“Knowledge is the first step towards solution”. This is the idea at the heart of Probiotics, the most complete collection of scientific and historiographical studies about probiotic’s world. This collection aims to examine in depth the usefulness and functioning of healthy bacteria. A real encyclopaedia, made up of 10 volumes, analyzes several fundamental aspects about this subject, such as Microbiology History, from the first scientific insights to the Nobel Prize Elia Metchnikoff’s studies, probiotic microorganisms’ types, from bifidobacteria to lactobacilli, studies on their beneficial effects on the human body and on their modern and future applications, also in food. For the first time, Probiotical offers to scholars and professionals this precious documentary collection, available in Italian and English language, which has been edited and published by Probiotical itself over the last 10 years; the most important researchers in the probiotic field has cooperated at it.