Jejunal histology of Wistar rats challenged by the regional basic northeast diet (RBD) and following the lactose administration. A. Goblet cell villus index and B. Representative jejunal histological sections from the experimental groups. Arrows indicate goblet cells. Methyl-green, x400. The RBD was given ad libitum for 14 days and lactose (30 g/Kg, by gavage) was administered after the 8th day of the experiment.