Effects of Regular Kefir Consumption on Gut Microbiota in Patients with Metabolic Syndrome: A Parallel-Group, Randomized, Controlled Study.

2019-09-04
Nutrients 11(9)
- Ezgi Bellikci-Koyu
- Banu Pınar Sarer-Yurekli
- Yakut Akyon
- Fadime Aydin-Kose
- Cem Karagozlu
- Ahmet Gokhan Ozgen
- Annika Brinkmann
- Andreas Nitsche
- Koray Ergunay
- Engin Yilmaz
- Zehra Buyuktuncer

PubMed: 31487797
DOI: 10.3390/nu11092089

Study Design

Type: Randomized Controlled Trial (RCT)
Population: patients with metabolic syndrome
Methods: parallel-group, randomized, controlled clinical trial; 180 mL/day kefir or unfermented milk for 12 weeks
Duration: 12 weeks

Rigorous Journal

Several health-promoting effects of kefir have been suggested, however, there is limited evidence for its potential effect on gut microbiota in metabolic syndrome This study aimed to investigate the effects of regular kefir consumption on gut microbiota composition, and their relation with the components of metabolic syndrome. In a parallel-group, randomized, controlled clinical trial setting, patients with metabolic syndrome were randomized to receive 180 mL/day kefir (n = 12) or unfermented milk (n = 10) for 12 weeks. Anthropometrical measurements, blood samples, blood pressure measurements, and fecal samples were taken at the beginning and end of the study. Fasting insulin, HOMA-IR, TNF-α, IFN-γ, and systolic and diastolic blood pressure showed a significant decrease by the intervention of kefir (p ≤ 0.05, for each). However, no significant difference was obtained between the kefir and unfermented milk groups (p > 0.05 for each). Gut microbiota analysis showed that regular kefir consumption resulted in a significant increase only in the relative abundance of Actinobacteria (p = 0.023). No significant change in the relative abundance of Bacteroidetes, Proteobacteria or Verrucomicrobia by kefir consumption was obtained. Furthermore, the changes in the relative abundance of sub-phylum bacterial populations did not differ significantly between the groups (p > 0.05, for each). Kefir supplementation had favorable effects on some of the metabolic syndrome parameters, however, further investigation is needed to understand its effect on gut microbiota composition.

Research Insights

Kefir→Reduced Diastolic Blood Pressure
Fasting insulin, HOMA-IR, TNF-α, IFN-γ, and systolic and diastolic blood pressure showed a significant decrease by the intervention of kefir (p ≤ 0.05, for each). However, no significant difference was obtained between the kefir and unfermented milk groups (p > 0.05 for each).
Effect
Beneficial
Effect size
Small
Dose
180 mL/day
Kefir→Reduced HOMA-IR
Fasting insulin, HOMA-IR, TNF-α, IFN-γ, and systolic and diastolic blood pressure showed a significant decrease by the intervention of kefir (p ≤ 0.05, for each). However, no significant difference was obtained between the kefir and unfermented milk groups (p > 0.05 for each).
Effect
Beneficial
Effect size
Small
Dose
180 mL/day
Kefir→Reduced Insulin Levels
Fasting insulin, HOMA-IR, TNF-α, IFN-γ, and systolic and diastolic blood pressure showed a significant decrease by the intervention of kefir (p ≤ 0.05, for each). However, no significant difference was obtained between the kefir and unfermented milk groups (p > 0.05 for each).
Effect
Beneficial
Effect size
Small
Dose
180 mL/day
Kefir→Reduced Interferon-gamma Level
Fasting insulin, HOMA-IR, TNF-α, IFN-γ, and systolic and diastolic blood pressure showed a significant decrease by the intervention of kefir (p ≤ 0.05, for each). However, no significant difference was obtained between the kefir and unfermented milk groups (p > 0.05 for each).
Effect
Beneficial
Effect size
Small
Dose
180 mL/day
Kefir→Reduced Systolic Blood Pressure
Fasting insulin, HOMA-IR, TNF-α, IFN-γ, and systolic and diastolic blood pressure showed a significant decrease by the intervention of kefir (p ≤ 0.05, for each). However, no significant difference was obtained between the kefir and unfermented milk groups (p > 0.05 for each).
Effect
Beneficial
Effect size
Small
Dose
180 mL/day
Kefir→Reduced Tumor Necrosis Factor Alpha
Fasting insulin, HOMA-IR, TNF-α, IFN-γ, and systolic and diastolic blood pressure showed a significant decrease by the intervention of kefir (p ≤ 0.05, for each). However, no significant difference was obtained between the kefir and unfermented milk groups (p > 0.05 for each).
Effect
Beneficial
Effect size
Small
Dose
180 mL/day