This controlled feeding trial will identify biomarkers in the metabolome and microbiome that may differ when consuming a healthy diet with or without red and processed meat.
This is a randomized cross-over feeding trial to test whether red and processed meat consumption, in the context of a controlled diet based on HEI-2015, will cause shifts in the metabolome and the microbiome compared to a controlled HEI-2015 diet with no red or processed meat. Twenty healthy adult volunteers will consume two diets in random order: 1) Diet A is based on the Healthy Eating Index-2015 (HEI-2015) and includes no red or processed meat; 2) Diet B is based on the Healthy Eating Index-2015 and includes red and processed meat (HEI-2015-M) as some of the protein sources. Both diet periods last 21 days and an approximately 21-day washout period occurs between diets.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
DOUBLE
Enrollment
23
Healthy Eating Index-2015 (HEI-2015) with or without red/processed meat (HEI-2015-M)
Fred Hutch/University of Washington Cancer Consortium
Seattle, Washington, United States
Test the Effects of Red and Processed Meat on Aqueous Biomarkers of the Blood Metabolome
Plasma aqueous metabolomics were evaluated via Liquid Chromatography/Mass Spectrometry (LC/MS). Data are relative concentrations - the concentration of a specified biomarker is relative to the concentration of all other biomarkers. Data are reported as the mean ratio of relative concentration on day 21 compared to day 0 \[(relative concentration day 21)/(relative concentration day 0)\]. A value above 1.0 indicates that the relative concentration of the metabolite increased from baseline at the end of the diet, whereas a value below 1.0 indicates the relative concentration decreased, and a value of 1.0 indicates no change from baseline.
Time frame: Day 21
Test the Effects of Red and Processed Meat on Lipid Biomarkers of the Blood Metabolome
Plasma lipid metabolomics were evaluated via Liquid Chromatography/Mass Spectrometry (LC/MS). Data are absolute concentrations. Data are reported as the mean ratio of relative concentration on day 21 compared to day 0 \[(relative concentration day 21)/(relative concentration day 0)\]. A value above 1.0 indicates that the relative concentration of the metabolite increased from baseline at the end of the diet, whereas a value below 1.0 indicates the relative concentration decreased, and a value of 1.0 indicates no change from baseline.
Time frame: Day 21
Test the Effects of Red and Processed Meat on Biomarkers on the Urine Metabolome
Effects of the intervention on urine metabolomic biomarkers were evaluated via Nuclear Magnetic Resonance (NMR). Urine metabolites are absolute concentrations standardized (as a ratio) to trimethyl-silylpropionic-2,2,3,3-d4 acid sodium salt (TSP). Data are reported as the mean ratio of relative concentration on day 21 compared to day 0 \[(relative concentration day 21)/(relative concentration day 0)\]. A value above 1.0 indicates that the relative concentration of the metabolite increased from baseline at the end of the diet, whereas a value below 1.0 indicates the relative concentration decreased, and a value of 1.0 indicates no change from baseline.
Time frame: Day 21
Test the Effects of Red and Processed Meat on Gut Microbiome
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Shannon's Diversity Index (SDI) was used as a measure of species diversity, calculated as the sum of -p/ln(p), where p is the proportion of the sample made up of each OTU using the QIIME2 shannon\_pd plugin. Sampled 16S rRNA sequences were organized into 'amplicon sequence variants' (ASVs), ASVs were filtered by abundance with a threshold of 1e - 5. This measure is a unitless scale proportion ranging from zero to infinity. Zero indicates a completely homogenous sample, and higher scores indicate greater species diversity.
Time frame: Day 21
Test the Effects of Red and Processed Meat on Fecal Bacterial Functional Genes
Fecal bacterial functional genes were evaluated via digital droplet PCR. Data are reported as the difference between day 21 and day 0 (calculated as day 21 - day 0) of each diet in the relative abundance (calculated as gene counts/16s rRNA gene counts) of fecal bacterial functional genes. A value that is positive indicates that the relative abundance increased from baseline to the end of the diet, whereas a negative value indicates the relative abundance decreased.
Time frame: Day 21