Associations between Live Dietary Microbe Intake and Cardiometabolic Health in Korean Adults

The consumption of live microbes beyond probiotics is associated with health benefits. Despite growing interest in live microbe intake, comprehensive data on its dietary sources and research on their potential health effects in Korean populations remain limited.

This study aimed to quantify live microbe intake in the 2016-2020 Korea National Health and Nutrition Examination Survey (KNHANES) and to investigate the associations between live microbe intake and cardiometabolic health outcomes.

We developed a KNHANES live microbe classification system based on the Sanders system and divided KNHANES food codes that overlapped with NHANES into 4 categories: no live microbes and low (<10⁴ Colony Forming Units (CFU)/g), medium (10⁴-10⁷ CFU/g), and high (>10⁷ CFU/g) amounts. Microbial data on various types of kimchi were obtained from the World Kimchi Institute, and data on other nonoverlapping food codes were derived from the literature and authoritative reviews. We conducted descriptive analyses of live microbe intake among adults aged ≥19 y. We then conducted survey-weighted adjusted regression analyses to evaluate the relationship between live microbe intake and cardiometabolic health outcomes (cholesterols, triglycerides, blood pressure, fasting blood sugar, C-reactive protein [CRP], and waist circumference), controlling for age, sex, body mass index, household income, physical activity level, current smoking status, and alcohol intake.

The mean daily intake of medium-amount live microbe foods was 180.24 g in the Korean population, whereas that of high-amount live microbe foods was 122.89 g. Kimchi contributed a significant portion, with a mean intake of 102.76 g. Although no significant association was found between total live microbe intake and CRP concentrations, a significant association was observed for kimchi foods: higher intake was associated with a greater reduction in CRP (coefficient: -0.037; 95% confidence interval: -0.043, -0.032 mg/dL). The association with total cholesterol was positive and statistically significant, albeit small in magnitude, and was therefore not considered clinically significant. No significant associations were found with other outcomes.

This study provides new data on dietary intake of live microbes and their potential health benefits from a nationally representative dataset of Korean adults.