Location: Small Grain and Food Crops Quality Research
Project Number: 3060-21650-002-048-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2023
End Date: Dec 31, 2024
Objective:
(1) Determine the effects of dietary pea fiber during pregnancy and lactation on energy balance, glucose tolerance, gut microbiota composition, hormones, and blood pressure, in diet-induced obese (DIO) and spontaneously hypertensive (SHR) rat mothers and their offspring; (2) Determine whether altering the neonatal gut microbiota of pups born to DIO and SHR rat dams by cross-fostering them with pea fiber fed dams protects the pups against the development of obesity and hypertension in adulthood; and (3) Determine whether endogenous cholecystokinin and peptide YY signaling mediate satiety, and enhanced sympathetic tone mediates the energy expenditure effects of pea fibers.
Approach:
In study-1, pregnant diet-induced obese (DIO) and spontaneously hypertensive (SHR) rats will be randomized to either a low fat (LF) diet, high fat (HF) diet, or the pea fiber (PF) diets: high fat diet + pea cell wall fiber, and high fat diet + pea hull fiber. Diets will be fed throughout pregnancy and lactation. The pups will be weaned at 3 wks to a control high fat diet, segregated by sex and maternal diet groups, and continued for 16 wks postweaning. A subset of LF pups will continue LF diet (internal controls). In study-2, within 24 – 48 h after birth, litters will be randomized to seven groups. The groups include: 1) LF (nursed by LF fed DIO or SHR mothers), 2) HF (nursed by HF fed mothers), 3) Pea fiber (nursed by mothers fed PCF and PHF mothers from study1a), 4) LF-HF foster (offspring from HF dams nursed by LF fed surrogate mothers), 5) HF-LF foster (offspring from LF dams nursed by HF fed surrogate mothers), 6) HF-Pea fiber foster (offspring from Pea fiber dams nursed by HF fed surrogate mothers) and 7) Pea fiber-HF foster (offspring from HF dams nursed by Pea fiber fed surrogate mothers). Pups will be nursed by their respective mothers, weaned at 21 days to HF diet for all groups, except that a subset of LF pups will continue LF diet. After weaning, genders will be separated, and siblings of the same sex and group will be cohoused for another 16 wks. In study-3, male DIO SD rats will be randomized to identical groups as in study 1. During wks 1-3 of diet intervention, rats will be injected IP with vehicle, CCK-1 receptor antagonist, PYY-Y2 receptor antagonist, and a combination of both, at ~48 hr intervals in a counterbalanced design. At 2-3 days later, rats will receive IP injections of vehicle, beta1/beta2-adrenoreceptor antagonist, beta3-antagonist, and both antagonists. Food intake, energy expenditure, and body composition will be measured. At termination, fecal/cecal contents will be sampled for gut microbiota analyses, plasma for gut and metabolic hormones and metabolites, and tissue samples collected for quantifying transcripts and protein abundance of key molecules of glucose and energy metabolism.
