Conclusion: The mechanisms of their action were diverse, indicating that they can act by different signaling pathways. Still, industrial and artisanal kefir may differ regarding functional potential-OR of 8.56 (95% CI: 2.27-32.21, P ≤ .001)-according to the observed health effect, which can be associated with differences in the microbial composition between both types of kefir.
PubMed 34745425 ↗Kefir
People mainly take Kefir for mood, digestion, focus. Based on 31 first-hand reports and 22 meta-analyses & systematic reviews in the medical literature. Ranked #193 of 1,974 overall.
Of reports that state an outcome, 100% are positive.
What Kefir does, according to users
Of the people who reported each effect, the share who said it got better.
5 more with fewer than 3 reports
What the research says
Systematic reviews and meta-analyses from PubMed, with their published conclusions.
3+ meta-analyses or systematic reviews and 10+ randomized controlled trials in humans. The grade measures how much human research exists — read the conclusions below for what it found.
Conclusion: Kefir is a dairy product with a unique microbiological profile that appears to be a safe for generally healthy populations to consume. However, efficacy and safety data from high-quality human trials are essential before any recommendations may be made for conditions of the oral and gastric microbiota and metabolic health.
PubMed 35913411 ↗Conclusion: The results of this systematic review suggest that kefir may be associated with cancer prevention and it also has beneficial effects in cancer treatment. This protection may be associated with kefir bioactive components including peptides, polysaccharides and sphingolipids.
PubMed 26621019 ↗Conclusion: We found low certainty evidence that transcranial direct current stimulation may improve pain intensity compared to sham stimulation. We could not reach any conclusions on the efficacy of any other interventions on pain intensity, pain frequency, and treatment success. The certainty of the evidence was very low due to the low numbers of studies and participants in each comparison and clinical heterogeneity amongst the studies. While no serious or total adverse events were elicited explicitly with any of the treatments studied, the reported events were very low. The certainty of the evidence fo
PubMed 34844288 ↗Dosage people report
As stated by users — not a recommendation. Follow the label or your doctor.
Reported side effects
How often each side effect came up across all reports.
What users say
Verbatim quotes, shortened only — each links to the original discussion.
“The first time I tried Kefir it felt like a drug. I really felt it get to my stomach and it felt great. Now when I have it, it can cheer me up”
“Make your own Kefir at home with raw milk. A minor commitment but one of the best health habits in my arsenal.”
“drinking kefir has more beneficial GI effects than taking a probiotic pill”
“Some versions of Kefir that are strong (have high bio count). Most are not. Wallaby (unflavored) is my favorite. All of those make me feel great.”
“Kefir grains (or other fermented cultures) will make you a lifetime supply of way stronger than OTC probiotics”
Top discussions (5)
- This will sound crazy but supplementing high amount of fiber has been nearly equivalent as a GLP1 in benefits for me ↗
- I'm truly convinced nearly all mental issues are rooted from the gut ↗
- 24M – HRV went from 28 to 71 after i started eating an alarming amount of fermented cabbage every morning ↗
- BDNF-related mechanisms underpin the learning and memory benefits of many brain healthy activities, including some compounds (like omega-3) that might loosely be termed nootropics, but also activities like exercise. Learn more about BDNF in this new >100 reference article on FoundMyFitness. ↗
- Can probiotics (bacteria) be nootropic? I've been taking a probiotic intended for boosting immune system, but it seems to help me wake up clear-headed. Can someone explain how this works and which one is potentially exerting such an effect? ↗
Other options for mood
User data from public discussions; research from PubMed. Information only, not medical advice — talk to a doctor before starting, stopping or combining anything. Data updated October 2, 2026. How we rate