Oligosaccharides production from coprophilous fungi: An emerging functional food with potential health-promoting properties

Functional foods are essential food products that possess health-promoting properties for the treatment of in?fectious diseases. In addition, they provide energy and nutrients, which are required for growth and survival.  They occur as prebiotics or dietary supplements, including oligosaccharides, processed foods, and herbal  products. However, oligosaccharides are more efficiently recognized and utilized, as they play a fundamental  role as functional ingredients with great potential to improve health in comparison to other dietary supplements.  They are low molecular weight carbohydrates with a low degree of polymerization. They occur as fructooligo?saccharide (FOS), inulooligosaccharadie (IOS), and xylooligosaccahride (XOS), depending on their mono?saccharide units. Oligosaccharides are produced by acid or chemical hydrolysis. However, this technique is liable  to several drawbacks, including inulin precipitation, high processing temperature, low yields, and high pro?duction costs. As a consequence, the application of microbial enzymes for oligosaccharide production is recog?nized as a promising strategy. Microbial enzymatic production of FOS and IOS occurs by submerged or solid-state  fermentation in the presence of suitable substrates (sucrose, inulin) and catalyzed by fructosyltransferases and  inulinases. Incorporation of FOS and IOS enriches the rheological and physiological characteristics of foods. They  are used as low cariogenic sugar substitutes, suitable for diabetics, and as prebiotics, probiotics and nutraceutical  compounds. In addition, these oligosaccharides are employed as anticancer, antioxidant agents and aid in  mineral absorption, lipid metabolism, immune regulation etc. This review, therefore, focuses on the occurrence,  physico-chemical characteristics, and microbial enzymatic synthesis of FOS and IOS from coprophilous fungi. In  addition, the potential health benefits of these oligosaccharides were discussed in detail.