Lactobacillus kefiranofaciens

Probiotic

What is it

Lactobacillus kefiranofaciens is a lactic acid bacterium found primarily in kefir grains, where it produces the characteristic exopolysaccharide called kefiran. It is one of the dominant lactic acid bacteria in traditional kefir cultures and is studied as a probiotic.

Evidence for 2 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Kefir fermentation (food technology)

Mixed Evidence

Established role in kefir grain structure (via kefiran production) and fermentation. Food technology utility rather than direct supplement benefit.

Probiotic gut and immune support

Mixed Evidence

Preclinical studies show immunomodulatory and antimicrobial effects. Human clinical evidence specifically for this species is limited.

How it works

L. kefiranofaciens (recently reclassified as Lentilactobacillus kefiri or Lactobacillus kefiri in some taxonomic schemes) is a Gram-positive, anaerobic to microaerophilic bacterium that ferments milk sugar to lactic acid. It also synthesizes kefiran, a water-soluble polysaccharide of glucose and galactose units that gives kefir grains their characteristic cohesive structure. Kefiran has been studied in preclinical models for immunomodulatory, anti-inflammatory, antimicrobial, and modest cholesterol-lowering effects. As a probiotic candidate, L. kefiranofaciens contributes to gut microbiota diversity. Human clinical evidence for this species specifically as a stand-alone probiotic is limited; most kefir research evaluates the whole product rather than isolated strains.

Dosage

There is no RDA. Whole kefir provides natural ongoing exposure (typically 1 to 2 cups daily). Probiotic supplements containing L. kefiranofaciens typically dose in CFU, ranging from 10^8 to 10^10 per serving.

When and how to take it

Whole kefir can be consumed daily as a beverage. Probiotic supplements containing L. kefiranofaciens can be taken any time, with or without food.

2 commercial forms

Compare the main delivery options and what they’re best suited for.

Live L. kefiranofaciens in kefir

Most exposure for most people comes from kefir consumption.

Naturally present in kefir grains; consumed in food matrix.

Probiotic supplement with L. kefiranofaciens

Specialty probiotic products.

Survival through GI tract depends on formulation.

Safety

Generally considered safe based on long history in kefir fermentation. Rarely, lactobacilli can be involved in opportunistic infections in immunocompromised patients. For healthy individuals at typical food and supplement levels, safety is not a concern. No formal Tolerable Upper Intake Level has been established.

Who should be cautious

Severely immunocompromised individuals or those with central venous catheters should consult a clinician before using concentrated probiotic supplements. Generally safe in pregnancy and breastfeeding at food and typical supplement levels.

Interactions

Limited interaction data. As with other lactobacilli, theoretical caution with immunosuppressants. Probiotics may modestly interact with antibiotic effectiveness if taken simultaneously.

Food sources

Kefir

Amount
1 cup
%DV
—

Traditional kefir grains

Amount
varies
%DV
—

Frequently asked questions

What is kefiran?⌄

An exopolysaccharide produced by L. kefiranofaciens that gives kefir grains their cohesive structure. It has been studied for various bioactivities in preclinical models.

Is L. kefiranofaciens unique to kefir?⌄

It is most associated with kefir grains, where it is a dominant species. It can occasionally be isolated from other dairy fermentations.

Is it a probiotic?⌄

It is studied as a probiotic candidate, though clinical evidence for this specific species is less developed than for major commercial probiotic strains.

References

Lactobacillus kefiranofaciens on Wikidata — Wikidata link

Lactobacillus kefiranofaciens on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on Lactobacillus kefiranofaciens (PubMed search) — PubMed link

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.