Changes in gut function caused by weight gain are linked with an increase in asthma severity, according to a study presented this week in the United Kingdom.
It is already known that obesity worsens several chronic inflammatory diseases, perhaps as as gut-derived bacterial fragments (endotoxins) and associated markers of endotoxin (lipopolysaccharide binding protein [LPB]), enter the circulation through a damaged gut barrier, provoking systemic inflammation. The current study investigated the role of body weight on gut permeability and systemic inflammation and the impact on asthma control and asthma status.
The researchers examined the relationship between body weight and gut permeability with the symptoms of 98 patients with severe asthma, with and without obesity. All the patients were White, with 29 men and 69 women participating.
Patients with lean to obese body mass index (BMI) reported their symptoms using the Asthma Control Questionnaire-6.
Blood tests were taken to measure levels of gut permeability markers LPB and calprotectin, as well as markers of asthma-related inflammation (granzyme-A, interleukin [IL]-5, IL-6, CCL-4).
Patients with poorly controlled asthma had significantly higher levels of LBP and levels of LBP increased with increasing body weight. Increasing concentrations of LBP also correlated with higher levels of asthma-related inflammatory markers. Increased body weight was linked with higher levels of inflammation, signs of gut permeability, and poorer control of asthma.
The current study included only a small number of patients with severe, uncontrolled asthma, so the researchers plan to recruit more patients to the study and to investigate the effects in participants with well-controlled asthma, over a range of BMIs, as well as examining whether targeting the gut can improve asthma control in affected patients.
The findings highlight the gut as a potential, alternative therapeutic target for improving asthma control in patients with obesity.
“These data therefore suggest that reducing body weight, or therapeutically targeting the gut to reduce gut permeability, may offer people with obesity and severe asthma some improvement in their chronic inflammation conditions and disease management,” the researchers concluded.
The study was presented at the Society for Endocrinology annual conference.
Parenti C, Murphy AM, Lad N, et al. Investigating the effect of obesity on gut damage, systemic inflammation, enhanced asthma severity due to gut derived bacteria, endotoxin. Presented at: Society for Endocrinology Annual Conference; November 14-16, 2022; Harrowgate, England. Abstract P211.