Final answer:
The normal flora of the genital tract includes microorganisms that protect against infections. Lactobacillus bacteria in the vagina secrete lactic acid to maintain an acidic pH and inhibit the growth of pathogens. Fluctuations in the vaginal microbiota can occur due to environmental changes and hormonal regulation.
Step-by-step explanation:
The normal flora of the genital tract refers to the microorganisms that are naturally present in the urogenital system and help protect against infections. In both men and women, the distal urethra contains bacterial species commonly found on the skin, while in women, the vagina also harbors a complex and dynamic population of bacteria. The most predominant type of bacteria in the vagina is from the genus Lactobacillus, which secretes lactic acid to maintain an acidic pH and inhibits the growth of pathogens. Fluctuations in the vaginal microbiota can occur due to environmental changes and hormonal regulation.