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Probiotics for Constipation and Bloating: What the Evidence Says About Strains

By the Gut Label Check team. Updated October 16, 2026. 4 min read

Probiotics are the most popular gut supplement, and the label usually promises billions of “good bacteria”. Whether they help constipation or bloating depends on which bacteria, how many, and what the trials actually found.

Why the strain matters

A probiotic’s full name has three parts: genus, species and strain. For example, in Lactobacillus reuteri DSM 17938, “DSM 17938” is the strain. Trial results belong to a specific strain. A different strain of the same species may do nothing, so a label that only says “Lactobacillus acidophilus” can’t be matched to any study.

Probiotics for constipation: what trials found

• A 2024 meta-analysis of 10 randomized trials found an overall benefit of probiotics over placebo for constipation. However, the results varied enormously between studies, and the authors called for larger, more rigorous trials.
• Within that review, positive trials included Bifidobacterium longum BB536 (bowel regularity in older adults), Lactiplantibacillus plantarum P9 and Lactobacillus reuteri (more frequent bowel movements). A separate 2018 randomized trial found L. reuteri DSM 17938 improved symptoms in functional constipation.
• Not every strain works. A 2024 randomized trial of 229 adults found that Bifidobacterium lactis HN019 did no better than placebo at increasing complete bowel movements.
• The BDA guideline reviewed this evidence and gave probiotics a positive overall recommendation. Because no single probiotic stood out when the data were pooled, it advises people who want to try one to pick a product and use it for at least 4 weeks to see whether it helps.

Probiotics for bloating and IBS

• The American Gastroenterological Association (2020) found the evidence insufficient for IBS and advised using probiotics for IBS only in the context of a clinical trial.
• The American College of Gastroenterology (2021) suggests against probiotics for global IBS symptoms. The recommendation is conditional, based on very low-quality evidence, because trial results have been inconsistent.
• The British Society of Gastroenterology (2021) is more open: probiotics can be tried for IBS, but there isn’t enough data to recommend a specific strain.

So for bloating, a probiotic is a reasonable experiment at best, not a proven treatment. For other approaches, see our guide to supplements for bloating and constipation.

How to read a probiotic label

What the gut capsules we checked contain

• Gut Save lists seven bacterial species in two blends. Only one has a full strain code (B. lactis BL-04). Its 1.25 billion CFU count is “at the time of manufacture”, and the second blend has no CFU at all. It lists L. reuteri without a strain code, so we can’t tell if it is the DSM 17938 strain from the constipation trial.
• GutOptim lists Lactobacillus acidophilus with no strain code and no CFU count.

Details: Gut Save vs DigestiStart vs GutOptim.

Questions people ask

Do probiotics help with constipation?

Some people may benefit, and some strains have positive trials. Pooled results are inconsistent, so treat a probiotic as a 4-week experiment.

What is the best probiotic for bloating?

No single strain is proven. US guidelines don’t recommend routine probiotics for IBS symptoms. If you try one, choose a named strain with CFU guaranteed through expiry.

How long should I try a probiotic?

About 4 weeks, as the BDA guideline suggests. If nothing changes, stop and save your money.

Can probiotics make bloating worse?

Some people notice more gas or bloating in the first days. It usually settles; if it doesn’t, stop.

Gut supplements we checked

GutOptim

Fiber, clay, aloe and one probiotic in a 1.5 g blend

Serving2 capsules a day

Cost per day$1.63–$2.30

Every dose shownNo

Full ingredient list, but the whole blend is a fraction of the fiber doses used in studies.

Check price on the official site Read the label check

Gut Save

Fish collagen, herbs and probiotics, 500 mg with every dose listed

Serving1 capsule a day

Cost per day$1.63–$2.63

Every dose shownYes

The most open label of the three, with small amounts of each ingredient.

Check price on the official site Read the label check

DigestiStart

11 traditional Chinese herbs in a 500 mg blend

Serving1 capsule a day

Cost per day$1.63–$2.63

Every dose shownNo

A herbal tonic blend, about 45 mg per herb, with mostly lab and animal studies behind it.

Check price on the official site Read the label check

HoneyBurn

Honey, bee products, herbs and berberine in a 550 mg blend

Serving2 ml liquid a day

Cost per day$1.63–$2.30

Every dose shownNo

Berberine is listed last, so a serving holds about 4 mg of it at most.

Check price on the official site Read the label check

Sources

1. Garzon Mora N., Jaramillo A.P. Effectiveness of Probiotics in Patients With Constipation: A Systematic Review and Meta-Analysis. Cureus, 2024;16(1):e52013. PMC10854359
2. Riezzo G. et al. Randomised double blind placebo controlled trial on Lactobacillus reuteri DSM 17938: improvement in symptoms and bowel habit in functional constipation. Beneficial Microbes, 2018. doi:10.3920/bm2017.0049
3. Randomized clinical trial of Bifidobacterium animalis subsp. lactis HN019 in functional constipation (229 participants). JAMA Network Open, 2024. jamanetwork.com
4. Dimidi E. et al. British Dietetic Association guidelines for the dietary management of chronic constipation in adults, 2025. PubMed 41081513; summary of the probiotic findings: gutmicrobiotaforhealth.com
5. Su G.L. et al. AGA Clinical Practice Guidelines on the Role of Probiotics in the Management of Gastrointestinal Disorders. Gastroenterology, 2020. PubMed 32531291
6. Lacy B.E. et al. ACG Clinical Guideline: Management of Irritable Bowel Syndrome. American Journal of Gastroenterology, 2021.
7. NIH Office of Dietary Supplements. Probiotics: Fact Sheet for Health Professionals. ods.od.nih.gov