2019/09/09 - A research team led by Tufts University engineers has developed a 3D printed ingestible pill that samples bacteria found in the gut – known as the microbiome – as it passes through the gastrointestinal tract (GI). The ability to profile bacterial species inhabiting the gut could have important implications for the understanding of conditions that affect and are affected by the intestinal microbiome, according to the researchers. The 3D printed pill represents the first non-invasive diagnostic tool capable of providing a profile of microbiome populations throughout the entire GI tract. The pill has been studied extensively in vitro and in vivo. It has been tested in pigs and primates.

The pill is manufactured in a 3D printer with microfluidic channels that can sample different stages of the GI tract. The surface of the pill is covered with a pH sensitive coating, so that it does not absorb any samples until it enters the small intestine (bypassing the stomach) where the coating dissolves. A semi-permeable membrane separates two chambers in the pill – one containing helical channels that take up the bacteria and the other containing a calcium salt-filled chamber. The salt chamber helps create an osmotic flow across the membrane which pulls the bacteria into the helical channels. A small magnet in the pill enables one to hold it at certain locations in the gut for more spatially targeted sampling using a magnet outside the body. A fluorescent dye in the salt chamber helps locate the pill after it exits the GI tract.