Actively Recruiting
Effects of Milk-based Drinks on Gut Microbiome, Sleep, and Cardiometabolic Markers in Adults With Poor Sleep A Randomised, Double-blind, Crossover Trial
Led by Sheffield Hallam University · Updated on 2025-07-17
40
Participants Needed
2
Research Sites
N/A
Total Duration
On this page
Sponsors
S
Sheffield Hallam University
Lead Sponsor
B
Biotiful
Collaborating Sponsor
AI-Summary
What this Trial Is About
Researchers are evaluating the effects of kefir on gut health, sleep quality, and biochemical markers in adults who have sleep problems. The study also looks at cognitive function, blood vessel stiffness, and blood pressure. The aim is to understand how daily kefir consumption may influence the gut microbiome and various health aspects related to sleep and heart health. This research follows a randomized, double-blind, crossover design in adults aged 40 to 70 with poor sleep and specific body weight ranges. Participants will consume 250 ml of either kefir or milk daily for 4 weeks each, with a 4-week break between study periods. Kefir contains live cultures to support gut health, while the milk does not. The order of drinks is randomized and counterbalanced to reduce bias. Participants will switch between the two drinks during the study to assess differences in outcomes. During the study, participants will attend four laboratory visits and provide blood and saliva samples. Researchers will measure LDL cholesterol, gut microbiome changes, sleep quality and duration, cognitive function, blood pressure, pulse wave analysis, and immune markers. Adherence to daily drink consumption will be monitored, and safety is ensured through regular assessments. The total study duration includes two 4-week treatment periods and a 4-week washout phase.
CONDITIONS
Brief Title
Effects of Milk-based Drinks on Gut Microbiome, Sleep and Cardiometabolic Markers
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Aged 40 to 70 years old
- Poor sleep with a Pittsburgh Sleep Quality Index score greater than 5
- Body mass index between 25 and 35 kg/m2
- Willing to consume each study drink daily for 4 weeks and attend 4 laboratory visits
- For women: Using stable contraception or hormone replacement therapy for at least 3 months before the study
You will not qualify if you...
- Allergy or intolerance to milk-based products
- Pregnancy or breastfeeding
- Insufficient English skills to complete questionnaires and cognitive tests
- Gastrointestinal disorders
- Unable to attend laboratory visits due to travel or mobility issues
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 4 weeks per treatment period, with a 4-week washout between periods
Participants will consume either 250ml of original flavour kefir or 250ml of milk daily for 4 weeks, then after a 4-week washout period, they will switch to the other drink for another 4 weeks.
4 laboratory visits during each treatment period
Trial Site Locations
Total: 2 locations
1
University of Leeds
Leeds, West Yorkshire, United Kingdom, LS29JT
Not Yet Recruiting
2
College of Health, Wellbeing and Life Sciences
Sheffield, United Kingdom, S1 1WB
Actively Recruiting
Research Team
T
Tony Lynn,, PhD
L
Lucy Ellis, PhD
How is the study designed?
Study Type
INTERVENTIONAL
Masking
TRIPLE
Allocation
RANDOMIZED
Model
CROSSOVER
Primary Purpose
OTHER
Number of Arms
2
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