The blue-green algae Spirulina platensis Geitler 1925 has been used by people since ancient times due to its high protein content. This study was conducted to determine the effect of a Probiotic-Prebiotic (P-P) product, which contains Bifidobacterium infantis, Bifidobacterium thermophilum, Leuconostoc mesenteroides as probiotic bacteria, and beta-glucan and oligosaccharide as a prebiotic mixture on S. platensis. In the study, four groups were one of which was a control. In this study, we investigated whether the P-P product contributed to the biomass development and protein production of S. platensis under different temperatures and lighting conditions. In terms of biomass, the P-P product gave different responses at different temperatures and light intensities, but its results were positive in all groups in terms of protein ratio. The most positive effect on biomass and protein content was in the group where 0.1 ml/L P-P product was added, at 40??C and 3200 lux with 68.71% protein content and an average OD of 0.727.