Microbial Spycraft: Amir Mani Explores Gut Health and Immune System Secrets

Gut health, antibiotic resistance, probiotics and the effects of bacteria on the immune system are specialties for Amir Mani, a new faculty member in the Department of Animal Science for the Arkansas Agricultural Experiment Station.

Mani joined the department as an assistant professor of microbiome and sustainability late last year following a postdoctoral fellowship at the University of Chicago Pritzker School of Medicine. He earned his doctorate in biology, focusing on microbiome and neuroimmune interactions, at the University of New Mexico.

The microbiome refers to communities of bacteria — beneficial, harmful or neutral — that live in specific environments, such as the human or animal gut. 

"How I describe myself is a microbiome scientist," Mani said. "I study the bacteria that escape the gut, in both healthy and diseased animals, and move throughout the body using blood circulation and some of the immune cells as a Trojan horse to get to other organs."

In addition to his role with the experiment station, the research arm of the U of A System Division of Agriculture, Mani is also part of the Dale Bumpers College of Agricultural, Food and Life Sciences at the University of Arkansas.

"Dr. Mani brings an exceptional record of interdisciplinary research, including discoveries that reshape our understanding of gut-brain communication and antibiotic resistance transfer," said Michael Looper, professor and head of the Department of Animal Science. "His innovative approach will strengthen research and teaching collaborations across animal science and our interdisciplinary efforts in the biomedical field."

Spycraft science

Starting with veterinary diagnostic testing, Mani uses big data analysis tools to study how microbiomes shape livestock gut health and immunity. What it all comes down to is research to keep animals healthy and productive, Mani said. But along the way, he has also been part of research that gives a peek behind the curtain of a microscopic drama with rogue spies and covert informants.

"Different bacteria have different genes that help them evade the immune system and the gut in different ways," Mani said. 

Thinking of Mani's research as high-level spycraft, the gastrointestinal tract is the first checkpoint, keeping friendly agents in and hostile actors out. His work on microbial translocation examines what happens when the border is breached and bacteria enter the bloodstream, triggering immune alarms that affect animal performance and health.

The immune system and microbiome function like counterintelligence and allied networks, Mani explained. When they're aligned, they share information and neutralize threats effectively. When communication breaks down, sleeper cells — harmful microbes — can exploit the confusion and increase susceptibility to disease.

Probiotic operatives

Mani is currently planning a collaborative study with fellow experiment station researcher Ali Ubeyitogullari, an assistant professor of food engineering with the departments of Food Science and Biological and Agricultural Engineering, on next-generation probiotics using 3D printing to encapsulate probiotics in microgel beads.

Keeping with the spycraft analogy, the micro-tech probiotics are like elite operatives going behind enemy lines. The capsules provide stealth and protection from early detection or destruction, allowing them to establish a safe house in the gastrointestinal tract and remain operational long enough to carry out their mission: stabilize the microbiome and improve health outcomes.

Bacteria in the brain

Mani's previous research on fish flipped the script on what was known about bacterial translocation. With colleagues at the University of New Mexico, Oregon State University, the Norwegian Veterinary Institute and researchers in the Czech Republic and Austria, he was the first author of a study published in the September 2024 issue of Science Advances that redefined the physiological relationships between the brain and bacteria in healthy trout. 

"We showed how some of these bacteria made their own way to the brain and live inside the brain of healthy fish," Mani said. "The study showed that not only is their brain receiving indirect signals and nervous signals from the gut, but there are some direct microbial signals."

The study was featured in Science News and Quanta Magazine articles, highlighting the novelty of the research as evidence that a brain microbiome can exist in healthy vertebrates, potentially offering clues for researchers studying human brain diseases.

"There is a whole new field now with how those bacteria may play a role in brain cognition diseases like Alzheimer's and Huntington's," Mani said.

Their follow-up research, which showed how those bacteria may affect the fish host's behavior and responses to different initiatives, was published in the Proceedings of the National Academy of Sciences. Their investigation into how the bacteria in the fish's brain and gut interact with the immune system was published in Nature Microbiology.

In addition to funding from the National Institutes of Health for some of his research, Mani also received a BrightFocus Foundation Postdoctoral Fellowship to study how IgA-producing plasma B cells, a specific type of immune cell, are "educated" in the gut and can travel to regions in the eye where they act as key communicators between the gut immune system and the eye. 

Mani noted that the work offers potential new approaches to diagnosing and treating macular degeneration based on immune and microbiome signals.

To learn more about ag and food research in Arkansas, visit aaes.uada.edu. Follow the Arkansas Agricultural Experiment Station on LinkedIn and other social platforms at @ArkAgResearch and sign up for our monthly newsletter, the Arkansas Agricultural Research Report. To learn more about the Division of Agriculture, visit uada.edu. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit uaex.uada.edu.

About the Division of Agriculture: The University of Arkansas System Division of Agriculture's mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation's historic land grant education system. 

The Division of Agriculture is one of 20 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on three system campuses.  

Pursuant to 7 CFR § 15.3, the University of Arkansas System Division of Agriculture offers all its Extension and Research programs and services (including employment) without regard to race, color, sex, national origin, religion, age, disability, marital or veteran status, genetic information, sexual preference, pregnancy or any other legally protected status, and is an equal opportunity institution.