Probiotic Safety: What to Know Before You Start

General Safety Profile of Probiotic Foods and Supplements

Probiotics have an extensive history of apparently safe use, particularly in healthy people. Common probiotic foods include yogurt, kefir, and fermented vegetables, while supplements come in capsules, powders, and liquids. For most healthy adults, these products are well tolerated.

However, the U.S. National Center for Complementary and Integrative Health (NCCIH) notes that few studies have looked at the safety of probiotics in detail, so there is a lack of solid information on the frequency and severity of side effects. This means that even though probiotics are generally safe, they are not entirely without risk.

In the United States, many probiotics are sold as dietary supplements, which do not require FDA approval before they are marketed. Supplement labels may make claims about how the product affects the structure or function of the body without FDA approval, but they are not allowed to make health claims (such as lowering risk of disease) without the FDA's consent. If a probiotic is to be marketed as a drug for treatment of a disease or disorder, it must be proven safe and effective through clinical trials and be approved by the FDA before it can be sold.

Thus, while probiotics are accessible, their safety and effectiveness are not as tightly regulated as pharmaceuticals. This section provides an overview of what is known and what to consider.

Sources: National Center for Complementary and Integrative Health (NCCIH)

Common Side Effects: Gas, Bloating, and Digestive Upset

Some people experience gas, bloating, or digestive upset when they start taking probiotics. These symptoms are usually mild and typically resolve within a few days to weeks as your gut adjusts. If you are new to probiotics, you might notice these effects more at first.

To manage these side effects, you can try taking a smaller dose or taking the probiotic with food. If the symptoms persist or worsen, consider reducing the dosage or stopping the product. Consult a doctor if you experience severe or persistent side effects.

Remember that side effects are not universal; many people take probiotics without any discomfort. Paying attention to how your body responds can help you decide whether to continue.

Sources: Medical News Today, WebMD

Who Should Exercise Caution

The risk of harmful effects from probiotics is greater in people with severe illnesses or compromised immune systems. The NCCIH specifically advises that children and adults with severe illnesses or compromised immune systems should avoid using probiotics. This includes individuals undergoing chemotherapy, organ transplant recipients, and those with HIV/AIDS or other immune deficiencies.

Additionally, cases of severe or fatal infections have been reported in premature infants who were given probiotics. The U.S. Food and Drug Administration (FDA) has warned healthcare providers about this risk. Therefore, probiotics should not be given to premature infants without close medical supervision.

People with certain digestive system conditions, such as short bowel syndrome, ulcerative colitis, or intestinal obstruction after abdominal surgery, have developed bloodstream infections after taking probiotics. If you have any of these conditions, talk with your healthcare provider before using probiotics.

Also, if you have a central line or indwelling catheter, you should discuss probiotics with your healthcare provider first, because bloodstream infections have been reported, especially with Saccharomyces boulardii.

• People with severe illnesses or compromised immune systems
• Premature infants
• Individuals with central lines or indwelling catheters
• People with short bowel syndrome, ulcerative colitis, or intestinal obstruction after surgery

Sources: National Center for Complementary and Integrative Health (NCCIH), WebMD

Drug Interactions and Probiotics

Probiotics may reduce the risk of antibiotic-associated diarrhea. A 2017 review of studies, as reported by NCCIH, found that giving probiotics to patients along with antibiotics was associated with a decrease of about half in the likelihood of antibiotic-associated diarrhea.

If you are taking immunosuppressive medications or antifungal drugs, you should be cautious because probiotics contain live microorganisms. The secondary source WebMD notes that people with weakened immune systems should avoid probiotics or use them only under medical supervision. Always inform your healthcare provider about any supplements you are taking, including probiotics, to avoid potential interactions.

Sources: National Center for Complementary and Integrative Health (NCCIH), WebMD

Regulation and Probiotic Supplements

The FDA does not approve dietary supplements before they are marketed. This means that probiotic supplements are not held to the same standards as drugs for safety and effectiveness. In the United States, dietary supplements are regulated under the Dietary Supplement Health and Education Act (DSHEA) of 1994, which places the responsibility for product safety and labeling on manufacturers.

Under DSHEA, the FDA has post-market oversight, meaning it can take action against unsafe products after they are on the market. However, there is no pre-market approval process for safety or efficacy as there is for drugs. The product label may contain claims that are not verified by the FDA, but it cannot claim to treat or cure a disease without approval.

Another concern is that some probiotic products have been reported to contain microorganisms other than those listed on the label. In some instances, these contaminants may pose serious health risks. Therefore, it is important to choose products from reputable manufacturers that follow good manufacturing practices, but even then, there is no guarantee of purity.

When selecting a probiotic supplement, look for products that have been tested by independent organizations, such as those that verify the contents match the label. However, be aware that such testing is not always available.

If you are considering a probiotic to treat a medical condition, know that it would need FDA approval as a drug. Most probiotic supplements do not go through this process, so their intended uses are not approved.

Sources: National Center for Complementary and Integrative Health (NCCIH)

When to Seek Medical Advice

You should consult a healthcare provider before starting probiotics if you have a severe illness, a compromised immune system, are critically ill, or are caring for a premature infant. Also, if you have a central line, indwelling catheter, or certain digestive conditions, as mentioned earlier, professional guidance is essential.

If you experience severe or persistent side effects from a probiotic, such as digestive upset that does not go away or signs of infection, stop taking the product and seek medical attention. Symptoms like fever, chills, or persistent diarrhea could indicate an infection.

General advice: always discuss any new supplement with your doctor, especially if you are taking other medications or have underlying health conditions. Your doctor can help you weigh the potential benefits against the risks for your specific situation.

Sources: National Center for Complementary and Integrative Health (NCCIH), Medical News Today

Safety During Pregnancy and for Children

The available authoritative sources do not specifically address the safety of probiotics during pregnancy and in children. Some secondary sources, such as WebMD, suggest that certain probiotic species are 'possibly safe' during pregnancy and for children, but the evidence is not conclusive. Because of the lack of detailed safety data, it is prudent to consult a healthcare provider before using probiotics during pregnancy or giving them to children, especially infants.

In particular, the FDA has warned about the risk of infections in premature infants given probiotics. Therefore, probiotics should not be given to premature infants without medical supervision.

For healthy full-term infants and older children, probiotics are often considered safe, but it is still wise to ask a pediatrician. They can provide personalized advice based on the child's health.

Sources: National Center for Complementary and Integrative Health (NCCIH), WebMD