Protein levels of serum SELENOP and GPX3 and skeletal muscle and liver GPX1, SELENOH, and SELENOW (Figure S6a–c) were reduced (26%–76%) by Se deficiency, but the changes were not influenced by A. muciniphila oral gavage, suggesting that A. muciniphila oral gavage did not alleviate type 2 diabetes‐like symptoms in the Se‐deficient mice through these selenoproteins. The gene discussed is GPX3; the disease is type 2 diabetes mellitus.