The Placental Microbiome Varies in Association with Low Birth Weight in Full-Term Neonates

TLDR

Low birth weight is an independent risk factor for later obesity, impaired glucose regulation, and diabetes, yet its association with the placental microbiome in full‑term neonates has been poorly studied. The authors collected placentas from low‑birth‑weight and normal‑birth‑weight full‑term infants at Peking Union Medical College Hospital, measured anthropometrics, and used 16S rDNA high‑throughput sequencing to profile placental bacterial communities. They found that low‑birth‑weight infants had smaller birth weight, ponderal index, head circumference, and placenta weight, lower OTU and Chao diversity, distinct microbiota composition at phylum and genus levels, and a positive correlation between Lactobacillus abundance and birth weight, establishing for the first time a link between birth weight and placental microbiome in full‑term neonates.

Abstract

Substantial evidence indicated that low birth weight was an independent risk factor for obesity, impaired glucose regulation, and diabetes later in life. However, investigations into the association between low birth weight and placental microbiome in full-term neonates are limited. Placentas were collected from low birth weight (LBW) and normal birth weight (NBW) full-term neonates (gestational age 37 w0d–41 w6d) consecutively born at Peking Union Medical College Hospital. The anthropometric measurements were measured and 16S ribosomal DNAamplicon high-throughput sequencing were utilized to define bacteria within placenta tissues. It showed that birth weight, ponderal index, head circumference, and placenta weight were significantly lower in LBW than NBW neonates (p < 0.05). The operational taxonomic units (OTUs) (p < 0.05) and the estimators of community richness (Chao) indexes (p < 0.05) showed a significantly lower diversity in LBW than NBW neonates. There were significant variations in the composition of placenta microbiota between the LBW and NBW neonates at the phylum and genus level. Furthermore, it indicated that Lactobacillus percentage was positively associated with birth weight (r = 0.541, p = 0.025). In conclusion, our present study for the first time detected the relationship between birth weight and placental microbiome profile in full-term neonates. It is novel in showing that the placental microbiome varies in association with low birth weight in full-term neonates.