As a PhD scientist who makes a living doing medical research, and has more than a passing interest in this subject because I am a type 2 diabetic, and I have worn a CGM, I think this study established nothing more than that by changing ones diet, you alter the gut microbiome. Layne is dead on that this is hard to interpret. It could be good, it could be bad, it could be neutral. There is no data in the study that supports am overall negative effect of NNS, and the authors even caution in the manuscript that based on this data one should NOT abandon NNS for sugar. Water will always be the best beverage, but I think for 100% of humans, drinking beverages sweetened with NNS’ is far better than drinking something sweetened with sugar. Having published in Cell myself, I agree with Layne that as high a profile journal as it is, there is plenty of great research and plenty of crap in the journal as well. This study is well designed on the whole, but its publication in Cell will cause its impact to be far greater than the dataset presented justify, in my opinion. Finally - an anecdotal finding with an N of 1; my pretty healthy 80 year old Mother drank TAB for decades and still uses Sweet-N-low in her multiple cups of coffee everyday. So if you are one of those people who insists that NNS’ are bad, you will likely cite this study, probably incorrectly, as supporting your point of view. If you think NNS is good, this paper does little to change your mind.

I love how Layne just sticks to the data, regardless of whether it matches his expectation bias and delivers the content with no bullshit. If only the media would report on scientific studies this way.

As a sports medicine physician, I LOVE these deep dives into the research! I also deeply appreciate Layne’s oft-repeated mantras: 1) Facts don’t care about your feelings 2) That which can be asserted without evidence can be dismissed without evidence.

Found you on the Huberman podcast and so happy I did. I love the way you think and explain. Appreciate it.

thanks for breaking down the study, and your criticism was very interesting and which teaches us a lot about the limitation of individual studies

Really good talking points! That stress response explanation makes major sense

Thank you for the information and summarizing it in such a straightforward way!!! 🙏🏻

This study also got my attention, Happy to hear your analysis!

Dude, I am hooked to your channel! I can't wait till you tell me one day if sweeteners are unhealthy or not. Till then, I will blast my system with this stuff

As someone who has lost almost 60 lbs within the past 5 months, I can pretty much thank artificial sweeteners for helping me keep myself satisfied with less/zero calorie alternatives (both more natural options like monkfruit and artificial ones like Splenda.) If I had to point to one culprit that made me go up to 300 lbs over the past two years, I think it would have to be the amount of sweet tea I drank on a daily basis. I know this is anecdotal and I can't say definitively that it was as simple as that alone; however, I know I used to drank 30 - 40 oz of sweet tea on a daily basis, and that is somewhere around 320 - 450 extra calories every day that I never considered to be an issue. Once I stopped drinking that stuff and made other low calorie switches to my normal meals--and I even curbed my tea intake to just one 20 - 25 oz just to help with my teeth staining--my weight has been melting off without too much hassle on top of increasing my weekly exercise and portion control.

Great breakdown layne

thanks, layne. interesting breakdown of the strengths and potential weaknesses of the study.

Coke zero is the peak achievement of the scientific community. FTA.

Every time there is unsupervised work being done by subjects, it turns out that most subjects lie, make up data, forget to do it... In one study I set up, we asked patients if they lied/made-up data/forgot at the end of the data collection, pretending that it wouldn't matter if they did and behaving like bros. More than half did the measurements wrong and made up the data to cover their mistakes. That is huge.

As a person who never liked the taste of diet soda, eating or drinking anything with non nutritive sweetners was a shock to my system - I'm glad I watched this video and have a better understanding of what is happening - thanks Layne for making published research understandable

Awesome summary and analysis mate! Cheers from Australia!

Sound knowledge Layne !! Thank you

Always great content from you! Thank you

As someone doing their PhD in microbiome research, I can say for sure that increases in SCFA-producing bacteria is almost always considered a plus. SCFAs, especially butyrate, are extremely beneficial when it comes to intestinal barrier integrity and reduced inflammatory tone.

I really love that you break down the science in a way that the average non-science person can understand. I appreciate your perspective and your opinion. Always entertaining and well informed. I feel like after watching your videos that I learn something new all the time. Thanks for all your hard work!

Well done- Thank you for the analysis.

Great explanation Dr. Norton!👏🙂

Great video. Thanks Layne!

One of the few voices of reason in nutrition. Thanks man

Thank you for helping me understand, great channel !

Whenever I need clarity on these matters I turn to use @biolayne. You cut through the bullshit and simplify the complex in doses the layman can understand. You also show how the vaguely understood scientific method is actually applied IRL and give it depth and context. Thank you sir.

Again a great nuanced non-biased analysis. This is so valuable. Thanks Biolayne, for always keeping it real💪🏼💪🏼💪🏼

Always interesting to hear all the different things that can alter an outcome, influence a study etc!

Very informative and insightful. Thanks man.

As always very well done 💪🏼

What a freaking phenomenal breakdown great job dude, killer info!

Love your content. Much love from London

Thank you so much for this video and for breaking down the facts in such a simple and unbiased way! I've seen so many fear-mongering videos regarding non-nutritive sweeteners in the last few days (especially following the WHO's recent recommendation), so this was incredibly refreshing.

Thanks for the review and explanation.

Been using liquid Splenda for several years and more recently liquid Splenda monk fruit. Never had any problems with yearning for food containing actual sugar as so many claim results from using no-sugar sweeteners. Have lost more than 60 lbs in conjunction with keto and IF. And my last blood and urine test results were the best in a couple of decades. So I'm fine with taking the opinion that no-sugar sweeteners have been a blessing for me.

A fair summary, critique, and conclusion

I feel like whenever I see the term gut micro biome, I think of how big and vast the ocean on planet earth is, and how little we know, in depth, about all the creatures that may exist in it

This is the longest "I don't know" response I've ever witnessed

I've been reading your work, Layne, since before you entered into your Ph.D. program. As always, enjoy your content. From your MD days to the KZfaq days. Love it.

So helpful. Thank you.

Power of placebo! Great call out! Thank you!

Excellent video, learned a lot but sorry I am already subscribed to REPS!

Loved this!!

Fascinating! Can’t give up my Dew Zero.

18:55 most important part of this video. The study is legit. The interpretation by people with out this sort of critical thinking (aka the media) is what will be dangerous.

Thank you layne👍, amazing video you make studies so easy to understand

Great video!!

Something I have learned wearing a CGM is that if you do not know precisely when to insert the cannula (can't do it when you are dropping sugar or it will be off by a good bit), calibration techniques etc, then the data from it is useless. It was an interesting study to read for sure, but I did wonder how they managed to do some of the data as you spoke to. I will continue with my occasional Coke Zero and motor on. Thanks for the interpretation.

Not sure if I missed some fact, but it seems like the most emphasis was on the participants potential bias against artificial sweeteners. However around 7:26 in it was stated aspartame didn't affect blood glucose like the sucralose and saccharin, which proves that is not the case.

I appreciate this review and discussing there effects on the micriobiome and the unknown

This was just the thing I was interested to know.

Great work 😮

It makes logical sense that it would take the body a bit to adapt to something new. It’s actually really cool to see a study on a population where they are trying something brand new to their body chemistry. Shame about the implementation. Fascinating study in any case.

My Doctor recommended you.... sure glad he did

Hey Layne, it’s great to finally see someone address this study and you make some great points. There is one minor thing I think you misunderstood about the study: the participants were screened for 6 months of nonconsumption, not ever in their lives. From the study: “We excluded participants who consumed any quantity of NNS-containing foods or beverages in the six months prior to the trial initiation”. This makes the supposition that the participants had unusually negative opinions on NNS far less likely.

I wonder if the researchers tracked dietary intake outside of the addition of non-nutritive sweeteners. Maybe the groups that were assigned to non-nutritive sweeteners ate differently as a result of knowing they were eating something they identify as "bad", because like mentioned, it's hard to blind here. Just adding my thoughts! Either way, great to know there is finally a human study!

I have been taking in enough artificial sweetener to satisfy an elephant on a daily basis for 17 years now. I am lucky to be alive.

Good start, now keep going.

Note on DURATION: 1. If something statistically significantly affects you in two weeks, it does. 2. If not, that *could be* because it’s too short.

WOW. God bless you! I wish you were the head of the FDA. 👏👏👏👏

Interesting study, thanks for sharing. Typically the microbiome tends to return to normal within a month after moderate diet changes. Especially as NNSs are prebiotics I would expect a permanent shift in the microbiome to occur after at least 6 months considering consistent and high use. It would be more interesting to see longitudinal studies in people consuming NNSs. Perhaps they could stratify into low-medium-high users. Also I would be interested to see use of NNSs within people with gut related conditions such as IBS, IBD, etc. How does the microbiome change then and what are the implications. How could we reverse the microbiome to “normal”?

When ever i start falling for woo...i rewatch Laynes videos.

You rule bro. Big fan here all the way from New Zealand.. Often share and post your content.. especially the bro science, whatever zealot bullshit..

I am here from Greg Doucette super interesting video thanks. Subscribed directly 👍

Would be interesting if you also mentioned who funded the studies.

I wonder if i will ever be able to discuss research like layne does , however I’ll keep trying

Liked, subscribed!

30 years using aspartame, 65 now. Feel great fit as I have ever been.

Life is turning out to be pretty dangerous, there are literally billions of things that can harm and kill you

BIG UP FROM FRANCE

Would have liked to see newer nns too like allulose, monk fruit and erithritol

Byolaine, can you do a video on how seasonal, household allergies affect weight loss/fat loss. I suffer from heavy allergies and I take Claritin daily, Flonase on and off, Prednisone when I get critical or pollen is high as needed, and now astepro daily. I have found that it's very hard to loose weight and my calories are pretty low and for sure on a calorie deficit, but the scale does not move as quick as when I was younger and did not suffer from allergies or take any medication to treat my allergies. I don't know what it is, if it's all the medication or inflammation that I always have. I would love for you to dive in to this issue because I know there are a lot of people that suffer from heavy allergies and it might be a reason why obese people like me struggle with weight loss. I'm at the point where I'm going to start treatment with an allergist in the next few months, but it's expensive and it takes years to desensitized my allergies. All I read is that antihistamines increase appetite, but I feel there is a lot more to this story.

I used to have basically a diet soda addiction and I don't think drinking a 2 litre of soda in a day is a good idea even if it is low calorie BUT these days I will have a single serving of diet soda a couple of times a week and I'm pretty confident that it's not causing me any issues. I'm in pretty good physical health and while I'm still a tiny bit overweight I used to be bordering on obese and I've been able to keep off 30 pounds for 2 years while drinking diet soda here and there. Of course that's just anecdotal but for me at least it doesn't seem to be a problem,especially compared to all the sugary treats I used to overindulge on.

excellent video

I would like to point out that prior to five years ago I had never consumed artificial sweeteners. Not because I thought they were bad I just liked regular sugar and preferred to make most of my own foods so it is completely within a realm of possibility that the participants just didn't consume them for non ideological reasons. Sounds really interesting, I'm going to go check out the article.

I drink a diet soda for lunch 5 days a week and I can tell you, for me, it keeps me from giving into my sugar cravings. The cravings are simply dulled because my brain thinks it got the sugar already.

I may have to watch again but did you ever mention what the study said or was that a prerequisite.

Physique on point: opinion respected.

Yea, people get caught up in this perfection complex. For someone who is drinking 2 sodas, regular, everyday and they switch to say one Celcius (Sucralose) a day, that would be a step in the right direction. While not perfect, though, it is better.

I wonder if he would be so soft on the researchers if they had done a weight loss study with controlling caloric and protein intake, but at the end of 2 weeks letting the participants measure the primary outcome 'bodyweight' at home ...

I would look into all health effects. Corporations also have funded studies so that their products are promoted in a favorable light. So one study is not enough.

I am wondering ultimately, with that study even if there is an rise in insulin or glucose, how much of an adverse effect it has on say someone with Diabetes 2? If the raise level is negligible compared to what sugar or carbs does, I am willing to keep using artificial sugar.

I use stevia daily and only have a little sugar once or twice a week. I use a teaspoon in my coffee and 1\4 teaspoon in my tea at bedtime. My mom is sure it will kill me because of some studies. I assured her that I would have to consume a bag or more of stevia a day to hurt me. It keeps me away from sugar and to me it’s a good trade off.

Overweight people have more medical issues than thinner or in shape people. Point being that people who for years without a break live in a calorie surplus tend to have the majority of health problems across the board. Not to say there could be something wrong with sweeteners, Just saying being overweight is much worse for your health and more worry some than sweeteners in my opinion.

Apologies if I missed this and maybe this was not something you considered relevant to the topic: What about past evidence pointing to aspartame, et al, being neurotoxic?

Does reps include the studies it talks about too?

Hey Layne, I use pure sucralose powder, that has no bulking agent in it. Is it better than regular Splenda, since bulking agents still have some calories?

Especially for diabetics, sugar substs helps to reduce carbohydrates.

This is another great video from Layne. However, I think that something important is not being addressed here. These test subjects started taking sweetener, but what did they replace with sweetener? If these people were comsuming lots of sugary beverages and such before the study and then started taking a sweetener instead, could that possibly mean that the lack/absence of sugar is that actual cause of the change in the gut microbiome and not the sweetener itself?

I've lost quite a bit of weight over the years and I give some credit to cutting out a lot of sugar. So even before I watch the video I thought to myself I will still continue to use some artificial sweeteners. But anyway another excellent video thanks!

The increase in SCFAs suggests to me that the non-nutritive sweeteners are being metabolized by gut microbes similarly to fiber.

I wish they’d do a long term study about the liquid forms. Without the added maltodextin or dextrose from the powdered forms. I’m sure the liquid wouldn’t spike blood glucose as much but who knows what it does the gut microbiome

I appreciate your science based analysis.

What about the rest of their diet? What about what other things they did? A lot of things can affect these results.

Well thank you

awesome video

The Placebo Effect may have some response in any study, but it's main role is to measure the standard of error vs. the control group. I hear too many people treating the PE as if it were some magical explanation when a large part of it is just how weak experiments explain or write off large, unexpected deviations.

Even if artificial sweeteners do raise glucose levels, they raise them far less than normL sweeteners. Even if artificial sweeteners aren't the best for the microbiome, sugar is not good for it either. This study might very well be 100% accurate, but still, relative to regular sweeteners, artificial sweeteners are still a net positive.

We knew all this. Didn’t t need the study. Can you imagine if people waited around for studies to declare if something is poison or not?

I don't think many willing participants who avoid this on a daily basis will be thát concerned over a 2 week trial period. Maybe some, and that might actually have an effect across all groups, but it's often the longterm effects that worry em. If they were as thorough with their screening as you said, they probably took this into consideration. Lot's of probabalies, but that's what happens when you argue like this. Having said I like the "we don't know enough about X" approach you took today. What I don't understand why they didn't have a third control group with people who have been consuming artificial sweeteners and did so during the trials as well. It's not like they had a lack thereof and it's much more representative to how we live. It could have accounted for many of your questions.