Kefir, Gut Microbiota, and Athletic Performance in Soccer Players

Not Applicable

Completed

• Conditions: Gut Microbiota Diversity and Composition; Athletic Performance; Functional Food Intervention (Kefir); Body Composition; Dietary Intake Patterns

• Registration Number: NCT06753422
• Lead Sponsor: Acibadem University

Brief Summary

This research work is a clinical trial that will assess the impact of kefir consumption on the gut microbiota profile and athletic performance of female soccer players of age 18-29 years. The participants were divided into two groups namely the kefir intervention group and the control group. The primary end points are the modifications in the alpha diversity of the gut microbiome and the beta diversity of the gut microbiome and also the athletic performance outcomes like VO2 max and finishing speed which will be measured using the 30-15 Intermittent Fitness Test. The other outcomes of the study are the changes in the body composition (measured through BIA and skinfold), the changes in the dietary intake and the variations in certain microbial genera such as Akkermansia muciniphila and Faecalibacterium prausnitzii.

The study will be the first to evaluate whether kefir intake can increase the microbial diversity, increase the VO2max and improve the body composition of professional athletes. The anticipated outcomes of this study are enhanced gut microbial diversity, enhanced VO2max and finishing speed, and positive alteration in the body composition parameters.

Detailed Description

This randomized controlled trial aims at evaluating the impact of kefir on the participants' gut microbiota and athletic performance among professional female soccer players of 18-29 years. The present study is intended to reveal the potential of kefir, a fermented milk product that is packed with probiotics , in altering the diversity and profile of gut microbiota, physical performance, and parameters of body composition.

This trial was carried out for a period of four weeks and the subjects were divided into two parallel groups; the kefir group in which the participants consume 200ml of kefir per day and the control group in which the participants continued with their normal diet without kefir supplementation. The subjects were assigned to either of the two groups at the beginning of the study. Since the study involved a dietary intervention, the trial was conducted without blinding the subject and the researcher. Measurements were made at the beginning and at the end of the intervention in order to evaluate the outcomes.

The main goals of the study were to observe the changes in the diversity and the composition of the gut microbiome with the help of 16S rRNA sequencing and to determine the changes in the athletic performance indices including VO2max and finishing speed which was measured by 30-15 Intermittent Fitness Test. Other objectives were to establish the effects of kefir on other body composition measures such as body fat percentage, fat free mass and total body weight , to examine the patterns of dietary intakes and their relationships with the microbiota and performance measures and to examine the changes in certain gut microorganisms including Akkermansia muciniphila and Faecalibacterium prausnitzii which are known to have positive effects on human health and performance.

The alpha diversity of the gut microbiome was measured with the Shannon and Chao1 indices and the beta diversity was calculated with the Bray-Curtis dissimilarity. The taxonomic analysis was done at the phylum, genus and species level in order to identify the changes in the microbial community due to consumption of kefir. The participants' athletic performance was evaluated with IFT Test to explore the changes in VO2max and finishing speed. Changes in the body composition were assessed by Bioelectrical Impedance Analysis (BIA) and skinfold callipers and the dietary intake data were collected through three-day food records, one off day and two training days to examine the macronutrients and micronutrients intake and their relationship with the microbiota and performance.

This trial seeks to fill an important research gap in the current literature on functional foods in sports nutrition with focus on professional female athletes. In this way, the current study seeks to link dietary interventions with the gut microbiota as well as performance parameters in order to provide empirical support for how kefir can improve the gut health and performance of athletes and to facilitate the development of personalised nutrition for athletes.

Study Timeline

• Study Start: 2024-05-01
• Primary Completion: 2024-06-05
• Status Verified: 2024-12
• Study Completion: 2024-12-01
• Study First Submitted: 2024-12-20
• Study First Submitted QC: 2024-12-30
• Last Update Submitted: 2024-12-30
• Study First Posted: 2024-12-31
• Last Update Posted: 2024-12-31

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 21

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Gut Microbiota Composition Change	At baseline and after 4 weeks of intervention (Week 5)	Changes in gut microbiota diversity and abundance at genus and phylum levels, assessed through 16S rRNA gene sequencing of stool samples.
Athletic Performance Improvement	At baseline and after 4 weeks of intervention (Week 5)	Improvement in athletic performance as measured by the 30-15 Intermittent Fitness Test, evaluating VO2max and finishing speed.

Secondary Outcome Measures

Name	Time	Method
Dietary Intake Assessment	At baseline and after 4 weeks of intervention (Week 5)	Changes in macronutrient and micronutrient intake, assessed through 3-day food records analyzed using nutritional analysis software (BEBIS).
Body weight (kg)	At baseline and after 4 weeks of intervention (Week 5)	Body weight will be measured using a bioelectrical impedance analysis (BIA) device (Tanita BC 545-N ) to assess participants' total body weight.
Body Fat Percentage (%)	At baseline and after 4 weeks of intervention (Week 5)	Body fat percentage will be measured using a bioelectrical impedance analysis (BIA) device (Tanita BC 545-N ) to assess the proportion of body weight composed of fat tissue.
Fat mass (kg)	At baseline and after 4 weeks of intervention (Week 5)	Fat mass will be measured using a bioelectrical impedance analysis (BIA) device (Tanita BC 545-N ) to quantify the total weight of fat tissue in the body.
Fat-free mass (kg)	At baseline and after 4 weeks of intervention (Week 5)	Fat-free mass will be measured using a bioelectrical impedance analysis (BIA) device (Tanita BC 545-N ) to determine the weight of lean tissue, bones, and fluids, excluding fat mass.
Height (m)	At baseline and after 4 weeks of intervention (Week 5)	Height will be measured using a SECA 213 stadiometer with participants standing upright, without shoes, and with their head in the Frankfurt plane.

Trial Locations

Locations (1)

Fatih Vatan Sports Club; 🇹🇷 İstanbul, Turkey