Can We Use Bacteria to Treat Diseases? | Nat Geo Live

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My laboratory gets in and explores, and we really explore a world that's invisible to the naked eye. And so, if we take a look at these scanning electron microscopy images, you'll get a closer view. So, we are looking in now, at over 3000-times zoomed and you can see our inner intestines. There are all of these cells that are—turns out aren't our own cells but are actually microbial cells. Largely bacteria, but also viruses and fungi and protozoa that inhabit our bodies. And the same can be said about virtually every exposed environmental site on our bodies.

And so, here is a picture of the mouth where you see not really our own cells but other microbial cells. And so, I think that you can see from these pictures that these are actually really, really like habitats that are within our own body world. And it turns out that they are not passive members either. They form communities and they interact and they divide and replicate and they even wage wars against each other. These microbes outnumber at our own human eukaryotic cells ten-to-one. And this actually means not ten-times amounts of genes but it turns out that for every human gene that we have there are over 360 bacterial genes. So, they outnumber our own human genomes.

And we are just starting to learn about what they can do and how we've co-evolved with these microbes to influence our own biological function. These microbes are very diverse. So there are over 10,000 unique species that inhabit us. And they outnumber greatly all of the disease causing microbes or pathogens that we are used to studying in the laboratory. And so, my lab in particular is interested in how these microbes aside from affecting digestion and immunity and metabolism, can influence the brain and behavior.

So, in terms of brain and behavior, one thing that's really important to note is that the brain itself is a very complex organ. But adding on to that another whole layer of complexity is that the brain doesn't act in isolation. It responds to the needs and experiences of all our other body sites. And so, the microbiota, as you know, as an important organ turns out to feed into brain and behavior as well.

Many, many conditions now are known to be linked to changes in the communities of microbes that inhabit our bodies. And some of these also include neurological disorders. The frontier of this is to see whether we could use bacteria to really hack into brain function, a relatively inaccessible area. And so, we really need to study in these— in these diseases whether we can use microbes to cause or correct diseases. The implications are huge, because microbes we know are relatively accessible by us. We know how to engineer them and modify them and eradicate them if we need to. And in our bodies they colonize persistently.

And the idea is can we use these microbes to treat neurological disorders in a relatively non-invasive way to provide long-lasting impacts and with regulatory controls that we build in and design in on these microbes when we modify them. Thank you very much. ( Applause )