Furman undergrads win award for research about gut-brain-sensory axis, autism and Fragile X syndrome

Neuroscience major Camila Vargas Calatayud ’26, and biology and French double major Holly Bragdon ’26 earned one of only three poster awards at the meeting of the South Carolina Autism and Neurodevelopmental Disorders Consortium (SCAND). Their project explores the relationship between the gut microbiome, the brain and auditory processing in a mouse model of autism spectrum disorder (ASD).

“We are investigating the gut-brain axis and nutritional neuroscience in a lab where we work specifically with mice that have Fragile X syndrome (FXS),” said Vargas Calatayud. FXS has many symptoms that overlap with autism, and one of those is hyperacusis, or an outsized, overwhelming sensitivity to sound.

From left: Brent Wilkerson (MUSC), Holly Bragdon, Camila Vargas Calatayud and Linnea Freeman.

Working with Associate Professor of Biology and Neuroscience Linnea Freeman, researchers at Furman and at the Medical University of South Carolina are studying whether manipulating the gut microbiome can impact hearing deficits observed in the mouse model of Fragile X syndrome. FXS is the most common inherited form of intellectual disability and leading single-gene cause of ASD, Freeman said.

Researchers alter the makeup of the gut bacteria through cross-fostering, where a mouse mom takes care of a different litter, Freeman explained. That process exposes mouse pups to a different microbiome through the mother’s milk, skin and feces.

“In our preliminary results, we saw that altering the gut microbiome had a corrective effect on hearing in mice,” Bragdon said. “That’s exciting news for treating auditory disorders in Fragile X syndrome and autism.”

Hearing deficits go hand-in-hand with behavioral differences including those related to anxiety and sociability, added Freeman. “This work highlights the gut-brain-sensory axis as a potential pathway for novel therapeutic strategies targeting sensory and behavioral dysfunctions associated with FXS and ASD.”

“Autism symptoms can become very debilitating or limiting for patients,” Vargas Calatayud said. “I’m excited about the possibility of alleviating some of the symptoms through less invasive approaches like introducing probiotics in patients with ASD.”

The study represents a continuation of NIH-funded research Freeman has undertaken with Brent Wilkerson and his team at MUSC. Furman biology major Luke McLeod ’27 was also a contributor to the project in 2025, and this summer he’ll pick up where Freeman’s lab left off.

“I’m incredibly proud of Camila’s, Holly’s and Luke’s work,” Freeman said. “Luke couldn’t attend SCAND, but Camila and Holly were the only undergraduate students to receive a poster award.” The other two awards went to Ph.Ds./postdoc fellows at the University of South Carolina and MUSC.

It’s worth noting that Furman undergraduate researchers can hold their own with Ph.Ds. as both students will seek doctorate degrees after graduating Furman – neurolinguistics for Bragdon and neuroscience for Vargas Calatayud.

“I’m grateful for Dr. Freeman for being an incredible mentor,” Bragdon said. “She prepared us well by holding weekly meetings over the summer where we’d discuss the literature, sort of like a science book club, so I felt equipped to present on our project and answer questions about the subject.”

“I’ve been lucky to have Dr. Freeman as a professor,” Vargas Calatayud said.  She has challenged me and satisfied my intellectual curiosity. She’s a role model for me. It’s inspiring to see a woman so well placed in the world of neuroscience research.”

Vargas Calatayud of Caracas, Venezuela, is also a Latin American studies minor. “As an international student, it’s very exciting to have opportunities to be involved in such cutting-edge research,” she said.

And when she’s missing home or facing challenges at Furman, Vargas Calatayud said it’s her hard work and sense of contribution that keep her motivated and on track. For her, the award holds special significance. “I feel like I’m representing my country. My successes are my country’s successes. That’s something I always keep very present,” she said.