People with longCOVID, where symptoms persist after recovery from an acute Covid-19 infection, may have distinct differences in the mix of bacteria living in their mouths and lungs, research has shown.
The participants were divided into four groups based on how bad their symptoms were five months after being discharged from hospital, ranging from ‘very severe’ with serious physical, mental, and cognitive impairments to ‘mild’, with few symptoms and good recovery. Six months after hospital discharge, samples were collected from patients’ mouths through saliva and from their lungs through sputum. DNA sequencing was used to identify the microbes present.
The study examined 771 people treated for Covid-19 at one of 38 UK hospitals between February 2020 and March 2021.
The differences in the lung microbiome are linked to respiratory symptoms, as well as the cognitive and digestive problems known to occur in longCOVID, researchers said. The findings, published in the European Respiratory Journal , may contribute towards understanding why some people develop long COVID and point to new ways to treat the condition, they said. “Prior studies have shown some changes in the gut microbiome with long COVID, but Covid is a lung disease and so it makes sense to look to see if the lung microbiome is changed in long COVID,” lead author Daniela Alferes de Lima Headley from the University of Dundee, UK, said. Lead researcher James Chalmers, chair of respiratory research at the University of Dundee, UK, said, “People who had the worst symptoms five to six months after COVID infection had big changes in the microbiome in their mouth and lungs.”
