Can Probiotics Cause Heartburn or Make Acid Reflux Worse?

Acid reflux is not a side effect the pooled trials record: across more than 9,000 adults in the antibiotic-diarrhoea trials, adverse events were no more common on live cultures than on placebo. What people do report in the first days is wind, bloating and a looser stool, which can feel like reflux if you are prone to it.¹ This page is one spoke of the Wellgard probiotics guide.

Evidence at a glance

• Trials: three pooled safety analyses reporting adverse events (36, 55 and 37 trials; more than 28,000 people) and one 2020 systematic review of 13 reflux studies.
• Largest reflux trial: 120 adults with reflux disease, 12 weeks, double-blind, 2026.
• Strongest measured outcome: in that trial, a reflux symptom score 36.51% lower than placebo at 12 weeks (P = 0.017), after eight weeks alongside prescribed rabeprazole and four alone.
• Not yet tested: whether live cultures cause reflux (no trial was designed to ask), and when first-days gut symptoms start or stop.

Sources checked on 5 November 2026.

So, can probiotics cause acid reflux?

Not according to any pooled analysis we can find. Three large pools, run for other reasons, report their adverse events.

• Across 36 randomised trials in 9,312 adults taking antibiotics, the risk of an adverse event on live cultures was the same as on placebo (relative risk 1.00, 95% confidence interval 0.87 to 1.14).¹
• Across 55 trials in more than 7,000 adults with irritable bowel syndrome, the risk of any adverse event was not significantly higher with live cultures.²
• In a 2025 Cochrane review of people on antibiotics, 37 trials in 11,911 people recorded adverse events in 10.9% of those on live cultures and 12.2% of controls (relative risk 0.86, 0.72 to 1.01, not statistically significant). The most common events in both groups were abdominal cramping, nausea, fever, soft stools, flatulence and taste disturbance.³

Reflux and heartburn do not appear on those lists, and we found no randomised trial reporting that live cultures caused reflux. That is a count, not a guarantee: the trials were not designed to look for reflux, and a 2015 safety review notes that trials report safety outcomes inconsistently.⁴ The first-days symptoms people notice, wind, bloating and a looser stool, are on that list; no trial has timed them, and none shows people getting worse before they get better; see feeling worse before better.

Why do probiotics sometimes feel like heartburn?

The recorded early symptoms are gas symptoms: flatulence, soft stools and abdominal cramping.³ The usual explanation is fermentation: new organisms, and any prebiotic fibre in the same capsule, produce gas, which hurts where heartburn does. A fibre such as inulin follows its own tolerance curve: in a two-week study in 84 healthy volunteers, flatulence, rumbling and bloating rose mildly with dose, significantly only at 20 g a day.⁵

Can probiotics help with acid reflux?

The NHS defines heartburn as "a burning feeling in the chest caused by stomach acid travelling up towards the throat".⁶ A 2020 systematic review found 13 prospective studies of live cultures in adults with reflux disease, heartburn, regurgitation or dyspepsia. Of 14 comparisons, 11 (79%) reported a benefit on reflux-disease symptoms, five of them on reflux symptoms themselves and the rest on dyspepsia or other upper-gut symptoms such as nausea and belching. The authors, employed by a culture manufacturer, concluded that proper placebo-controlled, double-blind trials were still needed.⁷ None was designed as a reflux treatment.

Since then there has been one double-blind randomised trial. In 2026, 120 adults with reflux disease, all prescribed the proton pump inhibitor rabeprazole, took a multi-strain live culture (64 people) or placebo (56) alongside it and then alone, for 12 weeks in all. At 12 weeks the Reflux Disease Questionnaire score was 36.51% lower in the live-culture group than on placebo (P = 0.017); the endoscopic healing rate, 36.84% against 12.50%, was not statistically significant (P = 0.365). Some authors were employed by the product's manufacturer, and the culture was taken alongside the medicine, not instead of it.⁸ Neither abstract names the species or daily counts used; the 2026 trial reports only that after 12 weeks the live-culture group's stools held more Bifidobacterium animalis and Lactiplantibacillus plantarum, the second a 2020 renaming of Lactobacillus plantarum.^{7, 8, 9}

What are the signs of probiotic intolerance?

The symptoms the trials record are the ones above, at rates no higher than placebo, and no trial times how long they last.^{1, 3} If a new capsule brings symptoms that have not settled within a week or two, stop it and speak to a pharmacist or GP. The pooled rates are set out in full on the side effects of too much probiotics.

A few groups should ask before starting. The 2015 safety review records that live cultures "have been used safely for years", the risks in case reports being infections and excessive immune stimulation in susceptible people.⁴ Four groups ask the clinical team first: anyone with a weakened immune system, anyone seriously ill or in hospital with a central line, the parents of a premature baby, and anyone whose doctor has said so. In a 2021 Cochrane review of trials that gave live cultures in pregnancy to lower the chance of gestational diabetes, pre-eclampsia was more common in the women who took them, so speak to a midwife or GP before any supplement in pregnancy.¹⁰

Reflux has its own red flags. See a GP if "you have heartburn most days", if lifestyle changes and pharmacy medicines are not helping, or if you also have "food getting stuck in your throat, frequently being sick, or losing weight for no reason". If symptoms are getting worse, the NHS says to contact a GP or call 111.⁶

What else can help calm acid reflux?

The NHS self-care list is short and specific: "eat smaller, more frequent meals"; "do not eat within 3 or 4 hours before bed"; "do not smoke"; "do not drink too much alcohol"; and "try to lose weight if you're overweight".⁶ A GP may prescribe a proton pump inhibitor such as omeprazole or lansoprazole.⁶ The trials of live cultures in people on those medicines are on taking probiotics with omeprazole. One NHS line sits above all of it: "do not stop taking any prescribed medicine without speaking to a doctor first".⁶ If your main symptom is bloating rather than heartburn, its causes and the NHS thresholds for seeing a GP are on what causes bloating.

What we don't know

• No trial has been designed to test whether live cultures cause reflux; the "no excess" finding is an adverse-event count from trials run for other conditions.
• No trial has timed when first-days wind or bloating begins or ends.
• The 2020 review's abstract gives neither the species nor the doses its 13 studies used, and six of the 13 were rated low quality.
• No trial we found has given a live culture alone from the start in reflux disease; the one double-blind trial, not yet repeated, gave it alone only after eight weeks with medicine.

Frequently asked questions

Can probiotics make GERD worse?

No pooled analysis reports it: reflux and heartburn are not among the adverse events listed in the three safety pools above, and the one double-blind trial in people with reflux disease measured lower symptom scores, not higher.^{1, 2, 3, 8}

Should I take my probiotic at a different time if I get reflux?

No trial has compared times of day for reflux or any other side effect, so the pack's instruction stands; the NHS advice on trigger food and drink applies to a fermented drink like any other.⁶

Do probiotics help with H. pylori?

Only as an add-on to the course a GP prescribes. Across 91 randomised trials in 13,680 people, adding live cultures to standard eradication therapy raised the eradication rate from 62.43% to 78.75% (odds ratio 1.62, 1.41 to 1.87) and roughly halved diarrhoea during the course (relative risk 0.49, 0.40 to 0.61), always alongside the prescribed antibiotics.¹¹

Can a probiotic yoghurt drink cause acid reflux?

No trial has tested it, and the pooled safety analyses record no excess of reflux or heartburn on live cultures in any form.^{1, 3} A yoghurt drink delivers its cultures in fermented milk with some sugar; a sparkling one adds carbon dioxide, and gas is the one early symptom the trials do record. If a particular drink sets off your symptoms, the NHS rule applies: "do not have food or drink that triggers your symptoms".⁶

Can probiotics cause indigestion?

Not above the placebo rate. In the 2025 Cochrane count, adverse events occurred in 10.9% of people on live cultures and 12.2% of controls across 37 trials in 11,911 people, the commonest being abdominal cramping, nausea, soft stools and flatulence.³ Those overlap with what the NHS calls indigestion: "feeling full and bloated", "feeling sick", "burping and farting" and heartburn after eating.¹² So a new capsule can feel like indigestion in the first days without any trial finding it causes more of it; if it has not settled within a week or two, stop and ask a pharmacist, who can suggest antacids or alginates.¹²

Sources

1. Liao W, et al. Probiotics for the Prevention of Antibiotic-associated Diarrhea in Adults: A Meta-Analysis of Randomized Placebo-Controlled Trials. Journal of Clinical Gastroenterology, 2021. Pooled analysis of 36 randomised trials, 9,312 adults. PubMed 33234881.
2. Goodoory VC, et al. Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis. Gastroenterology, 2023. Pooled analysis of 82 randomised trials, 10,332 people; adverse events from 55 trials. PubMed 37541528.
3. Esmaeilinezhad Z, et al. Probiotics for the prevention of Clostridioides difficile-associated diarrhea in adults and children. Cochrane Database of Systematic Reviews, 2025. Pooled analysis of 47 randomised trials, 15,260 people; adverse events from 37 trials. PubMed 40931979.
4. Doron S, Snydman DR. Risk and safety of probiotics. Clinical Infectious Diseases, 2015. Review. PubMed 25922398.
5. Bruhwyler J, et al. Digestive tolerance of inulin-type fructans: a double-blind, placebo-controlled, cross-over, dose-ranging, randomized study in healthy volunteers. International Journal of Food Sciences and Nutrition, 2009. Randomised crossover trial, 84 healthy volunteers. PubMed 18608562.
6. NHS. Heartburn and acid reflux. nhs.uk. Page last reviewed 20 November 2023.
7. Cheng J, Ouwehand AC. Gastroesophageal Reflux Disease and Probiotics: A Systematic Review. Nutrients, 2020. Systematic review of 13 prospective studies. PubMed 31906573.
8. Li Y, et al. Adjunctive probiotic therapy sustains symptom relief in gastroesophageal reflux disease through gut microbiome-metabolome remodeling. mSystems, 2026. Randomised double-blind trial, 120 adults, 12 weeks. PubMed 41609355.
9. Zheng J, et al. A taxonomic note on the genus Lactobacillus: Description of 23 novel genera, emended description of the genus Lactobacillus Beijerinck 1901, and union of Lactobacillaceae and Leuconostocaceae. International Journal of Systematic and Evolutionary Microbiology, 2020. Taxonomic study. PubMed 32293557.
10. Davidson SJ, et al. Cochrane Database of Systematic Reviews, 2021 (live cultures in gestational-diabetes trials). Cochrane review, 7 randomised trials, 1,647 pregnant women. PubMed 33870484.
11. Tanashat M, et al. Efficacy of probiotics regimens for Helicobacter pylori eradication: A systematic review, pairwise, and network meta-analysis of randomized controlled trials. Clinical Nutrition ESPEN, 2025. Pooled analysis of 91 randomised trials, 13,680 people. PubMed 39642994.
12. NHS. Indigestion. nhs.uk. Page last reviewed 5 May 2023 (review overdue).

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