POTATO CARBOHYDRATE AND ASSOCIATED PHYTOCHEMICALS (PCAP) AS A DRIVER OF GUT HEALTH: A VALUE-ADDED TRAIT OF SELECT CULTIVARS

One of the emerging challenges of our century isnutrient insecurity, which is correlated withobesity and associated disorders such as cardiometabolicdiseases (CMDs). To combat this, research in food and agriculture is evolving fromcaloric-centric toward nutrient-centricapproaches.My goalis to understand the relationship between the complexmatrix of potatoes' carbohydrates and associated phytochemicals (PCAP)andgut health. This will guide breeders and public health providers in developing and providing nutritious crop varieties. With my unique research experience across agri-food sectors, I can establish strategic links between multi-omics approaches and breeding functional foods while addressing consumer demands.This proposal is based on three key tenets:Foods are not just isolated compounds undergoing separate digestion. Quite the opposite. Carbohydrates can sequester phytochemicals and modulate their bioavailability and absorption. In turn, phytochemicals can modulate carbohydrate metabolism, making them less digestible and decreasing the glycemic response. New omics approaches have reached the capability of allowing science to be free from a single-dimensional view of food science. This project will break this paradigm by exploring the important matrix interaction, unlike previous studies on in vitro or isolated metabolites.A diverse potato gene pool provides a unique chance to explore various matrices of phytochemicals and carbohydrates. These authentic crops' distinct chemical compositions create a unique avenue for precise food recommendations. This will open the door for utilizing different potato varieties to facilitate crucial targeted health interactions. Potatoes' bioactive (resistant carbohydrates, phenolics, etc.) have mainly been studied as isolated chemicals. Limited preclinical or clinical studies investigated whole potato matrices but are limited to one variety and overlook the variation in this crop. This study will introduce an innovative perspective by employing cutting-edge omics techniques. It not only endeavors to construct a standardized PCAP profile across diverse potato cultivars but also pushes the boundaries by delving into a profound comprehension of the metagenomic shifts.We hypothesize that potatoes' carbohydrates and associated phytochemicals (PCAP) are nutrient-rich resources that hold the potential to augment health. Moreover, this complex matrix, encompassing prebiotic elements is capable of mitigating risk factors associated with CMDs.Goal 1: Evaluate the composition of the PCAP in selected potato genotypes.Goal 1 is defined to address the question, "what is there?". Previous research has described distinctions in phytochemicals, minerals, and carbohydrates among various potato varieties. However, the impact of these studies is limited due to the lack of standardized methods, hindering direct comparison across laboratories and crops and a tendency to focus on a limited set of phytochemical classes, leading to the oversight of the broader spectrum of essential bioactive constituents within this crop. I hypothesize that the comprehensive phytochemical composition of potatoes will vary among phenotypically divergent potato varieties. To address this, the proposed study will leverage the metabolomics tools developed by the Periodic Table of Food Initiative (PTFI) toolset. Specifically, the PTFI has developed standardized analytical methods to enable the comprehensive characterization of food in a way that ensures the results are accessible and comparable worldwide. Furthermore, analysis will be performed on raw potatoes and as potatoes prepared using a range of common cooking methods. Finally, the total dietary fiber (TDF) will be characterized using an established method in Dr. Thompson's laboratory.Goal 1 - Objective 1: Characterize phytochemicals profile in selected potato varieties. High-throughput omics platforms will be utilized to profile the phytochemicals in potato tubers. We will use the established Periodic Table of Food Initiative (PTFI) methods for small molecule characterization (LC-MS) and elemental mineral analysis (ICP-MS).Goal 1 - Objective 2: Characterize the dietary fiber content in potato variety, including soluble and non-soluble polymers. Acknowledging that many aspects of carbohydrates in potatoes need to be elucidated, this proposal will focus on TDF, soluble and insoluble dietary fiber (SDF and IDF), and non-digestible oligosaccharides (NDO).Goal 2: Determine whether a whole potato diet (i.e., PCAP) will differentially alter gut health when compared to a refined carbohydrate source. Goal 2 is defined to address the question, "What do they do?". Evidence from limited studies indicates a positive impact of potatoes' metabolites, such as phenolics, on alleviating CMD risk factors and improving gut health. Furthermore, resistant carbohydrates (RCs) in potatoes exhibit prebiotic qualities due to their lower digestibility in the upper gastrointestinal tract. These RCs can engage with gut bacteria and their fermentation metabolites like short-chain fatty acids, which are known for their health-enhancing benefits. Knowledge gaps: 1) The primary focus in these studies is mainly on isolated metabolites from potatoes rather than considering the context of the whole food matrix. 2) These studies overlook the genotypic variation in potatoes, neglecting the variation of nutrient matrices. 3) Importantly, to our knowledge, there hasn't been a comprehensive metabolomics-metagenomics study that assesses the impact of different potato varieties' whole food matrices' health outcomes. To address these gaps, we will utilize a metagenomics approach to study the health outcome of 3 distinct potato varieties (microwaved with skin). We hypothesize that PCAP from distinct varieties of intricate matrices of nutrients in whole potatoes with prebiotic potential can enhance gut health and potentially alleviate CMD risk factors.Goal 2- Objective 1: Evaluate the impact of PCAP from different varieties on microbial community composition and function in the cecum.We will use metagenomics techniques to study cecum microorganisms as it contains the densest and most diverse microbiota of the GI. Metagenomics will provide a taxonomic composition of the microbiome as well as their functional contribution.Goal 2 - Objective2: Investigate how PCAP ingredients (per goal 1) alter gut barrier integrity.This objective is designed to provide information regarding the interaction of the host with the microbiome and the potential impacts of gut microbiota changes on systemic inflammation and possible downstream disease development.It is well-established that diet has an impact on intestinal morphology, including tight junction (TJ) integrity. The TJ proteins play a critical role as barriers by selectively filtering the passage of noxious luminal microbes and harmful substances. A healthy gut with maintained barrier function reduces the likelihood of exposure to microbial products, such as lipopolysaccharide (LPS). To evaluate the effect of PCAP on the intestinal barrier integrity, the following assays will be conducted:TJ mRNA expression: The mRNA expression of important apical junctional complex components (claudin, occluding, JAM-A, and E-cadherin) will be measured. These proteins play a crucial role in maintaining paracellular permeability.LBP/sCD14 Measurement:A leaky gut facilitates the translocation of LPS and other noxious stimuli, as they are continuously produced in the gut by resident bacteria. LPS binding protein (LBP) is a soluble acute phase protein that binds and presents LPS to its co-receptor CD14. Serum LBP and soluble CD14 (sCD14) are established markers of circulating LPS and are independently associated with cardiometabolic risk.