Little data on probiotics use by immunocompromised, preemies, and critically ill

Created September 2025

Three Groups Who Should Not Take Probiotics

Medical experts and health authorities consistently identify three main groups of people who should avoid probiotics due to significant safety risks:

Immunocompromised Patients

People with compromised immune systems are at the highest risk for serious complications from probiotics. This includes individuals who are: flore+2

Receiving chemotherapy or radiation therapy for cancer treatment singlecare+1

Taking immunosuppressive medications after organ transplants pmc.ncbi.nlm.nih+1

Using corticosteroids at high doses (greater than ½ mg per kg body weight) pmc.ncbi.nlm.nih

Living with conditions like HIV/AIDS, leukemia, or other blood cancers pmc.ncbi.nlm.nih

Receiving injectable immunosuppressive drugs for autoimmune diseases pmc.ncbi.nlm.nih

The risk stems from the fact that these patients' weakened immune systems cannot effectively control even "friendly" bacteria, potentially leading to serious bloodstream infections, sepsis, or fungemia. natap+2

Critically Ill Patients

Patients who are severely ill, particularly those in intensive care units (ICUs), face significant risks from probiotic use. This group includes: optibacprobiotics+2

Patients currently in the ICU pharmacyjoe+2

Those with central venous catheters optibacprobiotics+2

Individuals recovering from major surgery with open wounds optibacprobiotics

Patients with severe underlying medical conditions requiring hospitalization webmd+1

Recent research has shown that ICU patients receiving probiotics have a substantial rate of probiotic-associated bloodstream infections, with a number needed to harm of 270. These infections are associated with significantly increased mortality, with an odds ratio of 2.23. pharmacyjoe

Premature Infants

The FDA has issued specific warnings about probiotic use in preterm infants following documented deaths and serious adverse events. This vulnerable population includes: ods.nih+2

Very preterm infants (birth weight less than 1000 grams) empr+2

Very low birth weight infants in general fda+2

Infants with short bowel syndrome optibacprobiotics

Any premature infant in hospital NICU settings nbcnews+1

The American Academy of Pediatrics explicitly states that "current evidence does not support the routine, universal administration of probiotics to preterm infants, particularly those with a birth weight of less than 1000g". Since 2018, there have been more than two dozen adverse events in infants linked to probiotics, including at least one confirmed death in 2023. fda+3

Additional High-Risk Situations

While the three main groups represent the clearest contraindications, medical professionals also advise caution for:

Pregnant women in their third trimester flore

People with severe food allergies who may react to probiotic ingredients singlecare

Individuals with certain severe gastrointestinal disorders, like active inflammatory bowel disease singlecare

Patients with structural heart disease or valve abnormalities pmc.ncbi.nlm.nih

The consensus among healthcare providers is that while probiotics are generally safe for healthy individuals, these three vulnerable populations should only use probiotics under strict medical supervision, if at all. doylestownhealth+2

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Tags: Antibiotics and probiotics