Manipulating gut microbes to study human health
As microbiologist Jeffrey Gordon has said, “We never dine alone.” Bacterial communities in the gastrointestinal tract aid in human digestion and absorption of nutrients. In a paper published the September issue of the Journal of Animal Science, Harvard scientists David Gootenberg and Peter Turnbaugh discussed the need for in vivo studies of the microbiome.
Gootenberg and Turnbaugh proposed testing bacterial communities in a humanized animal model. A humanized model would require gut colonization of human microbes in germ-free animals. Humanized models could reveal natural patterns of bacterial growth and distribution. “Recent studies of the ‘human microbiome’ have emphasized the large degree of variation in the particular strains and species of bacteria that are found in each person’s gut and other body habitats,” said Turnbaugh in an interview.
Bacteria in the gut provide humans with vitamins, amino acids, and extra protection against pathogens. Individual host differences, such as environmental exposures, lifestyle choices, and genes add to the complexity of symbiotic bacterial communities. Turnbaugh explained that because each person’s microbiome is unique, it is important to study interactions between bacteria and hosts under controlled conditions.
Humanized models could show how bacteria respond to changes in diet and react to disease. “Hopefully, the findings from animal models of the human microbiome will allow us to better design and interpret future surveys of humans,” Turnbaugh said.
Turnbaugh believes humanized models could also have an impact on the livestock industry. “Many of the problems that are important for human health are also key problems for the livestock industry: immune system development, nutrition, body weight gain and antibiotic resistance, to name a few,” Turnbaugh said. He said it may be possible to either study livestock directly or use model organisms to study microbes isolated from animal donors.
Turnbaugh believes future scientists in the field should conduct experiments to determine methods to manipulate the gut microbiome. He hopes scientists can study the source of microbial variation from person to person. A humanized model would also make it easier to determine if it is possible to add “good” bacteria or remove “bad” bacteria.
Scientific Communications Associate