ITHACA, NY (607NewsNow) — In recent years, scientists and healthcare providers have begun to recognize a crucial truth about health and nutrition: one-size-fits-all dietary advice doesn’t work for everyone.
As research into the human microbiome—the vast ecosystem of trillions of bacteria living in and on our bodies—has grown, so too has the realization that these microscopic communities may hold the key to understanding how and why people respond differently to the same foods. The Precision Nutrition New York (PNNY) Study, led by Dr. Angela Poole and her team at Cornell University, aims to unravel these complexities by taking a closer look at one dietary component known to support long-term health: fiber.
Dietary fiber is widely recognized as essential for digestive health, weight management, and reducing the risk of chronic diseases like diabetes and heart disease. But despite these universal benefits, studies have shown inconsistent results when it comes to the type of fiber and how it affects different individuals. This inconsistency has sparked a growing interest in precision nutrition, a field that seeks to understand how individual biological factors—like your gut microbiome—can influence the way your body responds to specific foods.
The PNNY Study, led by Dr. Angela Poole at Cornell University, is a 12-week dietary intervention designed to explore the role of dietary fiber in shaping the human gut microbiome. Participants will follow two different fiber-rich eating plans—one that emphasizes whole grains and another that emphasizes fruits and vegetables. These interventions will be spaced with a baseline week, a washout period, and a follow-up week, giving researchers the opportunity to analyze how changes in diet impact each participant’s unique microbial ecosystem.
Each week, participants will submit stool samples (using collection kits provided by the study team), receive a supply of fiber-rich foods and sample recipes, and attend 4 short in-person nutrition coaching sessions. Participants will also provide saliva samples, allow for body composition measurements, and complete short online surveys throughout the study. All resources, support, and materials will be provided by the research team to make participation easy and convenient.
The PNNY Study is at the forefront of this movement. Its primary goal is to determine whether increasing dietary fiber through whole grains or through fruits and vegetables produces different effects on the gut microbiome and metabolic health—and more importantly, whether certain individuals benefit more from one source of fiber over the other.
Over a carefully structured 12-week period, participants will switch between eating plans that emphasize either whole grains or fruits and vegetables. The research team will collect and analyze stool and saliva samples, track dietary intake, and measure changes in body composition, with a particular focus on the composition and diversity of gut bacteria. The study also incorporates personal coaching sessions and survey assessments to explore behavioral factors—such as motivation and adherence—that influence the success of dietary changes.
This research goes far beyond simply asking “Is fiber good for you?” Instead, it poses a more advanced question: “Which kinds of fiber are best for which kinds of people?” The answer could have far-reaching implications—not just for individual participants, but for the future of nutritional science and healthcare. By understanding how specific fibers interact with specific microbiomes, researchers can begin to build more tailored, effective dietary guidelines that account for individual differences.
Ultimately, the findings from the PNNY Study will contribute to a growing body of evidence supporting precision nutrition, with the potential to inform future policies, treatment plans, and even food design. This could lead to a future where diet recommendations are as personalized as prescriptions, helping people eat in ways that are truly right for their bodies.
In this way, the PNNY Study isn’t just looking at what people eat—it’s helping redefine how we think about food and health in the 21st century.
Are you interested in contributing to cutting-edge nutritional science while earning up to $500? The Poole Lab at Cornell University is currently recruiting participants for an exciting 12-week dietary research study. The Precision Nutrition New York (PNNY) Study investigates how dietary fiber affects the gut microbiome and overall health. Participants will follow guided dietary patterns, attend brief nutrition sessions, and provide regular samples and feedback. This study aims to uncover how individual differences in gut bacteria influence the way our bodies respond to different types of fiber-rich foods.
To be eligible for participation in this health and nutrition study, individuals must be 21 years of age or older and have a body mass index (BMI) between 25 and 30, which can be verified using the CDC’s BMI calculator. Participants should be willing and able to have their height, weight, and body composition measured, as well as provide both saliva and stool samples. They will be expected to record their dietary intake, attend brief nutrition coaching sessions, and increase their fiber intake according to the study protocol.
Additional requirements include completing short surveys and self-reports throughout the study. Eligible individuals must not be pregnant or lactating (if applicable), must not have used antibiotics within the past four months, and should not have any untreated chronic or acute gastrointestinal conditions. If you meet these eligibility criteria and are interested in participating, you can either scan the QR code on this page or email the research team at [email protected] for more information.