Probiotics with Antibiotics – When to Take Them, How Long to Separate Them and How Long to Continue

When a doctor prescribes an antibiotic, another question often arises: when should a probiotic be started, how many hours should it be separated from the antibiotic and how long should it be continued after treatment?

An antibiotic acts on bacteria that cause infection, but it may also affect some of the microorganisms that naturally live in the digestive tract. In some people, this may result in loose stools, diarrhoea, bloating, gas or abdominal discomfort. Certain probiotic strains may reduce the risk of antibiotic-associated diarrhoea, but not every probiotic has been studied equally and there is no single preparation that is best for everyone.

The most important point is to select a probiotic according to the precisely identified strain, age, health status and complete product composition, rather than only according to the number of billions of microorganisms stated on the package.

How do antibiotics affect the gut microbiota?

The gut microbiota is a complex community of microorganisms involved in digestion, the production of certain metabolic substances, protection of the intestinal lining and prevention of excessive growth of some harmful microorganisms.

Antibiotics are not all the same. Their effect on the gut microbiota depends on:

• the type and spectrum of the antibiotic;
• the prescribed dose;
• the duration of treatment;
• the number of antibiotics used at the same time;
• the patient’s age;
• diet and the previous condition of the microbiota;
• previous antibiotic treatments;
• the presence of other illnesses and treatments.

It is not accurate to say that an antibiotic “destroys the entire gut flora”. It may reduce the number of certain sensitive bacteria and change the balance of the microbiota, while other microorganisms may be less affected or may temporarily multiply.

Most changes partly or largely resolve over time, but the speed of recovery is not the same for everyone. A probiotic does not automatically restore the gut microbiota to its original state. Instead, certain studied strains may provide temporary functional support and reduce the risk of some gastrointestinal adverse effects.

Does everyone taking an antibiotic need a probiotic?

There is no rule stating that every person prescribed an antibiotic must also take a probiotic. Many people complete a short course of antibiotics without significant gastrointestinal problems.

A probiotic may be more relevant for people who:

• have previously experienced diarrhoea during antibiotic treatment;
• are prescribed a broad-spectrum antibiotic;
• are taking more than one antibiotic at the same time;
• have a longer course of treatment;
• have a sensitive digestive system;
• are hospitalised or have additional risk factors;
• are children for whom a paediatrician or pharmacist has assessed that probiotic support is appropriate.

A probiotic should not be regarded as permission to use antibiotics unnecessarily or as protection against all their adverse effects. An antibiotic should be taken only when prescribed, at the correct dose and for the period determined by the doctor.

When should a probiotic be started with an antibiotic?

In studies showing a benefit, probiotic use was usually started as early as possible – immediately before the first antibiotic dose, on the same day or during the first one to two days of antibiotic treatment.

There is no need to wait until the antibiotic course has ended before introducing a probiotic. When it is used to reduce the risk of antibiotic-associated diarrhoea, it is more rational for the probiotic to be present during the period in which the antibiotic affects the digestive tract.

How much time should be left between an antibiotic and a probiotic?

For most probiotic preparations containing live bacterial cultures, it is reasonable to leave approximately two hours between the antibiotic and probiotic. The purpose is to reduce the possibility that the antibiotic will inactivate sensitive probiotic bacteria before they reach the intestines.

This may mean:

• taking the probiotic two hours before the antibiotic;
• taking the probiotic two or more hours after the antibiotic;
• taking it between two daily antibiotic doses.

It is not essential for the probiotic to be taken only before or only after the antibiotic. It is more important to maintain an appropriate interval, take it regularly and avoid disrupting the prescribed antibiotic schedule.

Example schedules for probiotics and antibiotics

The following examples are provided only to illustrate the interval. The actual schedule must follow the instructions for the antibiotic and probiotic being used.

If the schedule becomes so complicated that maintaining the interval leads to missed antibiotic doses, consult a pharmacist. Correct adherence to antibiotic treatment is more important than achieving a perfect supplement schedule.

Saccharomyces boulardii with antibiotics – is a time interval required?

Saccharomyces boulardii is a probiotic yeast rather than a bacterium. Antibacterial antibiotics do not target yeasts, so a pure S. boulardii preparation is not affected in the same direct way as bacterial probiotic cultures.

In practice, this means that a time interval is usually not required to protect a pure S. boulardii preparation from the direct effect of an antibacterial antibiotic. However, the full composition of the product should be checked.

A product may contain:

• only probiotic yeast;
• yeast and bacterial probiotic strains;
• yeast, a prebiotic and additional vitamins or minerals;
• other ingredients with specific administration requirements.

If a preparation contains bacterial cultures in addition to S. boulardii, separating it from the antibiotic may still be relevant because of those bacterial strains.

Bacterial probiotic or S. boulardii – which should you choose?

The choice is not based only on whether a product contains bacteria or yeast. The specific strain should have been studied for the purpose for which it is being used.

Certain evidence particularly supports strains such as Lacticaseibacillus rhamnosus GG and Saccharomyces boulardii in specific situations. This does not mean that every product carrying the general name “Lactobacillus” or “Boulardii” has the same quality, dose and level of evidence.

Are more billions of probiotics always better?

No. A higher number of CFU does not guarantee a better result.

When choosing a product, consider all of the following:

• the precisely stated probiotic strain;
• the intended clinical use of the product;
• the quantity of live microorganisms in the recommended daily dose;
• whether the stated amount is guaranteed until the end of the shelf life;
• the age group for which the product is intended;
• storage conditions;
• the presence of prebiotics, vitamins, minerals and allergens;
• the product form and the ability to take it correctly.

A preparation with one well-defined strain at an appropriate dose may be a more rational choice than a product containing a large number of imprecisely identified cultures.

Can a probiotic reduce the effectiveness of an antibiotic?

There is no evidence that a correctly used probiotic reduces the ability of an antibiotic to act on the bacterial infection for which it was prescribed.

The interval for bacterial probiotics is not intended to protect the antibiotic. It is intended to reduce the possibility that the antibiotic will inactivate the probiotic bacteria.

A probiotic should not be used instead of an antibiotic, and the prescribed dose or treatment duration should not be changed independently.

Should a probiotic be taken before or after a meal?

There is no single rule for every probiotic product. Some are taken before a meal, some with food and others independently of meals.

The method of use may depend on:

• the resistance of the specific strain to stomach acid;
• the capsule or microencapsulation technology;
• whether the powder must first be activated in water;
• the presence of vitamins, minerals or other ingredients;
• the manufacturer’s instructions.

It is therefore not correct to advise that every probiotic should automatically be taken only on an empty stomach or only with food.

Can a probiotic be mixed with a hot drink?

Live bacterial cultures and probiotic yeast may be sensitive to high temperatures. Powder or capsule contents should not be added to hot tea, coffee, milk, soup or baby food unless the manufacturer specifically states otherwise.

The following are usually used for mixing:

• cold or lukewarm water;
• a cold or lukewarm drink permitted by the label;
• a small amount of food at room temperature, when permitted.

The prepared dose should usually be taken immediately. It should not be left for several hours or prepared in advance for the following day.

How long should a probiotic be continued after antibiotics?

In clinical studies, probiotics were often continued for approximately 7–14 days after the antibiotic course ended. This is a commonly used approach, but it is not a mandatory or universal rule for every product and every person.

The duration depends on:

• the specific probiotic strain and product;
• the duration of antibiotic treatment;
• whether diarrhoea or other symptoms developed;
• age;
• previous episodes of antibiotic-associated diarrhoea;
• health status and professional advice.

The same preparation should not be continued randomly for months simply because it was used with an antibiotic. If symptoms continue after treatment, their cause should be assessed.

Probiotics with antibiotics in children

Children should not automatically be given the product used by an adult. The preparation must be appropriate for the child’s age, body weight, method of administration and health status.

Before use, check:

• the minimum age stated on the label;
• the exact probiotic strain;
• the recommended daily dose;
• whether the capsule may be opened;
• the amount of liquid required to dissolve a sachet;
• whether the preparation contains vitamin D, zinc or other added ingredients;
• whether a time interval from the antibiotic is required;
• storage conditions.

Paediatric guidelines state that, when risk factors are present and prevention of antibiotic-associated diarrhoea is being considered, certain studied strains may be used, including Lacticaseibacillus rhamnosus GG and Saccharomyces boulardii. This recommendation cannot be applied to every probiotic preparation.

Probiotics with Helicobacter pylori treatment

Treatment for Helicobacter pylori infection often includes two antibiotics and a medicine that reduces stomach acid, and sometimes additional medicines. Because the treatment is complex, nausea, a metallic taste, abdominal discomfort or diarrhoea may occur.

Certain probiotic strains may be used as additional support to improve treatment tolerability. A probiotic:

• does not eradicate H. pylori by itself;
• does not replace antibiotics or prescribed treatment;
• must not be used as a reason to shorten the treatment;
• must be fitted into a complex medicine schedule.

When several medicines are taken multiple times a day, a pharmacist can help create a clear schedule without unnecessary overlap.

What is antibiotic-associated diarrhoea?

Antibiotic-associated diarrhoea may occur during treatment or after the antibiotic course has ended. It usually means more loose or watery stools than is normal for the person.

Not every change in bowel habits is equally serious. A mild, short-term change may settle spontaneously, while frequent watery diarrhoea requires assessment.

Pay attention to:

• the number of stools;
• the duration of symptoms;
• the presence of blood or mucus;
• temperature;
• abdominal pain and cramps;
• vomiting;
• the ability to drink fluids;
• urination frequency;
• the person’s general condition.

Should the antibiotic be stopped if diarrhoea develops?

An antibiotic should not be stopped, skipped or reduced without professional advice. Stopping treatment too early may lead to treatment failure and recurrence of the infection.

If diarrhoea develops, contact a doctor or pharmacist for assessment. The doctor may decide that:

• treatment should remain unchanged;
• the antibiotic should be replaced;
• additional tests are needed;
• appropriate rehydration or another treatment should be introduced.

The decision depends on the reason the antibiotic was prescribed and the severity of the adverse symptoms.

When should more serious diarrhoea or C. difficile be suspected?

Clostridioides difficile, also known as C. difficile, may cause diarrhoea and inflammation of the colon, particularly during or after antibiotic use. Not every episode of diarrhoea after antibiotics is caused by this bacterium, but symptoms should not be ignored.

A probiotic is not a treatment for confirmed C. difficile infection and should not delay medical examination or laboratory testing when these are required.

What should you do if diarrhoea develops while taking an antibiotic?

1. Do not stop the antibiotic independently.
2. Contact a doctor or pharmacist and describe the number of stools, duration and other symptoms.
3. Replace fluids and electrolytes. With frequent stools, an oral rehydration solution may be more important than the probiotic itself.
4. Continue a light diet according to tolerance. Fasting is not necessary, but very fatty meals and alcohol should be avoided.
5. Do not take medicine to stop bowel movements without advice if there is fever, blood in the stool or severe pain.
6. Monitor urination and general condition, especially in children and older people.

Should several probiotics be taken at the same time?

Taking two or three probiotic products at the same time does not automatically provide better protection. Combining products may unnecessarily duplicate:

• the same or similar strains;
• the daily quantity of microorganisms;
• prebiotic fibres that may increase gas;
• vitamins and minerals;
• costs without clear additional benefit.

It is better to select one appropriate product and use it correctly than to combine several formulas randomly.

How should a probiotic be stored during antibiotic treatment?

Probiotic products do not all have the same storage requirements. Some require refrigeration, while others are stable at room temperature because of their manufacturing and packaging technology.

• Read the storage temperature stated on the package.
• Do not keep the product beside a cooker, radiator or in direct sunlight.
• Do not leave it in a hot vehicle.
• Protect it from moisture.
• Do not transfer capsules to an unlabelled container if this removes information about expiry and storage.
• Do not use a preparation with damaged packaging.

Recommended products and categories

A product should be selected according to age, composition, specific strain, method of use and instructions. The following are examples of different formulations available from ApotekaOnline.

View the complete range in the Probiotic Preparations and Diarrhoea After Antibiotic Use categories.

The listed products are examples of different formulations and are not a universal recommendation for every patient. Before use, check the composition, specific strain, age restrictions, dose, warnings, storage instructions and possible interactions.

Related topics and useful guides

• Probiotics – facts, myths, strains and correct use
• Helicobacter pylori – causes, symptoms and treatment
• Stomach virus – symptoms and what to do

Frequently asked questions about probiotics with antibiotics

When should a probiotic be started with an antibiotic?
Usually on the same day that antibiotic treatment begins or during the first one to two days. Follow the instructions for the specific product.

How many hours should be left between an antibiotic and a probiotic?
For bacterial probiotic cultures, it is reasonable to leave approximately two hours.

Should a probiotic be taken before or after the antibiotic?
It may be taken before or after, provided that an appropriate interval is maintained. It does not always have to be taken only after the antibiotic.

Does S. boulardii need to be separated from an antibiotic?
Pure probiotic yeast is not directly sensitive to antibacterial antibiotics. If the product also contains bacterial cultures, follow the instructions and consider a time interval.

Can a probiotic weaken the antibiotic?
There is no evidence that a correctly used probiotic reduces antibiotic effectiveness. The interval is mainly intended to protect the probiotic bacteria.

How long should a probiotic be continued after antibiotics?
In studies it was often continued for 7–14 days, but the duration depends on the product, strain, treatment and individual needs.

Is a probiotic required with every antibiotic?
It is not required for every person. It may be useful in the presence of certain risk factors or previous digestive problems, but the choice should be rational.

Which is the best probiotic with an antibiotic?
There is no single best product for everyone. The exact strain, level of evidence, age, dose, method of use and health status are important.

Are more billions better?
Not automatically. A higher number of microorganisms does not guarantee a better effect if the strain is unsuitable or has not been adequately studied.

Should a probiotic be taken on an empty stomach?
This depends on the product. Some are taken before food, some with a meal and others independently of meals.

Can a probiotic be added to warm tea or milk?
It should not be added to a hot liquid because high temperatures may reduce the viability of live cultures. Use a cold or lukewarm drink when mixing is permitted.

Can two probiotics be taken at the same time?
There is usually no need. Strains, doses, prebiotics, vitamins and minerals may be unnecessarily duplicated.

Should a child take a probiotic with an antibiotic?
Certain strains may be useful in specific situations, but the product must be appropriate for the child’s age and should be selected with advice from a paediatrician or pharmacist.

Should the antibiotic be stopped if diarrhoea develops?
Not without professional advice. Contact a doctor, who will decide whether treatment should be continued, changed or whether the cause of the diarrhoea requires further investigation.

Is a probiotic enough if diarrhoea develops?
Not always. With frequent stools, replacing fluids and electrolytes takes priority, and more severe symptoms require medical assessment.

Can S. boulardii be taken with an antifungal medicine?
An antifungal medicine may act on the probiotic yeast. This combination should be checked with a doctor or pharmacist.

Can diarrhoea begin after the antibiotic course has ended?
Yes. Antibiotic-associated diarrhoea and certain infections may develop after treatment has finished. Frequent or severe symptoms should be reported to a doctor.

Conclusion

A probiotic used with an antibiotic is most meaningful when it is selected according to the specific strain and used correctly, rather than chosen only because it contains the highest number of billions.

It is usually started on the same day as the antibiotic or as early as possible during treatment. For bacterial cultures, an interval of approximately two hours may reduce the possibility of inactivation. Pure Saccharomyces boulardii preparations are not directly sensitive to antibacterial antibiotics, but combination products may also contain bacterial strains.

A probiotic is often continued for several days after the antibiotic course has ended, but the exact duration should be adapted to the specific product and individual. A probiotic does not replace correct antibiotic use, oral rehydration or medical assessment when serious symptoms develop.

Frequent watery diarrhoea, fever, severe abdominal pain, vomiting, blood in the stool or signs of dehydration are not reasons simply to increase the probiotic dose. These symptoms require assessment by a healthcare professional.