Inclusion Criteria:  Pregnant women who can have a regular labor inspection and delivery in the labor inspection hospital; The range of age is between 18 to 45 years; Pregnancy naturally and singleton pregnancy; Pregnant women with or without gestational diabetes diagnosed by oral glucose tolerance test at 24 to 28 weeks of pregnancy; Those who can skillfully use social software in mobile phones and obey the plan of follow-ups; Those who voluntary signing of informing consent.  Exclusion Criteria:  Patients with pre-pregnancy diabetes or abnormal oral glucose tolerance test screening in early resulting from high risks or known pre-pregnancy glucose intolerance; Those who were estimated by endocrinology that their value of blood glucose is controlled by not only diet interventions but also drugs; Pregnant women who used antibiotics before 1 month enrollment ; Those who combined some metabolic diseases, such as hematological system diseases and nervous system diseases; Those who reject signing inform consent.