The effects of Korean-DASH diet on metabolic syndrome, insulin resistance and gut microbiota

Abstract

Introduction: The prevalence of metabolic syndrome (MetS) has increased in Korea and it has been important issue in public health. The risk of MetS is associated with lifestyle and Dietary pattern is important factor to prevent and control the MetS. In addition, the intestinal microbiota is modulated by host diet and affects human metabolic health. The aim of this study is to assess the influence of a Korean DASH diet on metabolic syndrome, insulin resistance improvement in Korean adults and the changes of intestinal microbiota composition and diversity.

Methods: Based on Dietary Approaches to Stop Hypertension (DASH) diet patterns, the modified traditional Korean diet was developed. This K-DASH diet is rich in grains, vegetables, nuts, poultry and low in sodium and red meat. K-DASH diet intervention was conducted during 10-days with two sub groups of traditional Korean diet based Korean (TK group) who have been adhering traditional Korean diet and Western diet based Korean (WK group) who have been adhering western diet. A total 65 subjects participated in 10-days intervention. (TK group n=46, WK group n=19) We collected data of anthropometric, biochemical measurements and microbial materials at pre-post intervention each. The microbial sequencing were completed by the Illumina Miseq platform and after quality check the sequences, quantitative metagenomics analysis were performed using QIIME 1.8.0 software.

Results: During 10-days K-DASH diet intervention the intakes of protein and fiber were significantly increased and the dietary sodium intakes were decreased (p<0.05). In metabolic syndrome indicators, the body weight and waist circumference were decreased (-0.90kg, -0.42cm

p<0.001) and systolic blood pressure (SBP) and diastolic blood pressure (DBP) were reduced in whole subjects (-4.85mmHg, -2.45mmHg

p<0.01). Also the total cholesterol and triglycerides level were significantly decreased (-14.4mmo/L, -14.3 mmol/L

p<0.001). Furthermore, there were significant reduction in insulin resistance index HOMA-IR and fasting insulin level. (-0.48, -2.30 pmol/L

p<0.01) Comparison of gut microbiota composition between groups showed that TK group have more diverse microbiota than WK group and TK group have relatively higher in Bacteroidetes and lower in Firmicutes than WK group. After 10-days K-DASH intervention the microbiota diversity and composition were altered including decreased Firmicutes / Bacteroidetes ratio and increased alpha diversity. And the changes of F/B ratio and the abundances of L.reuteri, L.zeae, C. butyricum, Roseburia sp were positively correlated with insulin level and HOMA-IR (r>0.65, p<0.01)

Discussion: These results suggest that K-DASH diet could play a protective role in the treatment of metabolic syndrome in Korean. The K-DASH diet was modified to remedy the disadvantages of traditional Korean diet, on this account K-DASH had an effect on both group. Dietary modulation altered gut microbiota composition and the carbohydrate dependent microbial abundance was reduced. Even though the absolute amount of nutrient was not changes, the relative amount of nutrient could affect the microbiota composition. For the more efficient treatment of metabolic syndrome, comprehensive lifestyle modification is needed with K-DASH diet