Association of Dietary Live Microbe Intake With Mortality: Results From the National Health and Nutrition Examination Survey, 1999-2018.

Background: The association between dietary intake of live microbes and mortality remains unclear.

Objective: This study aims to investigate the relationship between dietary live microbial intake and all-cause and cause-specific mortality among adults in the United States.

Design: This is a cross-sectional study of adults aged 20 years or older who participated in the 1999-2018 National Health and Nutrition Examination Survey.

Participants and setting: The study utilized data from adults aged 20 years and older with complete dietary and mortality data from the National Health and Nutrition Examination Survey from 1999 to 2018.

Main outcome measures: Deaths from any cause are defined as all-cause mortality. The International Statistical Classification of Diseases, 10th Revision, and the National Center for Health Statistics classifications of heart disease (054-064) and malignant neoplasms (019-043) were used to identify disease-specific causes of death.

Statistical analyses performed: Cox proportional hazard regression was utilized to examine the associations between the consumption of dietary live microbes and all-cause and cause-specific mortality. Restricted cubic spline regression modeling was used to assess potential linear associations between dietary live microorganism intake and mortality. In addition, stratified analyses and sensitivity analyses of the association of dietary live microorganism intake with all-cause and cardiovascular deaths were performed to validate the robustness of the results.

Results: The study included 31 836 participants, of whom 4160 died, including 1109 cardiovascular deaths and 915 cancer deaths. The study found that consuming live microbes from the diet was linked to a lower rate of all-cause and cardiovascular mortality, respectively (hazard ratio 0.80, 95% CI 0.72 to 0.89; P < .001; hazard ratio 0.79, 95% CI 0.65 to 0.95; P = .014). However, there was no significant association observed between microbial intake and cancer mortality (hazard ratio 0.93, 95% CI 0.75 to 1.17; P = .545). Restricted cubic spline demonstrates a linear association between dietary live microorganism intake and all-cause and cardiovascular mortality (P < .001). Furthermore, sensitivity analyses indicated that a high intake of live dietary microorganisms was associated with a lower risk of all-cause mortality and cardiovascular mortality (P < .05).

Conclusions: The study found that consuming live microbes through diet was linked to a lower rate of all-cause and cardiovascular mortality but not cancer mortality.