Specific Amino Acids Increase Mucin Synthesis and Microbiota in Dextran Sulfate Sodium–Treated Rats

Abstract

During the anabolic response associated with inflammation, mucin synthesis and colonic protection may be compromised by the limited availability of specific amino acids. We therefore determined the effect of dietary amino acid supplementation on the microbiota, mucin status, and mucosal damage in dextran sulfate sodium (DSS)-treated rats. From 8 d before to 28 d after colitis induction, male Sprague-Dawley rats (10 mo old, n = 8/group) were fed a control diet supplemented or not with 2 different doses of an amino acid cocktail containing L-threonine, L-serine, L-proline, and L-cysteine. All diets were isonitrogenous (adjusted with L-alanine). The higher dose of amino acids increased the number of Muc2-containing goblet cells in the surface epithelium of the ulcerated area, stimulated mucin production in the colon, and restored the mucin amino acid composition and mucosal content to healthy, control values. The colonic mucin synthesis rate was specifically stimulated by 95%, whereas the protein turnover was unchanged. All bacterial populations, markedly altered by the DSS treatment, were promoted. In conclusion, in inflammatory situations, an increase in threonine, serine, proline, and cysteine dietary supply can promote mucin synthesis, reequilibrate the gut microbiota, and thus favor colonic protection and mucosal healing.

Oxygen metabolism and barrier regulation in the intestinal mucosa

“…Other metabolites have demonstrated roles in barrier restoration and maintenance (62), including arginine and tyrosine through focal adhesion kinase-dependent signaling mechanisms (63)(64)(65), polyamines biosynthesized from ornithine (66,67), n-3 and n-6 fatty acids (68,69), vitamin D (70,71), and zinc (72). In indirect support of mucosal homeostasis, cysteine, serine, proline, and especially threonine induce mucin synthesis, and thus aid barrier function by bolstering formation of this first line of defense against microbial invasion (73,74).…”

Effect of threonine on immunity and reproductive performance of male mice infected with pseudorabies virus

“…MUC1 was detected in the human male urogenital tract epithelia (Russo et al,200), and de novo synthesis of mucosal and mucin proteins is acutely sensitive to luminal Thr concentration (Nichols and Bertolo, 2008). Increasing dietary Thr, serine, proline and cysteine can promote mucin synthesis under inflammatory situations (Faure et al, 2006). Thus, PRV-induced activation of TLR signaling may provide an explanation for increased IL-1b and TNF-a.…”

Effects of Oral Administration of Camel Milk and Urine on Gut Microbiota: Biochemical and Microbiological Profiling in Rats

“…There are more than 10 14 organisms in the human colon alone with at least 400 species, approximately 10 times more than the sheer number of somatic cells [1] [2]. Microbiota in the colon and rectum is much more diverse and larger than the population of upper parts of GIT.…”

“…Medical uses of camel milk and urine which were known in previous generations were proven by modern scientific research. The lactoferrin found in camel milk (ten times greater than in cow milk), has anti-microbial and anit-viral activities such as lysozyme and immunoglobulins [10] [11]. Also it is effective against pathogens including Staphylococcus aureus and E. coli [12].…”