Changes in bacterial community structure in the colon of pigs fed different experimental diets and after infection with Brachyspira hyodysenteriae

Bacterial communities in the large intestines of pigs were compared using t erminal restriction fragment length polymorphism (T-RFLP) analysis targetin g the 16S ribosomal DNA. The pigs were fed different experimental diets bas ed on either modified standard feed or cooked rice supplemented with dietar y fibers. After feeding of the animals with the experimental diets for 2 we eks, differences in the bacterial community structure in the spiral colon m ere detected in the form of different profiles of terminal restriction frag ments (T-RFs). Some of the T-RFs were universally distributed, i.e., they w ere found in all samples, while others varied in distribution and were rela ted to specific diets, The reproducibility of the T-RFLP profiles between i ndividual animals within the diet groups was high. In the control group, th e profiles remained unchanged throughout the experiment and were similar be tween two independent but identical experiments. When the animals were expe rimentally infected with Brachyspira hyodysenteriae, causing swine dysenter y, many of the T-RFs fluctuated, suggesting a destabilization of the microb ial community.