II – Imbalance
Dysbiosis occurs when the balance of gut microbiota is disrupted, promoting the growth of pathogenic bacteria and reducing bacterial diversity. A study by Morgan et al. (2012) [4] has shown that factors such as antibiotic use, stress, and unbalanced diet can contribute to the development of dysbiosis. Dysbiosis is associated with many inflammatory diseases, including IBD.
Research conducted by Frank et al. (2007) [5] revealed that IBD patients show significant alterations in the composition of the gut microbiota compared to healthy individuals. These findings suggest a link between dysbiosis and the development of inflammatory diseases, highlighting the importance of maintaining a balanced microbiota to preserve intestinal health.
A – Chronic Inflammation
Dysbiosis can trigger a chronic inflammatory response in the intestine, characterized by increased production of pro-inflammatory cytokines. A study conducted by Zhu et al. (2018) [6] has shown that dysbiosis is associated with increased levels of inflammatory cytokines in the intestinal microbiota, thus contributing to the development of inflammatory diseases. This chronic inflammation is associated with inflammatory diseases such as Crohn’s disease and ulcerative colitis. Research conducted by Neurath (2014) [7] has revealed that chronic intestine inflammation is characterized by an infiltration of immune cells and an alteration of the intestinal barrier, which contributes to the progression of inflammatory diseases. These results highlight the critical role of dysbiosis in the pathogenesis of inflammatory bowel disease.
B – Parainflammation
Parainflammation is a low-grade inflammatory condition that can occur in response to chronic stimuli, such as dysbiosis. Unlike acute inflammation, para-inflammation is a prolonged condition that can contribute to the development of chronic diseases such as IBD, type 2 diabetes, and cardiovascular diseases. A search conducted by
Chovatiya and Medzhitov (2014) [8] revealed that para-inflammation is mediated by immune cells such as macrophages and T cells, which release inflammatory cytokines to regulate the immune response in dysbiosis.
C – Innate & Adaptive Immunity
The microbiota plays an essential role in developing and regulating innate and adaptive immunity. Innate immunity, our body’s first line of defense, acts instantly against invaders thanks to recognition mechanisms that target pathogens and organisms of the non-care. It comprises physical obstacles like skin, specialized cells, and molecules that can neutralize threats before they multiply. Moreover, adaptive immunity is a more specific defense system that develops over time following a first exposure to a pathogen. This immune memory enables the body to recognize and fight future infections with the same pathogen more effectively, thanks to the production of specific antibodies and the activation of T and B lymphocytes. In our intestinal walls, immune reactions take place, where Immunoglobulin A (IgA), secreted by plasma cells, which are cells derived from B lymphocytes, play a crucial role in secreting specific antibodies that line the intestinal mucosa, thus protecting the body from infections and helping to maintain the vital balance between pathogens and the beneficial microbiota.
A study by Belkaid and Hand (2014) [9] has shown that gut microbiota educates the immune system by promoting tolerance to commensal bacteria while stimulating appropriate immune responses against pathogens. Dysbiosis can disrupt this delicate balance, causing dysfunction of intestinal immunity. Research conducted by Peterson and Artis (2014) [10] has revealed that dysbiosis is associated with an impaired immune response in the intestine, thus promoting the development of inflammatory diseases. These results underscore the importance of maintaining a balanced microbiota to preserve intestinal health and regulate the immune response adequately.
D – Metabolism & Obesity
The gut microbiota plays an essential role in nutrient metabolism and energy homeostasis. Studies have shown that alterations in the composition of the microbiota, such as the decrease in bacterial diversity and the predominance of certain bacterial species, are associated with obesity and metabolic disorders. A research conducted by Turnbaugh et al. (2006) [11] revealed that mice deprived of microbiota show an increase in fat mass compared to mice with normal microbiota, even when their caloric intake is controlled.
These results suggest that the gut microbiota may play a role in regulating body weight and energy metabolism and that alterations in the microbiota composition may contribute to the development of obesity.
E – Neurological Diseases
Recent research also suggests a link between the gut microbiota and neurological diseases such as depression and Alzheimer’s disease. A study by Jiang et al. (2017) [12] has shown that alterations in microbiota composition are associated with depressive symptoms in irritable bowel syndrome (IBS) patients, suggesting a link between intestinal microbiota and mental health. In addition, studies in animal models have shown that altering the composition of the microbiota can affect brain behavior and function, suggesting a potential link between the intestinal microbiota and neurological diseases.
