Participants are enrolling for Particulate Matter as a Contributor to Gastrointestinal Disease and Symptom Burden in Cystic Fibrosis, a Stanford Snyder Lab study that runs on StudySync. It asks whether the microscopic particles a person breathes help drive the gut symptoms of cystic fibrosis. Each participant wears an exposometer and a Fitbit and provides samples and surveys, and all of that data moves through StudySync, the platform the team uses to bring those measurements together.
Up to 30% of people with cystic fibrosis live with gastrointestinal symptoms: abdominal pain, bloating, and difficulty with bowel movements that add to the daily weight of the disease. This study looks past the lungs that usually define the condition and toward the gut, and it treats the air each person breathes as something worth measuring one individual at a time.
The gut is part of the cystic fibrosis story
Cystic fibrosis is a genetic disease that thickens the mucus lining the lungs, pancreas, and other organs, and it is best known for the lung infections it causes (NHLBI overview). The gut is affected too. Alongside the respiratory symptoms, a large share of people with the condition carry a steady burden of abdominal pain, bloating, and disrupted bowel movements.
Part of that burden appears to sit in the gut microbiome, the community of bacteria that lives in the intestine and helps regulate digestion and the immune response. In cystic fibrosis the makeup of that community shifts, and those shifts travel with intestinal inflammation that can produce the symptoms people feel day to day. Current cystic fibrosis therapies have not moved the gut community back toward a healthier balance of bacteria, and the reason they fall short is still unknown. Understanding what keeps the gut inflamed is a starting point for doing something about the symptoms.
Why the air a person breathes belongs in a gut study
The environment offers one candidate. Particulate matter, the main ingredient of air pollution, is a mixture of solid particles and liquid droplets small enough to travel deep into the body (EPA, Particulate Matter Basics). Exposure to it can change the gut microbiome and inflame the intestine, which places it in the same pathway this study is trying to explain.
The problem is measurement. Exposure is usually reported as an average across a neighborhood or a city, a figure that smooths over the real differences between two people standing on the same corner. One of them may spend the day beside a busy road, the other indoors with filtered air. A shared average cannot say why one person’s gut reacts and another’s does not, which is exactly the gap between a population statistic and a single patient’s experience.
Measuring one person’s exposome with a wearable
The exposometer closes that gap. It is a small wearable device that samples the air its wearer actually breathes, trapping particulate matter along with the chemical and biological material carried on it and building a personal profile of exposure over time. The Snyder Lab developed and tested this approach in a two-year study that followed individuals across dozens of locations (Jiang et al., Dynamic Human Environmental Exposome Revealed by Longitudinal Personal Monitoring, Cell, 2018; PubMed), and later paired the exposome with multi-omics profiling of health.
Exposometer studies have so far covered healthy volunteers and people living with asthma or obesity, and the lab has used StudySync to run related environmental-exposure work such as its Beneficial Exposome study. Cystic fibrosis has not been examined this way. That absence is the opening this project takes up: a personal exposure profile has never been placed next to the gut microbiome, inflammation, and symptoms of a person with cystic fibrosis.
The question the study is built around
The hypothesis is direct. An individual’s particulate-matter exposure influences that individual’s intestinal microbiome, intestinal inflammation, and gastrointestinal symptoms. By collecting a personal exposure profile and setting it beside the gut microbiome, markers of inflammation, and reported symptoms from the same person, the team can test the link where it matters, at the level of one body rather than a group average.
That framing is what makes the wearable useful here. Instead of asking whether polluted cities have sicker residents, the study asks whether the exposures a specific person accumulates line up with changes inside that person’s gut.
What taking part involves
Participation runs about three months. During that window a participant wears a personal exposometer and a Fitbit, provides blood microsamples along with respiratory and stool samples, and answers surveys about their condition. Together those streams describe what a participant was exposed to, what their gut bacteria and inflammation looked like, and how they felt.
The study is open to individuals aged six or older who have been diagnosed with cystic fibrosis, are not currently pregnant, and can read and understand English or Spanish. People interested in joining can contact Carolena Trocchia, MD, MPH, at ctrocch1@stanford.edu. The data itself is handled through StudySync.
Bringing the data together on StudySync
A study like this only works if the pieces stay connected. StudySync carries each participant’s wearable data and keeps it alongside the study’s samples and surveys in one research environment, so the team can watch data arrive, notice gaps early enough to follow up, and export organized datasets when it is time to analyze them.
That matters most at the analysis stage. The value of the exposometer comes from comparison: holding a participant’s exposure profile against their microbiome, their markers of inflammation, and the symptoms they reported over the same weeks. Keeping those records together for each person is what lets the team look for a signal that a group average would hide.
The team behind the study
The work is based in the Snyder Lab at Stanford University, led by Carolena Trocchia, MD, MPH, and Michael Snyder, PhD. It sits within the lab’s broader effort to read personal environmental exposure with wearable sensors, an effort that also includes the Beneficial Exposome study and the omics analysis the lab contributes to studies like the UC Irvine electroacupuncture trial.
Carolena Trocchia, MD, MPH, leads the study. Trocchia is Chief Fellow in Pediatric Gastroenterology at Stanford and Lucile Packard Children’s Hospital, completed pediatric residency at Johns Hopkins All Children’s Hospital, and earned a Master of Public Health. Their clinical interests center on pediatric gastroenterology with a focus on inflammatory bowel disease.
Michael Snyder, PhD, co-leads the study. Snyder directs the lab whose wearable exposometer work this project builds on, and is a scientific advisor to StudySync.
Where the study stands
Enrollment is ongoing. As more people join, the team will begin assembling the paired record at the center of the project: what a participant breathed, what their gut microbiome and inflammation looked like, and what symptoms they lived with, all read one individual at a time.