Bioactive dietary peptides and amino acids in inflammatory bowel disease

Abstract

Inflammatory bowel disease (IBD), most commonly ulcerative colitis (UC) and Crohn's disease (CD), is a chronic inflammation of the gastrointestinal tract. Patients affected with IBD experience symptoms including abdominal pain, persistent diarrhea, rectal bleeding, and weight loss. There is no cure for IBD; thus treatments typically focus on preventing complications, inducing and maintaining remission, and improving quality of life. During IBD, dysregulation of the intestinal immune system leads to increased production of pro-inflammatory cytokines, such as TNF-α and IL-6, and recruitment of activated immune cells to the intestine, causing tissue damage and perpetuating the inflammatory response. Recent biological therapies targeting specific inflammatory cytokines or pathways, in particular TNF-α, have shown promise, but not all patients respond to treatment, and some individuals become intolerant to treatment over time. Dietary peptides and amino acids (AAs) have been shown to modulate intestinal immune functions and influence inflammatory responses, and may be useful as alternative or ancillary treatments in IBD. This review focuses on dietary interventions for IBD treatment, in particular the role of dietary peptides and AAs in reducing inflammation, oxidative stress, and apoptosis in the gut, as well as recent advances in the cellular mechanisms responsible for their anti-inflammatory activity.

Roles of Dietary Amino Acids and Their Metabolites in Pathogenesis of Inflammatory Bowel Disease

“…It is triggered as a consequence of excessive proinflammatory cytokines production, persistent macrophage activation, and cell death induced by subsequent bacterial or/and viral infections. IBD is the major intestinal health concerns causing severe diarrhea, abdominal pain, weight loss, metabolic disorder, and malabsorption, and it mainly comprises two major forms: Crohn's disease (CD) and ulcerative colitis (UC) [2, 3]. CD and UC have different inflammatory location in the gastrointestinal tract.…”

“…CD and UC have different inflammatory location in the gastrointestinal tract. CD affects all layers of the gastrointestinal tract and is associated with excess expression of IL-12/IL-23 and IFN- γ /IL-17, while UC mainly occurs in colon affecting the mucosa with primarily excess production of IL-13 [3, 4]. Currently, the incidence and prevalence of IBD are increasing with time around the world, especially the rate within elderly patients [5].…”

“…The typical clinical inflammation of the gastrointestinal tract leads to IBD with excessive production of proinflammatory mediators and loss of the intestinal mucosal barrier integrity. Since there is no complete cure for IBD, the therapies of IBD primarily focus on inducing or maintaining remission and promoting the expression of anti-inflammatory genes [3]. …”

“…Functional nutrients have aroused growing interest, which help prevent or remit malnutrition, moderate the mucosal immune response, and benefit intestinal homeostasis [20–22]. Essential nutrient has the potential to ameliorate restore redox balance and inflammation in the gastrointestinal tract showing the possibility of nutrients in IBD treatment [3]. Part of the nutrients that benefit the management of IBD had been listed in Table 1.…”

“…Lacking of effective medical therapies for IBD makes it of utmost importance to find alternative therapeutic strategies [3]. AAs can relieve intestinal inflammation through regulation of proinflammatory cytokines suggesting a possible approach to IBD treatment.…”