Diane Boudreau: Welcome to ASU KEDtalks, The Podcast, I’m your host Diane Boudreau, and I’m here today with Meli’sa Crawford, an ASU PhD candidate in Biology who studies the microbes that live in our guts. Welcome, Meli’sa.
Meli’sa Crawford: Thank you.
Boudreau: So one of the first things that you said when we met was, “My whole life is poop.”
Crawford: Right. [laughs]
Boudreau: I don’t think I’ll ever forget that. What specifically can we learn from looking at poop?
Boudreau: Well, you can tell a lot about a person from their…poop. More specifically you can tell about their health. So if they’re unhealthy, their microbes in their poop would be different than a person who is healthy. So for example what we eat can affect the microbes that live in our gut. And so in a healthy person who’s probably active, and who works out, and who eats like a normal balanced diet they would have more diversity in their gut, in comparison to someone who is unhealthy (“unhealthy”) so maybe not as active, who eats a diet that is more enriched with fat, you would have less diversity in your gut. So less microbiome, or less microbial diversity. And that can pose a problem.
So basically your poop can tell you how healthy you are. It can tell you if you’re active or not. It can tell you…yeah, a lot about your metabolic health overall.
Boudreau: I’m intrigued by this notion that we have this whole ecosystem living in our gut—
Boudreau: —this microbiome. What is in there specifically?
Crawford: So there’s bacteria. There’s fungi. And they interact with each other, basically. So in the sense of other things, I’m not quite sure. But I am aware that there are like over trillions of microbes. So trillions of these bacteria and fungi species living your gut. These interactions can have a broader impact on our health. And so in terms of the microbiome, if there’s less diversity—so if there’s only a couple of species within our gut, it’s basically indicative of a problem. So it’s indicative of like either obesity or diabetes. Where in a healthy person, there’s more diversity there like we discussed. And that greater increase in diversity leads to a greater effect. So bacteria can metabolize things, can release short-chain fatty acids that can help in terms of eliminating metabolic risk factors.
Boudreau: So what effect do they have on our bodies? What do they impact?
Crawford: The microbes in your gut like bacteria, they can metabolize things that we can’t. And so they use what we eat as an energy source. So we share this nice symbiotic relationship with them. They help us, we help them. In some cases there are bacteria in our gut that can be harmful.
And so if we’re not careful with what we eat, or just around that notion of being healthier and eating better foods, there are bacteria that are gram-negative, and they have a wall that has something called lipopolysaccharides. And so in most cases, once you’re eating all this bad food and you’re increasing the abundance of these gram-negative bacteria, it can have a terrible effect on your gut. And so that can release endotoxins. So endotoxins can cause inflammation. And that inflammation can flow systemically throughout your system and can affect other organs. And so basically we want our bacteria to be happy in our gut. We don’t want the pathogenic bacteria causing inflammation. So this is why it’s important for us to increase that abundance of “good” bacteria. And then they can also promote good immunity in our gut. And so they can promote the immune system to work actively instead of the negative aspects of the microbiome.
Boudreau: And then you said these endotoxins can get into the rest of your body.
Crawford: Yeah. So they can flow systemically.
Boudreau: So what kinds of health issues are we looking at here?
Crawford: So one of the things I look at the most is how that affects the actual gut barrier. And so, once you’re eating fatty foods and your immune cells can attack these gram-negative bacteria, releasing endotoxins, those endotoxins can promote the production of inflammatory proteins. So these inflammatory proteins can then affect the tight junction, so what’s holding ourselves together. They can affect that by breaking them apart and causing holes in our gut. And so that’s what I want to look at more into how that’s causing gut disease. And then the inflammatory proteins that flow systemically throughout our blood, they can affect the heart. They can affect your liver. They can promote other inflammatory diseases. And so that’s what we want to focus on too, is just how is your bacteria in your gut affecting every organ in your body and causing all these diseases.
Boudreau: So okay, these bacteria have an effect on us. How do we affect them in turn?
Crawford: We don’t take care of them like we should. And again, that goes with how healthy we are and of course every environmental factor around this. So we can affect the microbes in our gut by just eating healthy, and then…air pollution, that’s another big factor. And so there’s been a lot of research on how the particulate matter in the air—so basically all of these bacteria and fungi in the air, how they’re causing a negative reaction in our gut and how that can actually increase the risk of inflammatory diseases or metabolic complications like obesity and diabetes and things like that.
And it’s complicated, because everyone’s different. So even if I were to say that I can help my microbiome this way, by exercising or eating healthy or staying indoors because air pollution is scary, that may not have the same effect for everyone. And so that can cause a really big problem too.
Boudreau: You’ve kind of touched on this a little bit, but do you have any advice for listeners who are saying oh my gosh, I want to have a healthy microbiome, what can I do? Obviously staying away from a high-fat diet would be one piece of advice. Is there anything else that we know that we can tell people?
Crawford: Yeah, that would be ideal. I know there’s a lot of information on the market. I was talking about maybe you should increase supplementation of probiotics and prebiotics. Or you should exercise because that’ll always have a huge impact on the gut microbiome. Or yeah, eating healthy. But it really depends on who you are. But those are some of the easier way is to shift your microbiome in a more positive direction. But if we wanted to know how to drastically change it I think that it starts with knowing exactly who you are and knowing the composition of your poop, you know. Knowing what’s in your poop and the type of microbes that are there, that are residing in your gut. And then we can take it from there, and I feel like that’s where treatment is going towards. It’s going towards that direction.
Boudreau: Is there a way now to know, to be able to find out what your gut microbiome is?
Crawford: Yeah, which is so funny because I was so excited when I found this out, that you can donate your stool samples to OpenBiome. Although, in a sense OpenBiome is there to collect your stool samples, and then to…just to see if it’s healthy enough…like the microbes in your poop are healthy enough to treat someone who’s actually diagnosed with a gut disorder. So of course they make fecal pills, so poop pills that contain these healthy microbes. So maybe they can give you an idea of your fecal composition.
And of course there might be clinical studies that are actually trying to get people in to donate their fecal samples to identify the composition of their poop. And then the huge Human Genome Project of course has been one of the most defining factors in microbiome research. And so I feel like in the Western culture we have an idea of like the average composition of our microbiome. You know, the Bacteroidetes, the Firmicutes, how they interact with each other. But really if you want it to be more personalized I feel like that’s what we need to do more research on. That’s what we need to find out, yeah. Maybe there are other sources out there, but you know.
Boudreau: So you mentioned the need for more research on this. What do you personally want to study in the future?
Crawford: So, obviously I love what I do. I love microbiome research. But my true passion really does lie in knowing how the microbes, and knowing what we eat, and knowing…environmental factors, how all of that is contributing to intestinal permeability. So basically again those holes in your gut, an increase of holes in your gut and how that can lead to other gut disorders. So yeah, I’m passionate about that and then how is that even developing or increasing the risk for gastrointestinal cancers.
Boudreau: When we talked before, you talked about food deserts and how you grew up in a food desert, and how that affects the quality of your diet, and then that affects your microbiome and that affect your health. So there’s this cascading effect here. And you mentioned that you were sort of interested in looking at also food accessibility.
Boudreau: Is that something that you’d like to do more with in the future, do you think?
Crawford: Oh, definitely. Yeah. I think that comes into getting more involved into science policy, so food policy, and how to regulate what’s being shipped to stores on the South Side in comparison to Sun City, you know. There’s a huge difference in the quality of food in these two areas, and why is that? Why is this more underprivileged area receiving food that’s of lesser quality? So there has to be an answer to that. And there could be a billion possibilities but I feel like that’s something I would want to pinpoint into why. Because yeah, in these underprivileged areas you also have a higher risk of metabolic syndrome, a higher risk of obesity and diabetes, and cardiovascular disease.
And of course, the majority of that starts with what you’re eating. And is it expensive? And are these families able to afford what they’re being given in these grocery stores? Because like I said before, my family could only afford these fast foods, you know. And I remember my mom would always complain like, gosh it costs so much to buy a salad. And it’s so much more cheaper to just go to Taco Bell and get a meal, you know. And that would always intrigue me, too. Like well, why? Why would it be so expensive. And so I think that would be something I would want to look more into.
Boudreau: In your KED Talk video, you mention being inspired by your grandmother when you were a child. Obviously other things happened in the course of your lifetime. How did you end up as a PhD student in a microbiome lab? What was the path you took?
Crawford: Yeah. So, it’s funny because I didn’t think I would ever be a PhD student. I didn’t think I would ever apply to a PhD program. But I worked at the Arizona Science Center forever. For about a year or so, and that really helped me increased my interest in the sciences right after my bachelor’s. But my grandma was one of the defining factors I think, because she was very…she insisted that whatever we did, no matter what it was, if we were having a bad day go poop. If you were sick, go poop, just get it over with. Or have you been pooping, whatever. And I’m always like why would she say that? Like why was this always a big component in her life? Like just poop, it’ll be okay? And it made me wonder yeah, a lot, like why would this be important?
And I feel like after I worked at the Arizona Science Center I did clinical research. And it was always in the back of my mind, gastrointestinal research. But I never…I don’t know, I think the interest—something just didn’t pique just yet, you know. So when I did clinical research I was working with obesity and diabetes patients a lot. And then when I got to ASU, I worked in a synthetic biology lab first, and that was completely out of my league. It was like an engineering program and I was like okay, this is not for me. And I need to find something a little—like…something that’s going to cater more to my interest.
And so after about a year in that engineering program, I applied to biology and got accepted. And my PI now, she’s not a microbiologist. We hardly do microbiome research. It was just an interest of mine that we were able to kind of push in the right direction. And so she actually does… She’s an avian physiologist, so she works with birds. But we also study obesity and metabolic syndrome in humans and rat models. And so I just had this interest of you know, the gut, and I watched a TED talk on the microbiome and that was like okay, this is actually going to work for me. And so she put me on a project looking at liver function in high-fat diets and that just kinda increased my interest a lot, piqued it a lot. And then I was like what else could I figure out about the GI system? There’s so much more to it. It excites me. It’s like one of the most exciting topics to me, so.
Boudreau: Since you’re in the throes of finishing your dissertation, right? Do you have any advice for students who are considering maybe getting an advanced degree in science?
Crawford: I would tell them to… Well first I would say this: that it’s okay if you don’t know exactly what you want to do in the beginning. Because I feel like I spent a lot of my time wishing I knew, just trying to figure it out because I felt like there was a lot of pressure to know, immediately. When I started my first PhD program before I applied to biology, I was kind of in the midst of trying to figure out what I wanted to do and rotating through labs and trying to figure out if this lab was the right one for me. But I realized that it takes time. You know, it takes time to find your passion sometimes. Like it doesn’t come immediately.
And then I would also say that it’s really important to find the right PI. I feel like a lot of grad students struggle with finding a lab for them. So they may think the topic is correct. But the PI may not match your personality. And that PI/mentee relationship is one of the most important relationships you’ll have throughout your entire PhD. Because they’re like a parent, basically. Yeah. And they’re there to help you. They’re there to guide you on your way throughout your PhD. But you also have to be happy. You have to love what you’re doing. And you need to be content with the work you’re doing, and happy with this relationship. And if you’re not I think that affects your entire experience.
Boudreau: Something you mentioned, too, you talked about the OpenBiome project.
Boudreau: And how they’re working to develop treatments.
Boudreau: So, you’re saying that you can take somebody’s poop…
Boudreau: And make medicine for somebody else, basically, with that. How does that work?
Crawford: There’s been this idea about poop pills, fecal pills that contain healthy microbes. So it’s really easy to isolate the microbes from your poop. And so I think that that— Or, even once they isolate it or sterilize the poop— Well not even sterilize because that eliminates all the microbes. But like yeah, just to isolate microbes, put it in a pill, give it to someone. Because the idea is that their microbiome is less diverse. And because of that, the less diverse their microbiome is, probably the more problematic it is. So they want to increase diversity in the gut. So again, the healthy microbiome has more diversity, more microbes running free, you know, that are more beneficial to the type that a person who’s suffering from a digestive disorder would have.
Boudreau: And are these being used?
Crawford: Oh yeah. Yeah yeah. There’s been a lot of clinical research on that, actually. Which is exciting. It makes me want to donate my own poop. I’m trying to figure out what the criteria would be. Because I’m sure there’s like a very selective process for it. I don’t think anyone can just walk on up and…poop for them.
Boudreau: If you’re interested in more from Meli’sa Crawford, watch her ASU KED Talks video at research.asu.edu/kedtalks. Subscribe to our podcast through your favorite podcast directory, and find us on Facebook and Twitter at “ASUresearch.”