Characterization of the Early Life Microbiota Development and Predominant Lactobacillus Species at Distinct Gut Segments of Low- and Normal-Birth-Weight Piglets.

Na Li,Junjun Wang,Shimeng Huang,Lili Jiang,Zhaolai Dai,Dandan Han,Tiantian Li

doi:10.3389/fmicb.2019.00797

Abstract

Microbial exposure during early life plays a pivotal role in modulating the health and intestinal development of the host. Our recent study showed that the low-birth-weight (LBW) piglets harbored a different fecal microbiota compared to normal-birth-weight (NBW) piglets during early life with a lower abundance of the genus Lactobacillus. Considering the spatial variations in gut microbiota at distinct gut locations, this study was designed to further investigate the differences in the microbiota composition and predominant Lactobacillus species in the ileum and colon between LBW and NBW piglets during early life, including day 7 (D7), day 21 (D21, before weaning), and day 35 (D35, 2 weeks after weaning). Compared with the normal group, LBW piglets harbored a significantly lower proportion of short-chain fatty acids producing microbes, such as Ruminococcaceae and Prevotellaceae in the ileum on D7, Alistipes and Lachnospiraceae in the colon on D7, Blautia in the colon on D21, and Ruminiclostridium 9 in the colon on D35. The relative abundance of the phylum Bacteroidetes was also declined in both ileum and colon of LBW piglets on D7. Meanwhile, the levels of total SCFAs on D7, D21, and D35, acetate and valerate on D7 and D21, propionate on D21, and lactate on D21 and D35, were also declined in the colon of LBW piglets. Moreover, functional alterations in the gut microbiota of LBW piglets were characterized by differentially abundant microbial genes involved in multiple pathways such as amino acid metabolism, energy metabolism, replication and repair, and metabolism of cofactors and vitamins in the colon. Additionally, lower numbers of L. salivarius on D7 and L. amylovorus on D21 resided in the colon of LBW piglets compared to those in the normal ones. Collectively, LBW piglets have altered bacterial communities, microbial metabolism and gene functions in the ileum and colon during early life, especially the colonic community. This work will help to develop novel ideas in identifying the reliable biomarkers affecting the gut microbiota development in LBW piglets during early life and facilitate the development of new nutritional interventions.

Highlights

Increased litter size by genetic selection for high-prolific sows in recent years has been accompanied by an increasing occurrence of piglets born with low birth weight (LBW) (Li et al, 2017)
The results revealed that the influence of LBW on the bacterial community composition were focused on the colonic digesta (Figure 4 and Supplementary Table S3)
For the first time, we found that LBW piglets had lower levels of total short-chain fatty acids (SCFAs), acetate, propionate, valerate, and isovalerate in the colonic content at different ages compared with the normal ones

Summary

Introduction

Increased litter size by genetic selection for high-prolific sows in recent years has been accompanied by an increasing occurrence of piglets born with LBW (Li et al, 2017). LBW pigs refer to those pigs with a birth weight less than 1.1 kg, accounting for 15–25% of the newborn piglets (Wang et al, 2017). LBW piglets are more susceptible to high postnatal morbidity and mortality, postnatal growth restriction (Wu et al, 2006), as well as malfunction in vital organs like the GIT (Li et al, 2017; Wang et al, 2018). Life colonization of microbes in the gut of the piglet sets the stages for adult microbiota and has lifelong influences on the development of the GIT and immune system (Matamoros et al, 2013; Houghteling and Walker, 2015). The gut microbiota of newborns is extremely unstable due to the fast growth of the GIT and its dysbiosis is closely connected with a higher risk of gut diseases and infections (Houghteling and Walker, 2015)

Methods

Results

Discussion

Conclusion