Fermented foods like kimchi and yogurt contain live microorganisms that have been associated with improved metabolic health and reduced disease risk. However, little is known about how much of the Western diet contains live microbes and what percentage of Americans consume them. To address this knowledge gap, Marco et al. (2022) conducted a study analyzing dietary recall data from over 74,000 adults and children in the NHANES study from 2001 to 2018. They aimed to estimate microbial content across food items, classify foods as low, medium, or high in microbes, and determine what proportion of Americans ingest live microbes through their diet.
2. Fermented foods—like kimchi and yogurt—and probiotic supplements have
been associated with improved metabolic health and, consequently, stronger
immunity and reduced risk against various cancers (Savaiano et al., 2021;
Wastyk et al., 2021). What these foods and supplements have in common is
the presence of living microorganisms (Montville, 2004; Jeddi et al., 2014;
Ziyaina et al., 2018). In fact, raw and unpeeled fruits and vegetables, dairy, and
certain proteins contain dietary microbes that have been demonstrated to
benefit human health (Roselli et al., 2021; Marco et al., 2022).
3. Raw and unpeeled fruits and vegetables, dairy, and certain proteins
contain dietary microbes that have been demonstrated to benefit
human health
However, compared to other macronutrients such as carbohydrates, fats, and
proteins which are reported on nutrition fact labels and databases, it is not
clear how much of the Western diet is actually composed of foods containing
live dietary microbes and, moreover, the percentage of U.S. adults and
children who consume them. Addressing this knowledge gap is not only
imperative in establishing safe daily intake values of live microbes but also
encourages further clinical studies to investigate the long-term health benefits
they may provide.
4. To quantify the level of microbes across food groups and the proportion of
U.S. residents that ingest them, Marco et al. conducted a 2022 study that
analyzed published dietary data from the National Health and Nutrition
Examination Survey (NHANES), an ongoing study led by the CDC’s National
Center for Health Statistics. NHANES study participants are selected through
statistical sampling and information is collected through both in-home
interviews and physical examinations at designated health centers.
5. For their retrospective analysis, Marco et al. used 24-hour dietary
recall results obtained from 74,466 adults and children, dating from
2001 to 2018. Their study aimed to use pre-existing data to estimate
the general amounts of microbes contained in food items reported in
the NHANES study, classify each item as low-, medium-, or high-
microbial content, and, ultimately, approximate the percentage of U.S.
adults and children who consume these live microbes.