There are so many probiotic choices on the market, it truly makes my head spin. For your child, the first thing to consider is, can they swallow capsules or will they require a liquid probiotic?
Dr. Ohhira’s is my current favorite capsule. Dr. Ohhira merged modern science with ancient Japanese fermentation artistry to create a product unlike any other probiotic supplement on the market. A three-year fermentation process at seasonal temperatures encourages survival of the strongest bacteria and makes the blend stable without refrigeration.
Mercola also makes their kid-friendly Probiotics Packs but, they contain stevia. (which we dislike the taste)
Liquid probiotics are an option if your child cannot swallow capsules. If you are comfortable with fermenting your own yogurt, then you are ready to ferment your own probiotics. A starter bottle of EM (Essential Microbes) can be purchased as SCD Essential Probiotics, and then used to culture large bottles of EM extended (also known as EM-X). Here’s some basic how-to make EM-X instructions. I make EM-X in my dehydrator at 95°F, and it’s ready in 3 days. I then store it in the refrigerator, and it stays good for a long time. Bonus: when you make your own probiotics this way, it is CHEAP!
If you’re curious, here is an article on The History of Probiotics.