Lactobacillus acidophilus Er-2 strain 317/402 Narine. Lactobacillus acidophilus Er-2 strain 317/402, Narine 2 x108 CFU 6 x108 CFU 12 x108 CFU 18 x108 CFU . Lactobacillus acidophilus bacteria. CFU – Colony Forming Unit – a unit used to estimate the number of viable microorganisms able to form colonies.