Guide
Does probiotics cause diarrhea, bloating or constipation?
What trials report about gas, bloating, loose stools and constipation with probiotics, how poorly harms were reported, and when to see a doctor.
In randomized trials, probiotics did not significantly increase gastrointestinal adverse events compared with control, and the events trials did report were primarily gastrointestinal. Our research gives no rates for gas, bloating, diarrhea or constipation specifically, and harms reporting is often poor. Persistent or severe symptoms need a doctor.
What trials reported about stomach and bowel effects
The AHRQ evidence report reviewed 622 studies. Controlled trials primarily reported gastrointestinal adverse events, and across the randomized trials probiotics showed no statistically significant increase in overall, gastrointestinal, infection or serious adverse events compared with control, in short-term use. "Short-term" matters: the report called long-term effects largely unknown. It did not break out gas, bloating, nausea or heartburn, so we cannot tell you how often any one occurs.
Why that is weaker than it sounds
A 2018 review of 384 trials of probiotics, prebiotics and synbiotics found 106 reported no harms-related data, 142 gave no safety results, and 309 did not give serious adverse events per group. A trial that does not report symptoms has not shown there were none. And the products tested were mostly named strains; the organisms in ours are listed by species only, so none of this is a measurement of it.
Do probiotics survive stomach acid, and what do they do in the gut?
In a study that sampled the gut lining of healthy volunteers, an 11-strain probiotic stayed viable through gut passage, but settling in the lining differed by person, region and strain, and the effect on the gut community was transient. A laboratory model of the upper gut found survival of one four-microbe capsule was best taken with or just before a meal, and poor 30 minutes after one; it tested different strains from ours. A review of 249 trials found effects are strain-specific. Whether a probiotic changes how often you go, or helps with gas or nausea, is a health question with its own research review, and we make no such claim for our product: see probiotics benefits: what the research does and doesn't show.
What our label says
Electric Tiger Probiotic 20 Billion CFU lists 20 billion CFU at the time of manufacture per capsule from 13 organisms (species only). Directions: one capsule daily with 6–8 oz of water. The warning tells anyone with a weakened immune system or a medical condition to ask a physician before use. We do not say it prevents or causes any symptom.
Questions people ask
Do probiotics make you poop, or help you poop, or help bowel movements?
We make no claim that ours does. Studies of specific strains for bowel habits exist and are reported, with their limits, in the benefits article linked above. Do not assume a different product's result applies to this one.
Can probiotics make you constipated?
Constipation was not separated out in the reviews we cite. If it is new after starting a supplement and does not settle, stop and ask a doctor.
Can probiotics cause gas, or smelly gas, and why?
Gas was not reported as a separate rate in the reviews. We cannot explain why it happens for any person without a named strain, and we do not guess.
Do probiotics make you bloated, or upset or hurt your stomach, or cause nausea or heartburn?
The trials reported primarily gastrointestinal events without a significant excess over control, but they did not give rates for these symptoms. Stop and ask a doctor if they persist.
Can probiotics cause a UTI or SIBO?
We found no study in our research on either, and we do not speculate. The only infections described were rare case studies of bloodstream infection, mostly in people with compromised health. See who should not take probiotics.
Do prebiotics plus probiotics make you poop?
That is a different product, covered by different studies. Our capsule has no added fiber or prebiotic. See inulin vs probiotics.
Sources
- Safety of probiotics used to reduce risk and prevent or treat disease Short-term trials found no more side effects with probiotics than with control, but safety reporting was poor and long-term effects are largely unknown.
- Harms Reporting in Randomized Controlled Trials of Interventions Aimed at Modifying Microbiota: A Systematic Review A review of 384 trials found harms were often poorly reported, so safety cannot simply be assumed.
- Personalized Gut Mucosal Colonization Resistance to Empiric Probiotics Is Associated with Unique Host and Microbiome Features In healthy volunteers given an 11-strain probiotic, whether the strains settled in the gut lining differed by person and by strain, and effects were temporary.
- The impact of meals on a probiotic during transit through a model of the human upper gastrointestinal tract In a lab model of the upper gut, a four-microbe capsule survived best when taken with or just before a meal, and worst 30 minutes after one.
- Choosing an appropriate probiotic product for your patient: An evidence-based practical guide A review of 249 trials found probiotic effects depend on the exact strain and the purpose, and many products have no trial of their own.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
