Relationship between the components of mare breast milk and foal gut microbiome: shaping gut microbiome development after birth

Abstract

The gut microbiota (GM) is essential for mammalian health. Although the association between infant GM and breast milk (BM) composition has been well established in humans, such a relationship has not been investigated in horses. Hence, this study was conducted to analyze the GM formation of foals during lactation and determine the presence of low-molecular-weight metabolites in mares’ BM and their role in shaping foals’ GM. The fecal and BM samples from six pairs of foals and mares were subjected to 16S ribosomal RNA metagenomic and metabolomic analyses, respectively. The composition of foal GM changed during lactation time; hierarchical cluster analysis divided the fetal GM into three groups corresponding to different time points in foal development. The level of most metabolites in milk decreased over time with increasing milk yield, while threonic acid and ascorbic acid increased. Further analyses revealed gut bacteria that correlated with changes in milk metabolites; for instance, there was a positive correlation between Bacteroidaceae in the foal’s gut microbiota and serine/glycine in the mother’s milk. These findings help improve the rearing environment of lactating horses and establish artificial feeding methods for foals.

Keywords:

• Horses
• gut bacteria
• breast milk
• metabolomics

Acknowledgements

We would like to thank Editage (www.editage.com) for English language editing.

Disclosure statement

The authors have no conflict of interest to declare.

Data availability statement

The datasets displayed in the present investigation can be found in online repositories. The repository/repositories’ names and the accession number(s) can be attained below: https://www.ncbi.nlm.nih.gov/genbank/, PRJNA1006090.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.