Consumption of increased dietary fiber is generally positively correlated to improved colon cancer prevention (1). Inositol hexaphosphate (IP6 or phytic acid) is an ingredient in plant foods such as legumes and cereals and has variously been shown to have anti-cancer activity (2). Our goal is to understand the influence of IP6 on the intestinal mucosal barrier function that may contribute to its anticancer activity. The objective in this study was to investigate the effect of IP6 on intestinal morphology and on mucosa mucin proteins that are constituent components of the intestinal barrier in mouse. In particular, expressions of specific mucins (Muc2, Muc3 and Muc4) were examined in the study (3, 4). C57BL/6 mice were randomized into 3 groups of 6 mice. Mice were orally dosed with IP6 (0, 1, 2 g/kg body weight) for 5 days and killed on the sixth day. Sections of the intestine were removed, fixed in methacarn, sectioned, stained with Alcian blue-PAS to visualize mucins, and immunostained for the presence of Muc2, Muc3 and Muc4 proteins. Mucosa from the jejunum and colon were removed and total RNA prepared using Trizol®. cDNA was prepared using random hexamers and specific primers were used for quantitative PCR amplification of the message for Muc2, Muc3 and Muc4. The iQ5 software (Bio-Rad, Hercules, CA) was used to calculate the expression of each gene at the different IP6 dose levels. Expressions at 1 or 2 g/kg dose were then calculated as fold changes relative to expression at the 0 g/kg dose. Expression of Muc2 in the jejunum increased 6.9 fold at 1 g/kg dose and 9.2 fold at 2 g/kg dose. In the colon it increased 1.6 fold at 1 g/kg dose but didn’t change at 2 g/kg dose in the colon. Expression of Muc3 in the jejunum was unchanged when IP6 was dosed. In the colon, the expression increased 2.1 fold at 1 g/kg dose but decreased 5 fold at 2 g/kg dose. Expression of Muc4 in the jejunum increased 1.5 fold at 1 g/kg dose but didn’t change at 2 g/kg dose. In the colon, it increased 1.3 fold at 1 g/kg dose but didn’t change at 2 g/kg dose. Immunostaining with specific antibodies confirmed similar expression of these mucin proteins in the respective intestinal sections. The goblet cell count increased in the duodenum but decreased in the jejunum and ileum in IP6-treated animals. Thus, IP6 seems to modulate the goblet cell count and mucin protein component of the intestinal mucosal barrier.