Higher dietary live microbe intake is linked to reduced risk of metabolic syndrome and mortality: a cross-sectional and longitudinal study

Abstract

Background: The association between dietary live microbe intake and metabolic syndrome (MetS) prevalence, as well as its impact on all-cause and cardiovascular disease (CVD) mortality in MetS patients, remains underexplored.

Methods: A total of 38,462 individuals from the National Health and Nutrition Examination Survey (NHANES) 1999-2018 were analyzed. Based on the live microbial level of the consumed foods, participants were divided into three dietary live microbe intake groups: low, medium, and high. Foods with medium and high live microbe content were aggregated into a medium-high consumption category. MetS was defined based on NCEP-ATP III criteria. Survey-weighted logistic regression assessed the cross-sectional association with MetS prevalence, while Cox proportional hazards models evaluated mortality risks in 12,432 individuals with MetS, among whom 2,641 all-cause and 901 CVD deaths occurred.

Results: Higher dietary live microbe intake was significantly associated with lower odds of MetS. Compared to the low intake group, participants in the high intake group had a 12% lower risk of MetS in the fully adjusted model (OR: 0.88; 95% CI: 0.80-0.97; p = 0.01). Among MetS components, significant inverse associations were observed for low HDL-C, elevated TG, and elevated BP. Participants with high dietary live microbe intake demonstrated a significantly lower risk of all-cause mortality (HR: 0.85; 95% CI: 0.77-0.94; p = 0.002) and CVD-specific mortality (HR: 0.71; 95% CI: 0.55-0.92; p = 0.001) compared to the low intake group. Kaplan-Meier survival curves revealed better survival probabilities in individuals with medium and high intake levels, with significant differences across groups (log-rank p < 0.005). Quantitatively, each 100g increase in MedHi foods was associated with 6% lower all-cause mortality (HR: 0.94; 95% CI: 0.90-0.99; p = 0.01) and 8% lower CVD mortality (HR: 0.92; 95% CI: 0.84-1.00; p = 0.05).

Conclusion: Dietary live microbe intake is inversely associated with the prevalence of MetS and its key components, particularly low HDL-C, elevated TG, and elevated BP. In individuals with MetS, higher live microbe intake is associated with reduced all-cause and CVD-specific mortality. These findings suggest that dietary live microbes are a promising modifiable factor for MetS prevention and management, as well as for improving long-term survival outcomes.

Keywords: NHANES; all-cause mortality; cardiovascular mortality; dietary live microbe; metabolic syndrome.

Figure 1

Flowchart of the sample selection from the National Health and Nutrition Examination Survey 1999 to 2018. MetS, Metabolic syndrome; BMI, Body mass index; NHANES, National Health and Nutrition Examination Survey.

Figure 2

Dose–response relationships between MetS (A), Elevated TG (B), Low HDL-C (C), Elevated FPG (D), Elevated WC (E), Elevated BP (F) and medium-high live microbe (MedHi) food intake. Model was adjusted for age, sex, race, education level, marital status, PIR, BMI, smoking status, drinking status, and physical activity. MetS, Metabolic syndrome; TG, triglycerides; HDL-C, high-density lipoprotein cholesterol; FPG, fasting plasma glucose; WC, waist circumference; BP, blood pressure; PIR, poverty income ratio; BMI, body mass index.

Figure 3

Kaplan–Meier curves were used to present the relationship of the dietary live microbe intake with all-cause and cardiovascular mortality among patients with MetS. (A) Refers to all-cause mortality by dietary live microbe intake groups. (B) Refers to cardiovascular mortality by dietary live microbe intake groups. MetS, Metabolic syndrome; CVD, cardiovascular disease.