Not a GI specialist here, but I've read plenty of randomized controlled trials. The one-liner here might be "high quality[1] study shows substantial reduction i

Not a GI specialist here, but I've read plenty of randomized controlled trials. The one-liner here might be "high quality[1] study shows substantial reduction in infant infections in rural India[2]." The biological mechanism makes sense, and as discussed in the article could be more than just good bacteria fighting off bad bacteria. A cynic may say the immunomodulation stuff is kind of hand-wavy and not being a GI specialist, pediatrician or immunologist myself I don't know. That would be an important point because all infections were reduced (not just GI infections), which may point to confounding variables. More on that later. [2] As far as how the study applies to most of Europe and the US where infant mortality is 10x less, hard to say. The number of infants needed to treat to prevent a single infection was 27 which is low assuming these drugs are cheap and without side effects. Immediate side effects are unlikely given the low and comparable drop out rates among control and treatment groups. However, long-term effects are unknown given the timeframe of the study. Forming a recommendation for countries with more rigorous pasteurization/food preparation/etc, perhaps more access to care and well-child checkups, and much lower infant mortality in general isn't particularly easy here. I'm not up to date on other studies with probiotics. Again, not my specialty. [1] The study quality looks sound and exclusions were reasonable, the control (placebo) and treatment groups matched up well in many ways and were sizable. There wasn't very much in the way of dropouts. The study looked at too small a population to determine differences in infant deaths, if there is one at all.