Kefir

Kefir is a fermented dairy (or water) drink studied for gut and metabolic outcomes. Effects vary by strain and product.

Overview

What is kefir?

Kefir is a drink produced by fermentation of bacteria and yeast from kefir grains.

Dosage

A typical dose of kefir is 100-500 ml per day.

Effect graph

Effect heatmap

Possible clinical benefit at 4 stars or greater.


Glycemic control	★★★★★	Medium
Helicobacter pylori (H. pylori)	★★★★★	Medium
Type 2 diabetes	★★★★★	Low
High cholesterol	★★★★★	Low
Cardiovascular disease	★★★★★	Low
Ulcerative colitis	★★★★★	Low
Osteoporosis	★★★★★	Low
Obesity	★★★★★	Low
Inflammatory bowel disease (IBD)	★★★★★	Low
Crohn's disease	★★★★★	Low
Menopause	★★★★★	Low
Constipation	★★★★★	Low
Cerebral palsy	★★★★★	Low
Athletic performance	★★★★★	Very Low / None
Oral mucositis	★★★★★	Very Low / None
Nonalcoholic fatty liver disease	★★★★★	Very Low / None
Metabolic syndrome	★★★★★	Very Low / None
Antibiotic-associated diarrhea	★★★★★	Very Low / None

Weakest

Strongest

12345

SupplementDEX Database

18 conditions for , and rated at least stars. All purchase bands. No minimum star filter.

Antibiotic-associated diarrheaView condition →

Antibiotic-associated diarrhea

Do not purchase★★★★★

How we scored this

Effect SizeVery Low / NoneEvidenceLowTrustMedium

A small study in children aged 1–5 years found that giving a kefir drink (Probugs, Lifeway Foods, Inc.) daily for 10 days during antibiotic treatment did not prevent diarrhea compared with a placebo drink.

Evidence Review

A small study in children aged 1–5 years found that giving a kefir drink (Probugs, Lifeway Foods, Inc.) daily for 10 days during antibiotic treatment did not prevent diarrhea compared with a placebo drink.

Browse 1 study

RCTA randomized clinical trial measuring the influence of kefir on antibiotic-associated diarrhea: the measuring the influence of Kefir (MILK) Study2009n=125

In 125 children aged 1–5 on antibiotics, kefir did not reduce antibiotic-associated diarrhea incidence (18% kefir vs 22% placebo; RR 0.82) over 14 days of follow-up.

Effect: No Benefit
Population: Children/adolescents
Participants: 125
Ages: 1–5

Athletic performanceView condition →

Athletic performance

Do not purchase★★★★★

How we scored this

Effect SizeVery Low / NoneEvidenceMediumTrustMedium

Small studies in healthy adults and recreational athletes found that drinking kefir (16 ounces once a day or twice a week for up to 15 weeks) did not improve running performance or recovery.

Evidence Review

Small studies in healthy adults and recreational athletes found that drinking kefir (16 ounces once a day or twice a week for up to 15 weeks) did not improve running performance or recovery.
However, another very small study in untrained men showed that taking kefir powder (20 g mixed with water daily for 4 weeks) helped them last longer during exercise and lowered lactic acid levels compared with a placebo.

Browse 3 studies

RCTMilk or Kefir, in Comparison to Water, Do Not Enhance Running Time-Trial Performance in Endurance Master Athletes2024n=15

In 11 endurance master athletes, 14 days of kefir before a 5 km time trial did not improve running performance versus milk or water, though kefir reduced GI symptom scores after exhaustive exercise.

Effect: No Benefit
Duration: 14 days
Population: Athletes
Participants: 15
Ages: 40–75

RCTThe Effect of Kefir Supplementation on Improving Human Endurance Exercise Performance and Antifatigue2021n=16

In 16 adults, SYNKEFIR 20 g/day for 28 days increased time to exhaustion by 1.29-fold versus placebo and lowered post-exercise lactate without changing gut microbiota.

Effect: Benefit
Duration: 28 days
Dose: 20 g/day
Population: Healthy adults
Participants: 16
Ages: 20–30

RCTThe effects of postexercise consumption of a kefir beverage on performance and recovery during intensive endurance training2015

In 67 adults in a 15-week endurance training study, post-exercise kefir did not improve fitness or body composition but attenuated the rise in C-reactive protein versus control beverage.

Effect: No Benefit
Population: Adults
Ages: 18–24

Cardiovascular diseaseView condition →

Cardiovascular disease

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceMediumTrustMedium

A summary of six small studies in people with conditions that raise the risk of heart disease (such as type-2-diabetes, high cholesterol, metabolic syndrome, or obesity) found that drinking kefir (180–600 mL daily for 3–12 weeks) did not improve weight, cholesterol, or blood sugar compared with a control.

Evidence Review

A summary of six small studies in people with conditions that raise the risk of heart disease (such as diabetes, high cholesterol, metabolic syndrome, or obesity) found that drinking kefir (180–600 mL daily for 3–12 weeks) did not improve weight, cholesterol, or blood sugar compared with a control.
The findings are less certain because the studies varied widely in size, dose, duration, and type of participants.

Browse 1 study1 meta-analysis

MetaEffects of Kefir Consumption on Cardiometabolic Risk Factors: A Systematic Review and Meta-analysis of Randomized Controlled Trials2023n=314

A meta-analysis of 6 kefir RCTs (314 subjects) found kefir reduced fasting insulin (−3.69 µIU/mL) and HOMA-IR (−2.56) but did not significantly change lipids, HbA1c, or body weight.

Effect: Benefit
Participants: 314

Cerebral palsyView condition →

Cerebral palsy

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceLowTrustLow

A small study in children aged 4–8 years with spastic cerebral palsy found that drinking kefir (250 mL daily for 7 weeks) reduced constipation and made stools softer compared with starting levels.

Evidence Review

A small study in children aged 4–8 years with spastic cerebral palsy found that drinking kefir (250 mL daily for 7 weeks) reduced constipation and made stools softer compared with starting levels.
These changes were not seen in children given regular yogurt, but the results are uncertain because the two groups were not directly compared.

Browse 1 study

Effects of a Modern Kefir on Conditions Associated with Moderate Severe Spastic Quadriparesis Cerebral Palsy2022n=12

In 12 children with spastic quadriplegic cerebral palsy, modern kefir for 7 weeks increased weight and height, reduced constipation, and raised lymphocyte counts versus yogurt control.

Effect: Benefit
Duration: 7 weeks
Population: Children/adolescents
Participants: 12
Ages: 4–8

ConstipationView condition →

Constipation

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceLowTrustLow

A small study in adults with chronic constipation found that drinking kefir (500 mL daily for 4 weeks) increased bowel movements by about 2.5 times per week and made stools softer in half of those who had hard stools at the start of the study.

Evidence Review

A small study in adults with chronic constipation found that drinking kefir (500 mL daily for 4 weeks) increased bowel movements by about 2.5 times per week and made stools softer in half of those who had hard stools at the start of the study.
The results are uncertain because there was no comparison group.

Browse 1 study

Clinical trialEffects of a kefir supplement on symptoms, colonic transit, and bowel satisfaction score in patients with chronic constipation: a pilot study2014n=10

In 20 adults with chronic constipation, kefir 500 mL/day for 4 weeks increased stool frequency, improved consistency, accelerated colonic transit in slow-transit patients, and improved bowel satisfaction.

Effect: Benefit
Duration: 4 weeks
Dose: 500 mL/day
Population: Constipated patients
Participants: 10

Crohn's diseaseView condition →

Crohn's disease

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceLowTrustMedium

It isn’t clear if kefir helps people with Crohn’s disease.

Evidence Review

It isn’t clear if kefir helps people with Crohn’s disease.
A small study found that drinking kefir (200 mL twice a day for 4 weeks) reduced bloating and improved overall symptoms, but the findings are uncertain because there was no comparison group.

Browse 1 study

RCTEffect of administering kefir on the changes in fecal microbiota and symptoms of inflammatory bowel disease: A randomized controlled trial2019n=45

In 45 IBD patients, kefir 400 mL/day for 4 weeks increased fecal Lactobacillus, reduced bloating in Crohn's disease, and improved feeling-good scores without major adverse effects.

Effect: Benefit
Duration: 4 weeks
Dose: 400 mL/day
Population: Ulcerative colitis patients
Participants: 45

Glycemic controlView condition →

Glycemic control

Consider purchase★★★★★

How we scored this

Effect SizeMediumEvidenceMediumTrustHigh

A summary of six clinical trials (323 participants) found that drinking kefir lowered fasting blood sugar by about 10 points and reduced insulin levels, but did not improve long-term blood sugar control (measured by HbA1c).

Evidence Review

A summary of six clinical trials (323 participants) found that drinking kefir lowered fasting blood sugar by about 10 points and reduced insulin levels, but did not improve long-term blood sugar control (measured by HbA1c).
Another analysis of six clinical trials (314 participants) looked at heart health and metabolism.
Kefir lowered insulin levels and improved insulin resistance but did not change cholesterol, blood sugar, body weight, or long-term blood sugar control.

Browse 2 studies2 meta-analyses

MetaEffects of Kefir Consumption on Cardiometabolic Risk Factors: A Systematic Review and Meta-analysis of Randomized Controlled Trials2023n=314

A meta-analysis of 6 kefir RCTs (314 subjects) found kefir reduced fasting insulin (−3.69 µIU/mL) and HOMA-IR (−2.56) but did not significantly change lipids, HbA1c, or body weight.

Effect: Benefit
Participants: 314

MetaEffect of kefir beverage consumption on glycemic control: A systematic review and meta-analysis of randomized controlled clinical trials2021n=323

A meta-analysis of kefir trials found kefir consumption significantly reduced fasting glucose and HbA1c in patients with type 2 diabetes versus control.

Effect: Benefit
Participants: 323

Helicobacter pylori (H. pylori)View condition →

Helicobacter pylori (H. pylori)

Reconsider purchase★★★★★

How we scored this

Effect SizeMediumEvidenceLowTrustMedium

A small study in people with H.

Evidence Review

A small study in people with H. pylori infection found that drinking kefir (250 mL twice a day for 2 weeks), along with standard antibiotic therapy, increased the chance of clearing the infection by 56% compared with placebo milk.

Browse 1 study

RCTKefir improves the efficacy and tolerability of triple therapy in eradicating Helicobacter pylori2010n=46

In 46 H. pylori patients on triple therapy, adding kefir 250 mL twice daily improved eradication rates and reduced diarrhea and taste disturbance versus triple therapy alone.

Effect: Benefit
Duration: 14 days
Dose: 250 mL 2×/day
Population: H. pylori patients
Participants: 46

High cholesterolView condition →

High cholesterol

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceMediumTrustMedium

A very small study in men with high cholesterol showed that drinking kefir (500 mL daily for up to 4 weeks) did not lower total cholesterol or LDL cholesterol compared with placebo milk or starting levels.

Evidence Review

A very small study in men with high cholesterol showed that drinking kefir (500 mL daily for up to 4 weeks) did not lower total cholesterol or LDL cholesterol compared with placebo milk or starting levels.

Browse 3 studies

Kefir improves blood parameters and reduces cardiovascular risks in patients with metabolic syndrome2021

A clinical study in adults with metabolic syndrome reported kefir consumption improved blood lipid parameters and cardiovascular risk markers compared with control.

Effect: Benefit
Population: Metabolic syndrome patients

No source link

RCTEffect of probiotic fermented milk (kefir) on glycemic control and lipid profile in type 2 diabetic patients: a randomized double-blind placebo-controlled clinical trial2015n=30

In 30 type 2 diabetes patients, probiotic kefir 600 mL/day for 8 weeks lowered fasting glucose, insulin, HOMA-IR, and LDL cholesterol versus fermented milk control.

Effect: Benefit
Duration: 8 weeks
Dose: 600 mL/day
Population: Diabetic patients
Participants: 30
Ages: 35–65

RCTKefir consumption does not alter plasma lipid levels or cholesterol fractional synthesis rates relative to milk in hyperlipidemic men: a randomized controlled trial [ISRCTN10820810]2002n=11

In 11 healthy adults, 4 weeks of kefir did not change fasting plasma lipids or LDL particle size distribution versus milk control despite prior evidence for fermented dairy effects on cholesterol.

Effect: No Benefit
Duration: 4 weeks
Population: Men
Participants: 11

Inflammatory bowel disease (IBD)View condition →

Inflammatory bowel disease (IBD)

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceLowTrustMedium

There is not enough evidence to determine if kefir has any benefit for inflammatory bowel disease (IBD).

Evidence Review

There is not enough evidence to determine if kefir has any benefit for inflammatory bowel disease (IBD).

Browse 1 study

RCTEffect of administering kefir on the changes in fecal microbiota and symptoms of inflammatory bowel disease: A randomized controlled trial2019n=45

In 45 IBD patients, kefir 400 mL/day for 4 weeks increased fecal Lactobacillus, reduced bloating in Crohn's disease, and improved feeling-good scores without major adverse effects.

Effect: Benefit
Duration: 4 weeks
Dose: 400 mL/day
Population: Ulcerative colitis patients
Participants: 45

MenopauseView condition →

Menopause

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceLowTrustLow

A small study in women with menopause symptoms and sleep problems found that drinking kefir (250 mL twice a day for 1 month) improved sleep by about 67% compared with no kefir, and also helped with hot flashes, overall physical health, and sexual symptoms.

Evidence Review

A small study in women with menopause symptoms and sleep problems found that drinking kefir (250 mL twice a day for 1 month) improved sleep by about 67% compared with no kefir, and also helped with hot flashes, overall physical health, and sexual symptoms.

Browse 1 study

Effects of Kefir on Quality of Life and Sleep Disturbances in Postmenopausal Women2019

In postmenopausal women, kefir supplementation improved quality of life and sleep disturbance scores versus control in a clinical study of menopausal symptoms.

Effect: Benefit
Population: Postmenopausal women

Metabolic syndromeView condition →

Metabolic syndrome

Do not purchase★★★★★

How we scored this

Effect SizeVery Low / NoneEvidenceLowTrustMedium

Two small studies in people with metabolic syndrome found that drinking kefir (180 mL daily for 12 weeks) did not improve weight, blood pressure, cholesterol, or blood sugar when compared with unfermented milk.

Evidence Review

Two small studies in people with metabolic syndrome found that drinking kefir (180 mL daily for 12 weeks) did not improve weight, blood pressure, cholesterol, or blood sugar when compared with unfermented milk.

Browse 2 studies

Kefir improves blood parameters and reduces cardiovascular risks in patients with metabolic syndrome2021

A clinical study in metabolic syndrome patients reported kefir improved blood parameters and cardiovascular risk markers compared with control.

Effect: Benefit
Population: Metabolic syndrome patients

No source link

RCTEffects of Regular Kefir Consumption on Gut Microbiota in Patients with Metabolic Syndrome: A Parallel-Group, Randomized, Controlled Study2019n=12

In 12 metabolic syndrome patients, kefir 180 mL/day for 12 weeks modulated gut microbiota composition versus baseline, though overall diversity changes were limited.

Effect: No Benefit
Duration: 12 weeks
Dose: 180 mL/day
Population: Metabolic syndrome patients
Participants: 12
Ages: 18–65

Nonalcoholic fatty liver diseaseView condition →

Nonalcoholic fatty liver disease

Do not purchase★★★★★

How we scored this

Effect SizeVery Low / NoneEvidenceLowTrustMedium

There is not enough evidence to determine if kefir has any benefit for nonalcoholic fatty liver disease.

Evidence Review

There is not enough evidence to determine if kefir has any benefit for nonalcoholic fatty liver disease.

Browse 1 study

RCTThe effects of kefir drink on liver aminotransferases and metabolic indicators in patients with nonalcoholic fatty liver disease: a randomized controlled trial2025n=80

In 80 NAFLD patients, kefir improved liver aminotransferases and metabolic indicators versus control in a randomized trial of probiotic fermented milk.

Effect: No Benefit
Population: NAFLD patients
Participants: 80

ObesityView condition →

Obesity

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceLowTrustMedium

There is not enough evidence to determine if kefir has any benefit for obesity.

Evidence Review

There is not enough evidence to determine if kefir has any benefit for obesity.

Browse 1 study

RCTKefir drink leads to a similar weight loss, compared with milk, in a dairy-rich non-energy-restricted diet in overweight or obese premenopausal women: a randomized controlled trial2015n=75

In 75 overweight adults on a dairy-rich diet for 8 weeks, kefir and milk led to similar weight loss with no significant difference between beverages.

Effect: Benefit
Duration: 8 weeks
Population: Women
Participants: 75
Ages: 25–45

Oral mucositisView condition →

Oral mucositis

Do not purchase★★★★★

How we scored this

Effect SizeVery Low / NoneEvidenceLowTrustMedium

A small study in people with colorectal cancer found that rinsing the mouth with kefir and then drinking kefir (250 mL twice a day for the first 5 days of chemotherapy with 5-influenzaorouracil) did not prevent mouth sores compared with rinsing with salt water.

Evidence Review

A small study in people with colorectal cancer found that rinsing the mouth with kefir and then drinking kefir (250 mL twice a day for the first 5 days of chemotherapy with 5-fluorouracil) did not prevent mouth sores compared with rinsing with salt water.

Browse 1 study

RCTEffect of oral administration of kefir on serum proinflammatory cytokines on 5-FU induced oral mucositis in patients with colorectal cancer2008n=40

In 40 cancer patients on 5-FU chemotherapy, kefir reduced serum proinflammatory cytokines and improved antimicrobial activity versus control during treatment.

Effect: No Benefit
Duration: 5 days per chemotherapy cycle
Dose: 250 mL kefir twice daily
Population: Cancer patients
Participants: 40

OsteoporosisView condition →

Osteoporosis

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceLowTrustMedium

A small study in people with osteoporosis found that taking kefir (1600 mg) together with calcium (1500 mg daily) for 6 months did not improve bone density compared with calcium alone.

Evidence Review

A small study in people with osteoporosis found that taking kefir (1600 mg) together with calcium (1500 mg daily) for 6 months did not improve bone density compared with calcium alone.

Browse 1 study

RCTShort-Term Effects of Kefir-Fermented Milk Consumption on Bone Mineral Density and Bone Metabolism in a Randomized Clinical Trial of Osteoporotic Patients2015n=40

In 40 postmenopausal women, kefir 1,600 mg/day for 6 months improved bone mineral density at lumbar spine and femoral neck versus control.

Effect: Benefit
Duration: 6 months
Dose: 600 mg/day
Population: Osteoporosis patients
Participants: 40
Avg age: 67.94±8.37

Type 2 diabetesView condition →

Type 2 type-2-diabetes

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceHighTrustMedium

A summary of six small studies in healthy people and in those with type-2-diabetes, metabolic syndrome, or overweight found that drinking kefir (180–1200 mL daily for 2–12 weeks) lowered fasting blood sugar by about 10 points, but did not improve long-term blood sugar control (HbA1c).

Evidence Review

A summary of six small studies in healthy people and in those with diabetes, metabolic syndrome, or overweight found that drinking kefir (180–1200 mL daily for 2–12 weeks) lowered fasting blood sugar by about 10 points, but did not improve long-term blood sugar control (HbA1c).
The findings are less certain because the studies varied widely in dose, length, and participants.

Browse 3 studies1 meta-analysis

MetaEffect of kefir beverage consumption on glycemic control: A systematic review and meta-analysis of randomized controlled clinical trials2021n=323

A meta-analysis of kefir trials found kefir consumption significantly reduced fasting glucose and HbA1c in patients with type 2 diabetes versus control.

Effect: Benefit
Participants: 323

Effect of Probiotic Fermented Milk (Kefir) on Some Blood Biochemical Parameters Among Newly Diagnosed Type 2 Diabetic Adult Males in Gaza Governorate2019

In newly diagnosed adult males with type 2 diabetes, probiotic fermented kefir milk improved several blood biochemical parameters versus control over the intervention period.

Effect: Benefit
Population: Adults

No source link

RCTEffect of probiotic fermented milk (kefir) on glycemic control and lipid profile in type 2 diabetic patients: a randomized double-blind placebo-controlled clinical trial2015n=30

In 30 type 2 diabetes patients, probiotic kefir 600 mL/day for 8 weeks lowered fasting glucose, insulin, HOMA-IR, and LDL cholesterol versus fermented milk control.

Effect: Benefit
Duration: 8 weeks
Dose: 600 mL/day
Population: Diabetic patients
Participants: 30
Ages: 35–65

Ulcerative colitisView condition →

Ulcerative colitis

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceLowTrustMedium

A small study in people with ulcerative colitis found that drinking kefir (200 mL twice a day for 4 weeks) did not lessen abdominal pain or bloating.

Evidence Review

A small study in people with ulcerative colitis found that drinking kefir (200 mL twice a day for 4 weeks) did not lessen abdominal pain or bloating.
The results are less certain because the study did not include a comparison group.

Browse 1 study

RCTEffect of administering kefir on the changes in fecal microbiota and symptoms of inflammatory bowel disease: A randomized controlled trial2019n=45

In 45 IBD patients, kefir 400 mL/day for 4 weeks increased fecal Lactobacillus, reduced bloating in Crohn's disease, and improved feeling-good scores without major adverse effects.

Effect: Benefit
Duration: 4 weeks
Dose: 400 mL/day
Population: Ulcerative colitis patients
Participants: 45

Database Snapshot

Studies per condition

Kefir evidence base by condition

Most kefir research is concentrated in a handful of conditions.

Athletic performance accounts for 3 of 26 studies (12%).
High cholesterol accounts for 3 of 26 studies (12%).
Type 2 diabetes accounts for 3 of 26 studies (12%).
Sparse coverage remains for Glycemic control, Metabolic syndrome, Antibiotic-associated diarrhea.

Studies per year

Kefir publications over time

Safety

Kefir is likely safe.

However kefir contains lactose, and may cause gastrointestinal side effects in those with lactose intolerance.

Frequently Asked Questions

References

Sources21 references

SupplementDEX uses only high-quality sources to determine supplement effectiveness.

SupplementDEX Database · Glycemic control

2 references

1.SupplementDEX Database: Glycemic control — Effects of Kefir Consumption on Cardiometabolic Risk Factors: A Systematic Review and Meta-analysis of Randomized Controlled Trials2023
A meta-analysis of 6 kefir RCTs (314 subjects) found kefir reduced fasting insulin (−3.69 µIU/mL) and HOMA-IR (−2.56) but did not significantly change lipids, HbA1c, or body weight.
View on PubMed 371024912023
2.SupplementDEX Database: Glycemic control — Effect of kefir beverage consumption on glycemic control: A systematic review and meta-analysis of randomized controlled clinical trials2021
A meta-analysis of kefir trials found kefir consumption significantly reduced fasting glucose and HbA1c in patients with type 2 diabetes versus control.
View on PubMed 342806892021

SupplementDEX Database · Helicobacter pylori (H. pylori)

1 reference

3.SupplementDEX Database: Helicobacter pylori (H. pylori) — Kefir improves the efficacy and tolerability of triple therapy in eradicating Helicobacter pylori2010
In 46 H. pylori patients on triple therapy, adding kefir 250 mL twice daily improved eradication rates and reduced diarrhea and taste disturbance versus triple therapy alone.
View on PubMed 211869842010

SupplementDEX Database · Antibiotic-associated diarrhea

1 reference

4.SupplementDEX Database: Antibiotic-associated diarrhea — A randomized clinical trial measuring the influence of kefir on antibiotic-associated diarrhea: the measuring the influence of Kefir (MILK) Study2009
In 125 children aged 1–5 on antibiotics, kefir did not reduce antibiotic-associated diarrhea incidence (18% kefir vs 22% placebo; RR 0.82) over 14 days of follow-up.
View on PubMed 196521082009

SupplementDEX Database · Athletic performance

3 references

5.SupplementDEX Database: Athletic performance — Milk or Kefir, in Comparison to Water, Do Not Enhance Running Time-Trial Performance in Endurance Master Athletes2024
In 11 endurance master athletes, 14 days of kefir before a 5 km time trial did not improve running performance versus milk or water, though kefir reduced GI symptom scores after exhaustive exercise.
View on PubMed 384748452024
6.SupplementDEX Database: Athletic performance — The Effect of Kefir Supplementation on Improving Human Endurance Exercise Performance and Antifatigue2021
In 16 adults, SYNKEFIR 20 g/day for 28 days increased time to exhaustion by 1.29-fold versus placebo and lowered post-exercise lactate without changing gut microbiota.
View on PubMed 336691192021
7.SupplementDEX Database: Athletic performance — The effects of postexercise consumption of a kefir beverage on performance and recovery during intensive endurance training2015
In 67 adults in a 15-week endurance training study, post-exercise kefir did not improve fitness or body composition but attenuated the rise in C-reactive protein versus control beverage.
View on PubMed 262987522015

SupplementDEX Database · Constipation

1 reference

8.SupplementDEX Database: Constipation — Effects of a kefir supplement on symptoms, colonic transit, and bowel satisfaction score in patients with chronic constipation: a pilot study2014
In 20 adults with chronic constipation, kefir 500 mL/day for 4 weeks increased stool frequency, improved consistency, accelerated colonic transit in slow-transit patients, and improved bowel satisfaction.
View on PubMed 255997762014

SupplementDEX Database · Metabolic syndrome

2 references

10.SupplementDEX Database: Metabolic syndrome — Effects of Regular Kefir Consumption on Gut Microbiota in Patients with Metabolic Syndrome: A Parallel-Group, Randomized, Controlled Study2019
In 12 metabolic syndrome patients, kefir 180 mL/day for 12 weeks modulated gut microbiota composition versus baseline, though overall diversity changes were limited.
View on PubMed 314877972019
9.Kefir improves blood parameters and reduces cardiovascular risks in patients with metabolic syndrome. See external sourceExternal source
View source

SupplementDEX Database · Obesity

1 reference

11.SupplementDEX Database: Obesity — Kefir drink leads to a similar weight loss, compared with milk, in a dairy-rich non-energy-restricted diet in overweight or obese premenopausal women: a randomized controlled trial2015
In 75 overweight adults on a dairy-rich diet for 8 weeks, kefir and milk led to similar weight loss with no significant difference between beverages.
View on PubMed 256487392015

SupplementDEX Database · Oral mucositis

1 reference

12.SupplementDEX Database: Oral mucositis — Effect of oral administration of kefir on serum proinflammatory cytokines on 5-FU induced oral mucositis in patients with colorectal cancer2008
In 40 cancer patients on 5-FU chemotherapy, kefir reduced serum proinflammatory cytokines and improved antimicrobial activity versus control during treatment.
View on PubMed 187628642008

SupplementDEX Database · Osteoporosis

1 reference

13.SupplementDEX Database: Osteoporosis — Short-Term Effects of Kefir-Fermented Milk Consumption on Bone Mineral Density and Bone Metabolism in a Randomized Clinical Trial of Osteoporotic Patients2015
In 40 postmenopausal women, kefir 1,600 mg/day for 6 months improved bone mineral density at lumbar spine and femoral neck versus control.
View on PubMed 266558882015

SupplementDEX Database · Type 2 diabetes

2 references

15.SupplementDEX Database: Type 2 diabetes — Effect of probiotic fermented milk (kefir) on glycemic control and lipid profile in type 2 diabetic patients: a randomized double-blind placebo-controlled clinical trial2015
In 30 type 2 diabetes patients, probiotic kefir 600 mL/day for 8 weeks lowered fasting glucose, insulin, HOMA-IR, and LDL cholesterol versus fermented milk control.
View on PubMed 259050572015
14.Effect of Probiotic Fermented Milk (Kefir) on Some Blood Biochemical Parameters Among Newly Diagnosed Type 2 Diabetic Adult Males in Gaza Governorate. See external sourceExternal source
View source

SupplementDEX Database · Cerebral palsy

1 reference

16.SupplementDEX Database: Cerebral palsy — Effects of a Modern Kefir on Conditions Associated with Moderate Severe Spastic Quadriparesis Cerebral Palsy2022
In 12 children with spastic quadriplegic cerebral palsy, modern kefir for 7 weeks increased weight and height, reduced constipation, and raised lymphocyte counts versus yogurt control.
View on PubMed 358890112022

SupplementDEX Database · Crohn's disease

1 reference

17.SupplementDEX Database: Crohn's disease — Effect of administering kefir on the changes in fecal microbiota and symptoms of inflammatory bowel disease: A randomized controlled trial2019
In 45 IBD patients, kefir 400 mL/day for 4 weeks increased fecal Lactobacillus, reduced bloating in Crohn's disease, and improved feeling-good scores without major adverse effects.
View on PubMed 306620042019

SupplementDEX Database · High cholesterol

2 references

19.SupplementDEX Database: High cholesterol — Kefir consumption does not alter plasma lipid levels or cholesterol fractional synthesis rates relative to milk in hyperlipidemic men: a randomized controlled trial [ISRCTN10820810]2002
In 11 healthy adults, 4 weeks of kefir did not change fasting plasma lipids or LDL particle size distribution versus milk control despite prior evidence for fermented dairy effects on cholesterol.
View on PubMed 118253442002
18.Kefir improves blood parameters and reduces cardiovascular risks in patients with metabolic syndrome. See external sourceExternal source
View source

SupplementDEX Database · Menopause

1 reference

20.SupplementDEX Database: Menopause — Effects of Kefir on Quality of Life and Sleep Disturbances in Postmenopausal Women2019
In postmenopausal women, kefir supplementation improved quality of life and sleep disturbance scores versus control in a clinical study of menopausal symptoms.
View on PubMed 307684392019

SupplementDEX Database · Nonalcoholic fatty liver disease

1 reference

21.SupplementDEX Database: Nonalcoholic fatty liver disease — The effects of kefir drink on liver aminotransferases and metabolic indicators in patients with nonalcoholic fatty liver disease: a randomized controlled trial2025
In 80 NAFLD patients, kefir improved liver aminotransferases and metabolic indicators versus control in a randomized trial of probiotic fermented milk.
View on PubMed 397736572025

Kava

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Kohlrabi

Kohlrabi is a cruciferous vegetable. Clinical evidence for supplemental use is lacking.

On this page

Overview Dosage Effect graph Effect heatmap SupplementDEX Database Database Snapshot Safety Frequently Asked Questions References