A completely different take on this phrase is that discretion means being discrete as in protecting people or information from exposure in some manner. If one is to be perceived as possessing valor by others, then they cannot express this by being merely brash and powerful.
Probiotics are essential (for at least a month or two after the antibiotics stop, depending on the potency) when you have had antibiotics to replenish the beneficial bacteria.
At their most basic, probiotics can be defined as live microorganisms that are beneficial to the host organism. Probiotics can be beneficial as an aid to help prevent disease, aid in recovery after illness or to restore microbial balance. Most often the term probiotic is used as it applies to digestive tract health.