(P19-032-25) Dietary Resistant Maltodextrin Alters Cecum Short Chain Fatty Acids and TotalFeed Intake in Mice

Objectives: The AIN93 standard mouse chow diet lacks any fermentable fibers in its formulation. This experiment aims to examine if adding maltodextrin fiber to the AIN93 diet formula will improve rodent metabolic health markers.

Methods: The study used 72 four-week-old mice, 36 C57/BL6J (Jackson Laboratory; Bar Harbor, ME, USA) and 36 Swiss Webster (Charles River Laboratory; Wilmington, MA, USA) with 18 males and 18 females per strain. Mice were group housed (n=3) with standard bedding and fed a standard chow diet during a two-week acclimation period. After acclimation, mice were sex- and weight-matched into diet groups and singly housed. Diet groups were assigned either a standard control diet (AIN-93G; Dyets, INC., Bethlehem, PA, USA) or a diet containing Fibersol®-2 (Dyets, INC) for 13 weeks. Fasting plasma samples were collected at weeks 0 and 13 and plasma albumin, ALT, creatinine, glucose, total cholesterol, HDL cholesterol, and triglycerides were quantified using a COBAS INTEGRA 400 plus Analyzer (Roche Diagnostics, Indianapolis, IN, USA). After 13 weeks, mice were euthanized and liver and cecum tissues were collected. Cecal levels of acetate, propionate, butyrate, isobutyrate, valerate, and caproate were quantified by LCMS. Body composition data was obtained via Echo MRI at weeks 0, 7, and 13. Food disappearance was calculated at the end of each week.

Results: ANOVA and TUKEY’s HSD tests showed no significant difference in weight gain, blood plasma phenotypes, or body fat percentage between diet groups. There was a significant difference in food consumption between diet groups. While mice on the AIN+Fiber diet ate more than their AIN93 counterparts by weight, their caloric intake was lower than AIN93-fed mice. Cecum content mass was between 1.3 to 1.9 fold increased in the AIN+Fiber diet group compared to AIN93 fed mice (P < 0.05 for all groups). Concentrations of acetate, propionate, and valerate concentrations were 1.5 to 2.0 fold increased (P < 0.05 for all groups).

Conclusions: Addition of fermentable fiber had limited effects on most parameters measured. Future analysis of microbial composition via 16s RNA sequencing may elucidate mechanisms behind observed food consumption differences and cecum short chain fatty acid concentrations between diet groups.

Funding Sources: Funding Provided by USDA Agricultural Research Service (ARS).