Clinical and review evidence demonstrates that specific probiotic strains, such as Streptococcus salivarius administered via nasal spray or lozenge, are designed and shown to target upper respiratory tract tissue to prevent and reduce infections.
The retrieved papers consistently demonstrate that certain probiotic strains (e.g., Streptococcus salivarius 24SMB and K12) are specifically formulated and administered (such as via nasal sprays or oral targets) for the upper respiratory tract to prevent infections. There is robust evidence supporting this claim and no papers refuting the existence of such targeted probiotics.