HONOLULU – , and the days immediately following the 9/11 attacks.
Among NYC firefighters enrolled in the randomized FIREHOUSE (Food Intake Restriction for Health Outcome Support and Education) study who took part in a microbiome substudy, those who followed a low-calorie, Mediterranean-style diet had higher levels in stools samples at 6 months of Bacteroides ovatus, a bacterial species associated with protection against bowel inflammation.
In contrast, participants who followed a usual-care diet had elevated 6-month levels of a species associated with high-fat diets and inflammation, reported Rachel Lam, a predoctoral fellow in the Nolan Lab at NYU Langone Medical Center, at the annual meeting of the American College of Chest Physicians (CHEST).
“Overall, we found that in our validation cohort, Bacteroides ovatus was increased in the LoCalMed arm after 6 months, and this bacterial species is associated with fewer negative health effects,” she said.
Ms. Lam noted that in a murine model of high-fat diets, mice gavaged with Bacteroides ovatus had reductions in body mass index and decreased serum LDL cholesterol and triglyceride levels.
FIREHOUSE cohort
Senior author Anna Nolan, MD, whose lab members study predictors of lung function loss in a cohort of firefighters who were exposed to the particulate matter clouding the air of lower Manhattan on 9/11 and the ensuing days, told this news organization that the findings, while preliminary, support previous research findings on potential links between intestinal microbiota and lung function.
“It’s interesting that we saw this done in other models, like mouse models and such, where certain bacteria were viewed as healthy for the system, and if they were able to bring that bacteria out in larger amounts they saw anti-inflammatory effects, so we’re hoping to mirror that and also do a mouse model,” she said.
Dr. Nolan’s group has previously shown that markers for the metabolic syndrome, inflammation, and vascular injury detected in serum samples taken within 6 months of 9/11 were predictive for later abnormal lung function. In addition, their group has found that elevated serum levels of an LDL metabolite after intense World Trade Center dust exposure is a risk factor for future impaired lung function as measured by forced expiratory volume in 1 second (FEV1).
In the FIREHOUSE trial, 89 patients were randomly assigned either to a technology-supported educational and behavioral intervention targeting calorie restriction for weight loss while following a low-calorie Mediterranean diet, or to usual care. The usual-care arm included participants who were informed about their weight, BMI, and other standard measures at annual visits and were given general advice about healthy eating, but were not assigned to a specific diet.
Participants in the LoCalMed group had significant decreases in BMI and increases in FEV1, compared with those in the usual-care group. In addition, the LoCalMed group had improved vascular health, better dietary habits, decreases in fats and calories from sweets, and decreases in inflammation as measured by a lower white blood cell count.