Good bacteria after antibiotics: when and how to take probiotics?

Antibiotics help treat bacterial infections, but their effects are not limited to the bacteria that caused the illness. During treatment, the gut microbiota can change, and some people experience diarrhea, bloating, or other digestive problems. This often raises the question of whether to take good bacteria during antibiotic treatment.

It is equally important to know when to start taking them, whether a break between antibiotics and good bacteria is necessary, and for how long to continue the course. Separate questions very often arise for parents considering good bacteria for children after antibiotics.

In this article, you will learn how antibiotics affect the gut microbiota, when and how to take good bacteria during and after treatment, in what cases they can be beneficial, and what to pay attention to when choosing them for children.

Antibiotics act on bacteria – they destroy them or inhibit their multiplication. This allows for the treatment of bacterial infections, but the drugs can affect not only the disease-causing bacteria but also some of the bacteria naturally residing in the gut. As a result, the composition of the gut microbiota may temporarily change and its diversity may decrease during treatment.

These changes in the microbiota do not automatically mean that it is necessary to take probiotics after every course of antibiotics. Scientific data best support the use of certain probiotics in reducing some adverse effects associated with antibiotic use, particularly the risk of antibiotic-associated diarrhea. Whether probiotics help the microbiota itself "recover" after antibiotics is a separate question that we will discuss further.

And what are good bacteria, how do they differ from probiotics, and what functions do they perform in the body, we invite you to read more in our article "Good bacteria: what are they and why are they important for the body?"

Most of the data on the benefits of probiotics when taking antibiotics refer to antibiotic-associated diarrhea. Antibiotics can change the composition of the gut microbiota, which may lead to diarrhea and other digestive disorders in some people during or after treatment.

A systematic meta-analysis of 42 randomized controlled trials, covering more than 11,000 adults, showed that probiotic use alongside antibiotics was associated with a 37% lower relative risk of antibiotic-associated diarrhea.

Interestingly, the benefit of probiotics was more pronounced in studies where the risk of antibiotic-associated diarrhea was higher. This suggests that not every person taking antibiotics will benefit equally from probiotics.

The type of good bacteria used is also important. Different types and strains of microorganisms, their combinations, and dosages were used in the studies, and the results were not always consistent. Therefore, a large number of bacteria on a product label alone does not indicate whether a particular probiotic will be suitable. It is much more important to pay attention to its composition, specific strains, and the purpose for which they were studied.

One of the most common practical questions is when to take good bacteria while on antibiotics and whether they can be started before finishing the treatment. In studies that found benefits in reducing the risk of antibiotic-associated diarrhea, good bacteria were most often started concurrently with the antibiotic course, not just after it. In some studies, they were started within the first 1-2 days of treatment.

Yes, they can be taken during the same treatment period, but supplements containing bacteria are usually advised not to be taken at the same time as the antibiotic dose. A gap of approximately 2 hours is recommended between them. This is a precautionary measure to reduce the likelihood that the antibiotic will affect the bacteria in the supplement. There are currently no direct studies that have established an optimal time gap. This rule does not apply to yeast-based probiotics, such as Saccharomyces boulardii, as antibiotics do not affect yeast.

There is no single duration suitable for everyone. It can depend on the chosen product and the goal. After finishing a course of antibiotics, it is worth following the recommendations for the specific product or consulting a doctor or pharmacist.

Antibiotic-associated diarrhea can also occur in children, so the use of good bacteria during treatment has been widely studied in this age group. Systematic review data show that certain probiotics can reduce the risk of antibiotic-associated diarrhea in children.

This does not mean that any good bacteria supplement is suitable for a child. Different products use different strains of microorganisms and their quantities, so when choosing, it is important to consider the child's age, the specific product's composition, and the manufacturer's indicated age for use. More caution is needed when choosing good bacteria for infants, as well as for severely ill children, those with weakened immunity, or other serious health problems.

• Choose a probiotic product suitable for your child's age.

• Adhere to the dosage specified by the manufacturer or doctor.

• If your child is seriously ill or has a weakened immune system, consult a doctor before use.

When choosing a probiotic supplement, a high number of microorganisms alone is not enough. It is important to consider the types and strains of bacteria used in the product, as the effects of different microorganisms can vary. If a specific strain is indicated on the product packaging or in the manufacturer's information, it can be used to check whether this particular microorganism has been studied for a specific effect.

Some product packaging indicates the CFU (colony-forming units) count, which shows the number of viable microorganisms. A higher CFU count does not necessarily mean that the product will be more effective – what matters is what microorganisms it contains and for what purpose they are used.

Key information:

Even with the right product, mistakes can be made when taking probiotics. The most common ones include:

• Probiotics are taken at the same time as an antibiotic dose. For supplements containing bacteria, it is generally recommended to leave an interval of approximately 2 hours from the antibiotic.

• Failure to follow specific product usage recommendations. Dosage and frequency of use may vary, so product instructions or the recommendations of a doctor or pharmacist should be followed.

• Expecting probiotics to solve all digestive problems. Diarrhea, abdominal pain, or other symptoms can arise for various reasons. If diarrhea persists, is severe, or is accompanied by fever, severe abdominal pain, blood in the stool, or signs of dehydration, a doctor should be consulted.

Quick reminder: probiotics when taking antibiotics

Probiotics after antibiotics can be beneficial in certain cases, and the most data has been collected on their effect on the risk of antibiotic-associated diarrhea. However, probiotics should not be considered an essential part of every antibiotic course. Their choice and use should depend on the specific situation, product composition, and individual needs.