Dietary Live Microbes Intake Associated with Biological Aging and Mortality.

Purpose: This observational study aimed to investigate associations between dietary live microbe intake and mortality, as well as biological aging.

Methods: Adults from the 1999-2018 National Health and Nutrition Examination Survey were categorized into low, medium, and high dietary live microbe groups. Foods with medium and high live microbe content were aggregated into a medium-high consumption category. The outcomes included all-cause, cardiovascular, and cancer mortality, along with biological age (BA) acceleration assessed by the Klemera-Doubal method (KDM) and PhenoAge. Multiple regression analyses and mediation analyses were conducted to assess associations, adjusting for potential confounders.

Results: A total of 34,133 adults were included in our analyses. Over an average follow-up period of 9.92 years, 5,462 deaths occurred. In multivariate adjusted models, every 100 grams of medium-high group foods consumed was associated with reduced all-cause mortality (hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.91 to 0.97, P < 0.001) and cardiovascular mortality (HR 0.91, 95% CI 0.86 to 0.96, P < 0.001), but not with cancer mortality (HR 1.01, 95% CI 0.95 to 1.07, P = 0.768). Every 100 grams medium-high group foods consumption was associated with decreased KDM BA acceleration (fully adjusted regression coefficient -0.09, 95% CI -0.15 to -0.04, P = 0.001) and PhenoAge acceleration (fully adjusted regression coefficient -0.07, 95% CI -0.11 to -0.03, P < 0.001). Mediation analysis showed that BA acceleration partially mediated live microbes-mortality associations.

Conclusion: Our results suggest that higher dietary live microbe intake is associated with lower mortality risk and slower biological aging. However, further research is needed to verify these findings.