Central for any activities in pig gut microbiota is to realise difference in composition of gut microbiota of nursed piglet and weaned pigs including sows. Microbiota of piglets before and after weaning differ substantially and sows as individuals far long after weaning need not represent an optimal source of gut microbiota for their piglets. This is why there is a space for active manipulation of gut microbiota in newborn and weaned piglets by probiotic administration. However, we strongly discourage from automatic association of lactobacilli as probiotic of choice. Alternative and better approach is to understand structure of microbiota of nursed and weaned piglets, and only then proceed with probiotic selection and design.