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Microbiome researcher here. Like many microbiome results - this paper has tantalizing evidence of a powerful and systemic effect, but extremely limited direct e
by wdwvt1 4y ago
Microbiome researcher here. Like many microbiome results - this paper has tantalizing evidence of a powerful and systemic effect, but extremely limited direct evidence. The primary experiment in the paper is the transfer of stool contents from old mice to young mice (and vice versa). The chemical complexity of stool is hard to overstate - it's one of the most chemically diverse environments known. While the microbes are ~75% of the weight of feces (and thus of the fecal transplant) there is a huge complement of other things including host-derived effector molecules, fungal, and viral components. Three things that I think are important to think about:
1) A critical experiment to determine that it is bacteria (or fungal/virus) per se and not a host effector would be the transfer of contents from aged germ-free control mice (mice without microbes of any type). The authors mention a transfer protocol that could be optimized for fungal commensals, but don't address the more important germ-free control.
2) It is hard to characterize individual immune metabolites/signals (e.g. IL-10, IL-6, etc.) as either good or bad. The context determines the effect and they show changes in at least 20 cytokines in Fig 3E. While they focus on IL-6 and TNF, it's not immediately clear those are necessarily a part of pathogenic inflammageing. LBP conversely, seems pretty hard to interpret as anything but evidence of barrier permeability and this result seems strong.
3) It's not clear how much of this effect would sustain over the long term. The amount of time between fecal transplant and mouse sacrifice/result generation was only 18 days. Experiments with such a short duration seem like they might capture an unrelated effect due to some other coincident factor.
Overall, a well done paper with a lot of interesting things, but also reasons to be very skeptical of the magnitude of this effect. As usual, I will end with: you can dramatically improve your microbiome health (whatever that term actually means) by eating a high fiber diet like most humans did for most of evolutionary time.
- wintermutestwin 4y ago>you can dramatically improve your microbiome health (whatever that term actually means) by eating a high fiber diet Is that (primarily) because high fiber food takes so long to digest that it gives more time for "stuff" to propagate in your gut?
- rootusrootus 4y agoI'm not an expert, but I would probably have guessed the opposite. Lots of fiber means nice, consistent bowel movements. I'm pretty sure it speeds up your digestive tract, if anything -- it doesn't take a long time to digest, it doesn't digest at all.
- tum92 4y agoWork in the field myself. The real answer is definitely we don’t know, but for whatever reason a high diversity (lots of different kinds of bacteria) seems to be almost universally good. Fiber is the major carbohydrate source for our gut microbiome, and a fiber-rich and fiber-diverse diet seems to provide lots of niches for various bugs to grow.
- majkinetor 4y agoNo, its mostly because it can't be digested at all by humans but are food for bacteria as every cow knows. The benefit of slow digestion by fiber is mostly for diabetes control. Fixing microflora (and hence influencing metagenome) however, is not that simple. You wont feed good bacteria only, but pathogenic too if you have them overpopulated, which will make things worst. You can't easily replace those with new ones coming from food because of the acid barrier. You might think that lowering it down is good idea, but its totally not, because you will soon find new neighbor h. pylory which can cause all kinds of shit, along with having less nutrientes available by stealing and unoptimal pH environment. Regular probiotics are usually meaningless (influencing environment like fart in the wind). Eating carnivoir diet makes your acid stronger which further strenghtens your defences (only great if you don't have invaders). Then, this is dynamic - good guys can become bad in specific context. The best way to improve your microbiome health is to find FT surogate, some great probiotic like Visbiome or VSL3, eat fermented foods, use prebiotics, and obviously dont use antibiotics in relaxed manner (save them for emergencies, like once in decade, and even then help flora repopulation and good luck with fungi proliferation) and do not remove your apendix just for the sake of it. Funny thing nobody mentiond antibiotics and how harmful they are. Yes, they can save your life but poping them every now and then borders to malpractice. I am a software architect, not a doctor, but machine is a machine.
- rebelos 4y ago> eating a high fiber diet like most humans did for most of evolutionary time Can supplementation be an effective substitute for fiber derived from real foods? If so, are there any particular kinds of supplements you'd recommend?
- curmudgeon22 4y agoPersonally, I've decided chia seeds are a good way to get more fiber. Also a good source of omega-3s. More calories than some other options, but I like the idea of whole foods. They have a decent mix of soluble/insoluble fiber.
- TedDoesntTalk 4y agoChia is not a good source of omega-3 because they are primarily ALA Omega-3: “ALA, the most common omega-3 fat, is an essential fatty acid that is converted into EPA and DHA. However, this conversion process is inefficient in humans. On average, only 1–10% of ALA is converted into EPA and 0.5–5% into DHA” https://www.healthline.com/nutrition/3-types-of-omega-3 https://www.healthline.com/nutrition/3-types-of-omega-3
- curmudgeon22 4y agoThanks, TIL.
- TedDoesntTalk 4y agoChia is still a great food anyway and I eat some almost every day! Good fiber. Just get your Omega 3 somewhere else.
- nextos 4y agoInulin: https://en.wikipedia.org/wiki/Inulin https://en.wikipedia.org/wiki/Inulin
- TedDoesntTalk 4y ago
- jimmytucson 4y agoAs a parent of young children, I have had sustained exposure to a diverse medley of fecal specimens varying in color, odor, consistency, and texture. Is there a particular stripe I should be targeting for transplanting from my children’s into my own microbiome?
- birdyrooster 4y agoI know you mean well but boy did this come off as profoundly weird.
- mushbino 4y agoI don't think we're too far off from people selling children's fecal specimens. I bet Peter Thiel is already doing just that.
- pkphilip 4y ago:) yes, quite disturbing!
- majkinetor 4y agoNo its not, people are just ignorant. You eat ton of shit. CTO of Microsoft wrote 6 books on molecular gastronomy named Modernist Cousine [1]. There are lots of pages in first book about managing environmental fecal matter (hint: there is a LOT of it around you and in the food you eat). [1]: https://www.wired.com/2011/02/ff-myhrvold/ https://www.wired.com/2011/02/ff-myhrvold/
- birdyrooster 4y agolmao "you eat ton of shit"
- LocalH 4y agoThe “fecal veneer”
- mionhe 4y ago
- beowulfey 4y agoI would slightly modify your suggestion for 1; it may be easier to gamma irradiate the fecal samples (or something) to kill all microflora instead. It won’t tell us whether the chemical effectors came from the host or the bugs but I would prefer comparing healthy mice than two separate classes of mice. Another idea I’m curious about would be to preserve fecal samples from a young mouse and transplant back to their older selves to see if that also shows the same effect.
- ce4 4y agoIt may not kill everything, eg. this one is known to be highly tolerant to irradiation: https://en.m.wikipedia.org/wiki/Deinococcus_radiodurans https://en.m.wikipedia.org/wiki/Deinococcus_radiodurans
- deleted 4y ago[deleted]
- emptysongglass 4y agoThis is going to sound crass but I am willing to be the sacrifical lamb to my own (and others) potential benefit: can my wife poop in my butt and can I poop in hers to gain some benefit? Along these lines, are there any potential health benefits to penis in butt sex? Or does the poop need to enter my butt?
- emptysongglass 4y agoI am legitimately asking a question in complete seriousness and I would like to know the answers. The subject itself is crass because it has to do with our excrement and sex. Please don't push this out of visibility because you find the subject (or the direct language I use) distasteful. Thank you.