Gene expression profiling in the intestinal mucosa of obese rats administered probiotic bacteria

We investigated whether the administration of Lactobacillus paracasei CNCM I-4034, Bifidobacterium breve CNCM I-4035 and Lactobacillus rhamnosus CNCM I-4036 modulate the expression of genes in the intestinal mucosa of obese Zucker rats. Forty-eight Zucker-Lepr(fa/fa) and 16 Zucker lean Lepr(+/fa) rats were used. Eight Zucker lean Lepr(+/fa) and 8 Zucker-Lepr(fa/fa) rats were euthanized as a reference. The remaining 40 Zucker-Lepr(fa/fa) rats were then assigned to receive 10(10) colony forming units (CFU) of one of the three probiotic strains, a mixture of L. paracasei CNCM I-4034 and B. breve CNCM I-4035, or a placebo by oral administration for 30 days. An additional group of 8 Zucker lean Lepr(+/fa) rats received the placebo for 30 days. Over 27,000 rat genes were studied using a DNA array. Four animals per group were used. Total RNA was extracted from intestinal mucosa and cDNA was synthesized, fragmented and labeled. Labeled cDNA was hybridized using GeneChip kits, and the latter were scanned. Intensity values of each probe were processed and normalized to obtain an individual value for each set of probes.