Lactobacillus acidophilus (LA) mitigates metformin-induced inhibition of Na+/H+ exchanger 3 (NHE3) in Caco-2bbe cells. A: Caco-2bbe/NHE3 cells were treated with metformin (Met; M), LA conditioned media (LCM), or Met + LCM, and NHE3 activity was determined. B: NHE3 expression in the apical membrane was determined by surface biotinylation. Representative Western blots for surface (S) and total (T) NHE3 expression are shown. S-NHE3/T-NHE3 ratios are shown on the right. **P < 0.01; ***P < 0.001; ****P < 0.0001; ns, not significant. Statistical analysis was performed by two-way ANOVA with Tukey’s post hoc test. Data (means ± SE) are combined from three independent experiments using cells of different passages. C: confocal immunofluorescence (IF) images for NHE3 (green), F-actin (red), and DAPI (blue) are shown. Top: focal plane xy views. Middle: vertical sectional xz view of NHE3. Bottom: vertical sectional xz view of NHE3, F-actin, and DAPI. Scale bar, 10 μm. Con, control.