Assessing the “Super” in Whole-Grain Superfoods

Authors: Ali Schultheis and Franck Carbonero

We are halfway through our Soil to Society series, so let’s do a quick recap. Following along the Soil to Society pipeline, this grant is working to identify soil-conscious cultivation practices with the Soil and Cropping Systems team, breed varieties of wheat, barley, buckwheat, quinoa, lentils, and peas with the Plant Breeding team, and engineer products that utilize these nutrient rich crop varieties with the Food Science team. Now, we must determine whether the more nutritious varieties correlate to better health outcomes in human consumers.

Flask in an experiment
In vitro experiments, those that happen under lab conditions, are important to establish specific interactions. Photo: Dr. Franck Carbonero

In Vitro Experimentation

To do this, our Human Health and Nutrition team is developing a high-throughput model to assess the impact of whole grains on the gut microbiome. Fiber, proteins, and phytochemicals have all been shown to alter the gut microbiome, so we expect the diverse nutrient profiles of the grant’s crop varieties to similarly affect the gut microbiome. To test this theory, project researchers are using a common method to simulate modulation of the gut microbiome that involves performing in vitro digestion followed by fermentation from human derived intestinal microbes.

This in vitro system allows researchers to replicate our body’s digestion processes in a lab using digestive enzymes and fecal samples obtained from healthy volunteers. They use these fecal samples to inoculate the reactors with microbiota, then add in ground and pre-digested forms of the selected crop varieties and observe their effect, collecting samples at regular intervals. This process is then repeated with all crop varieties and products developed by the Food Science team. From these samples, researchers will determine gut microbiota modulation, hierarchize foods by their “prebiotic” status, as well as identify and isolate microbes’ metabolites.

Person standing in front of experiment chamber in a lab
Experiments are designed to mimic the gut microbiota and establish interactional relationships between food intake and microbiota response. Photo: Dr. Franck Carbonero

Cell Respiration

It is now well accepted that the bioactivity and human health benefits of phytonutrients occur because of their interactions with gut microbiota (Sanchez-Patan et al 2011, Rehm et al 2011). Chronic diseases, specifically obesity, are closely connected to the gut microbiota. To determine if these crop varieties come with health benefits, the next step is to assess the cellular respiration and protein expression of muscle and adipose tissue cultures in response to treatment with the gut metabolites created from the in vitro fermentation. Researchers will conduct this experiment by preparing cell cultures and supplementing them with the phenolic-rich gut digestates produced in the above experiment, for 24 hours.

Samples in test tubes
Samples for in vitro experiments. Photo: Franck Carbonero

After treatment, the culture systems will undergo the established cellular respiration protocol and changes in mitochondrial activity and protein expression will be recorded. These changes are important because they will determine the food’s potential ability to improve the mitochondrial dysfunction associated with metabolic complications caused by poor diet and sedentary behavior.

Countless foods claim to be gut friendly or healthy, and diets claiming to improve gut health have soared in popularity. But there is often little scientific evidence backing these claimed health benefits. Our Human Health and Nutrition team is actively conducting research experiments to assess the validity of the claim that consuming crop varieties and food products designed by the various researchers on this grant do come with health benefits and a decreased risk of chronic disease.

Soil to Society

The Soil to Society grant is funded through the U.S. Department of Agriculture’s National Institute of Food and Agriculture’s Sustainable Agricultural Systems (SAS) program. The SAS Soil to Society project involves over 20 researchers from Washington State University and Johns Hopkins University and evaluators from Kansas State University to improve the soil quality where these crops are grown, develop more nutritional varieties and products that can be brought to market, and evaluate the impact of these foods on human health. By bringing together soil scientists, plant breeders, food scientists, and health researchers, the Soil to Society grant will cross disciplines to develop holistic agricultural management strategies and healthy, affordable food products to meet the needs of diverse individuals and communities.

This article is part of a series on the Soil to Society project. This series will explore the work of each project team, highlighting the different areas of collaboration across disciplines that work this project toward its common goal of creating a healthier food system and human population. Articles in this series will be released monthly- mark your calendars for Tuesday, October 24th so you don’t miss the next one.


Sanchez-Patan F., Monagas, M., Moreno-Arribas MV., Bartolome, B. Determination of microbial phenolic acids in human faeces by UPLC-ESI-TQ MS. J. Agric Food Chem. 2011;59(6):2241-2247

Rehm, CD., Monsivais, P., Drewnowski, A. The quality and monetary value of diets consumed by adults in the United Stated. Am J Clin Nutr. 2011; 94(5). doi:10.3945/ajcn.111.016650


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