image: M. Maya Kaelberer is assistant professor of physiology at the College of Medicine – Tucson.
Credit: Photo by Noelle Haro-Gomez, U of A Health Sciences Office of Communications
A University of Arizona College of Medicine – Tucson researcher will explore how maternal diet influences offspring food choices later in life thanks to a National Institutes of Health’s New Innovator award, a five-year, $1.5 million “high-risk, high-reward” grant given to early-career scientists advancing ambitious hypotheses with intriguing potential.
The funding will turbocharge investigations led by M. Maya Kaelberer, assistant professor of physiology, into cells called neuropods, which send signals from the intestine to the reward center of the brain via the vagus nerve.
Previous work showed that when mice ate high-fat and high-sugar diets during pregnancy, their offspring were more likely to gain weight — even when eating the same diet as other mice. Her upcoming studies will explore the extent of this maternal connection by making sweetened condensed milk freely available to the mom, then testing the gut sugar sensitivity of the offspring.
“I’m trying to create as natural a situation as possible, similar to how we eat. We have our fresh vegetables, but someone brings in cookies, and we have five of them,” she said. “We’re really good at supplementing our diet with stuff that is not very good for us. Likewise, mice will drink a ton of sweetened condensed milk, but they’ll have their normal chow as well.”
Her hypothesis is that mice exposed to a high-fat, high-sugar diet in the womb will have guts that are wired to require denser calorie sources to feel satisfied.
Kaelberer hopes a better understanding of the gut-brain connection will provide a peek into people’s differing food choices, discoveries that might someday allow dieticians to design diets that are easier to adhere to. An even more ambitious goal — straight out of the realm of science fiction — is to figure out how to “reprogram” the gut at a cellular level to push people toward favoring healthier foods.
She believes this understanding begins with exploring the “nutritional memory,” which is influenced by foods eaten during pregnancy. In addition to fat and sugar, she will investigate how neuropods sense other nutrients and communicate their presence to the brain.
“Maternal diet is going to influence the food choices of the offspring later in life,” Kaelberer said. “The gut is probably encoding nutrient signals that inform the offspring what to expect. Their sensory system gets set up to value certain foods over other foods.”
She hopes her work will enable dieticians to create more palatable personalized diets, such as heart-healthy or diabetes-friendly plans that cut out certain foods. If neuropods are priming people to want those foods, she wonders if a better understanding of the nutritional memory will help identify healthier foods that scratch the same itch.
“If you can supplement with other things, the diet is not going to be so restrictive and horrible to follow,” she said. “I’m interested in bringing my background in sensory neuroscience to the field of nutrition to figure out the complex interplay between the gut, brain and our food preferences. Maybe someday we can create new dietary guidelines that help us eat healthier while also taking the gut’s role in our dietary choices into account.
Kaelberer’s previous studies found a particularly long-lived type of neuropod that could be the key to storing nutritional memory and play a big role in the stability of our food preferences throughout our lives.
She will remove the long-lived neuropods that are sensitized toward certain types of nutrients — like fat and sugar — to see if the mice begin making different decisions. If that works, her hunch is that someday similar cells could be targeted in humans to influence food preferences.
“Could we develop a drug that targets only those long-lived cells and reverse their effects on our decisions? First, we have to show that it has an effect in mice,” she said. “Then, we need to show that it is the same with our neuropods. Translating this work to humans could be a gamechanger, as until now the global burden of diet-related disease has only grown, despite everything we’ve learned about nutrition.”