The indole-3-propionic acid-producing bacteria Clostridium sporogenes protects against influenza

We investigated the potential protective effects of Clostridium sporogenes, a human anaerobic commensal and indole-3-propionic acid (IPA) producer, in influenza A virus (IAV) infection. Relative to untreated mice, C. sporogenes supplementation was associated with less severe disease, lower pulmonary viral loads, and reduced lung inflammation. C. sporogenes administration modulated infection-induced gut dysbiosis and restored systemic IPA levels, which were positively correlated with reduced clinical scores and pulmonary viral loads. Similar effects were obtained using pasteurized C. sporogenes.