Engineered bacteria for a “gut” feeling

Roberto Saracco July 11, 2018 Blog 873 Views

MIT-designed biosensor capsule uses genetically engineered light-emitting bacteria (right) to detect molecules that identify bleeding or other gastrointestinal problems. Ultra-low-power electronics (left) sense the light and send diagnostic information wirelessly to a cellphone. Credit: Lillie Paquette/MIT

We are seeing the first signs of what the future two decades will be: the convergence of bioengineering with electronics and the shift from curative medicine to proactive health care.

Researchers at MIT have created an ingestible sensors by transforming bacteria into detectors of specific molecules that can signal their presence by becoming luminescent.

The bacteria have been modified genetically (CRISPR/Cas9) to respond to the presence of specific molecules, as an example if a doctor suspect a patient may have a bleeding ulcer in the stomach, rather than prescribing a gastroscopy, she can ask the patient to swallow a capsule containing bacteria sensitive to iron (a component of red blood cells). The capsule has a membrane that keeps the bacteria inside but allows external molecules floating in the patient’s stomach to get in contact with them. If red blood cells are present, that is there is bleeding, the bacteria intercept them and become luminescent. An electronic circuit inside the capsule detects the luminescence and send a radio signal that is detected by the doctor’s smartphone thus revealing the presence of bleeding.

The capsule can be used to explore the whole gastrointestinal system, making it possible to detect the exact location of bleeding in the gut, something that today will require complex (and unpleasant) procedures. You might say that MIT researchers have found a way to get a “gut feeling” …

You can take a look at the clip below.

Notice that this is providing a first glimpse of what is coming: by harvesting Nature and tweaking with it we have the possibility of expanding the characteristics of living forms and augment our capabilities.
Human beings, as all living forms, are a complex ensemble of sensors, actuators processing that keep the whole organism into a dynamical equilibrium, that is life. By extending sensing, complementing the actuators (e.g. creating new drugs…) and supplementing processing, we increase the power of the individual to keep the dynamic equilibrium also in situations where it would not be naturally possible: we are effectively extending the context in which life for that individual is possible.

To detect diseases or conditions, the genetically engineered bacteria (green) are placed into multiple wells (blue), covered by a semipermeable membrane (white) that allows small molecules (red) from the surrounding environment to diffuse through. The bacteria luminesce (glow) when they sense the specific type of molecule they are designed for. (In the experiment with pigs, heme — part of the red hemoglobin blood pigment — indicated bleeding.) A phototransistor (brown) measures the amount of light produced by the bacterial cells and relays that information to a microprocessor in the capsule, which then sends a wireless signal to a nearby computer or smartphone. Credit: Mark Mimee et al./Science

The first step, of course, is aimed at monitoring and overcoming diseases and disabilities, but it is unlikely humankind will stop there. After discovering lenses to make up for a impaired sight, humankind invented the telescope to be able to look further. Likewise for the future. What will be learnt and used to fight impairment will be adapted to augment our capabilities.