Foreword - Increase in clinical trials for probiotics and prebiotics.

After a steady increase over recent years, last year we experienced our first drop in Impact Factor (IF): from 3.301 to 2.923. Although last year I concluded that I was pretty awful at predicting the future (Venema, 2017; and I still haven't found a probiotic to improve that …), this result was not entirely unexpected. As a young journal (we have yet to celebrate our 10th anniversary), the IF will inevitably fluctuate a little. I keep track of the IF development over the course of the year and we are well on our way to achieving an IF of above 2 again (with still another 6 months to go until the end of June, when the new impact factors will be provided by Clarivate Analytics), which isn't bad at all for a young journal.