Abigail Raffner Basson
Case Western Reserve University, USA
Title: Replacing animal protein with soy-pea protein in an American Diet controls murine crohn disease-like ileitis regardless of firmicutes: Bacteroidetes ratio
Biography
Biography: Abigail Raffner Basson
Abstract
Statement of the problem: The current nutritional composition of the "American Diet" (AD; also known as Western diet) has been linked to the increasing incidence of chronic diseases, including Inflammatory Bowel Disease (IBD), namely Crohn Disease (CD). This study investigated which of the 3 major macronutrients (protein, fat, carbohydrates) in the AD has the greatest impact on preventing chronic inflammation in experimental IBD mouse models.
Methodology: We compared 5 rodent diets designed to mirror the 2011-2012 "What We Eat in America" NHANES. Each diet had 1 macronutrient dietary source replaced. The diets were AD, ADsoy-pea (animal protein replaced by soy+pea protein), AD-CHO ("refined carbohydrate" by polysaccharides), AD-fat [redistribution of n-6:n-3 PUFA ratio: Ì´10:1 to 1:1] and AD-mix (all 3 "healthier" macronutrients combined). In 3 separate experiments, 8-wk-old germfree SAMP1/YitFC mice (SAMP) colonized with human gut microbiota ("hGF-SAMP") from CD or healthy donors were fed an AD, an AD- "modified," or chow diet for 24 wk. Two subsequent dextran sodium sulfate-colitis experiments in hGF-SAMP (12-wk-old) and Specific Pathogen-Free (SPF) C57BL/6 (20-wk-old) mice and a 6-wk feeding trial in 24-wk-old SPF SAMP were performed [Figure 1].
Findings: The AD-soy-pea diet resulted in lower histology scores [mean ± SD (56.1% ± 20.7% reduction)] in all feeding trials and IBD mouse models than did other diets (P<0.05). Compared with the AD, the AD-soy-pea correlated with increased abundance in Lactobacillaceae and Leuconostraceae (1.5-4.7 log2 and 3.0-5.1 log2 difference, respectively), glutamine (6.5 ± 0.8 compared with 3.9 ± 0.3 ng/μg stool, P=0.0005) and butyric acid (4:0; 3.3 ± 0.5 compared with 2.54 ± 0.4 ng/μg stool, P=0.006) concentrations and decreased linoleic acid (18:2n-6; 5.4 ± 0.4 compared with 8.6 ± 0.3 ng/μL plasma, P=0.01).
Conclusion: Replacement of animal protein in an AD by plant-based sources reduced the severity of experimental IBD in all mouse models studied, suggesting that similar, feasible adjustments to human diets could help control/prevent IBD in humans.