Positive Health Outcomes Associated with Live Microbe Intake from Foods, Including Fermented Foods, Assessed using the NHANES Database

Background: Live dietary microbes have been hypothesized to contribute to human health but direct evidence is lacking. Objectives: This study aimed to determine whether the dietary consumption of live microbes is linked to improved health outcomes. Methods: Data from the NHANES 2001–2018 were used to assess microbial intake and their adjusted associations with selected physiological parameters (e.g., blood pressure, anthropometric measures, and biomarkers) among adults aged 19 y and older. Regression models were constructed to assess the microbial intake with each physiological parameter and adjusted for demographics and other covariates. Microbial intake was assessed as both a continuous variable and a 3-level categorical variable. Fermented foods were assessed in a separate model. Results: In continuous models, an additional 100-g intake of microbe–containing foods was associated with a lower systolic blood pressure (regression coefficient: −0.331; 95% CI: −0.447, −0.215 mm Hg), C-reactive protein (−0.013; 95% CI: −0.019, −0.008 mg/dL), plasma glucose −0.347; 95% CI: −0.570, −0.124 mg/dL), plasma insulin (−0.201; 95% CI: −0.304, −0.099 μU/mL), triglyceride (−1.389; 95% CI: −2.672, −0.106 mg/dL), waist circumference (−0.554; 95% CI: −0.679, −0.428 cm), and BMI −0.217; 95% CI: −0.273, −0.160 kg/m²) levels and a higher level of high density lipoprotein cholesterols (0.432; 95% CI: 0.289, 0.574 mg/dL). Patterns were broadly similar when microbial intake was assessed categorically and when fermented foods were assessed separately. Conclusions: To our knowledge, this study is the first to quantify, in a nationally representative data set of American adults and using stable sets of covariates in the regression models, the adjusted associations of dietary intakes of live microbes with a variety of outcomes, such as anthropometric measures, biomarkers, and blood pressure levels. Our findings suggest that foods with higher microbial concentrations are associated with modest health improvements across a range of outcomes.