A team of researchers affiliated with a large number of institutions in China, has found that low concentrations of a certain metabolite in diabetic patients may explain why they are more susceptible to COVID symptoms. In their paper published in the journal Nature Metabolism, the group describes their work in searching for and comparing metabolites in people with and without diabetes and then how they tested incubated cells from them against a SARS-CoV-2 infection and what they learned by doing so.