The following article points out the role of orally supplementing pre-term piglets with galactooligosaccharides/fructoligosaccharides (prebiotics), Bifidobacterium breve (probiotic) and glutamine (an amino acid) on brain and immune system development.

https://academic.oup.com/jn/advance-article/doi/10.1093/jn/nxy243/5273187