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— 

Crawford: Yeah. 

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.

Crawford: Yeah.

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.

Crawford: Yeah.

Boudreau: And how they’re work­ing to devel­op treatments.

Crawford: Yeah.

Boudreau: So, you’re say­ing that you can take some­body’s poop…

Crawford: Yes.

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/​k​e​d​t​a​lks. Subscribe to our pod­cast through your favorite pod­cast direc­to­ry, and find us on Facebook and Twitter at ASUresearch.”