Why Is There So Much Soluble Fibre In Human Breast Milk?

[tara]

@Stuart,
It might help to take a step back and realise that arguing that particular parts of what we did for survival and evolutionary reasons in the past should now be continued is a theory/philosophy itself.

I agree that humans have messed up some things.
I also value a number of inventions, constructions, environmental modifications, dietary modifications, social forms, etc devised by human minds. I have no intention of providing myself with the same environment that my ancestors have lived in through most of our evolution - even if it were possible.

I do agree that breastfeeding generally provides the best available food for infants. (If the mother has been poisoned, it won't be optimal, and formula may be preferable.)
I don't think your analogy necessary holds when you move on to adults.

 

[Stuart]

@tara
Who said anything about duplicating the environment that shaped us for most of our evolution? Aren't we discussing who we are not the environment that got us here. Isn't that the problem? We certainly wouldn't be having this discussion if we could duplicate the environment that shaped us. Nevertheless shape us it did. In ways that are fixed unfortunately. We are the product of our evolution. Nothing more, nothing less. ignoring who we are to suit a particular humans's dietary principles that ignore the our digestive system's design is unwise.

@ Zach
Why do you think human's are born sterile? They will be if delivered by caesarian section, but that is only a very recent technological development. Otherwise the mother's microbiome innoculates the emerging baby during delivery.
But Zach you'll get plenty of soluble fiber from a Peatarian diet as long as you eat things like onions/garlic, collagen, melons and other whole fruits. Doing things like straining orange juice to remove the pectin won't even dent that soluble fiber intake. You won't get anywhere near 70g, but your microbiome won't starve, I assure you. Just as you'll get plenty of pufa from a Peat diet too. Plenty of serotonin from even moderate exercise. The best ways of boosting serotonin are sunlight, massage, exercise, and remembering happy events. Just being happy creates a flood of serotonin. ln fact, so many of the things that Dr. Peat describes as 'bad' are provided in their evolutionary appropriate amounts by his own dietary principles. More soluble fibre would do you the world of good, but your microbiome certainly gets a lot from eating a according to his dietary principles automatically.
Stuart.

 

[Amazoniac]

I posted a study somewhere in this forum that they evaluated the effects of vaginal birth and c-sec. In the latter the babies acquired the microbes that they came in contact with first, on the surface of gloves, clothes, towels, etc. But then, after time, their microbes started to converge and started to look closer and closer to those who were breastfed.
I think that the amount of oligosaccharides in milk are there to encourage desirable microbes to stablish themselves in and close that window of opportunity for pathogens as soon as possible.
But you are right, people who follow Ray Peat's recommendarions probably get more fermentable carbs than they think they are getting.

Serotonin, happy hormone. Uh, oh; wait for it..

 

[XPlus]

Turning to evolution to find answers while our systems are constantly challenged with unnatural environment is irrelevant.

The amount of physiological stress inflicted upon us in modern time by toxic substances in air, water and food won’t be offset mimicking the diet and lifestyle of our ancestors.

unsaturated vegetable oils, ferrous iron and carrageenan in our foods, lead in air, food, and water, exposure to medical, military, and industrial ionizing radiation, vaccinations, pesticides, chlorinated hydrocarbons, nitric oxide (smog and medications) and oral contraceptives and environmental estrogens

The unconventional recommendations of Peat are thought of as a way to counter the unnatural exposures our ancestor haven’t faced.

Drinking water directly from the well or the river would be ideal in an evolutionary sense because it’s better than tap water and anything bottled. Nowadays, no one in their right mind drinks water directly from the ground. This is because we are aware of the potential dangers of drinking untreated water, in modern times, because it is likely contaminated.

We sometime have no choice but to drink chlorinated tap water, because the tradeoff of poisoning ourselves slowly compared to contracting something deadly or more poisonous than chlorine seems rational.

Similarly, the reason we "stupidly" encouraged to gulp and shower ourselves with unnatural things like aspirin, Vitamin E, magnesium and other things is the same reason we just kill the bacteria: it’s because desperate times call for desperate measures.

I’ve made my earlier argument of physiological stress making the body incapable of controlling bacteria and until the accumulated stress is reversed to some extent, the bacteria will have a negative impact on the system.

I do not disregard the idea that the gut flora can play a positive role in health. My argument is to challenge the idea that the bacteria are essential.

In modern time, it’s nearly impossible to have control on the gut flora when air, water and food isn’t in a natural balance. If one is to try living in the mountain area in Bali for a week and Dubai for another, they’d realise the impact of the environment on their health (and gut flora). In Bali the environment balance is much more natural and less toxic compared to an inorganic city like Dubai.

Since in modern times we’re mostly not in control of the environment we live in and the bacteria in that environment are in an unnatural balance, and it happens that the bacteria in themselves aren’t essential, then minimizing their activity seems to be best practice.

 

[Amazoniac]

Nothing that a good dose of supplemental pboyone won't solve. The ultimate happy hormone..

 

[Stuart]

@Xplus
I agree. we are exposed to a withering modern slew of environmental challenges. And I think it would actually be impossible to mimic the lifestyle practiced by early humans. Too much has changed. And besides, life until very recently was a constant struggle to find enough food, avoid being eaten, or just killed in some skirmish with the tribe in the next valley. But those humans just had to eat the way their bodies were designed. It was all that was available. We actually do have a choice. But isn't the best way to cope with all these new environmental challenges is to be in our best physical shape by not neglecting any part of our bodies, particularly as big a part of our digestive systems as our colon. I mean, our bodies are still exactly the same design. The colon still prefers soluble fiber, just as it always has. And we have ready access to fruit,collagen and vegetables, all of which contain varying amounts of that food. And if you need to add any extra firepower as well - Vit E Magnesium etc - but don't neglect the basics first. A well tended microbiome is an onboard vitamin factory as well, and also vastly improves mineral absorption. So you may find you actually need fewer supplements, because not as big a percentage of the ones your take as supplements or eat in food, end up in the toilet.
Also, don't forget tnat every single one of that aweinspiringly vast population of gut bacteria has only a 20 minute life to do its job in your colon. Why make it infinitely more difficult by denying it its preferred food? If we know that the beneficial ones prefer soluble fiber, don't you think it's a good idea to ensure those species are most able to thrive? If they don't, there's any number of pathogenic bacteria just itching to take their place. And the good bacteria actively control the bad ones too, as well as mediating so many important immune system networks. I get the impression that Dr. Peat is kind of annoyed to have a such a big sceptic tank at the lower end of his digestive tract. But you are stuck with your microbiome. Better to look after it properly than just ignore it surely. Or what seems infinitely worse, actively try to discourage it from doing its job. is it true that some people deliberately take antibiotics to try to 'sanitize'their colons?

@ amazoniac
Care to have a go at explaining to me why serotonin is considered bad? I thought serotonin wasn't the problem. That it's serotonin dominance that is undesirable. It's such an intrinsic hormone player in so many benefical processes isn't it? I understand that cortisol is always bad. But when is serotonin bad, and why?
Stuart

 

[Amazoniac]

There are a lot of opened threads discussing the problems derived from an excess of serotonin. Including a recent one by haidut associating with traumatic memories. But I agree with the balance and cortisol appears to protect the organism from furter damage. So we could imply the same thing for it, it depends on the context that they get a bad conotation.
On a side note, hypopboydism is a serious condition that must be treated as soon as possible to avoid a sense of emptiness and lack of general joy.

And regarding fiber, I don't think that fermentable carbs are able to select between beneficial and pathogenic microbes. It's food for whatever is inside..

 

[Zachs]

@tara
Who said anything about duplicating the environment that shaped us for most of our evolution? Aren't we discussing who we are not the environment that got us here. Isn't that the problem? We certainly wouldn't be having this discussion if we could duplicate the environment that shaped us. Nevertheless shape us it did. In ways that are fixed unfortunately. We are the product of our evolution. Nothing more, nothing less. ignoring who we are to suit a particular humans's dietary principles that ignore the our digestive system's design is unwise.

@ Zach
Why do you think human's are born sterile? They will be if delivered by caesarian section, but that is only a very recent technological development. Otherwise the mother's microbiome innoculates the emerging baby during delivery.
But Zach you'll get plenty of soluble fiber from a Peatarian diet as long as you eat things like onions/garlic, collagen, melons and other whole fruits. Doing things like straining orange juice to remove the pectin won't even dent that soluble fiber intake. You won't get anywhere near 70g, but your microbiome won't starve, I assure you. Just as you'll get plenty of pufa from a Peat diet too. Plenty of serotonin from even moderate exercise. The best ways of boosting serotonin are sunlight, massage, exercise, and remembering happy events. Just being happy creates a flood of serotonin. ln fact, so many of the things that Dr. Peat describes as 'bad' are provided in their evolutionary appropriate amounts by his own dietary principles. More soluble fibre would do you the world of good, but your microbiome certainly gets a lot from eating a according to his dietary principles automatically.
Stuart.

They are born sterile meaning they only become inoculated once entering into the world. So it would make sense that their first food would contain the soluble fiber. That does not in any way translate to adults and what fiber content they need.

I don't consider garlic or onions to be healthy foods and do not eat them. The same goes for almost all fruits since they are very under ripe when picked and contain too many gut irritants.

I believe that an evolutionary diet is not the perfect diet you or others make it out to be. I believe for much of our evolution, diet was all about survival and most of the time, not preferable. We have surpassed those times and our diets now should be tailed to best suit our health now in a world polluted with foods that in no way reflect the foods thousands of years ago. In that context, refined sugar might be a "super food".

 

[Stuart]

@amazoniac
'Supplying adequate soluble fiber to your colon absolutely encourages beneficial bacteria. It's a self regulating and whole body regulating system. Again, the amount of soluble fiber in breast milk demonstrates this so clearly. The baby''s immune system is very underdeveloped. The soluble fiber in its milk, from its first feed, selectively promotes the proliferation of the beneficial bacteria at the expense of the pathogens. Otherwise breast milk would be just as likely to make the baby ill, instead of being tailor made to get it's young microbiome on song as quickly as possible. And the immune system which colon and microbiome health has such an important role in ready to cope with the pathogens the world constantly throws at it. Don't forget, your microbiome is absolutely critical to your immune system. Germ free lab animals have to be kept in sterile environments, or environmental pathogens, which even the air we breathe is teeming with, would kill them in a matter of minutes. Your microbiome is your friend Amazoniac. Feed it the soluble fiber it is designed to consume. You are so much more likely to be exposed to the endotoxins pathogenic bacteria produce if you don't feed your microbiome a lot of soluble fiber. This is very well understood i'm afraid.
Whichever way you look at this, the amount of soluble fiber in breast milk clearly demonstrates how important soluble fiber is to colon health.
It sounds like pboy has a bit of a reputation here?
Stuart.

 

[Amazoniac]

The reason why the oligosaccharides in milk are beneficial is because the baby has an imature gut community and they encourage the growth of desired microbes. However in adults the situation changes and so does the circunstance in which someone ingest them and what type of fiber we are referring to. A baby drinking the mother's milk is much different than an adult with an infection ingesting undercooked starches.
I'm not questioning that fiber can be beneficial, just that it depends. And your health status will probably determine the ideal amount. Very little for those who are ill.

pboy doesn't have a repupation in here, he has a reputation in life. You can almost hear a choir of angels at the background when you read his posts.

 

[Stuart]

@ Zachs
If the an evolutionary diet wasn't ideal (you said 'preferable' I think) then you wouldn't have been as likely to survive. Evolution is driven by the need to survive. That's why it's called survival of the fittest. Just because we face new environmental challenges doesn't change the fact that you need to be as healthy as possible to survive the rigours they subject your body too. Why would an under functioning microbiome be any more desirable in the modern world than the world your forbears evolved in?
But can I ask you Zachs, if you don't eat the whole foods Dr. Peat recommends, what do you eat?
Stuart

 

[Stuart]

@ Amazoniac
So if a baby gets sick , you should stop feeding it breast milk because it contains HMO's?

 

[Amazoniac]

You have no choice. You have to feed breast milk hoping that his immune system takes care of the rest. However if you are an adult, you don't eat the same food every meal, so you can adapt according to your taste, which is a great indicator of how your meals should look like. Meals with too much fiber are unpalatable, and so do meals with too little since they are usually mushy or excessively liquid.
As an example, people that are sick often seek foods like broths..

 

[Zachs]

@ Zachs
If the an evolutionary diet wasn't ideal (you said 'preferable' I think) then you wouldn't have been as likely to survive. Evolution is driven by the need to survive. That's why it's called survival of the fittest. Just because we face new environmental challenges doesn't change the fact that you need to be as healthy as possible to survive the rigours they subject your body too. Why would an under functioning microbiome be any more desirable in the modern world than the world your forbears evolved in?
But can I ask you Zachs, if you don't eat the whole foods Dr. Peat recommends, what do you eat?
Stuart

Your belief is a biome deprived of lots of soluble fiber is under nurished, I don't believe this is true.

I eat mostly animal products rich in saturated fats and also simple sugars.

 

[EnoreeG]

@amazoniac
'Supplying adequate soluble fiber to your colon absolutely encourages beneficial bacteria. It's a self regulating and whole body regulating system. Again, the amount of soluble fiber in breast milk demonstrates this so clearly. The baby''s immune system is very underdeveloped. The soluble fiber in its milk, from its first feed, selectively promotes the proliferation of the beneficial bacteria at the expense of the pathogens. Otherwise breast milk would be just as likely to make the baby ill, instead of being tailor made to get it's young microbiome on song as quickly as possible. And the immune system which colon and microbiome health has such an important role in ready to cope with the pathogens the world constantly throws at it. Don't forget, your microbiome is absolutely critical to your immune system. Germ free lab animals have to be kept in sterile environments, or environmental pathogens, which even the air we breathe is teeming with, would kill them in a matter of minutes. Your microbiome is your friend Amazoniac. Feed it the soluble fiber it is designed to consume. You are so much more likely to be exposed to the endotoxins pathogenic bacteria produce if you don't feed your microbiome a lot of soluble fiber. This is very well understood i'm afraid.
Whichever way you look at this, the amount of soluble fiber in breast milk clearly demonstrates how important soluble fiber is to colon health.

Stuart.

Just catching up here, and reading thru all the posts. On about day one of this thread, Amazoniac said:

Probably the best term is fermentable carbohydrates, since that includes all types of it. Milk in this case contains oligosaccharides and there are many studies explaining its role in infants.
The main reason mammals have that is to avoid pathogenic opportunistic microbes from colonizing your gut before the desired ones get a chance to settle. But after that happens, you have to really put effort to disrupt that environment; and our modern lives are pretty effective for that.

There's a lot of agreement here, and I like how Amazoniac expressed that it takes EFFORT (or I'll add, maybe some ignorant carelessness) to disrupt a healthy gut that was inoculated with amniotic germs, vaginal germs and breast milk.

So our modern lives muck up the works down there. And we have people who claim fiber is the great savior (and I admit to being one of those) and people who claim following Peat and minimizing fiber has saved them from one form of dysbiosis or another.

So I see comments here as siding in favor of Peat's guidelines, or Stuart's ideas. Still lots of confusion for me. A lot of people seeing a change for the better in going on a Peatarian diet, and along with that, they attribute the improvement, in part, to reducing their fiber intake. That's still an open question for me. Many people rid themselves of bowel problems just by removing either dairy or grains or both from the diet. The fiber was not a factor. So I still don't see any proof that Peat's ideas on fiber (and no one has thrown in a single quote here yet except the recent one from Jennifer) are, by themselves, a solution.

From what I understood from all of your posts, Stuart, is that the overall message is that consuming fiber to a certain amount is beneficial and that fermentable carbs can improve the health of those who are already healthy. Which I agree.
But when you are ill, the situation is more delicate and nuanced..

Back to Jennifer's discussion with Ray:

Stuart, below is part of an email exchange I had with Ray this past February where he mentions his up-to-date view on fiber. I gave him my blood labs which showed low cholesterol and I told him about the intestinal inflammation from a bacterial overgrowth I'm currently dealing with.

Ray wrote: "Low cholesterol can be caused by intestinal inflammation, and starches are a common cause. Sweet potatoes are effective promoters of bacterial growth, rice and potatoes can cause gas especially if they aren't well cooked."

I wrote: "Do you think eating a diet that consists of milk, cheese, meat/shellfish, eggs, juice and small amounts of butter or coconut oil would be a nutritionally complete and healthy diet to do? After doing the fruitarian diet, I don't seem to tolerate fiber at all. It gives me a lot of painful trapped gas in my colon area. I could try the flowers of sulphur again and see if it helps, but for the time being I'm hoping to avoid fiber if I can."

Ray wrote: "I think fiber is always a risk (I avoid them all except for occasional well cooked mushrooms and bamboo shoots, which are germicidal). The foods you list contain all the essential nutrients."

If this is really Peat's latest take, then he's more stringent than ever, for I remember him saying to concentrate on insoluble fiber, which is aligned with the latest thinking on what does the most good for the immune system (assuming you still have sufficient soluble fiber to thoroughly feed your microbiome). The first quote above sounds like typical Peat. Avoid starch. It makes sense, as it's a way to lessen the feeding of bacteria in the small intestine.

Jennifer's next response implies (to me) that it well could be her following Peat's fruit guidelines that is causing her possible SIBO, so when she suggests a diet nearly empty of fiber other than the juice, my first thought is "Gosh, she's starving her poor bacteria and their only hope for survival is in her SI".

So when Ray answers "fiber is always a risk" its not unlike other quotes from him, but he has also praised cooked greens in the past, and other vegetables. It just depends on which interview you happen to catch. For him to say he now eats only mushrooms and bomboo shoots (or these are his only recognized fibers) is getting a bit extreme. He's focusing on germicidals, or thinks he is.

So I'm very interested in, not just the testimony of Peat followers as to his interpreted diet providing relief from bowel problems, but in finding out exactly what part of his diet gave the relief. Like Stuart, I still find it difficult to believe that heavily restricting fiber of any kind is a good long-term solution, considering the connection between adequate commensal bacteria and a healthy immune system.

Has anyone gone on a Peat diet to fix health problems, then gone back to more fiber in the diet?

I ask, because I would never try a Peat type diet. I have great health, no gut problems, and eat whatever fiber I wish (but don't happen to eat grains any longer - though I never noticed a problem with them) and actually think of my microbiome requirements before I think of my macro / micro - nutrient needs. That is, I always put fiber first and consider it the most important of my 4 macronutrients. Then, I follow with concerns of fats, protein and carbs, but that's probably after insuring I get lots of phytonutrients, enzymes, and vitamins from the fiber sources I use.

As someone said above, the average microbe lives 20 minutes? Populations die in a flash. They swell only slightly more slowly. They flourish and become famished based on your particular choices for your 3-4 meals a day. I can see someone radically changing their total microbe count in a single day. Either direction. So if numbers matter and bring a fix, a fix is only a day away if you have no other bowel concern than the numbers. You could cut your friendly bacteria in the gut down by 80% and not suffer, short term, because if you are healthy, they will still outnumber the pathogens 1000 to 1. That's part of their job - to keep count and stay dominant. And if you swell the numbers overnight because you ate a full half pound of green beans like I did tonight, you shouldn't even notice the change. But you might increase your microbiome size by millions of bacteria. If you ate some dirt with the beans, or some unfamiliar weeds, you might even add a few new species, or even several dozen. It's all good. I've never been hurt by eating dirt. I just don't eat more dirt than food. It's a trace of new species that you want, as I understand it.

I still hope to learn a lot on this thread.

 

[Amazoniac]

It's not that simple, they die fast but they grow fast, so that evens out. And if you eat constantly, you have a constant supply. I think this is why some fasting in your day can be beneficial.

There are many logs from people that engage in diets that restrict carbs like the SCD and after a long time they introduce the removed carbs and the problems remain, sometimes they get worse. Their proponents encourage the protocol for as long as 2 years. Haha! Yet, the success cases are rare.
This is a great example that removing fiber doesn't mean that you get rid of microbes. It's hard to starve them, in order to do that you have to starve yourself first. Very low-carb diets are pretty effective for that.
This also supports the idea that your immune system probably shape those microbes more efficiently than a diet high in fiber, and that you don't need excessive amounts of it to get their benefit. A modest amount every meal does the job.

 

[Jennifer]

Back to Jennifer's discussion with Ray:

If this is really Peat's latest take, then he's more stringent than ever, for I remember him saying to concentrate on insoluble fiber, which is aligned with the latest thinking on what does the most good for the immune system (assuming you still have sufficient soluble fiber to thoroughly feed your microbiome). The first quote above sounds like typical Peat. Avoid starch. It makes sense, as it's a way to lessen the feeding of bacteria in the small intestine.

Jennifer's next response implies (to me) that it well could be her following Peat's fruit guidelines that is causing her possible SIBO, so when she suggests a diet nearly empty of fiber other than the juice, my first thought is "Gosh, she's starving her poor bacteria and their only hope for survival is in her SI".

So when Ray answers "fiber is always a risk" its not unlike other quotes from him, but he has also praised cooked greens in the past, and other vegetables. It just depends on which interview you happen to catch. For him to say he now eats only mushrooms and bomboo shoots (or these are his only recognized fibers) is getting a bit extreme. He's focusing on germicidals, or thinks he is.

So I'm very interested in, not just the testimony of Peat followers as to his interpreted diet providing relief from bowel problems, but in finding out exactly what part of his diet gave the relief. Like Stuart, I still find it difficult to believe that heavily restricting fiber of any kind is a good long-term solution, considering the connection between adequate commensal bacteria and a healthy immune system.

Oh, I don't have SIBO, EnoreeG. I had the hydrogen breath test done and that came back negative. My issue is with trapped gas and piercing pain in my lower intestines when I have fiber. Cutting it out has been the best thing for me. My stomach now stays as flat by the end of the day as it is first thing in the morning and I no longer have acid reflux or heartburn. Also, my digestion is finally good. However, context is everything.

I did 80/10/10 for more than 2 years and was eating upwards of 200g of fiber a day. When I fractured, I was then put on a WAPF diet and was eating daily almost a jar of sauerkraut, quarts of yogurt, huge salads, lots of raw milk and cultured cheese. Then I did RBTI where I was put on a bunch of digestive enzymes and supplements. I think I was up to 16 or more at one point. Then I refed on 6000+ calories a day and close to 10,000 during times of extreme hunger that would last a week here and there. I take full responsibility for the current state of my gut. Doctors wrote me off as incurable and would only "manage" my disease so I was on my own and I did the best I could with what I knew at the time.

Anyhow, if you want, I can send you the original email exchanges between Ray and I. I'd post them here, but I'm not sure I'm suppose to be publicizing his email address?

 

[tara]

@tara
Who said anything about duplicating the environment that shaped us for most of our evolution? Aren't we discussing who we are not the environment that got us here.

I was considering the food we eat as environmental. You have been talking about maintaining the same conditions in our gut by feeding particular kinds of substances on the basis that we have evolved with this set up.

You don't seem to be seeing or acknowledging that you are choosing particular assumptions about what the past tells us about the future. It is common for people to think that how we see things is just how it is, while other people have misinformed or irrational theories or philosophies. It's hard to see the philosophy you are swimming in.

I am not saying you are wrong about everything, just that you are treating others views as (unnecessary or erroneous) theories, and your own as not a theory, just how things are.

That milk has particular substances may indicate that babies can do well with those substances. There are other differences between baby nutritional needs and nutritional needs at other ages, too (eg. iron, tryptophan). The fibre you have been promoting for adults is mostly not the same as the fibre in breast milk, anyway. The analogy seems irrelevant to me.

 

[tara]

So our modern lives muck up the works down there. And we have people who claim fiber is the great savior (and I admit to being one of those) and people who claim following Peat and minimizing fiber has saved them from one form of dysbiosis or another.

So I see comments here as siding in favor of Peat's guidelines, or Stuart's ideas.

I'm not completely fixed in either extreme on the fibre issue. I will argue with anyone who says we all need lots of fibre, since clearly there are many who do better with very little. But I will also argue with anyone who says that people who have maintained their health well while eating generous fibre should radically reduce it.

It seems to me that fibre can have both costs (eg sometimes endotoxin and/or serotonin) and benefits (reduced estrogen, sometimes improved motility, maybe improved immunity), and where the optimal balance of these lies depends on the kind of fibre, and a person's health state and microbiome, and it may change over time.

 

[EnoreeG]

It's not that simple, they die fast but they grow fast, so that evens out. And if you eat constantly, you have a constant supply. I think this is why some fasting in your day can be beneficial.

There are many logs from people that engage in diets that restrict carbs like the SCD and after a long time they introduce the removed carbs and the problems remain, sometimes they get worse. Their proponents encourage the protocol for as long as 2 years. Haha! Yet, the success cases are rare.
This is a great example that removing fiber doesn't mean that you get rid of microbes. It's hard to starve them, in order to do that you have to starve yourself first. Very low-carb diets are pretty effective for that.
This also supports the idea that your immune system probably shape those microbes more efficiently than a diet high in fiber, and that you don't need excessive amounts of it to get their benefit. A modest amount every meal does the job.

I think it is definitely simple though, Amazoniac, on a gross basis. Even though microbes die in minutes, I wasn't saying delaying a meal would accomplish a massive die off. But restricting fiber-rich carbs for a day or two might. Remember, microbes have a non-active state, spores or something. They come back when the food does, but don't have to eat in the meanwhile. So one might have to wait for some purging of the spores via a normal poop schedule to really cut the numbers. And the spores won't wake up until there is plenty of food. So I still believe the numbers of functioning microbes can be changed quite rapidly. Not that it matters as long as the dominant species remain the dominant species and that they are commensal.

I've never checked the SCD before. Quite interesting. How does it map to FODMAP diet? I don't know, but I could eat an SCD diet and have all the fiber I need. I just checked the page of foods beginning with "S" and found that legal foods include "seeds, spinach, split peas, squash, string beans, swede (rutabaga). The diet is not at all restrictive of fiber. There are foods there with all types of fiber so any fiber-nut could eat as much fiber as they wished and be quite healthy. However, they could also select foods that were quite deficient in fiber and still comply with the diet. From some articles I've read now on the SCD diet, it is not at all an anti-fiber diet, though it does recommend staying away from processed fibers that are added to manufactured "foods" that people eat.

So I don't see that you can categorically say that SCD is a carbohydrate poor diet, OR a fiber poor diet, nor that you can say with any meaning (regarding fiber) that "after a long time [on SCD] they introduce the removed carbs and the problems remain, sometimes they get worse.". The obvious case to use here that of wheat, which is thought of as mostly carbohydrate. It and other grains are ILLEGAL on the SCD. Yet they are fiber rich foods. Eliminating just grains and having success on SCD, and then restoring them to one's diet would totally explain many people's "getting worse". It has nothing to do with fiber or a failure of the SCD. The way I interpret SCD is that it is getting people OFF junk and ON real food. That's it. They understand that what's wrong with people's guts is not the food, it's the chemicals being introduced or the complete lack of nourishing foods that are spoiling the GI tract. Fiber doesn't even seem to be an issue on SCD from my brief readings.

On your final statement on immune system shaping, I think science today generally sees the microbiome as shaping the immune system, with very little ability for the human component to at all shape the microbiome's part in immunity. About all humans can do is, as you said in your first post on this thread, "The main reason mammals have that [fiber in human milk] is to avoid pathogenic opportunistic microbes from colonizing your gut before the desired ones get a chance to settle." Even though you seem to be off that track at the moment, for me that is key: The human element can choose and try to maintain a goodly number of pro-life microbial species, such that they can control all the pathogens. We don't get to select the numbers or the species of any of the critters. It's trust, and going by a few rules. The primary rule is that bacteria maintain environment over adversaries via quorum sensing. They continually count and diminish opponents selectively, by species. It's all up to them. So just make sure you don't do something to put those "pathogenic opportunistic microbes" as you called them into the majority. That's it. That's why I say it's "simple". We only need to follow that one rule and the microbiome will take it from there. I'd say 99.99% of the people participating on this forum have no idea which species, or even Genus of bacteria are predominant in their gut. Does it matter. Apparently not, if the species is not pathogenic.

I'm not trying to be especially difficult with you, but I just don't want a point of view regarding fiber to be misconstrued as being "anti-SCD". I don't have any issue against that diet.