Complex sentence: The healthy vagina of a woman of child-bearing age is acidic, with a pH normally ranging between 3.8 and 4.5 due to the degradation of glycogen to lactic acid by enzymes secreted by "Lactobacillus gasseri", a normal commensal of the vaginal flora.
Split into simpler sentences: The healthy vagina of a woman of child-bearing age is acidic, with a pH normally ranging between 3.8 and 4.5. This is due to the degradation of glycogen to lactic acid by enzymes secreted by "Lactobacillus gasseri", a normal commensal of the vaginal flora.