Next, we found that (‐) Leu‐FMT group showed improved insulin sensitivity, as demonstrated by decreased fed blood glucose levels (Figure 1B), decreased fed and fasting serum insulin levels (Figure 1C), decreased homeostasis model assessment of insulin resistance (HOMA‐IR) index (Figure 1D), and improved glucose tolerance test (GTT) (Figure 1E) and insulin tolerance test (ITT) (Figure 1F). Here, INS is linked to Insulin resistance.