Our daughter was born by un-planned C-section and stopped gaining weight after her first week. While drinking (mix of breast and formula) normal amounts, her digestion seemed to not do much, needing a new diaper 10-15x a day and with her poop watery. Seeing this and with two combined lifetimes of allergies in mind (us) we decided to try evivo's B.infantiis. We gave the first dose at the age of 4 weeks (took a while to get this into Japan) and the effect was immediate! No poop for two days (which started to get me worried a bit) and ever since it's been 1-2x a day on average. We've been giving the probiotics ever since.. From the initial dose onwards she's been gaining weight at a "normal" pace. Additionally, her rashes cleared up very nicely (which might have happened anyway?). All in all, I wouldn't hesitate a second to use this again, and will definitely order this earlier should we have another baby.