The Types axis of market taxonomy classifies probiotic strains by genus and functional attributes. Lactobacillus species, including L. acidophilus and L. rhamnosus, constitute the largest share, roughly 45 % of the strain portfolio, due to their robust survivability and extensive safety data. Bifidobacterium strains, such as B. longum and B. infantis, follow with an estimated 25 % share, prized for infant gut health applications. Saccharomyces boulardii, a yeast‑based probiotic, accounts for about 10 %, primarily in therapeutic formulations targeting antibiotic‑associated diarrhea. Bacillus spp., notable for spore‑forming resilience, represent 12 % of the market, enabling incorporation into dry‑mix feeds and shelf‑stable products. Streptococcus and other emerging genera together occupy the remaining 8 %, often explored for niche immunomodulatory effects. This type‑based segmentation informs R&D investment, regulatory pathways, and pricing strategies, underpinning the overall Probiotic Strains market dynamics.