Effect of prenatal cortisone on spontaneous bacterial translocation from gastrointestinal tract in neonatal rat.

The immature host is prone to the passage of bacteria across the gut mucosal barrier. Corticosteroids accelerate the maturation of the intestinal mucosa and alter the composition of the gut bacterial flora. The present study was performed to assess the effect of prenatal cortisone on bacterial translocation in the neonatal rat. Time-pregnant Sprague Dawley rats were randomized on the 19th day of gestation for intraperitoneal injection of either 20 mg/100 g body weight of hydrocortisone or saline. Rats delivered spontaneously and the offspring were suckled ad libitum by the dam. Rat pups (N = 82) were killed 1 or 9 days after delivery. Mesenteric lymph nodes, liver, heart blood, and the terminal ileal loop were excised and quantitatively analyzed for bacteria. After one day, the proportion of rats with positive translocation was not significantly different between the two treatment groups (saline 62%, cortisone 80%, P = NS). By day 9, translocation had increased in the saline group (P = 0.03 vs day 1), did not significantly change in the cortisone group, and was significantly lower in rats treated with cortisone compared with the saline control (saline 90%, cortisone 60%, P = 0.02). The decrease in bacterial translocation after treatment with cortisone was associated with significantly lower total bacterial counts in the ileum (P < 0.05). Cortisone did not reduce bacterial counts in extraintestinal organs with positive translocation. In conclusion, prenatal treatment with cortisone reduces the incidence of spontaneous bacterial translocation from the intestine but not the concentration of translocated bacteria in extraintestinal organs of 9-day-old rats. Cortisone-induced changes of the intestinal microflora may have contributed to the reduction in translocation frequency.