Interaction of dietary oils and microflora in experimental colitis

There is growing evidence indicating the benefits of Lactobacilli and Bifidobacteria in attenuation of colitis. On the other hand, some studies have shown that n-3 fatty acids can ameliorate inflammation in colitis. The aim of this study was to examine the interaction between different dietary oils and intestinal microflora in an experimental model of colitis. Eight week-old BALB/C mice (n=9) were fed isocaloric diets varying only in fat composition for 4 weeks. A group fed the chow diet served as control. The diets contained 20% fat from fish oil, canola oil, safflower oil, or beef tallow. Colitis was induced by intracolonic administration of acetic acid on day 21. Inflammation, fecal microflora and serum lipid profile were compared among the groups one week after induction. The highest degree of inflammation was seen in the chow-diet group, followed by safflower-, canola-, and fish oil-fed groups (p<0.05). As compared to the experimental groups, the number of fecal bacteroideceae was significantly higher (p<0.05), and the number of fecal bifidobacteria significantly lower, in the control group (p<0.05). Moreover, fish oil could reduce the plasma level of triacylglycerole significantly (p<0.05). These results indicate that n-3 fatty acids can affect intestinal microfloral populations in favor of increasing the number of bifidobacteria. They might be recommended as an adjunct therapy to patients with colitis.