Evaluation of the effect of kefir on sleep quality and gut microbiome in healthy subjects

Evaluation of the effect of kefir on sleep quality and gut microbiome in healthy subjects: A randomized, placebo-controlled, double-blind, parallel study - Evaluation of the effect of kefir on sleep quality and gut microbiome in healthy subjects: A randomized, placebo-controlled, double-blind, parallel study

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000049551

Enrollment

Registered

2022-11-18

Start date

2022-11-18

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy

Interventions

Subjects take 1.5 g of powder per day containing 1.0 g of kefir for 12 weeks. Subjects take 1.5 g of powder per day containing 0.4 g of kefir for 12 weeks. Subjects take 1.5 g of placebo powder per da

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1) Healthy 2) Constantly feeling unsatisfaction with sleep quality

Exclusion criteria

Exclusion criteria: 1) With a disorder requiring prompt treatment 2) Taking medicines or dietary supplements that may affect the trial 3) Participation in any clinical trial within three months of the commencement of the trial 4) In pregnancy or nursing a child 5) Judged as ineligible by the investigators

Design outcomes

Primary

Measure	Time frame
12-week change in Pittsburg Sleep Quality Index	—

Secondary

Measure	Time frame
12-week changes in the followings: the gut microbiome, Visual Analogue Scale (sleep quality, mental stress, physical fatigue), OSA-Sleep Inventory MA Version, State-Trait Anxiety Inventory, salivary cortisol, and natural stool frequency	—

Countries

Japan

Contacts

Public ContactFumiko Higashikawa

Hiroshima University Hospital Medical Center for Translational and Clinical Research

healthy-life@hiroshima-u.ac.jp082-257-1909

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026