INS and Obesity: According to the combined data, the level of fasting insulin after FMT therapy did not vary substantially from the level before therapy (WMD is equal to −1.06, 95 percent CI: −2.83~0.71, p is equal to 0.241; Figure 5), suggesting that patients suffering from obesity and related metabolic diseases may not benefit from FMT treatment in terms of fasting insulin levels.