Nutrigenomics: a high fat diet influences gut gene expression in a mouse model

A high fat level in a diet can cause local gut inflammation and leads to metabolic abnormalities, such as obesity and insulin resistance. This study aimed to investigate the effect of a high fat diet in C57BL/6 mice. Twenty-seven mice were divided into five groups. The experiment started at weaning (T0). Five mice were sacrificed at T0 (n=5), while high-fat-fed mice (n=11) and control-fed mice (n=11) were sacrificed after one (T1, n=5 for each treatment) and two weeks (T2, n=6 for each treatment) of such dietary regimens. Even though neither blood nor histological analysis gave evidence of a clear inflammatory state in the caecum after 1 or 2 weeks of treatment, we used 90K Combimatrix microarray technology to check if the expression level of genes was changed. A total of 29,435 probes in triplicates were considered, representing all the available mouse genes in database. After hybridization and scanning, the Cy5 signal intensities were analyzed using limma package from Bioconductor. Only 7 genes were detected differentially expressed between control and high fat diet mice, out of the whole transcriptome (qvalue ≤0.05), with a range of log fold change between -2.06 and 1.22. Among statistically significant genes 4 were successfully validated by real time PCR. In conclusion, genes differentially expressed after two weeks of treatment all shared an involvement in the regulatory pathway of the circadian clock system, which was recently shown to affect lipid metabolism and inflammatory processes.