scored 82/100
Also known as milk kefir
Kefir is a fermented dairy beverage rich in probiotics, protein, and bioavailable calcium, offering unique benefits for gut health and nutrient absorption.
Representative amounts for this food, not measured for this item. Real content varies widely by variety, ripeness and storage.
These are the scored components, not a sum: the published score also reflects normalisation across the catalog, so the parts above will not add to 82.
Kefir originated in the Caucasus region and has been consumed for centuries as a traditional fermented food. Unlike yogurt, kefir is produced through the action of kefir grains—complex colonies of bacteria and yeasts—which create a distinctive tangy flavor and unique microbial profile. Per 100g, kefir provides 3.4g protein, 119mg calcium, and 154mg potassium in just 62 calories, making it nutrient-dense for its caloric load. The fermentation process dramatically reduces lactose content (often by 90%+), making it tolerable for many lactose-sensitive individuals. Kefir contains numerous probiotic strains including Lactobacillus, Acetobacter, and Saccharomyces species, along with bioactive compounds like polysaccharides (kefiran) and organic acids. These factors support the gut microbiome diversity—a key marker of healthy aging—enhance intestinal barrier function, and improve systemic inflammation markers. The fermentation also increases bioavailability of minerals like calcium and magnesium while producing small amounts of bioactive peptides with potential ACE-inhibitory and immunomodulatory properties. For longevity-focused nutrition, kefir represents an efficient vehicle for probiotic diversity and calcium absorption.
Kefir contains 10-60+ different bacterial and yeast species that establish diverse microbial populations; polysaccharides like kefiran act as prebiotic substrates, feeding beneficial bacteria and improving microbial richness.
Probiotics in kefir increase tight junction protein expression, strengthen the epithelial barrier, and produce short-chain fatty acids that reduce lipopolysaccharide translocation and pro-inflammatory markers.
Fermentation lowers pH and increases organic acid content, enhancing calcium solubility and absorption; lactose reduction eliminates malabsorption in sensitive individuals, improving net bioavailability of the 119mg calcium per 100g.
Lactic acid bacteria and yeasts metabolize lactose during fermentation, reducing final lactose content to negligible levels while producing lactase enzyme, enabling consumption by lactose-sensitive individuals.
Kefir-derived bacteriocins and organic acids inhibit pathogenic bacteria; bioactive peptides from casein hydrolysis exhibit immunomodulatory properties affecting T-cell and IgA production.
Kefir can be consumed any time of day; however, morning or with meals optimizes probiotic survival through gastric passage. Evening consumption may support overnight microbiome activity and next-morning regularity.
Breaks a fast
While kefir is low in calories (62/100g), its protein and fat content means it is not truly fasting-compatible if strict zero-calorie fasting is the goal. However, some intermittent fasting protocols permit kefir during fasting windows due to its minimal caloric impact and probiotic benefits. Consuming with or shortly after meals enhances probiotic survival.
Per 100 g of the default form. Bars show how much higher or lower kefir is than the average across 25 peer foods in this category. Green means a favorable direction; amber means the opposite.
Kefir is classified as a fermented dairy (dairy). Kefir is a fermented dairy beverage rich in probiotics, protein, and bioavailable calcium, offering unique benefits for gut health and nutrient absorption.
Kefir scores 82/100 in Formulate, making it a great choice. Its strongest contributions come from Vitamin B6, Riboflavin, Vitamin B12. The score blends nutrient density, fiber, healthy fats, protein quality, bioactive compounds, and glycemic impact.
Moderately — it contributes meaningful protein. A 245 g serving provides about 8.3 g of protein (~17% of the 50 g daily value).
Not really. A 245 g serving provides about 0 g of fiber (~0% of the 28 g daily value).
In a 245 g serving, kefir is highest in Vitamin B6 (~55% DV), Riboflavin (~40% DV), Vitamin B12 (~32% DV), Calcium (~22% DV), Phosphorus (~19% DV).
Not really. A 245 g serving has about 25 g of net carbs (25 g total minus 0 g fiber).
Best any time of day. Kefir can be consumed any time of day; however, morning or with meals optimizes probiotic survival through gastric passage. Evening consumption may support overnight microbiome activity and next-morning regularity.
A typical serving is around 245 g (~152 kcal), based on the FDA's Reference Amount Customarily Consumed for this food category. There's no fixed daily target — most adults benefit from rotating kefir alongside several other dairy sources.
Kefir falls into the dairy (lactose) group, which is a common allergen. If you have a known allergy or sensitivity in this category, avoid it and consult a clinician before adding it back.
Kefir pairs nicely with: Pair with berries (blueberries, blackberries) because anthocyanins have prebiotic effects and synergize with kefir's probiotics to amplify anti-inflammatory signaling.; Pair with ground flaxseed or chia seeds because soluble fiber feeds kefir's probiotic strains, enhancing short-chain fatty acid production and improving colon health.; Pair with raw garlic or onions because inulin and fructooligosaccharides act as prebiotics, selectively promoting growth of beneficial Lactobacillus and Bifidobacterium species.; Pair with turmeric because curcumin's anti-inflammatory effects compound with kefir's barrier-strengthening probiotics, creating additive benefits for gut mucosal integrity.
Encyclopedia entries that supply the same signature nutrients kefir contributes. Click through to see clinical dose ranges, evidence quality, and bioavailable forms.
These are the nutrients kefircontributes meaningfully toward (≥10% DV per 100 g serving). Click one to see what it does in the body, which supplements concentrate it, and which other foods are top sources.