The mouth-and-lung microbes may explain why long Covid hits some people hardest

Why does long Covid devastate some people and spare others? A study of 771 patients treated at 38 UK hospitals found a striking clue in the microscopic communities living in their bodies. People with very severe long Covid carried markedly different mixes of microbes in their saliva and lungs - and the lung differences tracked not just with breathing problems but with brain fog, memory and concentration trouble, and gut symptoms. An overgrowth of lactic-acid-producing bacteria lined up with inflammation markers in the blood. The team, led by researchers at the University of Dundee and published in the European Respiratory Journal, says the microbiome - the community of tiny organisms living in and on us - could become a treatment target, and hopes the findings spark clinical trials of antibiotics, probiotics or other microbe-shifting therapies.