Microbiome and longevity. That's another big topic, how gut microbes talk to mitochondria, and who or what else the gut microbiome talks to. And that's important for the aging process. 

Yeah, I mean, you can think of your body as a reservoir, you've got estimates of up to 10 times as many bacteria in your body as you do your own cells. And I think that we were naive not to give more thought to that in the past, because we're really a system of many different organisms living together. And it's not surprising that these bacteria in your gut, in your saliva and in other places in the body, on your skin, are talking to the rest of your body and influencing how you behave. There's a lot of data on microbiome affecting the immune system, affecting cognitive function. 

I think that we have to keep that in the equation whenever we're looking at aging or interventions. And actually, a number of the interventions that extend lifespan, alter the microbiome. So we're trying to understand whether those alterations are important for the longevity effects that we see. If you swallow a pill. I mean, the bacteria in your gut see it before you do. And so we tend to ignore the fact that those pills affect microbiome. Dr. Brian Kennedy. Dr. Anton Titov, MD.

If you're looking at metabolites like alpha-ketoglutarate [AKG], that bacteria use, you've got to really think hard about not only what those things are doing to your body, but how they're influencing the microbiome. And that could be having a secondary effect on your health or your rate of aging. 

Is there any other specific examples of the microbiome and aging connection that your research showed? 

There are a number of examples from other labs and things like worms and flies. In worms, the bacteria in the gut of the worm are actually shortening the lifespan of the worm and you can kill them. And that work lives longer, even though they eat the bacteria. Those are kind of simple issues. Dr. Brian Kennedy. Dr. Anton Titov, MD.

And when you start to look at the human or even mouse microbiome, you've got 1000s of different species. And so I can't point to direct effects of the microbiome, but I strongly suspect that those changes are going to be relevant. 

And so a lot of the interventions that affect lifespan revert the microbiome back to the microbiome of a younger person. And so I think it would be naive to think that that doesn't have important signaling effects on the body. 

Probably at least they are reducing inflammation, like we see with alpha-ketoglutarate. I keep using that as an example. But you could use rapamycin as well, it is very anti-inflammatory. And it may be because they are suppressing inflammatory signaling from the gut microbiome. Dr. Brian Kennedy. Dr. Anton Titov, MD.