the intestine. 

So, now you have a “leaky gut” which allows bacteria and bacterial products (aka lipopolysaccharide LPS) to translocate, this in turn trigger a whole cascade of inflammatory response 

Thinking out loud, my two-cent worth opinion…this might explain why an anti-bacterial like Azithromycin would work in a viral infection. There’s a study showing treatment to be more effective when Azithromycin was combined with hydroxychloroquine (see previous posts). Because it is destroying the bacterial-viral soup? I don’t know, I’m only speculating. 

In the LUNGS…

The ACE2 receptors are also in the lungs. ACE2 has a protective role in acute lung failure. So when these virus comes along and binds to the receptors of ACE2, it reduces the role of ACE2, therefore causing severe and often lethal lung failure.

Some of the patients might only have gut symptoms or mild respiratory complaints.

Dr. Brennan M.R. Spiegel, Editor-in-Chief of The American Journal of Gastroenterology explained that some of the patients might only have gut symptoms or mild respiratory complaints and not think that they could have the coronavirus.

Spiegel urges caution in evaluating patients with only gut symptoms. “A large part of the population has diarrhea, abdominal pain, nausea, and vomiting regularly, so it’s clearly impossible and irresponsible to start testing everyone with diarrhea for COVID-19. But if somebody has new fever and diarrhea and suspects they may have had contact with a patient or carrier, I’d want to test them.”