Probiotics was a term first used by Lilly and Stillwell in 1965 to describe microorganisms that confer beneficial properties on other microorganism. Since then, the term has evolved to incorporate any organism that has beneficial impact on another organism. Research into probiotics and their health implications has been extensive. This collection highlights the latest research into probiotics published in Gut Pathogens. If you would like your manuscript to be considered for this collection, please indicate so at the time of submission.