Advances in Xylooligosaccharides Production From Lignocellulosic Materials and Its Application as Prebiotics.

With the growing interest in functional foods and their role in promoting health beyond basic nutrition, increasing attention has been directed toward the modulation of gut microbiota as a key determinant of human well-being. In this context, prebiotics and probiotics have emerged as central bioactive ingredients due to their capacity to selectively influence microbial composition and metabolic activity in the gastrointestinal tract. Prebiotics are defined as nondigestible food components that are selectively utilized by beneficial microorganisms, leading to improved host health, whereas probiotics are live microorganisms that, when administered in adequate amounts, confer health benefits to the host. This review explores the mechanisms of action, major sources, and documented health effects of both prebiotics and probiotics, with particular emphasis on their roles in digestive health, immune modulation, and the prevention or management of metabolic and inflammatory disorders. Special attention is given to xylooligosaccharides (XOS) as emerging prebiotics derived from lignocellulosic biomass, highlighting recent advances in enzymatic production processes using microbial enzymes, especially fungal xylanases. Furthermore, the paper discusses current biotechnological strategies for sustainable production, purification, and formulation of prebiotic and probiotic ingredients, as well as the growing evidence supporting their synergistic interaction when combined as synbiotics. Understanding the complex interplay between prebiotics, probiotics, and the gut microbiota is essential for the rational design of next-generation functional foods and dietary interventions aimed at improving human health.