This study characterizes the probiotic properties of Lactobacillus delbrueckii subsp. lactis UO 004 and examines its suitability for making cheese. This strain was isolated from infant feces and shows interesting features, such as acid and bile tolerance, adherence to intestinal epithelial cells, and inhibition of the growth of certain enteropathogens, that support its potential use as a probiotic strain. In this regard, the suitability of a washed-curd cheese (Vidiago type) made with goat's milk as a delivery system for this probiotic strain was assessed. Lactobacillus delbrueckii subsp. lactis UO 004 was incorporated into a starter culture (IPLA 001). Changes in the overall composition of control and experimental cheeses were determined during ripening through bacteriological, chemical, high-performance liquid chromatography, and gas chromatography analyses. Slight changes in the gross composition and appreciable differences in the flavor compounds profile were observed between control and experimental cheeses. This strain was capable of surviving at high cell numbers (10(8) to 10(9) CFU/g) in cheeses after 28 days of ripening without adversely affecting sensory criteria or appearance of the cheese, thus satisfying the criteria for a probiotic food product.