Microbiota and Immune Response Quiz

Microbiota and Immune Response

• Microbiota and immune system have co-evolved for 100 million years.
• Microbiota is associated with both local and systemic immune responses, influencing signaling and regulation.
• Microbiota plays a role in response to cancer immunotherapies and precision therapies.
• Microbiota influences both innate and adaptive immunity.
• Microbiota increases host metabolic capacity by digesting plant carbohydrates and milk products.
• Microbiota provides vitamins, such as B2, B12, K, and folic acid.
• Microbiota protects from pathogenic bacteria.
• Gut microbiota produces pathogen-associated molecular patterns and metabolites that regulate immune responses.
• Microbes are recognized by pattern recognition receptors in the immune system.
• Microbiota stimulation leads to B-cell switching to IgA and regulatory T-cell induction.
• Commensal bacteria induce CD4+ T-cell differentiation.
• Naïve CD4+ T cells differentiate into Th1, Th2, Tregs, and Th17.
• Once differentiated, each lineage secretes cytokines and performs specific functions.
• Commensal bacteria compete with and adhere to attachment sites in the intestinal epithelial, compete for nutrients, and produce antimicrobials.
• This process prevents pathogen attachment and entry.
• The intestinal barrier is important for the normal development of the immune system, useful for commensal bacteria as well.
• The gut microbiome is shaped by factors such as diet, antibiotics, and lifestyle.
• Human-based studies, using longitudinal intervention studies, are helpful in investigating microbiota-immune interactions in humans. These involve lifestyle interventions to create changes in microbiota composition and study the effects on the immune system.
• Traditional versus industrialized populations can contribute to identifying microbes/microbial functionalities involved in lifestyle-related immune disorders. This involves studying individuals across different lifestyles to identify shared microbial elements that vary along industrialization gradients, not geographic ones.
• Microbial communities differ substantially between industrialized and ancestral settings. Shifts in diet, antibiotic usage, and sanitation contribute to microbiome configuration.
• Colonocytes (epithelial cells in the colon) maintain physiological homeostasis by shaping the microbiota. This is based on the ecological relationships between the immune system and the microbiota.
• Antibiotic pressure reduces microflora and SCFA.
• Antibiotic pressure can also lead to failure in preserving epithelial hypoxia, decreased Treg triggering, and increased inflammation.
• Microorganism-derived secondary bile acids have anti-inflammatory properties.

Colonization Resistance

• Prevention of invading pathogenic bacteria.
• Inhibition of endogenous bacteria overgrowth.
• Protection against enteric pathogens is another key function.
• Fecal microbiota transplantation is used to re-establish healthy microbiota in the intestinal tract.
• Commensal anaerobic bacteria have various barriers against different pathogenic bacteria.
• C. difficile is an important example of colonization resistance-related factors.

Protective Function (Barrier Effect) of Microbiota/

• Commensal bacteria compete for attachment sites and nutrients which produces antimicrobials.
• The microbiome directly or indirectly protects the epithelium from invading pathogens.

Therapeutic Approaches for Microbiota-Immune Response Interactions

• Applying selective probiotics to introduce protective components of the microbiome to treat or prevent nosocomial diseases, potentially dealing with C. difficile-related colitis or damage related to enteric bacteria and vancomycin-resistant enterococci, are methods of therapeutic interventions.

Segmented Filamentous Bacteria (SFB)

• SFBs interact with host immunity by producing metabolites that impact the immune system.
• SFBs play a role in shaping the Th17 and IgA response.
• SFB has intestinal barrier function and anti-fungal and antibacterial effects.
• SFB and Clostridium spp. influence T-regulatory cells via SCFA production.
• Bacteria in the colon mucosa influences anti-infectious and anti-tumor immune responses through the interactions with CD8 T lymphocytes (CTLs).
• Interactions also occur through CD4 T helper cells (Th1, Th2, Tregs, Th17).

Bile Acids

• Microorganism-derived secondary bile acids have anti-inflammatory properties.
• IL-10 increases and IL-12 and TNF-alpha decrease.

Explore the intricate relationship between the gastrointestinal microbiota and host immunity through this quiz. Discover the roles of bacterial metabolites, the effects of specific bacteria on immune regulation, and how modern lifestyle changes impact gut health. Test your knowledge on therapeutic approaches aimed at restoring microbiota balance.