High-fibre diet {51111189}

Shared Notes

• [1.8] 
  - Long-term intake of fibers from fruit > protective against the development of CD, but not of UC
• [1.1] 
  - High fiber diet > Prevotella copri > improve glucose and insulin tolerance.
• - Fiber-rich diets > maintain a healthy, diverse microbiome > beneficial metabolites such as short-chain fatty acids (SCFAs) > promote mucus and antimicrobial peptides production > maintain intestinal barrier integrity > robust immunity.
• [1.2] 
  - Carbohydrate (fiber) consumption > increased Prevotella
• [1.5] 
  - Dietary fiber > competitive advantage to Bifidobacteria
• [1.3] 
  - Increased maternal dietary microbiome-accessible fiber and SCFA exposure during pregnancy > reduced incidence of asthma in offspring which persists into adulthood.
  - Reduced dietary fiber intake > reduced serum acetate levels in pregnant women > increased frequency of coughing/wheezing during the child’s first year of life.
  - During pregnancy > SCFA (such as acetate) > cross the placenta and affect the expression of fetal lung genes, such as NPPA, > encodes ANP (a molecule related to epithelial biology and immune regulation).
• [1.9] 
  - The high-fiber diet > increased microbiome-encoded glycan-degrading carbohydrate active enzymes (CAZymes) despite stable microbial community diversity > Cytokine response score (primary outcome) unchanged,.
  - Three distinct immunological trajectories in high-fiber consumers corresponded > to baseline microbiota diversity.
  
• [1.7] 
  - Higher Prevotella-to-Bacteroides ratios > human > lose significantly more weight on a high-fiber diet, particularly individuals with low salivary amylase levels
• - Higher dietary fiber > improved progression-free survival in 128 patients on immune checkpoint blockade (ICB) treatment, with the most pronounced benefit observed in patients with sufficient dietary fiber intake and no probiotic use.
• [1.6] 
  - Dietary fiber intake was inversely associated with risk of dementia.
  - The inverse association was more evident for soluble fiber intake and was confined to dementia without a history of stroke.
• [1.4] 
  - Epidemiological evidence indicates that children suffering from allergies have lower levels of dietary fibre-derived short-chain fatty acids (SCFA). Using an experimental model of AD-like skin inflammation,
  - a fermentable fibre-rich diet alleviates systemic allergen sensitization and disease severity.
  - particularly butyrate, which strengthens skin barrier function by altering mitochondrial metabolism of epidermal keratinocytes and the production of key structural components.
• [1.13] 
  - Of particular relevance to the gut microbiome are fermentable fibers, also referred to as microbiota-accessible carbohydrates (MACs)
  - Fiber provides growth substrates for microbes that inhibit mucus-glycan metabolism, preventing gut-mucus depletion, encroachment of bacteria into the mucus layer, and downstream inflammation andinfections.
  - Gut microbes are responsible for biotransformation of phytochemicals via processes such as demethylation, ring cleavage, and dehydroxylation, which can increase their bioavailability, absorption, and antioxidative and immunomodulatory effects.
  - Fruits and vegetables provide up to 8 g of dietary fiber per serving and contain a high diversity of fibers, including pectins, inulin, cellulose, xyloglucans, raffinose, and stachyose.
  - These fibers elicit both microbiome-independent (e.g., delayed macronutrient absorption) and microbiome-dependent (e.g., SCFA-mediated attenuation of insulin resistance) physiological effects
• - vegetables rich in inulin increased Bifidobacterium levels, promoted satiety, and reduced body weight