Giving antacids and antibiotics to babies can lead to allergies

Claire McCarthy, MD

Senior Faculty Editor, Harvard Health Publishing

Follow me on Twitter @drClaire

Allergies are on the rise, especially food allergies. While nobody knows for sure why this is happening, a leading theory is that we may be doing things that mess up our natural microbiome.

Our microbiome is the trillions of organisms that live on and in our bodies, such as bacteria, archaea, fungi, and viruses. We generally think of these organisms as “germs” that can cause illness — and while they can, in some situations it turns out that the right organisms in the right balance actually help keep us healthy. Our microbiome affects how we digest foods, stay at a healthy weight, fight infection, and stave off diseases like diabetes. Through its link to our immune system, our microbiome is thought to be linked to our risk of allergic reactions.

Two common types of medications, antacids and antibiotics, can mess up our microbiome. Antibiotics do it by killing not just the bacteria that make us sick, but also the bacteria that help keep us healthy. As for antacids, by making the stomach less acidic they make it more likely that bacteria from the mouth (that are normally killed by the acid in the stomach when swallowed) make it down into the intestine. Those mouth bacteria can crowd out the bacteria that our intestines need to function normally.

In a study published in JAMA Pediatrics, researchers studied almost 800,000 children from birth to about 4 years of age. They looked to see if the children got antacids or antibiotics in the first six months of life, and then tracked to see if they went on to have any allergic conditions. They found that children who got antacids were twice as likely to have food allergies as those who didn’t, and children who got antibiotics were twice as likely to have asthma as those who didn’t. Children who got either antacids or antibiotics showed an increased risk of other kinds of allergic conditions, from hay fever to severe allergic reactions.

This does not mean that infants should never get antacids or antibiotics. Antibiotics can be lifesaving for infants with bacterial infections, and there are situations when antacids can be extremely useful. But both medications are often overused. Antacids are often used in babies with reflux, or fussiness with feeding; while they can be helpful, the symptoms can be managed in other ways and usually resolve with time. Antibiotics are often used for upper respiratory infections, even though most upper respiratory infections are caused by viruses and don’t need antibiotics.

Moving forward, doctors need to be thoughtful and careful about how they prescribe antacids and antibiotics to infants, only doing it when truly necessary. Parents of infants need to be informed consumers. When given a prescription for either antacids or antibiotics, they should ask if it is truly necessary — and whether there are any alternative treatments that might be tried.

It’s about breaking old habits, and thinking about treatments in different ways based on what research is telling us. The more we learn, the more we can keep our children healthy, not just now but for the rest of their lives.


  1. vinu arumugham


    Drs. Pulendran and Ahmed of the Emory Vaccine Center write⁠:

    “Despite their success, one of the great iro-nies of vaccinology is that the vast majority of vaccines have been developed empirically, with little or no understanding of the immunological mechanisms by which they induce protective immunity. However, the failure to develop vaccines against global pandemics such as infection with human immunodeficiency virus (HIV) despite decades of effort has underscored the need to understand the immunological mechanisms by which vaccines confer protective immunity.”

    Since vaccinologists are themselves ignorant of vaccine mechanisms, how can we expect epidemiologists to understand the mechanisms? So most epidemiological studies ignore mechanism of adverse event causation. If you ignore mechanism, you cannot design the study with appropriate controls. So the results of such epidemiological studies have to be discarded due to confounding.

    Berin et al. write in
    Food Allergy: An Enigmatic Epidemic

    “The relevant site of exposure has been proposed to be the skin, and this is supported by the finding that peanut-responsive T cells in peanut-allergic patients can be found in the subset defined as skin-homing (CLA+), but not those defined as gut-homing (integrin β7+)”

    “Food allergy is associated with Th2-skewed CD4+ T cells that express skin-homing markers, suggesting skin exposure as a risk factor for the development of food allergy.”

    “Mice can be readily sensitized by skin exposure to allergens, but this is dependent on tissue damage (induced by tape stripping) or presence of adjuvant”

    Ever heard of parents tape stripping their kids and rubbing food mixed with cholera toxin as adjuvant, on the damaged tissue?
    Neither have I. So how did sensitization occur?

    Doctors however, regularly damage skin/muscle tissue and inject numerous food proteins along with aluminum salts as adjuvant.

    How long is the medical community going to beat around the bush and continue to sicken our kids instead of admitting and fixing the root cause – food protein contaminated vaccines?

    Please see details in the British Medical Journal:

    Vaccines and the development of food allergies: the latest evidence

    Vaccine safety claims do not stand up to scrutiny

  2. vinu arumugham

    Antacids and other acid reducing medication causing allergy has been known for a long time.

    Basically, if you interfere with or bypass protein processing, you alter the immune response to proteins.

    Acid reduction interferes with protein processing in the stomach and intestines.

    What happens if you completely bypass protein processing? Inject food proteins? The food allergy epidemic.

    Details in the British Medical Journal:

    Vaccines and the development of food allergies: the latest evidence

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