Armchair scientist mode: The Good: - Structural bio teaches the idea: show it, move it, block it to prove a mechanism. They do all of it, so I don't doubt it as a mechanism for the effect The Bad: - Mice ain't human. Can this happen in humans? Will it happen if I sprinkle splenda on my tea every day? Do I need a suppository to see the effect? What's the evidence to support the presence of this effect already in humans? - Comparisons to other diets (Paleo?), does it give the same effect? How long is this effect a problem for? It's interesting, but "more results needed", a good reason to run a larger randomized controlled trial, but not to immediately call your lawyer and start shoveling powdered sugar down your throat. P.S. Feel free to call me on my bullshit, I only read the abstract
Now that I have actual time to look at the article, this one is less a concern, since they did do small human trials (n = 7). That's still not enough to prove an effect and control for the many confounding factors. And I don't give much status to the correlation study, since it's still relatively small and neither direct (Measuring for the effect and not just "change in population") nor conclusive. kleinbl00: I ended up in a discussion with a guy who had taught a class including microbiome-related topics, and his conclusion after a head-first dive into the literature was: A lot of it is crap and the field as a whole is still quite immature. There's not many benchmark references for how the biome changes across different timescales with the many many possible diets a human may have on a given week / month. Seeing a change in proportion of bacterial populations in the stools is a far cry from even a smoking gun in a system as complex as the human gut. Still, this one made it into nature... (Not that they don't mistakenly accept crap on a semi-annual basis)- Mice ain't human. Can this happen in humans? Will it happen if I sprinkle splenda on my tea every day? Do I need a suppository to see the effect? What's the evidence to support the presence of this effect already in humans?
That may be true, and all we can say is that it's an exciting, but immature field. I'm no expert on microflora, and I won't critique it as such. However, I wouldn't take the main conclusion of the paper to be about the microflora anyway. That's the mechanistic part of the study, and perhaps the less relevant part (although I understand why they made the paper mostly about that). The more interesting finding here is the effect of artificial sweeteners on blood glucose. Feeding the mice glucose led to lower glucose levels than saccharin, sucralose, or aspartame. That's something right there, because insulin tolerance is one of the major drivers of diabetes and cardiovascular disease, or the shit that kills pretty much everybody who doesn't die of cancer. Some researchers have speculated that insulin metabolism may be a driver of aging and cancer, as well. It's a big deal, and reducing insulin tolerance could save mucho dinero for our health system going forward. The total costs related to cardiovascular disease is projected to be pushing a trillion dollars by mid-century. Not exactly chump change. These insulin tolerance data, whether they turn out to have anything to do with gut bacteria, should be repeated in humans. The data on that topic, so far as I can tell, are surprisingly sparse, considering how much these (IMO) poisons are added to actual food. I've been trying to get my mom to stop drinking Diet Coke for years. It's funnt that in health class in high school they tell you not to do drugs, and that one of the dangerous things about street drugs is that you never know what's in them. Then your teacher goes on conference hour and sucks down a diet soda and a bag of Cheetos, without giving any thought to wtf is in that shit. Hopefully, more attention can be paid to food additives in the future, and we can start to build a more logical food system.A lot of it is crap and the field as a whole is still quite immature. There's not many benchmark references for how the biome changes across different timescales with the many many possible diets a human may have on a given week / month. Seeing a change in proportion of bacterial populations in the stools is a far cry from even a smoking gun in a system as complex as the human gut.
Sure, but this is essentially the equivalent of research showing e-cigarettes cause more lung cancer than cigarettes. Possible, but a reason to raise eyebrows for sure, and also a reason to double down, because the stakes are worth more than 1 publication on the topic.
And I hope someone is studying the effects of e-cigarettes!!! "Here, inhale this evaporated chemical. It doesn't smell bad, so it must be fine, right?" But yes, I expect with the visibility of this paper, many people will try to replicate their work. It won't be long before this is confirmed or challenged. I'm sure the food industry is already having their lawyers draft memos about how unsound this science is, and I'm sure they'll sponsor their own "independent" research on the topic as well.
We eat too much sugar. This has a direct effect (diabetis) and an indirect effect through increasing fat storage, leading to increased inflammation of fat tissue (which is simply too much to handle) which is then connected to cardiovascular stress and type 2 diabetis. This is a death cycle, and we are not doing anything against it. Sweeteners gave people the "easy" wait out. Drink Coke zero (not diet coke, it still contains loads of sugar, just less than normal coke), it has the same taste and you can continue doing what you did before thinking to love healthier. This study (and probably others that will follow) shows that there is no easy way out. Those substances can also harm you. But but, what should I do? Eat less (OMG!!) drink more water and eat healthy. I don't know how it is in the US, but in Europe you can have equally priced meals that contain less carbs, more veggies and more protein. It is not easy, it's hard work. But it will be good in the long run. Not only for you, but for your whole country. With politics in the US shifting to a system which allows healthcare for everyone, the whole country will carry the burden for obese people (that will turn diabetic sooner or later) and that's loads of money. The country should also do something about it. Regulate the along of sugar that goes into some things. Sugar gets people addicted as well as any other substance. Treat it like this. Companies make use of this and make sweeter products that get their customers hooked. Earning big cash and not giving a shit. It is our biggest problem, and it will kill more people than cancer, because it will will you earlier (the majority of cancer deaths are in aging people) I wrote too much
/vent
Without reading the abstract, I remember a group that moved to our university and that did gut microbiome experiments having problems with the mice. The gut microbiome if the mice at their previous university were different than the ones at our... Giving different results The same happened with another group working on a hormonal stress model. Our mice appeared to have 3x of the stress hormones compared to the ones from the groups old uni.
Right, it's not like they're the lancet or anything. ;-) Appreciate the deep dive. I now know enough to bug my wife about it without having to attempt to understand it myself, which is good, considering how the day has gone.
Fun fact, Nature has already retracted six papers this year. We're not even in October yet!
I wonder if that's a result of the rising pressure on researchers to get things out ASAP. As the Ricky Bobby saying goes, "If you ain't first, you're last." It's equally as ridiculous in real life as it was in the movie. But it reflects the growing sense among many researchers that their number one goal has to be to get a research grant, and one of the best things one can do for oneself to that end is to get a paper in Nature, Science, Cell, etc. When a reviewer looks at your grant, if (s)he doesn't know your name already (especially likely for young researchers, or, the people who need grants the most but have the hardest time getting them), they're going straight to your publication list. Seeing a paper published in one of the big dogs is a way to impress, even if good research can be published anywhere, as can shitty research. Sometimes whether a paper gets published in a high or low impact journal can have mainly to do with who reviews it. The system is very arbitrary, but it's nice to see people seeing flaws and retracting on their own, instead of these being cases of fraud, which would be far more troubling.
I wouldn't be surprised in the slightest if that's the case, though I recall mention that the first oncogene gene sequence was published back in the 80s before the group had done all the proper controls. They just happened to be lucky in that a single mutation was able to turn the gene (ras) cancerous.