Microbiome, Metabolome and Inflammatory Bowel Disease

Abstract

Inflammatory Bowel Disease (IBD) is a multifactorial disorder that conceptually occurs as a result of altered immune responses to commensal and/or pathogenic gut microbes in individuals most susceptible to the disease. During Crohn’s Disease (CD) or Ulcerative Colitis (UC), two components of the human IBD, distinct stages define the disease onset, severity, progression and remission. Epigenetic, environmental (microbiome, metabolome) and nutritional factors are important in IBD pathogenesis. While the dysbiotic microbiota has been proposed to play a role in disease pathogenesis, the data on IBD and diet are still less convincing. Nonetheless, studies are ongoing to examine the effect of pre/probiotics and/or FODMAP reduced diets on both the gut microbiome and its metabolome in an effort to define the healthy diet in patients with IBD. Knowledge of a unique metabolomic fingerprint in IBD could be useful for diagnosis, treatment and detection of disease pathogenesis.

The Gastrointestinal Microbiome: A Review

“…Prebiotics are also speculated to protect the gut epithelium by increasing the mucus layer, elongating the microvilli, increasing numbers of epithelial cells, and by preventing adherence of pathogenic strains to the epithelial cells . Other SCFAs such as propionate appear to induce de novo generation of T regs in the peripheral immune system . A newly published study in mice revealed that when deprived of fiber, commensal bacteria will degrade the protective mucosal mucus layer, permitting invasion by commensals and pathogens alike …”

Therapeutic administration of the recombinant antimicrobial peptide microcin J25 effectively enhances host defenses against gut inflammation and epithelial barrier injury induced by enterotoxigenic Escherichia coli infection

“…4,5 Accumulating evidence suggests that the well-known enterotoxigenic Escherichia coli (ETEC) causes a high rate of intestinal disorders and diarrhea in newborns and young animals. 7,8 The intestinal barrier formed by the intestinal epithelium and its tight junction (TJ) proteins (TJPs), including zonula occludens (ZO), occluding, and claudins, provides a physical barrier that blocks the entry of pathogens into the lamina propria and protects against the invasion of enteropathogenic microorganisms. 7,8 The intestinal barrier formed by the intestinal epithelium and its tight junction (TJ) proteins (TJPs), including zonula occludens (ZO), occluding, and claudins, provides a physical barrier that blocks the entry of pathogens into the lamina propria and protects against the invasion of enteropathogenic microorganisms.…”

Byproduct Cross Feeding and Community Stability in an In Silico Biofilm Model of the Gut Microbiome

“…To date, the most widely studied system is the gut microbiome due to its critical role in food metabolism [26][27][28], profound influence on the immune system [29,30] and suspected role in a wide variety of diseases including gut infections [31], inflammatory bowel and Crohn's diseases [32,33], obesity [34], diabetes [35], cardiovascular disease [36], rheumatoid arthritis [37], colorectal cancer [38] and even depression [39]. The human gut microbiome is a highly complex multispecies system thought to consist of at approximately 1800 genera and 15,000-36,000 species of microbes [40].…”