Impact of obesity on allergic respiratory diseases and on mental and cognitive performance

Summary Background Obesity and allergies are among the most common diseases of our civilization. Given the simultaneous rise in the prevalence of these diseases in recent years, a potential causal link between the two has been proposed. In particular, obese patients are at an increased risk of developing bronchial asthma, likely due to mechanical restrictions but also to metabolic changes that adversely affect immune function. Neuroscience studies have also shown that obesity can lead to impaired brain function and mental health. In the following review, we will take a closer look at our studies that focus on the influence of obesity on allergic diseases and cognitive performance. Results Both human studies and animal models (mice) have shown that obesity leads to increased allergic responses in the airways. Our studies in a mouse model of obesity confirm that an obese phenotype is associated with increased allergic sensitization and manifestation. These changes are associated with significant shifts in the composition of the gut microbial flora. The microbiome changes are further associated with allergic airway inflammation and an increased incidence of T helper 1 (Th1) type pulmonary macrophages. Interestingly, despite the changes in the microbiome, it is possible to effectively prevent allergy development by inducing oral tolerance. Furthermore, it was observed that obese mice show increased signs of anxiety and depression, as well as reduced cognitive performance. Conclusion Obesity is a complex metabolic disease that significantly impacts our body’s gut microbiome and immune system, resulting in an increased incidence of allergic asthma and neurological/psychological changes. Attention should be given to both the prophylactic and therapeutic measures to mitigate the impact of obesity, including oral tolerance for managing existing allergic diseases.