Written By: Rutuja Medge, BPharm
Reviewed By: Pharmacally Editorial Team
Antibiotics are lifesaving medicines, but they often disturb the gut’s normal bacterial balance. One of the most common side effects is diarrhea, which can range from mild loose stools to serious infection.
A practical question many patients ask is whether eating yogurt during antibiotic therapy can help. Research suggests that yogurt with live cultures can lower the risk of antibiotic-associated diarrhea, especially when taken properly.
This article explains the science, what to choose, how to use it, and when to be cautious.
Why antibiotics cause diarrhea
Antibiotics are designed to kill harmful bacteria that cause infection. The challenge is that they also disturb the beneficial bacteria that normally live in the gut. When this balance is disrupted, digestion becomes less stable and symptoms such as loose stools, frequent bowel movements, gas, bloating, and abdominal discomfort can appear. In some cases, the change in gut flora allows harmful organisms like Clostridioides difficile to grow. This infection can be serious, especially in older adults and hospitalized patients, and is considered the most concerning complication of antibiotic use.
Why yogurt may help
Yogurt contains live microorganisms known as probiotics. Common species include Lactobacillus, Bifidobacterium, and Streptococcus thermophilus. These friendly bacteria help repopulate the gut with healthy microbes and compete with harmful organisms for space and nutrients. They also support the intestinal barrier, aid immune activity, and reduce inflammation in the lining of the gut. Put simply, yogurt can help restore balance in the digestive system after antibiotics disturb the natural ecosystem.
What research says
Research on yogurt and antibiotic-associated diarrhea shows mixed, but generally supportive findings.
Some randomized trials report no significant reduction in diarrhea when yogurt is used, suggesting that factors like yogurt type, dose, timing, and patient characteristics may influence outcomes.
Other studies show that yogurt containing live cultures, when taken with antibiotics, reduces both the rate and intensity of diarrhea, likely by restoring beneficial gut bacteria and stabilizing the intestinal environment.
A few trials fall between these extremes, showing no clear benefit but also no meaningful harm, which suggests yogurt may help certain groups more than others.
A pediatric trial published in BMJ Open showed that probiotic yogurt can help prevent antibiotic-associated diarrhea in children. In this randomized study, children who consumed yogurt containing live strains such as Lactobacillus rhamnosus GG, Bifidobacterium lactis Bb-12, and Lactobacillus acidophilus La-5 had fewer episodes of diarrhea compared with children given pasteurized yogurt without probiotics. Severe diarrhea was rare in the probiotic group, suggesting that adding probiotic yogurt during antibiotic treatment is a practical way to lower digestive side effects in children.
When these results are viewed together, most reviews conclude that yogurt with active cultures is a reasonable and safe supportive option during antibiotic therapy. It should be seen as a helpful add-on, not a replacement for medical treatment.
What kind of yogurt works best
Not all yogurt offers the same probiotic benefit. For meaningful support during antibiotic treatment, the best choices are products that clearly state they contain “live and active cultures.” Plain yogurt or low-sugar varieties are preferable because excess sugar can worsen diarrhea in some people.
Reading labels helps, especially when you can find strains such as Lactobacillus rhamnosus, Lactobacillus acidophilus, or Bifidobacterium. Greek yogurt is often a strong option because it is higher in protein, usually lower in sugar, and frequently contains more concentrated cultures.
Plant-based yogurts can also be useful, but only when they specifically list live cultures, so it is always worth checking the label.
How to use yogurt while taking antibiotics
To get the most from yogurt during antibiotic therapy, consistency matters. A daily serving taken throughout the course of treatment, and continued for about one to two weeks afterward, helps support the recovery of normal gut bacteria.
It is best to eat yogurt at least two hours before or after the antibiotic dose so the medicine does not immediately destroy the beneficial cultures. Fresh, refrigerated yogurt provides the greatest benefit.
At the same time, staying well hydrated is important. Water, oral rehydration solutions, and clear soups can help if loose stools develop.
Who should be careful
Although yogurt and probiotics are generally safe for healthy people, some groups should speak with a clinician before using them during antibiotic treatment.
This includes individuals with severely weakened immune systems, people with central venous catheters or serious illness, and those with a history of recurrent C. difficile infection or significant gastrointestinal disease.
Extra caution is also advised for preterm infants. Anyone who develops fever, bloody stools, worsening abdominal pain, or diarrhea that persists beyond two or three days should seek medical review, especially if there are signs of dehydration.
Yogurt helps, but it is not a substitute for medical treatment
Yogurt should be viewed as a supportive strategy alongside antibiotics, not as a treatment for infection itself. Regular intake can lower the chance of antibiotic-associated diarrhea, and when diarrhea does occur, it may reduce its duration and intensity.
It also contributes to overall gut health while the microbiome recovers. Even so, yogurt will not prevent every case of diarrhea, and it should never be used in place of prescribed medication.
The full antibiotic course should be completed unless a doctor advises otherwise.
Key takeaways
Antibiotics can disturb the normal balance of intestinal bacteria and trigger diarrhea. Yogurt that contains live cultures can help restore this balance and reduce the risk of symptoms, and many clinical studies support using probiotic-containing foods during treatment.
Choosing yogurt with active cultures, spacing it at least two hours from the antibiotic, and continuing use after therapy offers the greatest potential benefit.
People in higher-risk groups should check with their doctor first, but for most individuals, yogurt is a simple, practical step to support gut health during antibiotic use.
Reference
Diarrhea Myths and Facts, 20 February 2025, WebMD, https://www.webmd.com/digestive-disorders/ss/slideshow-diarrhea-myths-facts
Conway S, Hart A, Clark A, Harvey I. Does eating yogurt prevent antibiotic-associated diarrhoea? A placebo-controlled randomised controlled trial in general practice. Br J Gen Pract. 2007 Dec;57(545):953-9. Doi: 10.3399/096016407782604811. PMID: 18252070; PMCID: PMC2084134.
Shyoran, Rajesh; Kaur, Amanjot1; Bharat, Pareek2; Pathania, Rimple. Effect of probiotic yogurt on antibiotic-associated diarrhea among pediatric patients; randomized controlled trial. Journal of Education and Health Promotion 13(1):317, August 2024. | DOI: 10.4103/jehp.jehp_1497_23
Bernadeta Patro-Golab, Raanan Shamir, Hania Szajewska, Yogurt for treating antibiotic-associated diarrhea: Systematic review and meta-analysis, Nutrition, Volume 31, Issue 6, 2015, Pages 796-800, https://doi.org/10.1016/j.nut.2014.11.013.
Probiotic yogurt guide: Health benefits, types and recommended brands, https://www.tecnic.eu/probiotic-yogurt-guide-health-benefits-types-brands
Thad wilkins et al, Probiotics for Gastrointestinal Conditions: A Summary of the Evidence, m Fam Physician. 2017;96(3):170-178
Protocol for the use of probiotics, Luton and Dunstable University Hospital, NHS Foundation Trust, https://www.bedsformulary.nhs.uk/docs/Probiotic%20protocol%20June%202019%20FINAL.pdf
World Gastroenterology Organisation Global Guidelines: Probiotics and Prebiotics. WGO; 2017, https://www.worldgastroenterology.org/UserFiles/file/guidelines/probiotics-and-prebiotics-english-2017.pdf
Hill C, Guarner F, Reid G, et al. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nat Rev Gastroenterol Hepatol. 2014;11(8):506-514.