Influence of early exposure to bitter foods on bitter taste sensitivity in adulthood

Project Summary
Vegetable intake can contribute to many health benefits; however, the bitter taste of vegetables creates a
barrier to consuming a healthful diet. Therefore, to increase consumption of healthy foods, it is of utmost
importance to investigate factors that influence the consumption of healthy, nutritionally valuable foods. There
have been generations of work examining how to increase acceptance of vegetables, and to increase
vegetable “liking.” The most common, and successful, technique used in children to increase the acceptability
of novel or bitter foods is repeated exposure (RE). In adult rodent models, we have also shown RE to a bitter
diet increases acceptance of the bitter food. Our findings demonstrate that salivary proteins (SPs) mediate this
change in taste-driven responding to a bitter stimulus in rodent models. Human literature has alluded to the
idea that early-life interventions such as repeated exposure during infancy or toddlerhood can alter food
preferences into adulthood yet the research supporting this has been limited. In addition, both human and
rodent literature have demonstrated maternal diet has a large impact on offspring food preferences. We plan to
develop a rodent model to address these open questions. AIM 1 will test how vertical transmission of a
bitter maternal diet to offspring during gestation and lactation affects adult offspring response to a
bitter solution. We will examine taste-guided responsivity, two-bottle choice preference and salivary protein
(SP) expression in adult rats that were exposed to experimental diets via amniotic fluid and milk. AIM 2 will
determine the role of RE on the adult responding to sweet, bitter, or fat. We will expose rats to a bitter,
high-fat, or non-bitter control diet as weanling rats for two weeks and measure taste-guided responses and
two-bottle choice preference scores in adulthood. We will collect saliva and compare SP expression of animals
fed on different diets and use general linear models to look for relationships between measures of taste
sensitivity and SP expression. This project will provide a strong platform to enhance the trainee’s behavioral
skills and allow the trainee to master new molecular techniques such as Western Blots, 2-D gel
electrophoresis, and proteomic analyses.

Grant Number: 5F31DC022177-02
NIH Institute/Center: NIH
Principal Investigator: Verenice Ascencio Gutierrez