Yogurt vs Kefir
Yogurt and kefir are both fermented milks. What each research base shows, what live cultures do and do not mean, and why no direct comparison could be found.
Content last updated . This page has not been medically reviewed.
Safety first. Natural products can cause side effects and interact with medicines. Read functional food safety before you use anything on this page.
Short answer: both are fermented milks, and each has its own body of research, but we did not find a study that tested one against the other. So there is no documented winner. Proper evidence not found for a head-to-head comparison: we searched PubMed for yogurt and kefir comparisons and read the reviews below, which cover each food separately.
What each one is
Yogurt is milk fermented by bacterial cultures. Kefir is described in a systematic review as a traditional fermented-milk beverage. [1] Details are on the Yogurt and Kefir pages. A fermented food is not automatically a probiotic: an expert panel defines fermented foods as foods made through desired microbial growth and enzymatic conversions of food components, and keeps that separate from probiotics. [2]What the research found for each
| Question | Yogurt | Kefir | Strength of evidence |
|---|---|---|---|
| Size and type of review | A systematic review included 108 studies published 1979 to 2017 on fermented milks and yogurt, of mixed design. [3] | A systematic review of randomized trials included 18 publications reporting 16 studies. [1] | Different designs, so not directly comparable |
| Lactose digestion | The review concluded a causal relationship exists between lactose digestion and tolerance and yogurt consumption. [3] | Not described in the kefir review we read. | Established for yogurt; for kefir, evidence not found in this source |
| Cholesterol | A meta-analysis of 7 trials (274 people with mild to moderate high cholesterol) found lower total and LDL cholesterol with probiotic yogurt, and no change in HDL or triglycerides. [4] | The review said kefir may further aid treatment of adult dyslipidemia and hypertension, although evidence was very limited. [1] | Yogurt: promising but limited. Kefir: insufficient evidence |
| Risk of bias and safety data | The review authors argue for encouraging these foods in dietary guidelines; that is their conclusion, not a settled consensus. [3] | Safety was only assessed in 5 of the 18 publications, and 12 of the studies had an overall high risk for bias. [1] | Kefir trials are weaker |
| Death from any cause | A meta-analysis of 8 cohort studies found the highest versus lowest intake was not significantly related to all-cause mortality (hazard ratio 0.93, 95% CI 0.85 to 1.01). [5] | Not described in the kefir review we read. | Observational; mixed |
The kefir review also noted possible roles in reducing oral Streptococcus mutans and in Helicobacter pylori eradication therapy, based on limited trials. [1] Those are results for kefir in specific trials and do not apply to yogurt.
No universal winner
Which one suits a person depends on taste, digestion, allergies and what the label says, which this page cannot judge. For labels see Live cultures on labels.Frequently asked questions
Is kefir healthier than yogurt?
No source we read compared them directly. Each has a separate research base, and the kefir trials are fewer and weaker. [1]
Does yogurt or kefir help lactose intolerance?
A systematic review concluded a causal relationship exists between yogurt consumption and lactose digestion and tolerance. [3] The kefir review we read did not report this outcome. [1]
Are both probiotics?
Not automatically. A probiotic needs live microorganisms shown to confer a health benefit in adequate amounts. [8] Whether a given product qualifies depends on the product.
Who should be careful with live-culture foods?
NCCIH says harm from probiotics is more likely in people with severe illness or weakened immune systems. [6] Ask a clinician.
Do these foods lower cholesterol?
Probiotic yogurt lowered total and LDL cholesterol in a meta-analysis of 7 small trials. [4] For kefir the evidence was very limited. [1]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Limits and uncertainty
Safety and who should ask a clinician
- Live cultures. NCCIH states the risk of harmful effects from probiotics is greater in people with severe illnesses or compromised immune systems. [6] That statement is about probiotics generally. Anyone with a weakened immune system should ask a clinician about live-culture foods.
- Pasteurization in pregnancy. A university extension fact sheet advises pregnant women not to drink raw or unpasteurized milk or eat foods made from raw milk. [7] See Foods in pregnancy.
- Allergy and lactose. Milk allergy is not covered in these sources; see Food allergy basics. For lactose symptoms see Lactose intolerance.
- Medicines. Food-specific medicine interactions for these foods are not described in the sources we read. Ask a pharmacist; see Foods and medicine interactions.
References
- The effects of kefir consumption on human health: a systematic review of randomized controlled trials. 2023. PubMed 35913411. Read 2026-10-22.
- Salminen S, et al. The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods. 2021. PubMed 33398112. Read 2026-10-22.
- Yogurt, cultured fermented milk, and health: a systematic review. 2021. PubMed 32447398. Read 2026-10-22.
- Impact of probiotic yogurt consumption on lipid profiles in mild to moderate hypercholesterolemia: systematic review and meta-analysis of randomized controlled trials. 2020. PubMed 31748179. Read 2026-10-22.
- Yogurt intake and all-cause and cardiovascular mortality: a meta-analysis of eight prospective cohort studies. 2020. PubMed 31970674. Read 2026-10-22.
- National Center for Complementary and Integrative Health (NCCIH, US). Probiotics: Usefulness and Safety. Read 2026-10-22.
- Clemson University Home and Garden Information Center. Food Safety for Pregnant Women and Their Babies. Read 2026-10-22.
- Hill C, et al. Expert consensus document. The ISAPP consensus statement on the scope and appropriate use of the term probiotic. 2014. PubMed 24912386. Read 2026-10-22.