Long-chain, high-molecular-mass polymers that dissolve or disperse in water to give a thickening or gelling properties are indispensable tools in food products formulation. Such polymers are also used for secondary effects that include emulsification, stabilization, and suspension of particulates, control of crystallization, and inhibition of syneresis, encapsulation, and film formation in foods. Most of the biothickeners in current use by the food industry are polysaccharides from plants (e.g. starch, pectin, locust bean gum, guar gum) or seaweeds (i.e. carrageenan, alginate). The animal proteinaceous hydrocolloids gelatin and casein are also used. The functional properties of these polymers in foods are determined by quite subtle structural characteristics. However, these polysaccharides may not always be readily available in the quality needed or their rheological properties may not exactly match those required. Alternative biothickeners are microbial exopolysaccharides, either associated with cell surface in form of capsules or secreted into the extracellularly in form of slime, referred to as capsular or slime exopolysaccharides, respectively. Microbial exopolysaccharides are biothickeners that can be added to a wide variety of food products, where they serve as viscosifying, stabilizing, emulsifying or gelling agents. Many food grade microorganisms also produce exopolysaccharides, in lactic acid bacteria, propionibacteria and bifidobacteria. The quest to find food ingredients with valuable bioactive properties has encouraged interest in exopolysaccharides from LAB. Functional food products that offer health and sensory benefits beyond their nutritional composition are becoming progressively more important to the food industry. The sensory benefits of exopolysaccharides are well established, and there is evidence for the health properties that are attributable to exopolysaccharides from LAB. However there is a wide variation in molecular structures of exopolysaccharides and the complexity of the mechanisms by which physical changes in foods and bioactive effects are elicited. To give a desired texture and mouth feel to yoghurt, skim-milk powder or whey is frequently added to the milk. Although the consumer does not consider this as unnatural, it represents an extra cost for the producer. In some countries, however, gelatine or plant (e.g., starch, pectin, guar gum, and alginate) and microbial polysaccharides (e.g., xanthan and gellan) are added. Polysaccharides increase the viscosity and firmness, improve the texture, reduce susceptibility to syneresis, and contribute to the mouthfeel of low-fat products. Some polysaccharides, e.g., plant carbohydrates, xanthan and gellan, have the additional advantage of being suitable to chemical modification to improve their rheological properties. However, the modified molecules are perceived by the consumer as unnatural and the food regulation of several European countries forbids the use of additives in, for instance, yoghurt. The in-situ production of natural texture-improving sugar polymers (exopolysaccharides) by LAB for the manufacturing of yoghurts, of sour cream and whipped toppings of ice cream and of low-fat Mozzarella are being explored. Functional, exopolysaccharide-producing starters of Lb. delbrueckii subsp. bulgaricus or S. thermophilus are promising. Current research is investigating the biodiversity of exopolysaccharides produced by LAB from artisan yoghurts, fermented milks, vegetables, and cereals, the conditions for optimal production, and their technological implementation in the industrial production of fermented foods .