(P06-023-23) Novel Standardized Meals for Clinical Bioavailability Trials and In Vitro Macronutrient Digestion Studies

Objectives: Standardized test meals are often used to examine acute metabolic effects of diet, as well as effects of dietary supplement interventions on nutrient bioavailability. The most well-studied is a high-calorie, high-fat meal recommended by the FDA for pharmaceutical bioavailability and bioequivalence studies. We propose three new test meals for use in clinical trials and in vitro gastrointestinal (GI) simulations aimed at detailing macronutrient digestion and improving GI symptoms associated with food intolerances.

Methods: The first meal consists of grilled chicken, steamed peas, mashed potatoes, and butter. The design objective of this heated test meal (HTM) was to create a balanced meal within the Acceptable Macronutrient Distribution Range. A canned test meal (CTM) approximates the HTM macronutrient ratios with canned chicken and canned peas to provide a convenient substrate for laboratories not equipped with a kitchen. A third meal was designed to contain high amounts of fructans. The high-fructan test meal (FTM) contains a black bean patty, steamed Brussels sprouts, and sautéed garlic and onions ( > 10 g fructans/serving). Proximate analysis was performed to confirm meal specifications. The HTM and CTM substrates were used to determine the effects of mixture of six food-grade microbial enzymes (BC-006) on macronutrient digestion in the INFOGEST simulation of GI digestion. Separately, the effect of microbial inulinase on fructose release from FTM was also investigated. Free amino nitrogen (FAN), glucose, glycerol, and fructose concentration in gastric digestas were determined by HPLC.

Results: With the HTM substrate, escalating doses of BC-006 increased the FAN concentration of gastric digestas up to 85%, glucose 99% and glycerol 5-fold (all P < 0.01) compared to pepsin-only controls. For CTM, FAN concentrations increased up to 2-fold, glucose 23-fold, and glycerol 11-fold (all P < 0.001) compared to controls. For FTM, inulinase treatment increased the fructose concentration up to 3-fold (P < 0.0001) compared to a pepsin-only control. In a final application, the HTM is being used as the substrate in an ongoing clinical aminoacidemia trial of BC-006 (ClinicalTrials.gov ID NCT05211440).

Conclusions: These in vitro data support the use of these validated, standardized test meals as substrates for supplemental enzyme testing.

Funding Sources: BIO-CAT, Inc.