Short Term Effects of Probiotics in the Human Micro-vascular Physiology

Not Applicable

Completed

• Conditions: Microcirculation; Endothelial Dysfunction
• Interventions: Other: Kefir consumption

• Registration Number: NCT05234645
• Lead Sponsor: Sheffield Hallam University

Brief Summary

While the beneficial properties of kefir consumption have been thoroughly studied for many years, very little research has been conducted to explore the potential protective properties of kefir consumption to the endothelium in humans. Therefore, the aim of the current study is to explore the short-term efficacy of kefir consumption in improving endothelial function in older and younger healthy, sedentary adults.

Detailed Description

Not available

Study Timeline

• Study Start: 2019-04-01
• Primary Completion: 2021-04-30
• Study Completion: 2021-10-31
• Study First Submitted: 2022-01-20
• Status Verified: 2022-02
• Study First Submitted QC: 2022-02-01
• Last Update Submitted: 2022-02-01
• Study First Posted: 2022-02-10
• Last Update Posted: 2022-02-10

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 29

Inclusion Criteria

All recruited participants were either 18-35 yrs. or 55-75 yrs.

Exclusion Criteria

Pregnancy; chronic diseases with the potential to influence vascular function; smoking status; sedentary (defined via the completion of the international physical activity questionnaire; IPAQ); regular consumption of probiotic-containing products; any overt chronic diseases.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Younger group	Kefir consumption	Fifteen participants, between 18 and 35 years of age. Participants are not pregnant; are healthy and suffering from no chronic diseases with the potential to influence vascular function; non-smoker; sedentary (defined via the completion of the international physical activity questionnaire; IPAQ); and were not consuming regularly probiotic-containing products. Additionally, a medical questionnaire was completed to exclude anyone with overt chronic disease.
Older group	Kefir consumption	Fourteen participants, between 55 and 75 years of age. Participants are not pregnant; are healthy and suffering from no chronic diseases with the potential to influence vascular function; non-smoker; sedentary (defined via the completion of the international physical activity questionnaire; IPAQ); and were not consuming regularly probiotic-containing products. Additionally, a medical questionnaire was completed to exclude anyone with overt chronic disease.

Primary Outcome Measures

Name	Time	Method
Microcirculatory function	8 weeks.	Skin blood flow will be measured as cutaneous red blood cell flux using a Laser Doppler Flowmeter (LDF). Local thermal hyperaemia will be induced using a heating disc surrounding the probe. The probe will be attached to the skin using a double-sided adhesion sticker. Participants will be rested in a supine position in a temperature-controlled room with a constant ambient temperature of 24° C for 35 minutes. Baseline skin blood flow data will be recorded for 5 minutes with the local heating disc temperature set at 30° C. Following this, rapid local heating will be initiated to obtain maximal vasodilation and the temperature will be increased by 1° C every 10 seconds until 42° C was reached. This will then be maintained for 30 minutes following, which the test will be completed.

Secondary Outcome Measures

Name	Time	Method
SF-IPAQ	Baseline.	The SF-IPAQ questionnaire will be completed, to assess physical activity levels.
Anthropometry - 1	8 weeks.	Stature, waist and hip circumferences will be measured (all in cms).
Anthropometry - 2	8 weeks.	Body mass will be measured.
Blood pressure	8 weeks.	Diastolic and systolic blood pressure will be recorded from the left arm at 5-minute intervals throughout the protocol (Dinamap Dash 2500, GE Healthcare, USA).
A discontinuous, sub-maximal test, coupled with transcutaneous oxygen pressure (TcPO2).	8 weeks.	A discontinuous, sub-maximal test, involving four rounds of exercise will measure the participants' transcutaneous oxygen pressure (TcPO2).TcPO2 values will be measured and recorded by a sensor. Measurements will be taken, using a TINA TCM400 TcPO2 device (Radiometer, Copenhagen, Denmark). The electrode will be placed on the participants' back, below the right scapula. The testing protocol includes a total of 20 min on a cycle ergometer (Monark894E, Vansbro, Sweden) with a 2-min break after each 5 min of exercise. Participants will maintain a speed of 80 revolutions per minute, and after each 5-min period, an extra 0.2 kg of resistance will be added to the ergometer, with a 1 kg of starting resistance value. Participants will be encouraged to reach their maximum exertion limit before completing the assessment but could stop before the end of the test if they feel so.

Trial Locations

Locations (1)

Sheffield Hallam University; 🇬🇧 Sheffield, Yorkshire, United Kingdom