Book excerpt: This book explores recent advances in the microbial production of xylitol and its applications in food and medical sector. Xylitol is an important biomolecule from lignocellulose biorefinery which is produced from the xylose by chemical reactions or microbial fermentation methods. Currently, the demand of xylitol at commercial scale is being met through chemical methods. However, recent breakthroughs made in plant cell wall destruction, genetic engineering to develop the designer microorganisms, fermentation methods and media formulations and downstream processing have led the ways for sustainable production of xylitol at commercial scale in lignocellulose biorefineries. Microbial production of xylitol is preferred over the chemical processes as it is environmentally friendly, higher process efficiency with the desired product yield, and product recovery with minimum impurities. This book is a unique compilation of 11 book chapters written by experts in their respective fields. These chapters present critical insights and discuss the current progress and future progress in this area into fermentative xylitol production. Chapter 9 is licensed under the terms of the Creative Commons Attribution 4.0 International License. For further details see license information in the chapter.