What change does the microbiome of CD-affected individuals likely cause?

• A. Increased inflammatory response
• B. Increased immune tolerance
• C. Decreased immune tolerance
• D. Increased production of anti-inflammatory molecules

Answer: (C)

The microbiome of individuals affected by Crohn's Disease (CD) is associated with several changes that can contribute to the condition's pathology. In this context, the correct choice indicates a decrease in immune tolerance.

In individuals with Crohn's Disease, the gut microbiome often shows dysbiosis, characterized by an imbalance in microbial populations. This dysbiosis can lead to heightened immune responses and inflammation. The immune system, when encountering an altered microbiome, may produce heightened inflammatory responses to bacterial antigens that it perceives as threats, which can further exacerbate the symptoms of Crohn's Disease.

Decreased immune tolerance means that the immune system is less capable of distinguishing between harmful pathogens and the typically benign components of the gut microbiota. This breakdown in tolerance can result in overactive immune responses, contributing to the chronic inflammation observed in Crohn's Disease and its associated symptoms, such as abdominal pain and diarrhea.

Overall, the changes in the microbiome contribute to a pathophysiological state in which immune responses are not appropriately regulated, leading to decreased immune tolerance and increased inflammation.