Principal component analyses of fecal microbiomes. Fecal microbiomes for each animal at each time point were analyzed via principal component analyses. (A) Amoxicillin alone vs. Amoxicillin + Formulation 1, black, amoxicillin pretreatment, red, amoxicillin post treatment, light blue, Amoxicillin + Formulation 1 pretreatment, dark blue, Amoxicillin + Formulation 1, post-treatment. (B) Amoxicillin alone vs. Amoxicillin + Formulation 2, black, amoxicillin pretreatment, red, amoxicillin post-treatment, pink, Amoxicillin + Formulation 2 pretreatment, yellow, Amoxicillin + Formulation 2 post-treatment. (C) Amoxicillin alone vs. Amoxicillin + Formulation 3, black, amoxicillin pretreatment, red, amoxicillin post-treatment, purple, Amoxicillin + Formulation 3 pretreatment, green, Amoxicillin + Formulation 3 post-treatment.