ABSTRACT: In this study, the influence of a protein-based fat replacer, Versagel® added at 1% and 2% (w/v) to reconstituted skim milk (RSM), on the growth and metabolic activities of selected strains of yogurt starters (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus) as well as probiotic organisms (Lactobacillus casei, Lactobacillus acidophilus, and Bifidobacterium longum) was examined. Addition of Versagel resulted in significantly improved growth of S. thermophilus and B. longum but inhibited that of L. casei, L. acidophilus, and L. delbrueckii ssp. bulgaricus. This is also reflected in the extent of reduction of pH in RSM with added Versagel by these organisms. Among the biochemical activities, proteolytic activity of all the organisms except B. longum was adversely affected by the presence of Versagel, although the angiotensin-I converting enzyme (ACE) inhibitory and α-glucosidase (α-glu) inhibitory activities were improved. Versagel at 1% level influenced the growth, while ACE inhibitory and α-glu inhibitory activities of the organisms were better at 2% level.