Two primary goals of translational microbiota research are (1) to alter the gut microbiota in a beneficial manner and (2) to do so in a way that lasts.
In patients with liver disease, hyperammonemia-associated neurotoxicity and encephalopathy occurs when bacterial urease in the intestine converts urea from the host into ammonia and carbon dioxide. Researchers in this study wanted to interfere with this process by engineering the gut microbiota of mice to reduce urease activity. First, they wiped out the existing gut microbiota of the mice, and then they inoculated mice with altered Schaedler flora (ASF) — a defined consortium of 8 bacteria with minimal urease gene content.
The new microbiota persisted in the mice and led to a long-term reduction in fecal urease activity and ammonia production. Also, mice with hepatic injury who received this kind of microbiota transplantation showed a lower morbidity and mortality.
The study showed that giving a defined gut microbiota to a host can lead to metabolic changes that last and that have positive health effects. This shows the potential of a modified method of fecal microbiota transplantation (referred to as ‘ecobiotherapy‘) to have beneficial effects on health.
Shen TD, et al. (2015) Engineering the gut microbiota to treat hyperammonemia. Journal of Clinical Investigation doi:10.1172/JCI79214