We have previously shown that neutralization of IL-1α with a specific murine monoclonal antibody (FLO1) in 25-wk old SAMP1/YitFc (SAMP) mice with established CD-like ileitis, ameliorates ileitis severity. These results were associated with gut microbiome alterations. However, whether these effects are a consequence of decreased intestinal inflammation or a direct effect of FLO1 is unknown. Here, we treated inflammation-free SAMP mice (4-wk old) with FLO1 to confirm that this antibody modulates the gut microbiome in the absence of inflammation; secondly, we ought to test whether treated mice are more resistant to DSS-induced colitis.