... Going Nutty: Walnut Consumption Effects on Gut Microbiota and Cardiovascular Health Jillian Leister1,2, Mansi Chandra1,2, Alyssa M Tindall3, Christopher J McLimans2, Kristina S Petersen3, Penny M Kris-Etherton3, and Regina Lamendella1,2 1 Juniata College Biology Department, 2Wright Labs LLC, 3Department of Nutritional Sciences, The Pennsylvania State University Introduction Background An organisms gut microbiome has observable impact on its life history traits Microbes present within the gut are involved in extraction and metabolism of nutrients not fully digested in the small intestine1 Cardiovascular disease (CVD) is a leading cause of mortality globally and is highly impacted by diet1 Experimental Design Results (cont.) 1. Sample preparation Controlled-feeding study with 2-wk run-in on SWD followed by three 6-wk diet periods Fecal sample collection Store samples at -80C until extraction. 2. RNA extraction & Library preparation Extract RNA PCR amplification of V4 region of 16S rRNA Library preparation and dual index barcoding Assess quality of library and purify FIGURE 4. The average relative abundance of bacterial phyla in WD, WFMD and ORAD diets in individuals with increased CVD risk factors. Synthesize cDNA Figure 1. Etiology of cardiovascular risk in obesity due to microbiota shift2 Sequencing and Analysis The WD, WFMD and the ORAD diet showed enrichment of certain species of bacteria in the gut microbiome which play an important role in altering the gut environment. Walnuts contain ellagitannins which are metabolized by the bacteria to produce substances that provide cardiovascular benefits 5 These diets led to enrichment of bacterial species with positive effects on the gut epithelium, gut lining, and cardiovascular risk factors 6,7 Demonstrates that walnut consumption can alter the gut microbiota in a way that provides cardiovascular benefits and a stable gut environment. Results Metatranscriptomics is a method where functional genes and pathways are identified by isolating the mRNA of an organism Metabolizable energy from walnuts is overestimated by 21%, suggesting that walnut-derived nutrients are accessible to the gut microbiota3,4 Objectives 1. Analyze the effects on the gut microbiome of three different study diets: 1 containing walnuts and 2 containing different vegetable oil blends 2. Investigate how changes in the gut microbiome are related to CVD risk factors 3. Examine the chemical pathways being utilized and the subsequent impact on cardiovascular health Discussion Future Directions Acknowledgements Metatranscriptomic Analysis Gain a better understanding of what genes are turned on, rather than those that could be In-depth knowledge about which metabolic pathways are affected and altering the gut environment. References 1. 2. Figure 2. Relative abundance of the most prominent bacteria phyla in participants with overweight, obesity, and morbid obesity (n=42) FIGURE 3. Comparisons of enriched bacteria between walnut diet, walnut fatty acid matched diet, oleic acid replaces linolenic acid diet and the run-in diet in adults at increased cardiovascular risk (n=42) 3. 4. 5. 6. 7. David LA, Maurice CF, Carmody RN, Gootenberg DB, Button JE,Wolfe BE, Ling AV, Devlin AS, Varma Y, Fischbach MA, et al. Diet rapidly and reproducibly alters the human gut microbiome. Nature 2014;505: 55963. Kasselman LJ, Vernice NA, DeLeon J, Reiss AB. The gut microbiome and elevated cardiovascular risk in obesity and autoimmunity. Atherosclerosis 2018;271: 203-213. Rajaram S. Health benefits of plant-derived -linolenic acid. Am J Clin Nutr 2014;100:443S8S. West SG, Krick AL, Klein LC, Zhao G, Wojtowicz TF, McGuiness M, Bagshaw DM, Wagner P, Ceballos RM, Holub BJ, et al. Effects of diets high in walnuts and flax oil on hemodynamic responses to stress and vascular endothelial function. J Am Coll Nutr 2010;29: 595603. Selma M V, Beltran D, Garca-Villalba R, Espin JC, Tomas-Barberan FA. Description of urolithin production capacity from ellagic acid of two human intestinal Gordonibacter species. Food Funct 2014;5: 177984. Chiang JYL. Bile acid metabolism and signaling. Compr Physiol 2013;3:1191. Ajouz H, Mukherji D, Shamseddine A. Secondary bile acids: an underrecognized cause of colon cancer. World J Surg Oncol 2014;12:164. Liberal Arts Symposium 2021 ...