The human microbiome is a very active area of scientific research at the moment. It's one of those buzzword topics like CRISPR, that everyone is interested in knowing more about. This is largely due to the fact that we have known about the collection of microorganisms living in our guts for decades, but wrote them off as unimportant to human health. However as of the past decade researchers have come to find that not only are these gut bugs important, but human health is actually quite intertwined with the composition of organisms that are thriving there.[1]
Today we will discuss an article titled "Saccharomyces boulardii Administration Changes Gut Microbiota and Attenuates D-Galactosamine-Induced Liver Injury" which was published May 2nd 2017 in the journal Nature: Scientific Reports.
What Were They Studying?
This article discusses a strain of yeast called Saccharomyces boulardii, a strain which is sold all over the place as a probiotic [4], and its relationship in potentially healing liver damage due to hepatosis, which is a term referring to a disease of the liver that is not caused by inflammation but rather changes to the liver cells themselves.
The researchers were exploring accute liver failure, which is a disorder with an extremely fast and high death rate if and when it occurs.[5] It can be caused by a wide ranging set of things including viral infections and liver injuries due to drugs (drug in this being anything, including pharmaceutical medications). [6, 7]
The way they were modeling acute liver damage in humans, was (of course) through use of a mouse model...
and administration of D-Galactosamine, which is an amino sugar (galactose is the sugar, and amine indicates that there is an NH2, as one hydrogen is replaced by the bond to a sugar carbon) which looks like this:
D-Galactosamine (or D-GalN through out the figures) is known to cause liver injury, so it allows for quick induction of these conditions for studying the effect of the presence of Saccharomyces boulardii in the mouse microbiome.
So What Did They Find?
To look for the effects of liver damage the researchers monitored the blood levels of two liver enzymes: aspartate aminotransferase or (AST) and Serum alanine aminotransferase (ALT). The reason for this, is these two liver enzymes are normally found in very low levels in the blood, however if the liver is damaged, it ends up releasing them into the blood stream. In fact, testing for these enzymes is actually a common medical procedure looking for liver damage in us humans as well.[8]. So the researchers had three groups in the following experiment, a control which didn't receive any D-Galactosamine, a positive control which received D-Galactosamine but did not have the Saccharomyces boulardii (SB in the figure) in its microbiome and finally a mouse group which did.
What we are looking at here in A are the blood levels of ALT in the three groups which I described above. Now when you are looking at that Y axis, notice its in a log scale so each number is equivalent to 10 times the amount of protein as the preceding number. So when you see the D-GalN positive control group is at ~3 this means there is 100 times more of the ALT present then in the control which did not have its liver damaged. You can clearly see that the presence of the Saccharomyces boulardii results in a significant reduction in the amount of ALT present (5-10 fold) indicating that they protected the liver against damage. Looking to the right at figure B we are looking instead at AST, and we can see that the results are paralleled for this second indicator of liver damage.
They also looked at this from another perspective and perhaps it paints the picture a bit better than the bar graph of enzyme levels. Here they are showing what the liver cells looked like for the three groups:
What we are looking at here are light microscope images of liver tissue from each of the three groups. You can see that in the positive control group (B) the liver cells are pretty destroyed looking, but in the sample with the Saccharomyces boulardii (C) they look a lot more like the control group. Pretty cool!
TL;DR
The presence of Saccharomyces boulardii in the microbiome of the mice seem to protect the liver against damage in a pretty significant way. The authors state that these results "merits in-depth pathological and pharmacological study" on Saccharomyces boulardii and their potential use as a treatment for acute liver injury. It's pretty hard to argue with them on that point, hopefully more work can be done.
This article is another small piece in the picture coming into view showing us just how much an effect the composition of the microbiome can have with regards to our health. Studies like this are so very important to building up that understanding, and show the potential for health benefits that will undoubtedly come from further research.
Sources
- http://gut.bmj.com/content/65/2/330
- https://www.nature.com/articles/s41598-017-01271-9
- http://betargin.com.ua/en/zabolevaniya-pecheni/bolezni-pecheni/gepatozyi.html
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3296087/
- http://www.clinmed.rcpjournal.org/content/15/5/468
- http://emedicine.medscape.com/article/169814-overview
- http://annals.org/aim/article/715846/results-prospective-study-acute-liver-failure-17-tertiary-care-centers
- http://www.webmd.com/digestive-disorders/alanine-aminotransferase-alt#1
All Non Cited Images Are From Pixabay.com And Are Available Under Creative Commons Licenses
Any Gifs Are From Giphy.com and Are Also Available for Use Under Creative Commons Licences
Images from figures in Nature: Scientific Reports articles are available for reuse under a Creative Commons license.
If you like this work, please consider giving me a follow: @justtryme90. I am here to help spread scientific knowledge and break down primary publications in such a way so as to cut through the jargon and provide you the main conclusions in short (well compared to the original articles at least!) and easy to read posts.
Way over my head, but sounds useful :D What I know for sure is that there is a lot of yeast in beer. Good kind of yeast!
The yeast used in this study (Saccharomyces boulardii), and brewers yeast (Saccharomyces cerevisiae) are very very closely related.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1081240/
So these little guys have all sorts of useful applications :)
Is there anything about this that you would like to know to make anything more clear? I don't believe anything is over anyone's head, it just means that I am not explaining things clearly enough.
No, no. I just meant it is very textbook material. I wish we could get students post their assignments on steemit like this. Could spread the word like wildfire.
There is a teacher @giantbear who had/has her students doing just that!
Wow! Awesome. Will check out.
Yeah please do, shes a pretty nice person to chat with on here as well. Has always been very supportive and kind with regards to my science posting for sure!
Thank you for the kind words @justtryme90 I am a teacher in heart and mind...LOL!
Just followed her. Thanks!
My son, @cmp2020, has posted a few of his assignments - and he's working on an English paper now that he plans to post after it's submitted and graded. I agree that successful assignment posts should help with platform growth - and I think they improve the quality of the assignment submissions, too.
Hi @remlaps in the very near future we are going to absolutely target teachers and students positively here on Steemit. I can't wait! Watch out for our first post! Thanks for the following. I followed your son now too as well as you.
Gosh, correcting some stupid errors. Forgot to subscript some things, formatting issues with my citations brackets. I'm sure there is more, will keep periodically reviewing.
Corrected a chemistry mistake, as pointed out by @jaki01. Makes me a bit sad.
Haha: too much stress with the new job? :-) (Private message sent.)
Great article though (resteemed)!
No, but you are correct. :)
I think I have made all corrections that you pointed out to me. Don't be afraid to call me out on my mistakes in a comment when you notice them. :)
I won't get upset, I'm a human too :D
Still a little disappointed in my self for the stupidity of my errors in this post. Thankfully you were watching out for me.
Well thank you for the kind words man. Most appreciated.
Thank you for the excellent work!
Thank you for reading! Very glad you liked it. :D
Awesome article, as usual. Thank you very much @justtryme90. Are there already any trials with humans going on to confirm those findings?
Not that I know of, based on the author's discussions expanding research in this area seems promising and hopefully others are interested/actually do so. As we should all be aware these days, the mouse model (or any model for human body biochemistry: rat, dog, monkey etc.) Is not always the best representation, and this is because the cellular expression of metabolic enzymes is surprisingly varied from species to species. This actually may even require study in an additonal model or two to illustrate it's effecacy/consistency before people would be willing to look into any sort of human trial.
In short science is fascinating, but application of research onto humans is painfully slow (and for good reason, we really don't want to harm people in the trials).
Also, thanks for the kindness, and thank you for reading. :)
I'm very aware of all of these issues and you are also very right. It's an absolute necessity to make sure no humans are being harmed. I just hope that we will have better models (i.e. in silico for example) in the future that allow us to test things much faster. Right now, animal studies are they way to go but it doesn't have to stay that way forever...
Couldn't have said it better myself.
Very important data here. Thank you. Just for a fun FYI. As doctors we can lean towards the etiology of liver disease by studying the ratios of ALT to AST. From liver disease caused by alcohol the AST is usually twice the increase of ALT.
Interesting, so the ratio of AST/ALT changes for different liver diseases? Is there a wide range of possible ratios dependent on the source of liver damage?
Yeah! Ethanol produces more reactive oxygen species (ROS), which preferentially targets mitochondrial cells. Since AST is a mitochondrial enzyme, when those cells lyse, much more AST is released in the peripheral circulation.
Interesting article. Thank you.
I'm out of my depth here, but a friend was recently diagnosed with liver damage. She has also suffered from Celiac Disease for years. I never would have connected the two before your article, but a quick Google reveals that the two commonly occur together. Because of your comment about Saccharomyces boulardii being closely related to brewer's yeast, I'm wondering if the gluten free diet that controls Celiac disease is related to the liver problems. If so, continuing this line of research might be especially useful for people who suffer from Celiac Disease. i.e. How do you duplicate the protective effects of Saccharomyces boulardii without triggering the Celiac Disease?
I don't know enough about Celiac's disease, are they unable to supplement with yeast? Saccharomyces boulardii is a common probiotic supplement. I have read that yeast supplements are contaminated with gluten (due to growth of the yeast) so in that case it would be an issue, but I see no reason why the yeast couldn't be cultured in a gluten free environment.
Interesting. I didn't know that Saccharomyces boulardii is a common supplement. And Google tells me that there are gluten free products available. I think I'll e-mail her this link to discuss with her doctor. Thanks again!
But I now see that you did mention that in the article. Sorry. I shouldn't have skimmed through to the findings, I guess.
Any time my friend, thanks for reading. If this ends up helping her let me know!
Hey I posted a blog about psychedelic drug use and I would really like to know your opinion on the subject! Great post! Upvoted
Your friend's experiences are not uncommon. Psychedelic drug use is commonly associated with a heightened sense of well being in the after math. There have been some studies done on psylocybin showing people are happier during/after its use:
http://www.csp.org/psilocybin/Hopkins-CSP-Psilocybin2006.pdf
I don't have too many opinions on the subject. I generally default to a desire for further and in detailed study on any compound with the potential for benefits to people, drug or non drug.
This is fascinating to me.
AS I;m starting to brew my own kombucha [ which has a lot of probiotics and yeast! ] and my own kimchi..I read a lot about what actually ferments the batch and what happens.
There's this woman who's a microbiologist and analyzed the kimchi culture every day to see what happens there. I wish I could do that at home.
BUT I am very happy to see that probiotics and all kind of bacteria is good for us. I trust in the future people will take this much more serious than they are at the moment.
Have you read GUTS?
Sounds great. I have actually, never had kombucha I know it's a fermented drink (tea?) But thats about all.
Nope, I've never read guts, what is it about?
https://www.bookdepository.com/Gut-Giuli-Enders-David-Shaw/9781925228601?ref=grid-view&qid=1494400581399&sr=1-1
good book!
so @justtryme90 , is my skin chemical composition different from others?i have skin itches after bath from birth,which never goes away.Don't know if your science knowledge could answer a bit of my issue or i'm doomed for life.
You itch after a bath? Can you elaborate a bit more? Does it matter if you use soap/ or the type of soap?
it doesn't matter.Soap or no soap.
I have to seat in front of a fan or go outside in the sun on sunny days to get dry as fast as possible.I'm in Nigeria,West Africa and have gone to pharmacies and clinics for this.I guess i need a more advance science to turn to that's why i quickly dropped this.
Is your skin very dry? Flakey? cracked? The itching stops when you are no longer wet?
Yes it does.Once i'm dry,especially my feet the itching subsides.I have a oily skin and i'm a sweat merchant.I sweat profoundly naturally.Don't know if that's another reason.And Rain water is like acid on my skin,it itches me like i'm serving a sentence.
Perhaps: https://en.wikipedia.org/wiki/Aquagenic_pruritus
However I am not a medical doctor, so I don't know. Any opinions @tfeldman?
Thanks,i'm reading through now.
is he a Doc?