Gut Health
Kefir
A fermented milk drink with a broader range of probiotic strains than most yogurts, thanks to its unique grain-based fermentation.
Gut Health
Immunity
Bone Health
Serving
1 cup (243g)
Calories Per Serving
104
Key nutrients
Probiotics (diverse strains), protein, calcium, B12
Nutrient density
Not officially rated
Why it’s worth eating
Kefir is a fermented dairy drink rich in probiotics, calcium, and B vitamins. It supports gut, bone, and immune health. Drink plain, or add to smoothies for a tangy boost.
What you may notice
Digestive comfort and regularity
Cold/flu frequency
Markers worth tracking
Stool microbiome diversity (if tested)
Calcium and vitamin D status
How to eat it
Choose plain varieties with live cultures listed, and shake before drinking, kefir naturally separates and has a tangy, slightly effervescent quality from fermentation.
Pairs well with
Fiber-rich fruit, prebiotic fiber feeds the diverse probiotic strains kefir provides
Honey, a traditional pairing that mellows the tang
Storage
Refrigerate and consume by the date on the package; it will continue to ferment and grow more tangy over time.
The numbers, per 1 cup (243g)
0%
Vitamin K
46%
Vitamin A
1%
Vitamin C
24%
Calcium
0%
Iron
6%
Magnesium
8%
Potassium
30%
Vitamin B12
13%
Vitamin D
Fiber
0g
Kefir, lowfat, plain, Lifeway (FDC 170904)
Evidence
B
HONEST CORRECTION: kefir greater microbial diversity versus yogurt is a COMPOSITIONAL claim. In head-to-head data kefir performs comparably to yogurt or milk, not better. Several trials are industry-funded.
Study dose vs. serving
Acute 20 g lactose challenge: kefir lowered breath hydrogen and cut flatulence over 50% versus milk - comparable to yogurt, not superior. A T2DM trial (600 mL/day, 8 weeks) lowered HbA1c versus plain fermented milk, but the comparator was not yogurt. A lipid trial found NO effect.
Hertzler SR, Clancy SM. J Am Diet Assoc. 2003;103(5):582-587. DOI 10.1053/jada.2003.50111. n=15 lactose maldigesters. Funded by Lifeway Foods.
Use caution if
You're lactose intolerant, fermentation reduces much of the lactose, and many who react to milk tolerate kefir, but it's not guaranteed
You take certain antibiotics, separate timing by a couple of hours so the cultures aren't immediately killed
Details
Type
Season
Refrigerated, year-round
Forms
Drinkable, grains, water kefir
Price
Mid
Bioactive
Live mixed bacterial and yeast cultures
Heat stable
No - heat destroys live cultures
Watch
RAW MILK KEFIR: unpasteurised dairy carries documented Listeria, Salmonella, E. coli and Campylobacter risk. CDC and FDA advise against it, especially in pregnancy, childhood, older age and immunosuppression.
Reliability
4 / 5
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