The microbiome and its relationship to human health is a growing area of health research. Folate, a water-soluble vitamin, is needed especially in growth and development and whenever anabolic activity increases. The association of folate deficiency with neural cord birth defects led to mandated dietary fortification with folic acid in several countries, notably in North America since 1998. However, it has long been known that the human colonic microflora produces folate, and absorption of this microbial product was known to occur in animals. Here, it is shown that in healthy adults the colon is a secondary source of folate nutrition. Secondly, the results of a study are described on the use of prebiotics to increase microbial folate production in the colon of piglets, in order to increase the amount of folate absorbed.