Does the lung microbiome affect COVID severity?

Listener Joanne had this question, which Chris Smith put to microbiome expert Rob Finn...

Rob - To be honest with you we don't know at the moment, it's very difficult. So we do see some changes between individuals who are asymptomatic and symptomatic, or don't even have coronavirus, but usually people who do actually display symptoms, they're receiving other treatments. And it's really hard to tell -  are those treatments changing the microbiome? Or is it the fact that you've got an altered microbiome that has actually caused you to be symptomatic? So I would say that this is a really interesting research area. The lung microbiome is much harder to tackle than the human gut where stool is used. And so I think that's certainly an area for ongoing research in the future.

Chris - Is there actually a very big assemblage of organisms right deep down in your lungs? Or is the air and the airways right down there relatively clean and most of the bugs are in the back of your throat?

Rob - There is definitely a lung microbiome but it's nowhere near as complex, so the assemblage is much simpler and there are just fewer in terms of number. I mean, we know that your lung microbiome plays a key role in other diseases, so there are things like inflammatory diseases like COPD - the chronic obstructive pulmonary disease - is really a key area where lung microbiome has been implemented. So it definitely plays a role in some inflammatory disease, but with the COVID data it's just not sufficient for us to really draw concrete conclusions yet.