A Randomized, Two-Arm Crossover, Controlled-Feeding Trial Comparing Effects of Pork and Chicken Diets on System Biology, Microbiome and Metabolome Changes in Healthy Adults

Abstract

Abstract Objectives Majority of Americans practice a meat-based dietary lifestyle. We hypothesized that switching between chicken and pork meats within a nutritionally balanced diet would minimally impact gut microbiota composition, biogenic amine levels, and cardiometabolic health markers in healthy, non-diabetic adults. Methods 36 eligible men and women 50 years or older were randomized into chicken and pork meat groups consuming an isocaloric (1920 kcal/day) diet. The 10 day diet arms were separated by minimum of two weeks washout period. Following the current dietary guidelines for Americans, daily meals consisting of 156 g minimally-processed meat were provided to participants. Stool, urine and blood samples were collected before and after each diet phase followed by 16S targeted metagenomics and hydrophilic interaction chromatography analyses of metabolites. Proposed outcome measures were selected based on their ability to quickly respond to dietary changes and were assessed after overnight fasting. Linear mixed effect and regression models as well as other relevant approach were applied in R studio for data analyses. Results No differential outcome was observed between the chicken and pork diet groups for body weight and body composition features, lipid panel markers, blood pressures, inflammatory and oxidative stress markers, and kidney function measures (all, P > 0.05). Alpha diversity of the gut microbiome was not differential. A small number of OTU level differences in beta diversity measures were present (padj < 0.05). Plasma trimethyl amine-N-oxide, trimethylamine, carnitine, and choline levels were similar between the groups. Ongoing side-by-side examination of the impact of the two meats on an extended array of over hundred biogenic amine species may reveal novel changes. Several within group effects of the intervention were observed that were non-differential between the groups. Conclusions White meat is generally perceived as healthier than red meat. Our comprehensive data suggest minimal differential metabolic impact on the host and the gut microbiota when switched between chicken (white meat) and pork (red meat). Additional assessments are needed to reflect on the long-term metabolic outcome of routine red meat intake in healthy non-vegetarian individuals. Funding Sources National Pork Board and National Institute of Food and Agriculture.