Nutrition Integrated with Fermented Dairy (NIFTY) Study

Helping families explore fermented dairy foods

NIFTY stands for Nutrition Integrated with Fermented Dairy. Our research explores how foods such as yogurt, kefir, and cheese can fit into the everyday diets of families participating in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC).

By learning directly from families, we aim to develop practical, culturally relevant education and resources that make fermented dairy foods more accessible, appealing, and easier to use.

Nutrition matters for parents and children

Nutrition during pregnancy and early childhood helps build a foundation for lifelong health [1]. Pregnancy changes how the body regulates blood sugar, uses fat, and responds to inflammation, while also affecting the gut microbiome—the community of microbes living in the digestive tract [2]. Breastfeeding places additional demands on the body to support milk production [3]. These life stages offer important opportunities to support parents and children through nutrition.

Why fermented dairy?

Fermented dairy foods are made with microbes, often called "cultures", that transform milk into foods such as yogurt, kefir, and cheese. Fermentation can change a food’s flavor, texture, and the substances it contains. Depending on the product, fermented dairy foods can provide:

• High-quality protein to support growth and maintain body tissues.
• Calcium to support bones and teeth.
• Live yogurt cultures that help digest lactose. These cultures provide an enzyme that helps break down lactose—the sugar in milk—in people who have difficulty digesting it [4].
• Substances formed during fermentation that may contribute to health benefits [5].

Some fermented dairy products also contain probiotics—specific strains of live microbes that have been shown to provide a health benefit when consumed in adequate amounts. However, not all live cultures are probiotics, and not all fermented dairy foods contain live microbes when eaten. Having live cultures does not automatically mean a food offers the same benefits as products containing studied probiotic strains [6,7].

The potential health benefits of consuming fermented foods may come from their nutrients, live microbes, non-living microbial cells, parts of those cells, and substances made by microbes during fermentation [5–7].

What does the research show?

Research in healthy adults suggests that diets rich in fermented foods and beverages may increase gut microbial diversity and reduce markers of inflammation [8]. A review of human studies on fermented dairy foods also found improvements in some digestive symptoms and gut health markers, although results varied across products and study populations, and some studies found no benefit [7].

In a large U.S. observational study, eating more foods estimated to contain live microbes was associated with favorable measures of blood pressure, blood sugar, inflammation, and body weight. These foods included fermented foods as well as other foods. The study could not determine whether live microbes caused these associations or whether the findings were specific to fermented foods [9].

NIFTY builds on this research by exploring fermented dairy foods in the context of WIC families’ needs and everyday food choices.

Understanding families’ needs

Dairy consumption varies across U.S. population groups [10], and some WIC families may not fully use their yogurt benefits. A 2024 study of California WIC households with children ages 1–4 found that half redeemed one-third or less of their available yogurt benefits [11].

We want to understand what influences these choices. Families may have questions or face challenges related to:

• Taste preferences and familiar foods.
• Cultural traditions and household food choices.
• Product availability and cost.
• Understanding which products WIC benefits cover.
• Knowing how to select, store, serve, or prepare fermented dairy foods.

Learning about these experiences will help us develop resources that reflect what families want and need.

Two studies, one shared goal

NIFTY brings together two complementary studies:

• Listening to families. Through an online survey and interviews, we examine WIC participants’ knowledge, experiences, preferences, and barriers related to fermented dairy foods.
• Testing a practical approach. In a pilot randomized controlled trial, we evaluate the feasibility, acceptability, and preliminary effects of providing fermented dairy foods with education and resources informed by families. We examine dietary intake, diet quality, and health-related outcomes.

Together, these studies will help identify practical ways to support the use of fermented dairy foods among WIC families.

Led by UC Davis and informed by families

NIFTY is led by the ORIANE Lab at the University of California, Davis, under the direction of Jennifer T. Smilowitz, PhD, Assistant Professor of Cooperative Extension in the Department of Nutrition.

Our work brings together nutrition research and families’ experiences to develop approaches that fit their preferences, routines, and needs. By listening to WIC participants, we aim to create useful education and resources that families can put into practice.

References