Interventions during Early Life Impact the Microbial Colonization and Immune Development in Livestock Species

Intestinal microbiota form a dynamic ecological system, of which the diversity and composition changes over time and gastrointestinal location. The development, differentiation and programming of the host immune system is established during early life and is, to a significant extent, dependent on intimate interactions between microbiota and host intestinal tissue. During early life, the colonization of the gut may be affected by environmental factors, for example the use of antibiotics, administration of pre-selected microbiota or by diet composition (feed ingredients, prebiotics, and probiotics). To address the impact of such environmental factors, experienced during early life, on the composition and diversity of intestinal microbiota and on host intestinal immune development, we performed a series of experiments with pigs and chickens were the focus was to actively change the microbiota to investigate this host-microbe interaction. We used 16S ribosomal RNA gene-targeted array- and sequence-based approaches to investigate differences in microbiota diversity and composition as affected by early interventions. Genome-wide approaches were used to identify intestinal host genes and associated processes in intestinal tissue affected by the applied interventions. From the results, we conclude that the interplay between microbiota and host during early life is indeed important for immunological development. In addition, we show that it is possible to modulate microbial and immunological development by external factors such as the use of antibiotics and/or probiotics.