The optimization of in vitro culture growth conditions for human gastrointestinal tract microbiota. NCTR

A stable intestinal microbiota is important in maintaining human physiology and health. Although there have been a number of studies using in vitro and in vivo approaches to determine the impact of diet and xenobiotics on intestinal microbiota, less is known about the best culture conditions to simulate and optimize growth that occurs in the human gastrointestinal tract. To investigate the dynamics and activities of intestinal microbiota, it is important to cultivate representative intestinal microbiota from the fecal inoculum and optimize in vitro culture conditions. Here we compared the in vitro bacterial community in three culture media, Brain Heart Infusion broth, high and low carbohydrate with or without fecal supernatant to determine optimal inoculum concentration and growth conditions. The bacterial community was analyzed using denaturing gradient gel electrophoresis (DGGE), pyrosequencing and quantified by real-time PCR. Based on the molecular analysis, this study indicated that the bacterial community of 3% fecal inoculum in low-concentration carbohydrate medium with the addition of 1% fecal supernatant provided optimal growth conditions to conduct in vitro studies representative of the human intestinal microbiota in the gastrointestinal tract.