From Astral Codex Ten: Defying Cavity: Lantern Bioworks FAQ

From Astral Codex Ten:

Lantern Bioworks says they have a cure for tooth decay. Their product is a genetically modified bacterium which infects your mouth, outcompetes all the tooth-decay-causing bacteria, and doesn’t cause tooth decay itself. If it works, it could make cavities a thing of the past (you should still brush for backup and cosmetic reasons).

I talked to Lantern founder Aaron Silverbook to get an idea of how this works, both in a biological and an economic sense. Aaron was very knowledgeable and forthcoming, although he uses the phrase “YOLO” somewhat more often than most biotech founders. This post isn’t a verbatim interview transcript, just a writeup of what I learned based on his answers.

[Conflict of interest notice: Lantern is mostly rationalists and includes some friends. My wife consulted for them early on. They offered my wife and I free samples (based on her work, not as compensation for writing this post); she accepted, and I’m still debating. Consider this an attempt to spotlight interesting work that people I like are doing, not a hard-hitting investigation.]

1: What is BCS3-L1?

BCS3-L1 (brand name “Lumina”) is a genetically-modified strain of the tooth decay bacterium, streptococcus mutans.

S. mutans lives on your teeth and metabolizes any spare sugar that comes its way into the waste product lactic acid. If too much s. mutans gets together in one place, all the lactic acid dissolves the tooth’s enamel coating, causing cavities.

BCS3-LI has four genetic modifications:

1. It produces a weak antibiotic, mutacin-1140, which kills competing oral bacteria.
2. It’s immune to mutacin-1140, so it doesn’t kill itself.
3. It metabolizes sugar through a different chemical pathway that ends in alcohol instead of lactic acid.
4. It lacks a peptide its species usually uses to arrange gene transfers with other bacteria.

The antibiotic helps it win the Darwinian competition in your mouth to become King Of The Oral Bacteria. The alcohol metabolism means it won’t produce lactic acid (and so won’t cause tooth decay). The peptide knockout prevents it from transferring genes back and forth with other bacteria that might either inactivate it or leak its advantage.