Light micrograph phase contrast of Lactobacillus bulgaricus bacteria taken from live yoghurt The relatively long Grampositive bacteria appear as thin black rods They are commonly found among the normal human internal flora in places such as the stomach gut mouth vagina Lactobacillus produces lactic acid from the fermentation of carbohydrates This acidic environment notably in the vagina protects the host by inhibiting the growth replication of other more pathogenic bacteria Magnification x at mm size
