Berberine
supplementA plant compound sold as a supplement for blood sugar and weight. It is not a GLP-1 drug.
13 providers
No. 065supplement
Prebiotics
Prebiotics is a supplement that is sold over the counter.
Also known as Inulin, Fructooligosaccharides (FOS), Galactooligosaccharides (GOS), prebiotic fiber, chicory root fiber
Prebiotics are substances that gut microbes selectively use in a way that benefits health. The best-studied are inulin and fructooligosaccharides (often from chicory root) and galactooligosaccharides. They are sold as powders and added to foods, and occur in smaller amounts in onions, garlic, bananas and wheat.
Is Prebiotics FDA-approved?
Sold without a prescription. Supplements are not reviewed by the FDA before sale, so third-party testing matters. Sold as dietary supplements and food ingredients. FDA allows inulin-type fructans and GOS to be counted as dietary fiber on labels, and inulin has a GRAS notice with no FDA questions.
As of October 7, 2026.
Key takeaways
- Prebiotics are substances, usually specific fibers, that gut microbes selectively use in a way that benefits health.
- Probiotics are live microbes; prebiotics are their food.
- Inulin improved stool frequency and consistency in a constipation meta-analysis, but did not help IBS symptoms in another.
- Gas and bloating are common, and inulin, FOS and GOS are FODMAPs that can worsen IBS.
How does Prebiotics work?
Humans cannot digest fibers like inulin, fructooligosaccharides and galactooligosaccharides, so they reach the colon intact. There, certain bacteria such as bifidobacteria ferment them, growing in number and producing short-chain fatty acids.
The 2017 ISAPP consensus says a substance only counts as a prebiotic if it is selectively used by microbes and a health benefit is documented. Not all fiber qualifies.
What is the difference between prebiotics and probiotics?
NCCIH describes probiotics as live microorganisms and prebiotics as nondigestible food components that selectively stimulate the growth or activity of desirable microorganisms. NCCIH: Probiotics, what you need to know
ISAPP notes that onions, garlic, bananas, chicory root and Jerusalem artichokes contain prebiotics, but at low levels, and that not every dietary fiber is a prebiotic. ISAPP: Prebiotics
What does the evidence say about Prebiotics?
Emerging evidenceA meta-analysis found inulin improved stool frequency and consistency in constipation, but a meta-analysis in IBS found no symptom benefit and more gas with inulin-type fructans.
What do clinicians say about Prebiotics?
Gastroenterologists see prebiotic fibers as a reasonable option for some people with constipation, but not a proven fix for IBS, where they can make gas and bloating worse.
A meta-analysis of 5 randomized trials found inulin improved stool frequency, consistency and transit time in constipation, but not pain or bloating.
Collado Yurrita et al.: Inulin-type fructans and constipation, meta-analysis (Nutr Hosp 2014)A 2019 meta-analysis of 11 trials in IBS and other functional bowel disorders found prebiotics raised bifidobacteria but did not improve symptoms or quality of life, and inulin-type fructans worsened flatulence.
Wilson et al.: Prebiotics in IBS and functional bowel disorders, meta-analysis (Am J Clin Nutr 2019)The 2023 AGA-ACG constipation guideline found psyllium was the fiber that appeared effective and said data on inulin were limited.
AGA-ACG clinical practice guideline: pharmacological management of chronic idiopathic constipation (2023)FDA lists inulin-type fructans and GOS among the non-digestible carbohydrates that can be counted as dietary fiber on labels.
FDA: Questions and answers on dietary fiber
Summaries of published guidelines, drug labels, regulators and reviews, each attributed to its source. DiscoverMedica does not employ clinicians.
Is Prebiotics right for you, and who should avoid it?
Often considered for
- Adults looking to raise fiber intake, especially with occasional constipation
- People who tolerate fermentable fibers without significant gas or bloating
Not a fit, or needs extra care
- People with IBS who are sensitive to FODMAPs, unless guided by a clinician or dietitian
- Anyone with new or severe abdominal pain, bleeding or unexplained weight loss, which needs evaluation first
Only a licensed clinician who knows your history can decide whether it is right for you.
What are the risks and side effects of Prebiotics?
- Gas, bloating and cramping are common, especially when starting or with larger amounts.
- Inulin, FOS and GOS are FODMAPs, so they can worsen symptoms in people with IBS.
- Not all fiber is prebiotic, and a "prebiotic" label claim is not FDA-verified proof of a health benefit.
What should you ask a clinician about Prebiotics?
- Would a prebiotic, psyllium or a change in diet suit my gut symptoms best?
- Should I avoid fructans because of IBS?
These save with the compound when you add it to My Journal, so they’re on the printout for your visit.
How do people buy Prebiotics?
No prescription is needed. Supplement brands and retailers sell it online and in stores.
Check with a clinician or pharmacist first if you take prescription medication or have a chronic condition.
Choose a product with independent testing, such as NSF Certified for Sport or USP Verified, because FDA does not check supplements before they are sold.
Where some people buy it
- ThorneSells FiberMend, a fiber blend, direct to consumers.
- Life ExtensionSells a prebiotic chewable direct.
- iHerbCarries prebiotic fiber products from many brands.
From each provider’s own site, checked October 7, 2026. Programs change, so confirm the details before you sign up.
Where can I get Prebiotics?
12 providers list Prebiotics on DiscoverMedica, lowest listed price first.
$15.75listed price†
Buy at Life Extension $16.99listed price†
Buy at NOW Foods Garden of LifeDr. Formulated Organic Fiber powder, unflavored (prebiotic fiber, psyllium free)
No prescription
$18.39listed price†
Buy at Garden of Life $39.99listed price†
Buy at Momentous † Prices as listed by the provider when we checked; they change.
Prebiotics: questions, answered
What are the side effects of prebiotics?
Gas, bloating and cramping are the most common, because gut bacteria ferment these fibers. A 2019 meta-analysis found inulin-type fructans worsened flatulence in people with IBS. Monash University lists fructans and GOS as FODMAPs. Stop or cut back if symptoms are significant, and ask a clinician if they persist.
Prebiotic vs probiotic: what is the difference?
Probiotics are live microorganisms, such as certain Lactobacillus or Bifidobacterium strains. Prebiotics are nondigestible food components that selectively feed beneficial microbes already in the gut. NCCIH describes both. Each is judged on its own evidence, and neither is a cure-all for gut symptoms.
Do prebiotics help with constipation?
Somewhat. A meta-analysis of 5 trials found inulin improved stool frequency, consistency and transit time, though not pain or bloating. The 2023 AGA-ACG guideline found psyllium the fiber that appeared effective and called the inulin data limited. If constipation is ongoing, ask a clinician which fiber or medicine fits best.
Are prebiotics good for IBS?
Not usually. A 2019 meta-analysis of 11 trials found prebiotics did not improve IBS symptoms or quality of life, and inulin-type fructans increased flatulence. Inulin, FOS and GOS are FODMAPs, which many people with IBS limit. A gastroenterologist or dietitian can help decide whether any prebiotic is worth trying.
Are prebiotics regulated by the FDA?
They are sold as dietary supplements and food ingredients, which FDA does not approve before sale. FDA allows inulin-type fructans and GOS to count as dietary fiber on nutrition labels, and it had no questions about a GRAS notice for inulin in food. A "prebiotic" claim on a label is not FDA-verified proof of benefit.
Important safety information
Key risks
- Gas, bloating and cramping are common, especially when starting or with larger amounts.
- Inulin, FOS and GOS are FODMAPs, so they can worsen symptoms in people with IBS.
- Not all fiber is prebiotic, and a "prebiotic" label claim is not FDA-verified proof of a health benefit.
Talk to a clinician first, or avoid it, if
- People with IBS who are sensitive to FODMAPs, unless guided by a clinician or dietitian
- Anyone with new or severe abdominal pain, bleeding or unexplained weight loss, which needs evaluation first
This is not a complete list of risks. Talk to a licensed clinician or pharmacist about your own situation. If you have a severe reaction, call 911. You can report side effects to the FDA through MedWatch at 1-800-FDA-1088.
Sources
- ISAPP consensus statement on the definition and scope of prebiotics (Nat Rev Gastroenterol Hepatol 2017)
- FDA: Questions and answers on dietary fiber
- Collado Yurrita et al.: Inulin-type fructans and constipation, meta-analysis (Nutr Hosp 2014)
- Wilson et al.: Prebiotics in IBS and functional bowel disorders, meta-analysis (Am J Clin Nutr 2019)
Also checked for this guide
- ISAPP: Prebiotics
- NCCIH: Probiotics, what you need to know
- FDA GRAS notice inventory: GRN 118, inulin
- AGA-ACG clinical practice guideline: pharmacological management of chronic idiopathic constipation (2023)
- Monash University: High and low FODMAP foods
Guide reviewed October 7, 2026.
Educational information only, not medical advice. It does not replace a conversation with a licensed clinician.
Same goal
Related compounds.
BPC-157
peptideA lab-made peptide popular for injury recovery. Mostly animal data, and not an approved drug.
Education only
Probiotics
supplementLive microbes in supplements and foods. Benefits depend heavily on the specific strain.
17 providers
L-glutamine
supplementAn amino acid that fuels gut-lining cells; taken for "leaky gut" and recovery.
10 providers