Objective To analyze the exposure of food-borne antibiotics to pregnant women and their newborns in the third trimester of pregnancy, and further explore the impact of food-borne antibiotics exposure on the infant intestinal microbiota.

Methods Totally, 86 pregnant women had regular obstetric examinations from May 2018 to December 2018 in Beijing Obstetrics and Gynecology Hospital, Capital Medical University were collected, they were divided into control group (n=43) and antibiotic exposure group (n=43) according to the antibiotic exposure in the neonatal cord blood samples. UPLC-MS/MS and TRFIA were used to detect the exposure of antibiotics to serum of pregnant women in the third trimester, umbilical cord serum, and neonatal feces. 16S rRNA second-generation sequencing platform was used to detect and analyze the infant intestinal microbiota.

Results The serum of pregnant women, umbilical cord serum, and neonatal feces results showed a high proportion of food-borne antibiotics exposure. There was a significant difference in infant intestinal microbiota between the antibiotic exposure group and the control group (P < 0.05).

Conclusions Low-dose, continuous-exposure food-borne antibiotics can indirectly affect the infant intestinal microbiota through the mother and thus affect the health of infants and young children.