Classification and Estimation of Dietary Live Microorganisms and Fermented Foods Intake in Swiss Adults

Abstract

Background: Dietary live microorganisms and fermented foods may benefit human health by modulating gut microbiota composition and function. However, their classification and intake are not well-defined in population-based studies assessing whole diets.

Objective: The objectives of this study were to classify and quantify the intake of foods with live microorganisms and fermented foods among Swiss adults.

Methods: We analyzed data from 2086 adults aged 18-75 y in the cross-sectional Swiss National Nutrition Survey menuCH (2014-2015). Food items were classified by live microorganism levels (low, <10⁴ CFU/g; medium, 10⁴-10⁷ CFU/g; or high, >10⁷ CFU/g) and fermented food descriptors, including fermented ingredients and core microbiota. Intake of these foods was determined at the population level by demographic subgroups, food categories, and nutrient contributions.

Results: Mean intake of medium or high live microorganism foods (MedHi) was 269.3 g/d (8.0% of total food intake), primarily from fruit, vegetables, and fermented dairy products. MedHi foods contributed 12.3% of daily energy intake and >20% of daily intake of several nutrients, including β-carotene, vitamins A, C, B12, folate, calcium, and saturated fat. Fermented foods accounted for 717.1 g/d (21.0% of total food intake), mainly from coffee, bread products, alcoholic beverages, and fermented dairy, contributing 27.0% of daily energy and >30% of daily calcium, phosphorus, sodium, zinc, vitamins A and B12, starch, and saturated fat. Significant differences in MedHi food intake were observed between sexes and age groups but not linguistic regions, whereas fermented food intake varied across all population subgroups. We identified 186 microorganisms across 6 taxonomic levels in fermented foods.

Conclusions: This study provides a comprehensive classification of live microorganism levels and fermented foods, highlighting their intake and nutrient contribution to the Swiss diet. These results set the stage for future research linking the dietary intake of these foods to health outcomes in population studies.

Keywords: 24-h dietary recalls; GloboDiet; Switzerland; dietary live microbes; fermented foods; food microbiota.