What did we learn today?

W e learnt that the development of the intestinal microbiota (IM) is extremely complex and a giant puzzle to piece together from adults and children in both developing and developed countries, or more experimentally. Each piece may or may not have future consequences for the IM. However, we are now at the end of the beginning of finishing just one microbiological puzzle. Additionally, we have to show how the functional puzzle can be illuminated. The burning question is: will we ever succeed? The answer is simple: we will, if we to go time point by time point, species by species, function by function. And when we have a clearer picture of the continuous host/microbiota and microbiota/microbiota cross-talks going on all through childhood, we will be able to interact prophylactically and therapeutically We learnt that when focusing on specific microberelated metabolites there are consequences for the host functions. Irrespective of the size of the molecules, the interactions are several. The IM and the host clearly interact. We learnt that, when focusing on restoration of the IM dysbiosis either by transplantation of fresh feces or cultivated human IM, there are pitfalls that need to be addressed. However, there is hope we will eventually find a way to successfully restore the IM. Summing up, we learnt that there are complex interactions constantly going on between the IM and its host in health as well as in disease and also that we are now beginning to understand how to improve and optimize this interaction. More research is required, however. You are welcome to submit your papers to Microbial Ecology in Health & Disease. Tore Midtvedt Department of Microbiology Tumor and Cell Biology, Karolinska Institutet Stockholm, Sweden Email: [email protected]