Feeding Modes Shape The Acquisition And Structureof The Initial Gut Microbiota In Newborn Lambs

The aim of this study was to investigate the impact of feeding modes(suckling versus artificial feeding)on early intestinal microbial colonization of three-day old lambs,and explore the microbial sources and the corresponding proportions of the early gut microbiota by source under the two feeding modes.Six ewes and their twins were included in this trial with 6 lambs in each feeding group.After birth,one of the twin lambs was taken immediately from the ewe,caged individually in a sheep pen,and bottle-fed with milk collected from other lactating ewes,and the other lamb remained with the birth mother and was suckled ad libitum.Microbial samples from maternal and environmental niches and the jejunum of lambs were taken and detected.Effects of feeding modes on the structure of the initial gut microbiota in newborn lambsResults from 16S rDNA gene sequencing and qPCR showed that,the gut bacterial community composition in newborn lambs were dominated,at the phylum level,by the Bacteroidetes,Firmicutes,and Proteobacteria,and,at the genus level,by the Bacteroides.Different feeding modes significantly influenced the bacterial community in the gut.The bottle-fed group had significantly higher bacterial community richness than the suckled group.Compared with suckling,bottle feeding significantly increased the abundances of Escherichia/Shigella,Butyricicoccus,and Clostridium XlVa,while significantly decreased the abundance of Clostridium XI.The microbial sources and the corresponding proportions analysis of the initial gut microbiota in newborn lambsMaternal niches(maternal oral cavity,vagina,stool,milk,abdominal region skin,udder skin,teat skin)and environmental niches(sheep pen floor,pen wall,ambient air,)samples were detected using 16S rDNA gene sequencing.To identify possible sources and their proportions in the early gut bacterial community of newborn lambs,Bray-Curtis dissimilarity analysis,and SourceTracker were used.Feeding modes also affected the direct transmission of bacteria from the mother and the environment to newborns.The gut bacterial communities of suckled lambs tended to be composed mainly of bacteria from the mother’s teat(43%),vagina(7%),ventral skin(6%),oral cavity(5%),and ambient air(28%),whereas those of bottle-fed lambs were dominated by bacteria from the mother’s vagina(46%),ambient air(31%),and the pen floor(12%).In summary,our results provide preliminary information for understanding the relationship between the early intestinal microbiota and type of feeding,the sources of the early gut microbiota of newborns,and the role of maternal and horizontal transmission in the initial establishment of the newborn gut microbiota.These findings advance our understanding of gut microbiota in early life and may help design techniques to improve gut microbiota and health.