In Vitro Culture Conditions for Maintaining a Complex Population of Human Gastrointestinal Tract Microbiota

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, there is no consensus for the best in vitro culture conditions for growth of the human gastrointestinal microbiota. To investigate the dynamics and activities of intestinal microbiota, it is important for the culture conditions to support the growth of a wide range of intestinal bacteria and maintain a complex microbial community representative of the human gastrointestinal tract. Here, we compared the bacterial community in three culture media: brain heart infusion broth and high- and low-carbohydrate medium with different growth supplements. The bacterial community was analyzed using denaturing gradient gel electrophoresis (DGGE), pyrosequencing and real-time PCR. Based on the molecular analysis, this study indicated that the 3% fecal inoculum in low-concentration carbohydrate medium with 1% autoclaved fecal supernatant provided enhanced growth conditions to conduct in vitro studies representative of the human intestinal microbiota.