Probiotic During and After Antibiotic Treatment: How to Support the Gut Microbiota

During the autumn and winter seasons, respiratory infections become more common. Many of them are caused by viruses, which means that antibiotics are not always the appropriate treatment. Antibiotics act against bacteria, not viruses responsible for most common colds and many flu-like infections.

However, if a doctor diagnoses a bacterial infection or a secondary bacterial infection develops following a viral illness, antibiotic treatment may be necessary. In such cases, it is useful to understand not only how to take the medication correctly, but also what may happen to the gut microbiota during treatment and what role an appropriately selected probiotic may play.

Why should antibiotics not be used “just in case”?

Antibiotics are among the most important tools of modern medicine, but they should only be used when there is a clear indication.

Unnecessary and inappropriate use of antibiotics accelerates the development of antimicrobial resistance. This does not mean that the human body becomes resistant to the medicine. Instead, bacteria can develop mechanisms that allow them to survive antibiotic treatment, making certain infections more difficult to treat in the future.

For this reason, antibiotics should be taken according to a doctor’s instructions, at the prescribed dose and for the recommended duration. Antibiotic treatment should not be started independently, leftover antibiotics from previous treatments should not be used, and antibiotics should not be taken for an ordinary cold.

How do antibiotics affect the gut microbiota?

Antibiotics are used to target bacteria responsible for an infection, but their effects may also involve some of the bacteria naturally present in the digestive tract.

The extent of these changes depends on the type of antibiotic, its spectrum of activity, the dose, treatment duration, previous antibiotic courses and the individual composition of the microbiota.

This does not mean that every course of antibiotics “destroys the gut flora”. However, antibiotic treatment may reduce microbial diversity and temporarily alter the proportions of different bacterial groups. Some people may experience gastrointestinal symptoms such as loose stools or diarrhoea, abdominal discomfort, nausea or bloating.

One of the better understood complications is antibiotic-associated diarrhoea, commonly abbreviated as AAD.

Antibiotic treatment and Clostridioides difficile

Antibiotic treatment is also one of the major risk factors for infection with Clostridioides difficile.

This bacterium may multiply in the intestine particularly when the natural microbial community has been disrupted. Infection can cause diarrhoea and inflammation of the colon and, in severe cases, may lead to serious complications.

Not every episode of diarrhoea during antibiotic treatment means that C. difficile infection is present. However, if diarrhoea is severe or persists after treatment, particularly when accompanied by fever, significant abdominal pain, dehydration or deterioration in general health, medical advice should be sought.

Is it worth taking a probiotic during antibiotic treatment?

Research indicates that some specific probiotics may reduce the risk of antibiotic-associated diarrhoea. This does not mean, however, that every product described as a probiotic will have the same effect.

In probiotic therapy, the specific strain is particularly important, rather than only the genus or species of the microorganism.

Among the better-studied microorganisms in the context of preventing antibiotic-associated diarrhoea are Lacticaseibacillus rhamnosus GG ATCC 53103, still frequently referred to by its former name Lactobacillus rhamnosus GG, as well as certain preparations containing Saccharomyces boulardii.

Results obtained for one strain cannot automatically be applied to other strains of the same species or to all probiotic products.

Recommendations may also differ between patient groups. Factors such as age, health status, the antibiotic being used and the individual risk of complications may all be relevant.

Probiotic before or after an antibiotic? What interval should be maintained?

This is one of the most common questions during antibiotic treatment.

For probiotics containing bacteria, it is generally recommended to maintain a time interval between the antibiotic and the probiotic. In practice, an interval of approximately 2–3 hours is often used unless a doctor, pharmacist or the manufacturer of the specific product recommends otherwise.

It should therefore not be assumed that every bacterial probiotic strain can be taken at exactly the same time as an antibiotic.

The situation is different with Saccharomyces boulardii. It is a yeast rather than a bacterium, so antibacterial antibiotics do not affect it in the same way as bacterial probiotics. Nevertheless, the method of use should always follow the instructions for the particular preparation.

When a probiotic is used with the aim of reducing the risk of antibiotic-associated diarrhoea, available studies suggest that starting supplementation early during antibiotic treatment may be more relevant than beginning it several days after the antibiotic course has already ended.

How long should a probiotic be taken after antibiotics?

There is no single universal rule stating that a probiotic must be taken for one, two or three months after every course of antibiotics.

The duration of supplementation depends on the specific strain, the product, the purpose of supplementation and the individual situation.

In studies examining the prevention of antibiotic-associated diarrhoea, probiotic regimens often cover the period of antibiotic treatment and a defined period after it has ended.

At the same time, current evidence is insufficient to conclude that routine supplementation with any probiotic after antibiotics always accelerates complete restoration of the original composition of the gut microbiota.

Instead of following the principle that “longer is always better”, it is more appropriate to consider the specific strain, the manufacturer’s recommended duration of use and individual circumstances.

How to support the diet after antibiotic treatment

After completing antibiotic treatment, it is also worth paying attention to diet. The gut microbiota uses a wide range of nutrients from everyday food, which is why dietary diversity is important.

If health permits, a varied diet containing vegetables, fruit, whole grains, legumes, nuts and seeds can gradually be reintroduced or maintained. These foods provide different types of dietary fibre that may be used by intestinal microorganisms.

Naturally fermented foods such as yoghurt, kefir or fermented vegetables may also form part of the diet. It is important to remember, however, that fermented food and a probiotic containing a precisely identified strain are not the same thing.

People using the Narine strain may also prepare a homemade fermented milk product using an appropriate starter and according to the preparation instructions.

Narine and antibiotic treatment – why the specific strain matters

Narex products contain the specifically identified strain Lactobacillus acidophilus n.v. Er 317/402 Narine.

This is a different strain from LGG or Saccharomyces boulardii, which means that research results concerning those microorganisms should not automatically be attributed to Narine. This is one of the key principles when interpreting probiotic research: an observed effect should be linked to the strain that was actually studied.

If products containing Narine are used as part of supplementation during antibiotic treatment, they should be used according to the instructions for the specific product, including an appropriate interval from the antibiotic where applicable.

Probiotic and antibiotic – the specific strain matters most

Antibiotics are essential in the treatment of many bacterial infections, but their use may influence the gut microbiota and may be associated, among other things, with a risk of antibiotic-associated diarrhoea.

Not all probiotics have the same properties. When choosing a preparation, it is worth checking the complete strain designation, the context in which that strain has been studied, the recommended method of use and the dosage instructions.

With bacterial probiotics, a time interval of a few hours from the antibiotic is generally maintained during antibiotic treatment. At the same time, there is no universal recommendation that everyone should take any probiotic for several months after every course of antibiotics.

If severe or persistent diarrhoea, fever, significant abdominal pain or other concerning symptoms develop during or after antibiotic treatment, medical advice should be sought rather than simply extending probiotic supplementation independently.

This material is for educational purposes only and does not replace medical consultation. A dietary supplement is not a medicinal product and cannot replace prescribed treatment.