• Original Articles By Dr. Lavin Featuring Expert Advice & Information about Pediatric Health Issues that you Care the Most About

    How Pro Should We Be About Probiotics? The Latest on How They Help, and How They Do Not

    By Dr. Arthur Lavin

    It is a very reasonable stance to be skeptical about any medical intervention.  Why is that?  Because none are perfect.

    This is why we at Advanced Pediatrics always ask two key questions of any proposed intervention:

    1. Does it work?
    2. Does it cause harm?

    Obviously, if the answer to the first question is no, no need to go further, why expose your child to it, why even find out if it causes harm.

    This is why recent findings on the use of probiotics is of such interest.  And the original article in the journal Nutrition.

    What is a Probiotic?

    The part of the word, -biotic, refers to living things, as in biology.  But often that suffix refers to one form of life, bacteria, and it does here for sure.

    So a probiotic is a friendly bacteria of the gut.

    Why Should a Probiotic Help?

    The whole notion that swallowing a bunch of friendly bacteria would help is based on the very profound truth that bacteria that normally live in our gut are essential for our health, really our lives.

    Consider this.  Each person is made up of about 10 trillion cells.  But in and on each person are 100 trillion bacteria, that’s right, we are 10x more bacteria than human in cell count!

    A great majority of these 100 trillion bacteria live in our guts, largely in the colon.  We know very little about the complex web of life these trillions of gut bacteria weave.  Their complex world is captured in the word used to refer to them now, the microbiome.

    There is very good evidence, that is expanding rapidly, that the microbiome plays a central role in sustaining our lives and health.  And, that disruptions of the microbiome are harmful.

    It is now established practice, in certain select instances, to replace a person’s gut microbiome with another person’s gut microbiome, known as a fecal transplant.  Quite dramatic recoveries from serious gut diseases have occurred with this technique.

    So we think there is tremendous potential in further understanding the gut microbiome and being able to act on it and promote health and even recovery from serious illness.

    But the honest truth is that we know very, very, very little about any details of the microbiome in terms of how to adjust it and improve it.  Very little.

    So Do Probiotics Help?

    The promise of a probiotic is that they will restore one’s gut microbiome to an optimal, healthy state.   It is a restoration strategy, based on the idea that there are situations in which the microbiome of the gut is damaged, and by swallowing healthy gut bacteria, the complex weave of gut bacteria can be healed, restored to a healthy state, thereby making the person taking the probiotics healthy once again.

    It is the opposite of the strategy of antibiotic.  Antibiotics, notice the same word structure, are designed to kill harmful bacteria.  Probiotics promote healthy bacteria.

    Now here is what JAMA had to say in the fall of 2019.

    Many articles have been published on the study of the impact of probiotics on a variety of conditions, here is a list of what they help with, and what they do not:

    Probiotics Help

    If you take antibiotics, taking probiotics can prevent infection with the harmful germ C. diff.

    If you have an acute bout of diarrhea due to viruses, taking probiotics can shorten the course of stomach flu, or infectious diarrhea.

    The impact of taking probiotic on diarrhea across a number of studies yielded these average improvements:

    In time of diarrhea- 24 hours less

    The chance of diarrhea lasting 4 or more days- 59% less chance

    Number of fewer diarrheal stools on Day 2 of illness- 1

    If you are a premature baby, use of probiotics reduces the risk of a very serious failure of the gut in premature infants called NEC

    Probiotics Do Not Help

    Unfortunately studies of the use of probiotics in these conditions yields evidence they offer no help or benefit:

    Chronic diarrhea

    Crohn’s disease

    Ulcerative colitis

    No Proof that Probiotics Help, Some Indication that they Do Not Help

    A further disappointment comes from a look at all these conditions, in each instance the evidence falls short of recommending their use, or even hints

    probiotics don’t help at all:


    Premature labor

    Gestational diabetes

    Bacterial vaginosis


    Urinary tract infections


    Prevention of tooth cavities

    Infant colic

    Might help, but the evidence on the might is mighty small

    Yeast infections of the vulva or vagina

    Pneumonia for people on ventilators

    Colds in healthy people

    Can Probiotics Cause Harm?


    One study measured the complex integrity of people’s microbiome after taking a course of oral antibiotics.  Sure enough, it damaged the microbiome, but the surprise was that for people who took probiotics after a course of antibiotics, it took longer for the microbiome to recover, than in people who did not.  The whole point of probiotics is to restore the microbiome to its better self, and this study shows it can to just the opposite!

    Another potential harm.  Probiotics are bacteria and their production is not under standards anywhere near those applied to prescription drugs, so there have been cases, mainly in people with weakened immune systems, of infections occurring from the probiotics.


    1. Everyone is pro probiotic just now.  It sounds like such a great idea, swallow friendly bacteria, restore gut microflora to its original integrity.  It’s like adding ladybugs to your yard, all good, what could go wrong?
    2. But it turns out probiotics are just like every other intervention, it has to work to work.
    3. A very large number of studies demonstrate that probiotics are proven to work in only 3 settings: preventing C. diff infections after antibiotics, mildly shortening the course of diarrhea in stomach flu, and preventing a bad condition of the gut in premature infants.
    4. These studies then demonstrate a rather dismal record of failing to work very well across a massive range of conditions, from eczema to diabetes, from obesity to colic.
    5. And, like all interventions, there are risks with this one too.

    Like so many hopeful interventions, most things do not work very well.  It turns out the body is truly a complex phenomena, that is brilliant at staying as it is, wily in resisting our chemicals, bugs, and other interventions.

    To your health,
    Dr. Arthur Lavin

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