Fiber: Is it Good, Bad or More Complex?

A war of videos. TRUTH ABOUT FIBRE <--SEO ignore.

I came across this video by Shawn Baker, who I don’t follow—but I know who he is (and he didn’t make the list) talking about fibre. I also wanted to talk about fibre so this is a good starting point.

I hate presenting a bunch of boring old ancient information that everyone's heard before. If you can get the same info and opinions from a billion other sources what is the point of me writing up the same stuff again ?

But, just to recap briefly for the purposes of this:

Fibre is the indigestible components in plants— cellulose, lignin etc. For human purposes fibre tends to be classified into two kinds: soluble—which forms a gel-like substance with water and has a regulating role on the gut, potentially assisting with both constipation and diarrhea, and insoluble, which promotes movement of material through the digestive tract and affects stool bulk.

Fibre is nutritionally inaccessible in us due to its chemical bonds, as we don't make enzymes to break those bonds, and other animals have different, sometimes complex adaptions to access more of it (it’s not “fibre” to them), so in humans it passes through the small intestine intact. Some fibre is fermented by bacteria in the colon having other effects.

There is a non-plant compound also grouped as a fibre sometimes— chitin, found in seafood (the shells of shrimps and crabs), insects (eat your bugs) and also in fungi. But in terms of human nutrition fibre means plants.

A diet that's high in fibre (i.e plants) is broadly associated with some health benefits on a population level.

There's many other attributes of plants than just their fibre content. I don't know how that's been distinguished scientifically or what variables have been controlled for in these studies that identify these recommendations about fibre specifically over plants in general. It’s an interesting question.

Fibre itself is not an essential nutrient for life, and you may come across well-meaning but confusing terms describing fibre as “essential”. Carbohydrates, of which most fibres are, are also not essential nutrients. Most of us eat carbs, they are an excellent way of consuming energy and our bodies knows well how to use them, but they not technically essential.

If you do a search on this topic, you may be presented with quite different answers.

Even ChatGPT got it wrong when I put the question to it.

“Essential nutrient” has a specific biological meaning. ChatGPT has absorbed more of an advocacy meaning from this junk on the internet.

The health roles fibre are associated with are:

Lower cholesterol, some control of blood sugar with some fiber types (not others), a lower cardiovascular risk and cancer risk. Fibre affects gut motility— and certain kinds of fibre feed the gut microbiome.

Here I’ll inject another video, by Jerry Brainum. He takes a more pro-fibre position.

The role of the microbiome and human health is a complex one, and not well understood, but it is thought to be significant.

To jump back to Baker’s video, where he’s commenting on a study, the point he is making is fibre is not necessarily needed to feed the gut microbiome either and the gut microbiome itself is adaptable and can change.

Considering people on a carnivore type diet, this seems at least possible to me.

Let us also consider individual medical circumstances. For someone with IBS for example, fibre may be helpful or a disaster, depending on the kind of IBS.

I imagine for autoimmune gut problems, and I don't know— put possibly other autoimmune illness, extra fibre could be helpful of harmful. For some kind of bowel obstruction, my understanding is excess fibre can even be contraindicated.

And this last point brings up a paradox with fibre for gut motility, it seems to have the potential to both assist and hinder gut motility, probably because it’s not just doing one thing in that regard, making it conditionally appropriate or not.

Some people use fibre supplements for medical reasons or because they struggle to eat the amount of fibre they think they should from plants.

When it comes to fibre supplements, not all are equal. Fibre supplements can be different things, but they are often some kind of psyllium husk, which also goes under the name ispaghula or plantago. As far as I have been able to tell these are all the same thing.

I have found, and others I know have found, that the unrefined psyllium husk you buy in a bag from a health store or online from some supplier, where you can see the seeds is junk and likely to cause more gut problems; cramping, constipation and misery.

If you have a sensitive gut and the product looks like this, don’t touch it:

This product is poison

The refined and more expensive kind sold under brand names like Fybogel or Metamucil—often prescribed by doctors, is far superior and much more likely to do what you want in terms of gut motility if that's the goal, or be far more benign and less aggravating generally.

This product is fine

For people with gut problems who associate a higher fibre intake with worse symptoms, it would seem reasonable to experiment with reducing fibre intake.

I think what I'm trying to say is what I often find myself saying— fibre (plant) intake on a population level may associate with some positive health outcomes with specific markers. But on an individual level, and with other health markers the picture may be quite different.

I’m open to Shawn Baker’s ideas on this one, rather than Jerry Brainum, in that although I can see some positives in the mainstream nutritional position— intending to foster healthier eating generally, and some people may do well on lots of fibre, it’s not fully clear to me everyone needs significant amounts of fibre all the time, especially what would be found naturally. And in some people, with or without GI illness, it may cause more problems than good.

I’m not convinced by Jerry’s view that eating less fibre necessarily causes dysbiosis, meaning:

disruption to the microbiome resulting in an imbalance in the microbiota, changes in their functional composition and metabolic activities, or a shift in their local distribution

It seems possible too much fibre, or too much at certain points, might equally cause this in some people.

I also very much doubt fibre is necessary to maintain healthy bodyfat levels.

For prevention of colon cancer, management of cholesterol and blood sugar, I’m more open to the mainstream position presented by Jerry that fibre may be helpful, while it’s also possible a lower carb diet more towards carnivore has other anti-cancer potential.

High fibre diets may be proxy for general healthier eating, and a healthier lifestyle.

It also seems that on an individual level some kinds of dietary fibre are better tolerated than others.

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