Skip to main content
UK clinical trials - updated daily from ClinicalTrials.gov
TrialConnect
← Back to Search
Looking for participantsNA

Effects of Milk-based Drinks on Gut Microbiome, Sleep and Cardiometabolic Markers

Sponsor: Sheffield Hallam University

NCT ID: NCT07071181

View on ClinicalTrials.gov ↗

At a glance

What the study gets you
Access to the study treatment being tested
Type of study
Interventional (receives a drug or procedure)
Time in hospital
In-person visits at study sites — visit count not specified by the sponsor
Drug or intervention
Original flavour kefir (supplement), Milk (other)
How long the study runs
Study runs about 7 months (dates as stated)
About the drug or intervention
Original flavour kefir — supplement: Participants will consume 250ml of original flavour kefir daily for 4 weeks. · Milk — other: Participants will consume 250 ml milk daily for 4 weeks.
Patient visit burden
Not specified by the sponsor
Type of study
Testing a treatment
Ages
40 Years to 70 Years
Who
All
Number of participants
40
Started
2025-08
Last checked
2025-06

Plain English Summary

What is this study?

  • • Testing a new treatment for sleep
  • • NA - 40 participants
  • • The purpose of this study is to evaluate the effects of kefir on gastrointestinal health, sleep quality, and biochemical parameters in adults who have sleep problems

Who can take part?

  • • Ages 40 Years to 70 Years
  • • Diagnosed with sleep

Where?

  • • Leeds - University of Leeds
  • • Sheffield - College of Health, Wellbeing and Life Sciences

This is a simplified summary. Always discuss with your doctor before making any decisions.

About This Trial

The purpose of this study is to evaluate the effects of kefir on gastrointestinal health, sleep quality, and biochemical parameters in adults who have sleep problems. Further measurements of cognitive function, arterial stiffness and blood pressure will also be assessed. The following questions will be addressed during the study: 1. What effect does repeated ingestion of kefir have on the gut microbiome and can this positively influence sleep performance (quality and duration) in adults with sleep problems? 2. Does repeated ingestion of kefir impact LDL, triacyglycerols and non-HDLc in adults with sleep problems? 3. What effect does repeated ingestion of kefir have on cognitive function and mood? 4. What effect does repeated ingestion of kefir have on vascular function, inflammation and markers of immunity in adults with sleep problems? In a randomised, crossover design study, participants will consume 250 ml of kefir (original flavour) or milk for 4 weeks with a 4-week washout.

More detail

The gut microbiome is recognized as a key regulator of host health, influencing various physiological processes. Dysbiosis of the gut microbiome has been implicated in a range of adverse health outcomes, including disruptions in sleep architecture and impairments in cardiometabolic function. There is growing interest in identifying dietary interventions that can modulate gut microbiota composition and functionality. In particular, the consumption of fermented foods, such as kefir, has emerged as a potential strategy for promoting microbial homeostasis and improving health outcomes This study conforms to a randomised, double-blind 2-arm crossover design. Participants will consume either Kefir (original flavour) or milk. Each arm will involve daily consumption of the drink for 4-weeks with a 4 week washout before crossing over to the opposite condition. Drinks will be administered in a counterbalanced order to minimise potential order effects. The primary outcome of this study is a 5% change in LDL based on a previous study (Bellikci-Koyu et al., 2022). Assuming type I error probability α = 0.05 and power of 80%, and effect size of 0.2 G\*power calculated that 32 participants would need to be recruited. To account for potential drop out and balanced randomization, we will aim to recruit 40 participants. Participants will be recruited through the use of posters around Sheffield Hallam University and the University of Leeds, through emails to staff and students, and contacts at surrounding universities. Potentially eligible participants will be identified through the use of a recruitment questionnaire before being invited to a screening visit for full consideration for the study. All participants will provide written informed consent before participating. A linear mixed model analysis will be used to assess the effect of kefir on outcome parameters.

SleepCardiovascular DiseasesGut MicrobiomeCognitive Function and MoodLDL Cholesterol

How this trial compares with your answers

Answer 2 more questions to improve match

What we know so far

Condition· Matched your search
Age· Tell us your age for better matching
Gender· Tell us your sex for better matching

Still need:

  • • Tell us your age for better matching
  • • Tell us your sex for better matching

Preliminary match based on your answers. Full eligibility requires on-site assessment including medical history, physical exam, and lab tests. This does not guarantee enrolment.

Eligibility at a Glance

Key info

  • Age: 40 Years - 70 Years
  • Who can join: All genders

What the study is looking for

  • ✓Aged 40-70 years old
  • ✓Suffer with poor sleep (measured using the PIttsburg Sleep Quality Index with a score \> 5)
  • ✓BMI in range of 25-35 kg/m2
  • ✓Willingness to consume each study drink daily for 4 weeks and attend the laboratory on 4 separate occasions
  • ✓For women: Medication in the form of contraception or HRT providing these have not been modified 3 months prior to...

Who cannot take part

  • ✗Intolerance or allergy to milk-based products
  • ✗Pregnancy/breastfeeding
  • ✗Insufficient English language skills to complete all study questionnaires and perform the cognitive tests
  • ✗Gastrointestinal disorders
  • ✗Inability to attend the laboratory due to travel/mobility difficulties
See the full criteria
Inclusion Criteria: * Aged 40-70 years old * Suffer with poor sleep (measured using the PIttsburg Sleep Quality Index with a score \> 5) * BMI in range of 25-35 kg/m2 * Willingness to consume each study drink daily for 4 weeks and attend the laboratory on 4 separate occasions * For women: Medication in the form of contraception or HRT providing these have not been modified 3 months prior to the first study day Exclusion Criteria: * Intolerance or allergy to milk-based products * Pregnancy/breastfeeding * Insufficient English language skills to complete all study questionnaires and perform the cognitive tests * Gastrointestinal disorders * Inability to attend the laboratory due to travel/mobility difficulties

Where Is This Study? (2 UK sites)

University of Leeds

Leeds LS29JT, United Kingdom

NOT_YET_RECRUITING
Site contact (verified)
Professor Kieran Tuohy01133432876k.tuohy@leeds.ac.uk
Dr Anthony Buckleya.buckley1@leeds.ac.uk

College of Health, Wellbeing and Life Sciences

Sheffield S1 1WB, United Kingdom

Recruiting
Site contact (verified)
Tony Lynn, PhDPrincipal Investigator
Lucy Ellis, PhDLucy.Ellis@shu.ac.uk

How to Get in Touch

Tony Lynn,, PhD

Sponsor contact

CONTACT

0114 2252065 T.lynn@shu.ac.uk

Lucy Ellis, PhD

Sponsor contact

CONTACT

Lucy.Ellis@shu.ac.uk
Data sourced from ClinicalTrials.gov · Last verified: 2025-06