Episode 41: Could we take a pill to eradicate Staph aureus on the skin?

Jul 23

Written By Global Parents for Eczema Research

Is getting rid of Staph aureus in the gut the key to improving eczema? And can we control it without antibiotics? Join us as we ask these questions and more of Dr. Michael Otto, Chief of the Pathogen Molecular Genetics Section at the National Institute of Allergies and Infectious Diseases. (And if you like our podcast, consider supporting it with a tax deductible donation). Read the transcript.

EP41: Staph aureus with Dr. Otto
[00:00:09] Lynita: Hello and welcome to the podcast. I'm here with Korey Capozza, founder of GPER, and today our topic is Staphylococcus aureus or Staph aureus for short. Staph aureus is a bacterium that can live on our skin, in our gut, our airways, our nasal passages, and even in our blood. It has been accused of making eczema worse if it grows out of control on our skin, but we are still learning exactly how it exacerbates eczema.
Our guest today. Dr. Michael Otto is a Staph aureus researcher. He leads the Pathogen Molecular Genetic section at the National Institute of Allergies and Infectious Diseases in Washington, DC and his research team focuses on how bacteria like Staph aureus interact with the human microbiome and impact human health.
[00:01:19] Dr. Otto: Hello. Thanks for having me.
[00:01:21] Lynita: Dr. Otto, can you please introduce us to Staphylococcus aureus and how it can impact human health?
[00:01:30] Dr. Otto: So, Staphylococcus aureus is a germ that many of us actually have, as you mentioned already. 20 to 30 percent or so of people have this colonization of Staphylococcus aureus. So normally nothing much happens, but it can cause many, many different types of infections. For example, you have other underlying conditions, or, you might undergo surgery and it's not been so clean, and then it can cause a blood infection although it is normally not a threat.
[00:02:03] Lynita: We are more interested in what it can do on the skin because the word is that if you have Staphylococcus aureus on your skin, then your eczema is going to be worse, or it's going to cause a flare. So how does it interact with our skin?
[00:02:18] Dr. Otto: I am a bacteriologist. I am not a dermatologist, not even a doctor, so my angle here is that of a researcher. Now, of course I know a little bit about atopic dermatitis and skin infections. It is a relatively recent development that people have acknowledged that Staphylococcus makes it worse.
This research stems from associations where Staphylococcus aureus is found much more frequently in atopic dermatitis lesions and I think it's like around 90 percent or so, whereas normally, healthy people don't really have Staphylococcus on their skin. So that distinguishes them clearly from atopic dermatitis patients.
But there is always this thing about causality. You know, what is first? If you have an atopic dermatitis lesion, it's like a little wound or so, and that is a great place for Staphylococcus aureus to be. So, is Staphylococcus aureus associated with atopic dermatitis lesions, because this is a nice place for it to thrive, or is it at least part of the many causes that make it worse. And one very crucial study could, for the first time, show how it might exacerbate atopic dermatitis.
It's a little peptide toxin and we were part of the study because we have been working as Staphylococcus aureus researchers for quite a while on these peptide toxins. And Dr. Nunez found that one of these toxins causes a big inflammation that underlies atopic dermatitis. So this was a very clear hint that it's not just a bystander in these lesions, but that it actually contributes to the causation of them.
[00:04:11] Lynita: So it's a bit of a circle going on. You have a lesion of eczema and it's a nice place for Staphylococcus to grow, and then as it grows, it then releases something which causes inflammation and hence the cycle continues.
[00:04:26] Dr. Otto: Vicious cycle, so to speak.
[00:04:28] Lynita: Right. So most people don't have Staphylococcus aureus growing on their skin, but what about in their noses? Especially kids, they're rubbing their noses all the time.
[00:04:39] Dr. Otto: Yeah. So most people have Staphylococcus aureus in the nose, not everybody has it. And don't ask me, we don't know why. But usually if you have it in the nose, you usually also have it in other places. You either have it or you don't. Now our research more recently has highlighted a little bit more of the gut as a reservoir where Staph aureus hides. And we believe that these Staph aureus that are in the gut, they're probably in a dynamic interaction with the other Staph bacteria. So you, touch yourself always everywhere. I know it's a bit gross, you distribute it all over your body. I mean, that's how the bacteria get there. And we think it might be coming back from the gut.
[00:05:22] Lynita: Right. So maybe the source of it is not so much the nose, but it could be from our gut actually,
[00:05:28] Dr. Otto: Absolutely.
[00:05:29] Korey: I was just curious if the gut is a reservoir for Staph, or Staph is in the gut of some people and you say it's interacting with other sites. Is it interacting with the skin in such a way as to be sort of implicated in atopic dermatitis?
[00:05:47] Dr. Otto: Quite frankly, we don't know. I mean, I think that the gut might be where it comes back from, whether there are other interactions... We don't really know very much about Staph aureus and the intestine yet.
[00:06:01] Korey: But we do know that once Staph aureus takes a hold in the body, it's hard to get rid of it. And then it sticks around through these various places that it kind of hides out,
[00:06:12] Dr. Otto: It’s a normal colonizer. And some people are just prone to colonization, which is something perfectly normal and not directly threatening. It's just like, they have a higher risk of developing all these infections.
And there are also studies specifically for atopic dermatitis that showed this association of Staph aureus colonization and atopic dermatitis, this study where they looked at the cheek colonization of children, and they found that when the cheeks are colonized these children have higher risk of developing atopic dermatitis later. So in that case, it’s part of the causes of the atopic dermatitis lesions.
[00:06:50] Korey: And in the case of atopic dermatitis, studies have found it's the balance of Staph with other bacteria, it crowds out the other bacteria so that it's sort of the dominant signature in atopic dermatitis, whereas you don't see that in people who don't have atopic dermatitis.
Dr. Otto: Uh, yes, we believe nowadays that the Staphylococcus aureus participates in the pathogenesis of AD. And usually there is also signs of dysbiosis, which is an imbalance in the microbiome. Too many bad bugs and not enough good bugs.
[00:07:25] Lynita: Talking about dysbiosis and the imbalance of the bacteria on our skin. I know that you've done some work placing other bacteria on the skin to try and bring Staph aureus back into balance, for example, with Staph epidermidis. Can we create a cream that we can give to kids with eczema that contains this Staph epidermidis and then helps cure the Staph aureus?
[00:07:49] Dr. Otto: So I have done a study where we showed that Staph epidermidis has an enzyme that assists the host in producing ceramides. Ceramides are good for the skin barrier. And it was quite fascinating that we found that Staphylococcus epidermidis somehow helps us to produce the ceramides, right? Whether I would suggest everybody has to smear Staphylococcus epidermidis on the skin... It's there already. But I also should mention that other people have done studies where they try to make use of the competition that is there between Staphylococcus epidermidis, for example, and Staphylococcus aureus.
This is, in general, a very new field where we try to use the good bugs to combat the bad bugs. And Staph epidermidis produces a signal that inhibits the system that Staph aureus needs to survive on the skin. And they're trying to make use of this.
[00:08:44] Lynita: So let me see if I've understood correctly: when you have the two bacteria together, they try to outcompete each other. So they’re kind of releasing things that say, I'm going to try and suppress you so that I can grow better. And then we can give that other bacteria a boost to kind of suppress Staph aureus and reduce its overabundance in a microbiome, whether it's on the skin or in the gut. Did I get that right?
[00:09:12] Dr. Otto: In principle absolutely correct, but as it always it’s more complicated,
[00:09:17] Lynita: And you have found the same thing in the gut, but with a different bacteria. A Bacillus subtilis?
Dr. Otto: Bacillus subtilis. Other Bacilli do it too, but yeah, Bacillus subtilis.
[00:09:28] Dr. Otto: Yeah. We have a similar study, but a little bit different, and that's a fascinating study. I'll tell you a little bit about that if I may. So it was quite funny that a graduate student who came from Thailand to my lab came with fecal samples that he had obtained from rural Thai populations.
And he always only found Bacillus or he only found Staph aureus in the feces of those people. So this is something that nowadays we call colonization exclusion. So basically one bug excludes the other bug. The overall Staphylococcus percentage that we found in this Thai population was only about 12 percent, which is much lower than the 20 to 30 percent Staphylococcus that you usually have and that was already wow, you know, this is very, very low.
And then we did a whole lot of research until we found out that Bacillus also produces something that inhibits the Staph aureus. And then we tried to do all of this in mice and it all worked very well. So if you feed the mice, the Bacillus, they don't have Staph aureus in their gut anymore. Very nice. So we were really, really intrigued by that. So usually we stop there, right?
But in this case, we thought we really have to try something. So with our Thai collaborators they did a clinical trial in Thailand where they look first um, for people who were colonized by Staph aureus in their gut, and then they were given these oral Bacillus, a pill of a probiotic, something that you can buy in the supermarket and they had a very, very strong reduction of Staph aureus in the gut.
Now, why do I tell you all these things about the gut, right? It's about atopic dermatitis, who cares, right? We didn't directly look at the skin, but we checked the nose. And that's also why I mentioned before this potential reservoir role of Staph aureus. We found that even in the nose, the people who eat Bacillus, the Bacillus doesn't go in the nose, but it also suppressed the numbers of Staph aureus in the nose. And that to me means that there is probably this role of the gut replenishing, after a while, the nose. And based on all these results, there are people who have approached us who are very, very interested in recurring Staph aureus skin infections, and said, you know, we should really try this. And they will probably do this. They're still at the stage of getting funding, but the good thing is that, you know, you don't use antibiotics. You don't use steroids. You just take a pill that's good for you anyway. So that's the fascinating thing about it.
[00:12:04] Lynita: It's really interesting. You'll have to let us know who those researchers are so that we can look out for them in the research.
[00:12:09] Dr. Otto: Absolutely. I will do that.
[00:12:10] Lynita: I'm going to just step back a bit because we've talked about a whole lot of stuff here and it's very fascinating, but it's also very technical for mothers wondering how they're going to help their kids with eczema.
[00:12:23] Dr. Otto: Yeah.
[00:12:24] Lynita: so Bacillus subtilis does the same thing in our gut. As Staph epidermidis does in our skin, it releases something that tries to out compete with Staph aureus so that it can kind of proliferate rather than the Staph aureus.
[00:12:37] Dr. Otto: Correct. The little bit of a difference is that Bacillus subtilis is a soil bacteria and it only, you know, when people eat leaves or something, then it gets in the gut and it's not a permanent colonizer there. It stays for some days and it goes away again. But we believe that these Thai people, they eat a lot of leaves from the soil, you know, and that's why I think we found it there.
[00:12:56] Lynita: I didn't realize that Bacillus is something that comes from soil. There has been research that shows that kids that grow up on farms, for example, have less chance of developing eczema. So maybe there is some correlation between these natural environmental bacteria and being able to suppress Staphylococcus aureus.
[00:13:15] Dr. Otto: It's something that you cannot say as a scientist because it's entirely speculative, but looking at the situation that those Thai people always eat the leaves. You could make the argument for, look at the healthy original lifestyle, as opposed to our urban life. You can absolutely make that argument. But, there's no direct evidence. If we had done the same study somewhere in New York City, probably never would have found it, right? Because people eat everything super sterilized and out of plastic.
And that's another little touch to that Bacillus story, So Staph epidermidis on the skin is a bit different. It's there in everybody, right? And so this interaction is going on already anyway. but it doesn't seem always to work in nature. I mean, this is still basic science research. So there's still a lot to do.
I get several emails a lot and I try to answer all of them, but then I gave up at some point in time, from people, “Oh, which Bacillus should I buy?” And I feel very uncomfortable, you know, telling people what they should buy and to try that. And I always say, please go to your doctor. On the other hand, you don't do anything wrong if you swallow Bacillus. So it's, yeah, in this case, it cannot do any harm anyway.
[00:14:36] Korey: Well, I think that's kind of where people are at, like, they've been having trouble with Staph. They can't get rid of it. They read this paper and there's few downsides. So they think, why not? The problem is in part that it's not a very regulated industry. So there's all these different probiotic supplements and like, who knows how much is the right amount? What do they contain? Are there even live bacteria? We don't know.
[00:14:58] Dr. Otto: Yeah, absolutely. And this, this is when I still try to answer the emails, that's exactly what I said, you know. I can only say, if you want to try it, try it. You don't do anything wrong with Bacillus pills, you know.
[00:15:09] Korey: Well, just out of curiosity, like, how was it done in the trial?
[00:15:12] Dr. Otto: So what we did is we screened several preparations and then, if we found the preparation to be pure, we bought it and we packed it in little pills and we gave it to the patients.
[00:15:23] Korey: And this wasn't a small effect that you saw. I mean, in the paper, taking the Bacillus subtilis eliminated more than 95 percent of the total Staph, right?
[00:15:33] Dr. Otto: It's such a high percentage because most of the Staph aureus in absolute numbers in the body resides in the gut. And our study was the first evidence somehow to suggest that the gut might have this reservoir role, because if it didn't you would not have found any impact on the numbers in the nose, and we think that the same thing might go on with the skin.
And that's why we believe maybe that specifically people who suffer from recurring Staphylococcus aureus skin infections, maybe atopic dermatitis as well, that they might actually benefit from that. Now, you would have to take it basically the whole time, because Staphylococcus aureus will always come back. The nice difference here is that you don't want to smear steroids or antibiotic for longer periods of time on your skin but taking the Bacillus for longer time, it doesn't really cause any harm. So this would be a much more long term, suppressing the Staph aureus in general, so that it cannot come back. So we will push to get this trial done. Absolutely.
[00:16:41] Lynita: Changing tacts, Dr. Otto. I'd also like to ask you about using antibiotics on the skin. There is a treatment. It's not found in research. And it's known as the Aron Regime. And it's basically, it's a combination of a topical antibiotic, a topical steroid, and a cream. And there are a lot of families that swear by this treatment. The thing that concerns me with this treatment is these kids, that suddenly had this miracle cure, but now what's happened to their microbiome, is it gone?
[00:17:13] Dr. Otto: Very likely. I made myself knowledgeable today about this regimen and the special thing about this regimen, as you pointed out, is that it contains an antibiotic. And then the steroid. It’s like very repeated application of low amounts and the combination, you know, you might really attack AD from two different angles. So, I mean, the thinking behind it, is good. But the main thing is that there is an antibiotic. Now, the problems that I pointed out earlier with all these things is that this is not something that you want to do forever.
I found one paper and they report that they have a significantly better outcome in patients with this Dr. Aron regimen. but coming back and what you exactly asked the broad spectrum antibiotics, they will kill everything. problem with all of these things. Now in the nose, that might not be such a big problem. The skin already, maybe not so good. You want to have your good microbiome there. So if at all, if we can get away from using antibiotics, on the skin it would be good.
[00:18:23] Lynita: Sure.
[00:18:24] Dr. Otto: But still, as long as we don't have anything else, and if it works. Of course, I think people should use what works. I'm absolutely not saying anything against this regimen, but I think it's, it's using conventional things that we try ultimately to get away from.
Dr. Aron has discussed that I mean, with such things, there's not so much scientific evidence. So I think what he says is maybe true, but a little bit speculative, but. but yes, I mean, if this is on a level of if it works, it works, I think.
[00:18:59] Lynita: Sure.
[00:19:00] Lynita: It's been such a pleasure to speak to you today. So thank you very much for sharing your knowledge with us about Staph aureus, for explaining how it works and and maybe where the future will lead in terms of helping us control Staph aureus on the skin. But thank you.
[00:19:17] Dr. Otto: Thank you very much for having me.
[00:19:18] Korey: Thank you so much.
[00:19:18] Dr. Otto: Bye bye.