RX/CON 8 of 12 (75%); P < 0.05] (Fig. 2A). research use Using the gram-negative bacterial colonies isolated on MacConkey agar at 24 h, we identified three gram-negative facultative gut-derived bacteria (Enterobacteriaceae) present in MLN (Table 2). Escherichia coli accounted for most cases of bacterial translocation (60%), followed by Enterobacter cloacae (27%) and Klebsiella pneumoniae (13%) (Table 2). Fig. 2. Bacterial translocation to mesenteric lymph nodes (MLN) and serum total IgG and anti-LPS IgG levels. A: gram-negative bacterial translocation to MLN, defined as ��10 colony-forming units per gram tissue. B: serum total IgG measured by ELISA in … Table 2. Identification of bacteria in MLN Bacterial translocation in the RX/CON group was accompanied by a significant increase in serum total IgG (Fig.

2B) and in serum anti-LPS IgG levels (Fig. 2C). Treatment with an oral antibiotic cocktail (metronidazole, neomycin, and polymyxin B) (18) completely blocked bacterial translocation and was associated with control levels of serum total IgG and LPS-specific IgG (Fig. 2). Postoperative GLN supplementation decreased the incidence of bacterial translocation to MLN at 21 days postoperatively from 75 to 46% (Fig. 2A; NS vs. control, P = 0.214). Dietary GLN did not change total serum total IgG (P = 0.576, Fig. 2B) but was associated with a significant decrease in anti-LPS IgG (P < 0.05, Fig. 2C). We did not detect any changes in anti-flagellin IgG between groups (not shown). Effects of dietary GLN and oral antibiotics on total sIgA and LPS-specific IgA in the gut lumen.

Partial small bowel-colonic resection alone (RX/CON group) significantly increased luminal sIgA by day 13 compared with TX/CON rats (Fig. 3). However, this response was diminished by day 20 after operation, as values became statistically indistinguishable from baseline or day 6 values (Fig. 3). These data suggest possible intestinal immune adaptation to massive bowel resection, possibly in response to bacterial translocation. Carfilzomib Treatment with the oral antibiotic cocktail completely inhibited the increase in stool IgA induced by partial small bowel-colonic resection (Fig. 3), concomitant with the prevention of bacterial translocation. Supplementation of GLN in the diet after RX did not alter stool IgA at days 6 and 13 postoperatively compared with RX rats fed control diet. However, dietary GLN markedly increased stool IgA levels at day 20 after operation, at a time when values in RX rats given nonsupplemented diet were declining (P < 0.05 vs. TX/CON, RX/CON, and RX/ABX groups) (Fig. 3). To determine whether this GLN response was due to increased sIgA production by mucosal plasma cells, we performed immunohistochemistry studies.