Previous study found that 20% foxtail millet intake could effectively regulate the gut microbiota composition and increase the colonization of beneficial bacteria in mice in early life. However， excessive foxtail millet feeding (80%) reduced the diversity and homogeneity of intestinal flora and caused a decrease in the abundance of beneficial bacteria. The present study was based on non-targeted metabolomics to analyze the effects of intaking foxtail millet from the early life stage in mice on their fecal metabolic profile. Methods: Non-targeted metabolomics technique was used to detect changes in the fecal metabolic profile of mice after the intake of foxtail millet from the early life stage. Results: When the foxtail millet intake was 20%， compared to the normal group， there were 165 up-regulated， 11 down-regulated， and 467 non-significant changes in fecal metabolites， and these different express metabolites mainly enriched in taurine and hypotaurine metabolism， vitamin B6 metabolism， and neobiotics biosynthesis. When the foxtail millet intake increased to 80%， there were 178 up-regulated， 24 down-regulated， and 441 non-significant alternations in fecal metabolites， and the notably changed metabolism pathway mainly including tryptophan metabolism， vitamin B6 metabolism， and neobiomycin biosynthesis. In addition， both two foxtail millet intake dosages significantly influenced tryptophan metabolism， and the impact value of the tryptophan metabolism pathway greatly increased when the foxtail millet intake changed from 20% to 80%. Conclusion: Consumption of foxtail millet from the early life stage significantly affected fecal metabolite levels and related metabolism pathways in mice， especially the tryptophan metabolism pathway， which played a vital role in the cognitive ability and brain development of body. Thus， excessive foxtail millet supplementation might be detrimental to the organism's healthy development. The study aimed to provide a theoretical basis for improving the mechanism of millet's action in the daily diet， thus supporting data for the development and application of functional foods based on millet.