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

[Such_Saturation]

Clostridium histolyticum is a species of bacteria found in feces and the soil

 

[EnoreeG]

@EnoreeG, Kasper and Suikerbuik (intriguing nom de plume btw.)
As I indicated , I'm going to stay out of this for a while. I think I just antagonized too many people.
But I just wanted to congratulate you all for continuing this conversation in much more measured tones than I could even dream of.
EnoreeG, you are extraordinary. I warm more and more to Kris Kresser's thoughts. That wake up call about the limitations of classical endocrinology was very timely. Microbes' expertise in producing/modulating/mediating hormones predates their mammalian hosts complementary mechanisms by millennia after all.
But let's face it. We've only developed techniques to even sequence the genes of our microbiota in the last few years. So it's hardly surprising that classical endocrinology isn't seeing the big picture.
I've always been surprised by 'Dr. Peat not giving any apparent role to COLON microbiota. He only talks about keeping the S. I. sterile. The colon couldn't be even moderately sterile if you wanted it to be. Which is baffling enough.
I find it inconceivable that anyone would want to have sterile poo. I was looking at a diagram of the human digestive tract recently and I was struck by what a huge bag of bacteria the colon is.
Even if this thread peters out, which it may well do, you've all sharpened my wits incalculably.
I wish it were not so, but my presence is just far too inflammatory. It was exhausting for me and everyone else.

I agree with those who say "Don't go away!". There was only a brief tempest involving a couple of flames. And generally you were supported even after the disruption, so I'd say you are good to go! I think the latest contributors here are making some progress too, thanks in large part to your groundwork. As we know, it's difficult to grasp new ideas, not because they are weighty, but mostly because they are different and make us feel strange handling them. You've helped a lot with repeating the ideas and continuing the discourse until most of us are more familiar with the issues now. Keep up the good work.

Yes, the gene sequencing techniques are quite new, as a science even, and even newer to the doctors who are now starting to study the results of the studies, and really, really new to the rest of us, including a lot of doctors, who have only just opened up an article or two. So we shouldn't push ourselves too deeply into a dungeon for inciting a riot when we mention such new concepts. Realization has to start somewhere, and the reactions always have to be nasty for a while. Cognitive dissonance and all that stuff. If Peatarians know anything it is the vile reactions that often come from presenting obtuse ideas to unready minds. It's just that all over again here, I suggest.

 

[EnoreeG]

Ctrl F “fiber” is all you need to do :). Only maybe not if there were 48h hours in a day, sometimes 2 words are enough.

I am not looking for microbiome studies showing their importance or role of existance. I’m beyond that. I do like to find out about their role and interaction with the human immune system, epithelium and else, but that’s not point of discussion to me.
For me this discussion is about the essentiality of supplemental fiber or excess dietary fiber, I am just not convinced about it. And certainly not in the presence of gut dysbiosis.

Speaking for myself, I don’t aim for zero fiber.. I believe that what’s in our food, fruits, vegetables, collagenous parts of meat, etc. is sufficient.

Looking at your articles more closely. I can tell you that I’ve read the ncbi's before and even went through 'm more than once. As on the quote from Kresser. I’ve read such things several times too and it’s not new - thanks for sharing though.

I never disregarded the microbiome. I read multiple studies including your aforementioned, and indicated more than once that it is an integral and important aspect of the human body. I know it is involved in auto-immune diseases and every chronic disease.

The microbiome is not neglected. It’s just believed that it has amazing self regulating capabilities and emphasis should be put on different aspects all with the same goal in mind.

A decent hypothesis integrating all aspects and in line with, though not still completely covering: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4432792/

I finally hear you Suik! How dense I must be. No, we get sidetracked. But I did actually go search to see what we had been on 2 weeks ago (July 1), and there it was, you saying this same thing....

I too would like to see more convincing evidence for an high amount of fiber in our diets. I also would like to see conclusive amounts of butyrate produced by a more ancient diet and if current diets really lack this. I think the most butyrate stuff is done on mice but human evidence is lacking. Not that I think the studies are false, but I think there are other more important mechanisms at play in human diseases.

It is clear that you cannot avoid fiber completely, but the question is, do we really need additional fiber?

and I answered you, but here I'll put my answer to the same request from jyb on that date:

jyb, allmost every paragraph here is an argument against accepting the values of fiber that a typical, pro-fiber article touts, so I'm not trying to convince you that the "science" in my pro-fiber articles is looking at it any other way than you wish to see it....

I'll point out that when I praise fiber, I have yet to say "how much". So an argument against "a lot of fiber" is actually the most acceptable argument you've presented. It's a nebulous target and I totally agree with it. I'm certainly not for "a lot of fiber" and all that would imply. For all I know, what I actually now think of as a dangerously low level of fiber (I don't really have a number, but lets just say 8 grams of fiber!) may be fine for just about anyone's health....

I'd say in my contributions here, I mostly want people to be aware that the microbiome matters as a significant part of the immune system, and it does need some fiber to be robust in the large intestine. A carrot salad of some small size may be fine for meeting this goal. I don't know, so I don't quantify a minimum fiber intake.

I underlined that last part just now, just to be clear on how I feel.

So to answer you today, I'd have to say my definition of ample fiber is more a functional definition. Whatever fiber it takes to let your gut microbiota keep you from suffering from pathogens and vitamin shortages. Each can determine his own requirement.

For many unfortunate people, certain gut "conditions", seem to tell them they need to limit their fiber intake below what they would wish, thus never allowing them to achieve proper health. I hear the complaints. I admit I don't have much to offer except to encourage open mindedness. Because there are practitioners out there who treat IBS and Crohns, etc. with fiber and achieve good results. These type diseases, as Stuart pointed out, are often brought on by dozens of years of gut neglect. They won't fix easily. The body is seriously damaged and suffering continually. The road to health is going to be a rocky one and it may end before these people ever find success again. But all this, to me, doesn't mean that once they get healthy, they can maintain good health without sufficient fiber to maintain some commensal bacteria. That's what I get out of my research on this. In the meantime, these people may wish to ignore all I say. That's fine. We all have to do what we have to do. But I admit there are going to be people who have experiences that turn them away from fiber.

The fact remains though that more and more doctors, and health studies are looking at the gut microbiota to help fix almost every degenerative condition that now plagues modern man. So a person who is deficient in this healthy gut micriobiome is probably going to see themselves more and more clearly as lacking a significant key to health in the near future. The fact that they want to turn away and not view this, I can't help. This just happens to be one of the heavily hyped "fix all ails" going on right now. Doesn't mean it's wrong; doesn't mean it's going to be as great a solution as is thought. We'll see. Maybe soon there will be ways to more quickly get people over the horrible gut issues like IBS that seem to discourage people from confronting the values of fiber. I am hoping so, with a bit more study.

Suik, regarding your article, yes it seems to be integrating our study here, showing the interrelationship between the human and the microbiome, if I read it correctly. They both can effect the other. Stress can weaken the human, and cause invasion of the body by endotoxins. About all that can be done when that happens is to have as healthy an immune system as possible, to reduce the invasion. I assume, as the article implies, that your microbial mix is important in this regard, as the endotoxins talked about are generally from the gram-negative germs, and these tend to be minimized in a healthy gut environment. But definitely, stress plus endotoxins spells trouble. Did I read this right?

 

[Suikerbuik]

Revealing study Kasper, thanks! Almost a one of a kind study! Doesn't answer the question about fibers, but we shall leave that in the middle . Also in my perspective all their findings add up for Dr. Peat, certainly as long we don't know more about the microbiome.

For example I like the high concentration of ethanol in healthy people suggesting disinfecting properties and maybe/likely lower bacterial counts healthy control compared to in AD or PDD-NOS. The methanol producing micro-organisms by fermenting pectin is also noteworthy and, although it is esterified by other species, methanol compared to ethanol is really toxic and uptake will be the case. The increased free amino acids also suggest something, either the food is not digested or absorbed properly or there is an overgrowth present. The SCFA and butyrate aspect is interesting as well, but with so much going wrong it is hard expect what the effect on the interactome will be. All this suggests to me that instead of pre or probiotics, fecal transplant may be the only hope for resolution - depending on the severity of course since it also seems to be a quite plastic syndrome. Or a some really intriguing/ promising drug has to be developed e.g. affecting quorum sensing as is currently being tested for some types of cancer like pancreatic cancer and as 'antibiotic' for infectious diseases.

What this also does not answer is the origin of the microbiome. Preliminary research suggests that autism develops in a specific stage in the womb http://www.ncbi.nlm.nih.gov/pubmed/24670167. Other research I have seen come by (on the edge of questionable maybe) suggests that a mother with low thyroid function has 4 times higher chance of bearing a child with AD - a present . Since colonization is really going frenzy (thanks Stuart) after delivery it could well be that the brain directs bacterial colonization. You could think it is far fetched but it turns out the brains controls everything and I'd not be surprised if this were actually true!

Suik, regarding your article, yes it seems to be integrating our study here, showing the interrelationship between the human and the microbiome, if I read it correctly. They both can effect the other. Stress can weaken the human, and cause invasion of the body by endotoxins. About all that can be done when that happens is to have as healthy an immune system as possible, to reduce the invasion. I assume, as the article implies, that your microbial mix is important in this regard, as the endotoxins talked about are generally from the gram-negative germs, and these tend to be minimized in a healthy gut environment. But definitely, stress plus endotoxins spells trouble. Did I read this right?

Oh sure you are right. Chronic stress is always troublesome, but the definition of what stress means is context dependent. What also can be done besides focusing on a strong immune system, is having resilience and an abundance of resources.

My molecular definition of stress*. A moment in time in whereas, locally or systemic, the demand of energy or resources is higher than the amount being produced or reserved for a particular process involved in counteracting that stimulus, requesting for a rearrangement of energy expenditure, a temporal increase in energy production (read glycolysis), and, inextricably bound, a shifting of resources. Otherwise commonly known as “General adaption syndrome” originally presented by Hans Selye.

I especially like the next quote:
“Every stress leaves an indelible scar, and the organism pays for its survival after a stressful situation by becoming a little older.” – Hans Selye.

*I say my definition as this is not quoted and I stand behind what I write, but ALL credits belong to Dr. Peat and others.

A healthy 'microbial mix' of course important and they also state that fiber found in amounts that are present in natural foods is preventative against a chronic low endotoxin burden compared to a SAD control, but they referred to a study with healthy controls.
If I may make a note though, the notion of someone else that bacteria are interpreted by the body as stressful is kind of substantiated. But in a good way. It seems that it learns the brain how to filter ' non harmful' treats, and being sterile leaves you with NO resilience to stress after reintroducing a microbiome.

edit see added link

 

[HDD]

I think the following from Ray Peat's article is relevant to this discussion. Women of child bearing age have a peculiar flora - gram-positive lactobacilli.

"Since the bowel becomes inflamed in influenze, it is reasonable to think that some of the symptoms of "the flu" are produced by absorbed bowel toxins.

The variations in the post-influenza syndromes are very likely influenced by the nature of the bacteria or foods which are present, chronically or at the time of an uncompensated stress or inflammatory disease. K.M. Stevens has argued that while rheumatic fever and glomerulonephritis are caused by the antigens of streptococci, systemic lupus erythematosis (SLE) is probably caused by the antigens of gram-positive lactobacilli found in the normal flora.

Migraine, SLE, chronic fatigue syndrome, thyroid problems, and some kinds of porphyria seem to be more common in women of re-productive age, and are often exacerbated by premenstrual hormone changes. According to Stevens, "SLE is almost entirely a disease of women of child-bearing age. One possibility for this selection could be that women during this period harbour a peculiar flora. This is indeed the case; large numbers of gram-positive lactobacilli are present in the vagina only during the thirty-odd years when regular menstrual activity is present."

On a typical diet, tissues progressively accumulate linoleic acid, and this alters the structure of mitochondrial cardiolipin, which governs the response of the mitochondrial enzymes to the thyroid hormone. This process is especially evident in the female liver. In the “autoimmune” diseases, such as lupus, there are typically antibodies to cardiolipin, as if the body were trying to reject its own tissues, which have been altered by the storage of linoleic acid. The altered mitochondrial function, which is involved in so many symptoms, can become part of a vicious circle, with endotoxin and estrogen having central roles, once the stage has been set by the combination of diet, stress, and toxins.

The premenstrual estrogen-dominance usually leads progressively to higher prolactin and lower thyroid function. Estrogen is closely associated with endotoxinemia, and with histamine and nitric oxide formation, and with the whole range of inflammatory and “autoimmune” diseases. Anything that irritates the bowel, leading to increased endotoxin absorption, contributes to the same cluster of metabolic consequences."

http://raypeat.com/articles/nutrition/carrageenan.shtml

 

[cantstoppeating]

...
Even if this thread peters out, which it may well do, you've all sharpened my wits incalculably.
I wish it were not so, but my presence is just far too inflammatory. It was exhausting for me and everyone else.
...

...
If that's the case - if he thinks there's even an iota of truth to it - then I clearly don't belong here. I suspect there's a few people here who already think that

All the best everyone. It's been a very interesting experience. And my apologies for ruffling a few feathers.
...

...
I'll continue to keep an eye on what people are posting if that's O.K. But the people who think I'm a troll will be very relieved to hear I won't be commenting further. The Peat quote HDD posted makes it abundantly clear that Dr. Peat see's the very notion of a healthy gut microbiota as an oxymoron. And this is The Ray Peat Forum after all.
...

Stuart, no need to victimise yourself and act as though you're being shunned because you simply said something contrary. You're not a bearer of truth among amass of sheep. Your reasoning didn't (and still doesn't) make sense and you're rightly being called out.

In reality you haven't yet grasped what evolution is about. And instead of addressing it you seem to fallback on the idea that bacteria are 'optimal' because it's an evolutionary trait and then talk about downstream effects of bacteria y having beneficial effects on some thing x as justification. I don't need to know a single thing about bacteria to know that your premise doesn't hold.

The 'support' you're getting is from others who are equally in the dark as you are. This isn't about Ray Peat vs 'bacteria' or Right vs Wrong or Me vs You. This is about Thinking clearly vs Thinking unclearly and so far all you've done is the latter while trying to mask it as anything but. :)

Edit: Added smiley face.

 

[narouz]

https://www.youtube.com/watch?v=_Twre6ItGEI

 

[cantstoppeating]

https://www.youtube.com/watch?v=_Twre6ItGEI

Taking passive aggressive jabs at me in you posts (here and elsewhere), does seem as though you're quite stressed.

It's all banter until you get obsessive. Relax narouz, take some thyroid. Let's not derail this thread but keep it on track.

 

[Stuart]

Thanks CSP, you're an inspiration!
So for all you other poor souls out there who are, as our learned friend points out, 'equally in the dark', here's another article to mull over.

http://www.gidoctor.net/client_files/fi ... f-SIBO.pdf
I think the number one indication that your S.I. is a SIBO train wreck is not being able to tolerate fermentable fiber (bloating particularly'). I wonder why populations that eat a prodigious amount of fermentable fiber,like the Hadza or breast feeding infants don't suffer from SIBO? No wonder Dr. Peat recommends raw carrot. I think anyone with SIBO produces a lot of endotoxin. You're only meant to have a small population of bacteria in your S.I. (similar to your stomach, mouth and skin - Amazoniac posted the ideal bacterial populations of the various parts of the human microbiome ages ago) unlike your colon, which has more bacteria than all the other cells in your body by a factor of 10.

And CSP. Could be a serotonin excess man. Get it looked into. But please stop trying to claim your're right. Here let me help you .
I COULD BE WRONG. See, I'm still alive. Worth a try don't you think? Effective communication is all about being able to respectfully disagree. Not about pretending to be the only sane person in the room. Or claiming someone who is disagreeing with the prevailling opinion A LOT is a troll.

 

[cantstoppeating]

Thanks CSP, you're an inspiration!
So for all you other poor souls out there who are, as our learned friend points out, 'equally in the dark', here's another article to mull over.

http://www.gidoctor.net/client_files/fi ... f-SIBO.pdf
I think the number one indication that your S.I. is a SIBO train wreck is not being able to tolerate fermentable fiber (bloating particularly'). I wonder why populations that eat a prodigious amount of fermentable fiber,like the Hadza or breast feeding infants don't suffer from SIBO? No wonder Dr. Peat recommends raw carrot. I think anyone with SIBO produces a lot of endotoxin. You're only meant to have a small population of bacteria in your S.I. (similar to your stomach, mouth and skin - Amazoniac posted the ideal bacterial populations of the various parts of the human microbiome ages ago) unlike your colon, which has more bacteria than all the other cells in your body by a factor of 10.

And CSP. Could be a serotonin excess man. Get it looked into. But please stop trying to claim your're right. Here let me help you .
I COULD BE WRONG. See, I'm still alive. Worth a try don't you think? Effective communication is all about being able to respectfully disagree. Not about pretending to be the only sane person in the room. Or claiming someone who is disagreeing with the prevailling opinion A LOT is a troll.

Well, here you go again.

You post again referring to x, y, z populations and say that because they have bacteria and are 'healthy', bacteria are thus 'optimal'.

If you still cannot see the fault in your reasoning, then you are in the dark and yes you are wrong. This is the case of you trying to insist that 1 + 1 = 6, and I'm saying it's not but that 1 + 1 = 2 and you're rebutting with '...effective communication is all about being able to respectfully disagree.'

Goodluck to you.

 

[Stuart]

Goodluck to you.

That's a start :)
And to you.

 

[Nicholas]

the only reason any of us regularly visit this forum is because we are messed up in some way. yes, even pboy (well, when he did visit).

 

[Stuart]

the only reason any of us regularly visit this forum is because we are messed up in some way. yes, even pboy (well, when he did visit).

Yes he's been awfully quiet lately. Maybe he's not messed up any more?

 

[Amazoniac]

I think that he's been down lately. I heard that Aphrodite rejected him claiming that she couldn't stand being the beast of the beauty.

 

[Amazoniac]

Stuart, I haven't posted about the ideal bacterial populations, it was the average.
But I think that what you are doing is valuable, provoking people's beliefs; 40 pages so far of that. Unnecessary to leave when you cleary don't want to do that.

This obsession about GI microbes most of the time is a clue that a person is trying to fix something there. Otherwise - generally - they'll just take that for granted and wouldn't even care that much. Healthy GI microbes are a consequence of a healthy person, not the contrary, with the exception of some acute infection.

 

[EnoreeG]

Thanks CSP, you're an inspiration!
So for all you other poor souls out there who are, as our learned friend points out, 'equally in the dark', here's another article to mull over.

http://www.gidoctor.net/client_files/fi ... f-SIBO.pdf

Thanks, Stuart. I got a lot out of the reference. It emphasized some things I didn't even realize, or had read and forgotten. Like that lower gut bacteria make fat soluble vitamins available to the body, and actually make vitamin K2 (our storage form) from K1 in veggies.

And that "balance of protective versus harmful enteric bacteria determines whether there is mucosal
homeostasis or inflammation."

And "C. difficile commonly colonizes infants without harm," Hmmm. Probably all the olygosaccharides in human milk that feeds the commensal bacteria that in turn, keep C. difficile totally in check.

Along those lines, this is interesting:

Despite the role of milk to serve as a sole nutrient source for mammalian infants, the oligosaccharides in milk are not digestible by human infants. This apparent paradox raises questions about the functions of these oligosaccharides and how their diverse molecular structures affect their functions. The nutritional function most attributed to milk oligosaccharides is to serve as prebiotics - a form of indigestible carbohydrate that is selectively fermented by desirable gut microflora. This function was tested by purifying human milk oligosaccharides and providing these as the sole carbon source to various intestinal bacteria. Indeed, the selectively of providing the complex mixture of oligosaccharides pooled from human milk samples is remarkable. Among a variety of Bifidobacteria tested only Bifidobacteria longum biovar infantis was able to grow extensively on human milk oligosaccharides as sole carbon source. The genomic sequence of this strain revealed approximately 700 genes that are unique to infantis, including a variety of co-regulated glycosidases, relative to other Bifidobacteria, implying a co-evolution of human milk oligosaccharides and the genetic capability of select intestinal bacteria to utilize them. The goal of ongoing research is to assign specific functions to the combined oligosaccharide-bacteria-host interactions that emerged from this evolutionary pressure.

which was not from your link, but this one:

http://www.ncbi.nlm.nih.gov/pubmed/18626202

Back to the article you provided, I thought the many studies mentioned that showed significant success by using probiotics (more germs added to the gut) to treat IBS, Crohn's, and Ulcerative Colitis. I see your article provided over 100 references, in case others wish to delve into this further. Thanks again.

This obsession about GI microbes most of the time is a clue that a person is trying to fix something there. Otherwise - generally - they'll just take that for granted and wouldn't even care that much. Healthy GI microbes are a consequence of a healthy person, not the contrary, with the exception of some acute infection.

Yes, "most of the time", Amazoniac. In my case, I'm not trying to fix anything so much as to just stay healthy. And the reason I'm concentrating on the gut now is that in every field of healthy I wish to study, they are all turning to the relationship of different bodily "systems" to the health of the gut. So I am also turning to look more at the gut. To protect my vascular system, my endocrine system, my bones, etc. From what I'm reading by practitioners in various health fields now, the conclusion happens to be the opposite from your last sentence. They are looking at the body as very much (though not totally) the consequence of a healthy gut, including a healthy mix of microbes.

 

[narouz]

...This obsession about GI microbes most of the time is a clue that a person is trying to fix something there. Otherwise - generally - they'll just take that for granted and wouldn't even care that much...

So...the healthy person
is the person who does not reflect upon or seek to improve their health?
Who does not think much about their microbiome?

And if they do think about it
or seek to improve it,
they are obsessed...?

 

[Amazoniac]

Enoree and narouz,
The obsession seems to be when you neglect many important aspects of gut health and instead focus on just gut microbes. They are much more a consequence than a cause..

 

[narouz]

Enoree and narouz,
The obsession seems to be when you neglect many important aspects of gut health and instead focus on just gut microbes. They are much more a consequence than a cause..

I'm not picking on you, Amazon. :)
I appreciate your thoughts about gut health, etc.

I'm just saying,
from your viewpoint,
wouldn't this thread--
or any thread exploring the microbiome--
qualify as "obsessive"?

What would be your idea of the "many important aspects of gut health" we are neglecting
in favor of our obsession? :)

As I'm understanding you,
Enoree should actually be an exemplar of your approach,
because (if I've formed an accurate picture of Enoree's way of eating)
he just eats his organic vegetables from his own garden
and trusts the innate genius of his gut microbiome to do its thing.
That is the non-obsessive approach you favor, yes?

Or, pboy might also be noted as an exemplar of your non-obsessive approach, I would think:
just eat a strict Peat diet (without much fiber or starch, to name one crucial aspect),
then beyond that "don't trip on it" (to use a pboy turn of phrase ).
Get sun and access nature,
go into the world with a noble purpose and do noble actions,
eat pure Peat,
and the biome will take care of itself...

...going beyond that sort of approach is, in your view, obsessive, yes?

 

[narouz]

Amazon, there just so happens to be an on-going discussion
over in another thread...

http://www.raypeatforum.com/forum/viewtopic.php?f=2&t=7219&e=1&view=unread#p90659

...which explores some of the same notions you talk about here.
You will see at the end, below, in answersfound's reply to 4peats
some of the same ideas you put forth, I think.
Do you share answersfound's view...?

As much as you want. It doesn't matter. As long as you adequately balance it with Gelatin, you have nothing to worry about. That does not include dairy. This is just my opinion...

That's really interesting. How does the dairy tryptophan factor in? Is this a controversial notion in Peatdom?
And do you think there's a magic x grams of tryptophan needs to be balanced by y grams of gelatin?
Or it varies between individuals?

Things become clearer when you read and reread RP's articles and newsletters and listen to his audios.
You won't get an accurate understanding of RP's ideas from a comment here or there.

af says this is his/her opinion.

It is disconcerting to see someone would come away with a notion of a "Peatdom" controversy from a random comment on a single amino acid. No offence af, I understand what you are saying but I doubt Peat would express it that way.

It's important to be careful where you get your "Peatdom" ideas from.

From RP's article Gelatin, stress, longevity
The part in bold is bolded by Peat.

The amino acids in proteins have been defined as “essential” on the basis of their contribution to growth, ignoring their role in producing long life, good brain development, and good health. The amino acid and protein requirements during aging have hardly been studied, except in rats, whose short life-span makes such studies fairly easy. The few studies that have been done indicate that the requirements for tryptophan and cysteine become very low in adulthood.

Although Clive McKay's studies of life extension through caloric restriction were done in the 1930s, only a few studies have been done to find out which nutrients' restriction contributes most to extending the life span. Restricting toxic heavy metals, without restricting calories, produces about the same life-extending effect as caloric restriction. Restricting only tryptophan, or only cysteine, produces a greater extension of the life span than achieved in most of the studies of caloric restriction. How great would be the life-span extension if both tryptophan and cysteine were restricted at the same time?

Both tryptophan and cysteine inhibit thyroid function and mitochondrial energy production, and have other effects that decrease the ability to withstand stress. Tryptophan is the precursor to serotonin, which causes inflammation, immunodepression, and generally the same changes seen in aging. Histidine is another amino acid precursor to a mediator of inflammation, histamine; would the restriction of histidine in the diet have a longevity promoting effect, too?

It happens that gelatin is a protein which contains no tryptophan, and only small amounts of cysteine, methionine, and histidine. Using gelatin as a major dietary protein is an easy way to restrict the amino acids that are associated with many of the problems of aging.

The main amino acids in gelatin are glycine and proline; alanine is also present in significant quantity. Glycine and proline are responsible for the unusual fibrous property of collagen.

As for the tryptophan in milk, RP in the email exchanges posted at the former Peatarian site, was quoted as saying:

Regarding milk and its tryptophan content, The calcium helps to keep the metabolic rate high, and the other nutrients help to steer tryptophan away from the serotonin path.

don't overcomplicate things. that is what gets people into issues in the first place.

If quoting RP complicates things for people, I daresay they are in big trouble. :P
How are you supposed to apply his ideas accurately, if you don't bother to read and understand them?

Because at the end of the day, it doesn't matter. There are plenty of healthy people in this world, that don't understand why the food they eat is helping them. This is about innate intelligence. The foods that are recommended have been around for thousands of years. Take away all the dogma and social conditioning around what is healthy, and EVERYONE is eating a "Peat diet". No one is eating salads, drinking soy milk, PUFA's. "Apply them correctly?" Tell that to a baby who wants to eat fruit and drink milk. There is no learning that needs to be done. It's unlearning that needs to be done.

Of course it may interesting to understand the ideas, but it certainly is far from necessary. When you demand that people understand ideas and a protocol, you restrict them. You deactivate their internal guidance system and suggest they operate mechanically.