Microbiome changes linked to improved outcomes following dietary intervention in WTC firefighters
Presenter: Rachel Lam, BS, NYU Grossman School of Medicine, Department of Medicine, New York, NY
Diet and the microbiome in WTC particulate matter exposed firefighters with lung disease: The FIREHOUSE randomized clinical trial. Presented Oct 8, 2023.
A low-calorie Mediterranean-type diet may improve health outcomes and quality of life in some firefighters with lung disease associated with particulate-matter exposure at the World Trade Center (WTC), possibly due to positive effects on the microbiome, according to research reported at CHEST 2023.
In the randomized, controlled trial, known as FIREHOUSE (Food Intake REstriction for Health OUtcome Support and Education), 89 firefighters with WTC-associated lung injury were randomized to a low-calorie Mediterranean dietary intervention or to usual care. For this abstract, investigators studied the changes in microbiome in some of these firefighters following 6 months of exposure to the Mediterranean diet.
Compared to firefighters who received usual care, those randomized to receive the Mediterranean diet had an increase in Bacteroides ovatus, a bacterial species associated with fewer negative health effects, said presenter Rachel Lam, BS, NYU Grossman School of Medicine, Department of Medicine, New York, NY. Furthermore, increases in Bacteroides ovatus have been linked to reductions in body mass index (BMI) reductions, decreased serum LDL-C, and triglyceride levels in a high fat diet murine model.
“Surprisingly, even though our study was small and focused on a homogeneous population of WTC-exposed firefighters, we were able to find a microbiome signature that we continue to explore in this patient population,” said senior study author Anna Nolan, MD, FCCP, Professor of Medicine and Environmental Medicine in the Division of Pulmonary and Critical Care at NYU School of Medicine, New York, NY.
The dietary intervention improved lung health, vascular health, and quality of life while attenuating contributing risk factors of metabolic syndrome, according to their research. From baseline to 6 months, there was a significant decrease in BMI for the Mediterranean diet arm as compared to usual care (decreases of 1.84 kg/m2 and 0.608 kg/m2, respectively; P < .001). There was also a significant improvement in forced expiratory volume (FEV1) percent predicted in the Mediterranean diet arm versus no significant change in the usual care arm.
Researchers also performed a pilot and feasibility study of the gut (stool) microbiome samples that they had collected from subjects in the low-calorie Mediterranean diet and usual care arms of the FIREHOUSE trial. In the pilot study, which included 5 patients each from the Mediterranean diet and usual care groups, researchers found that a reduction in BMI was associated with an increase in the abundance of Bacteroides ovatus.
The validation cohort included 15 Mediterranean diet participants and 16 usual care participants. In this part of the study, investigators found an increase in Bacteroides ovatus (P = .03) from baseline to 6 months in the diet arm.
“Our study shows that the microbiome of your gut can change even in a very short time,” Dr. Nolan said. “These changes may be associated with clinically relevant outcomes such as loss of weight.”
Looking beyond this population of firefighters, Dr. Nolan said the study results emphasize how diet and overall health are important for clinicians to discuss with their patients. It is also important to clearly define goals for patients and provide them with targets for weight loss and healthy eating, she added.
“These goals and targets need to be tailored to your patient population,” she said. “(Clinicians) should also be realistic about the goals they set for their patients and provide frequent follow-up.”
Although the findings of FIREHOUSE are provocative, future studies are needed to validate these findings in other populations with environmental particulate exposure and metabolic risk factors such as elevated BMIs.
“This is a crucial step, since without validation in other cohorts our finding will be less generalizable,” Dr. Nolan said.
Disclosures:
Rachel Lam and Anna Nolan reported no relevant financial relationships with respect to this study.
References:
Kwon S, Crowley G, Caraher EJ, et al. Validation of predictive metabolic syndrome biomarkers of World Trade Center lung injury: A 16-year longitudinal study. Chest 2019; 156(3):486-496. doi:10.1016/j.chest.2019.02.019
Kwon S, Lam R, Crowley G, et al. 282 Food Intake REstriction for Health OUtcome Support and Education (FIREHOUSE): a proof of concept randomized clinical trial. J Clin Transl Sci 2023; 7(Suppl 1):84. doi:10.1017/cts.2023.338
Lam R, Kim J, Ramprasad M, et al. Diet and the microbiome in WTC particulate matter exposed firefighters with lung disease: The FIREHOUSE randomized clinical trial. Chest 2023; 164(4 Suppl):A5111-A5112. doi:https://doi.org/10.1016/j.chest.2023.07.3309