Antibiotics wipe out much of the bacteria in your body without discriminating between good and bad. While this can help get rid of bacterial illnesses, it can also deplete your immune system, which may take a while to recover. Probiotics, particularly those strains that are known for boosting immunity, can help speed up this process. It’s a good idea to start taking probiotics with your antibiotics and continue taking them for about a month afterward to ensure that your good bacteria returns to a healthy level.