Although in vitro data with mixed ruminal fluid has shown positive effects of a blend of probiotics on measures of fermentation, digestibility, and microbial profiles, there is a lack of in vivo data with mature small ruminants. Therefore, the current stud y evaluates the potential of a blend of probiotics (ABLB) alone or combined with Saccharomyces cerevisiae (SC) on rumen characteristics, digestibility, and blood biochemistry in sheep Five males Saidi sheep (54.14 ± 1.67 kg body weight) were randomly allo cated in a 5 × 5 Latin square design. Animals were fed basal diet or supplemented alone with 1 g/day/animal of a bacterial formula containing Lactobacillus acidophilus , Lactobacillus bulgaricus , Bacillus licheniformis , and Bifidobacterium bifidum (1:1:1: at two levels: 2 × 10 9 (ABLB2) and 4 × 10 9 cfu/g (ABLB4) as the 2 nd and 3 rd alone or combined with SC (1 gram/ animal/day) as 4 th (ABLB2+SC) and 5 th (ABLB4+SC) tested diets. The results show that all probiotic supplements significantly reduced (P<0.05) NH3 N concentrations and pH values at 0 and 3 hours after feeding compared to the control. In contrast, ruminal TVFA, MCP, and protozoa count increased (P<0.05) with ABLB2+SC at both sampling times. Compared to the control, significant improvements (P<0.05 ) were observed with ABLB2+SC in DM, CF, CP, and EE digestibilities, as well as TDN, SV, and DCP (%) values of the tested diets. Additionally, ABLB2+SC supplements led to significant increases in serum protein and glucose concentrations (P<0.05). AST activ ities showed a slight statistical increase (P=0.031) with the inclusion of SC in the probiotic formula. Conversely, ABLB2+SC resulted in the lowest levels of serum urea, creatinine, triglycerides, and cholesterol (P<0.05). This study highlights the potenti al benefits of using probiotics in ruminant nutrition, particularly in improving rumen physiology, blood health, and nutrient utilization.