Butyric acid qualifies as a previously unrecognised vitamin, part 1
Subtitle: One secret of balanced nutrition may be a malodorous acid that human cells cannot make for themselves.
Readers, before reading this Post, please see http://thehomeschoolingdoctor.com/tag/butyric-acid/. Nearly a decade ago, a blogger called Terri educated us about the importance of butyric acid. However, she may not have realised that this substance qualifies as a new vitamin.
A conventional view is as follows:
"Osteoporosis and skin cancer are both caused by effects of sunlight on the human skin, with osteoporosis resulting from too little exposure to ultraviolet rays, and skin cancer resulting from too much exposure to the same rays. In the case of osteoporosis, a more direct cause is deficiency in calcium and vitamin D1. The way to prevent osteoporosis and skin cancer is moderate exposure to sunlight, with boosted consumption of calcium-rich dairy products, particularly those fortified with vitamin D. This makes sense because nutritional sufficiency can be achieved without a risk of skin cancer, by firstly sunning the skin just enough to produce vitamin D, and secondly supplementing the diet with dietary calcium and vitamin D."
That is what many readers have been led to believe.
However, here is a different interpretation.
See the following concise summary of butyric acid: http://www.newworldencyclopedia.org/entry/Butyric_acid.
Further information on butyric acid, freely available on the web: http://hubpages.com/hub/Butyric-Acid-Bacteria-and-Colon-Health.
It seems paradoxical that human populations appear to suffer from insufficient exposure to sunlight, causing osteoporosis, at the same time as excessive exposure to sunlight, causing skin cancer.
One or both causes must be mistaken.
If it were true that ultraviolet rays are causal, we would expect that any population beset by osteoporosis would tend to be free of skin cancer, and any population beset by skin cancer would tend to be free of osteoporosis.
What if sunlight, although harmful in excess, is more likely mechanism than cause? And what if dairy products are valuable for their vitamin content2, rather than their calcium3 ?
The illogicality in the current consensus reflects a confusion of cause and effect in both osteoporosis and skin cancer, corrected as follows.
Vitamin D4 is made from cholesterol5 (https://en.wikipedia.org/wiki/Cholesterol) in a process depending on the availability of butyric acid, an unrecognised6 vitamin found in few foods other than milk.
Butyric acid is a chemical relative of saturated fatty acids. It cannot be made in human cells7, and is absent from most fats and oils. However, it is present in butterfat, and is also synthesised from resistant starch8 (https://en.wikipedia.org/wiki/Resistant_starch) by bacteria9 in the healthy human colon.
If insufficient butyric acid is absorbed10 from the gut, a likely result is deficiency of vitamin D, leading to osteoporosis.
At the same time, diets poor in butterfat and fibre tend to oversupply glucose and polyunsaturated fats11 (https://en.wikipedia.org/wiki/Polyunsaturated_fatty_acid), both of which are likely to be carcinogenic12.
In summary, I suggest that
- skin cancer13 is caused partly by deficiency of a previously unrecognised vitamin14, and
- osteoporosis is a parallel disorder in which proliferation of cells15 – although not cancerous – demineralises the bones.
Butyric acid may seem an unlikely contender for a newly discovered vitamin.
This substance stinks of vomit. The bacteria that make it are clostridia, a category of bacteria usually associated with botulism, tetanus, and colitis.
If there is anything good that has been said about clostridia in the past, it is that their toxins can be applied cosmetically as Botox (https://en.wikipedia.org/wiki/Botulinum_toxin).
Also making it hard to conceive of butyric acid as a vitamin is its description in the literature as a fatty acid. This is because none of the known vitamins are fatty acids - vitamin C being a different kind of acid.
Furthermore, butyric acid is saturated, unlike those fatty acids (particularly linolenic acid, alias omega-3) that have held the nutritional limelight for the past several decades. So, could this ‘saturated fatty acid’ possibly be better-described as a vitamin?
Well, please consider
- the merits of butyric acid in human physiology, and
- how hard it can be for us to absorb butyric acid in sufficient quantity.
Experiments in the domestic rat (Rattus norvegicus) and domestic pig (Sus scrofa) show that butyric acid
- reduces inflammation,
- boosts the immune system,
- induces apoptosis,
- helps stabilise blood sugar,
- helps satiation,
- helps to heal nerve damage after stroke,
- acts as an antioxidant,
- prevents constipation,
- helps to regulate the permeability of the gut wall and to heal a leaky gut, and
- supplies energy directly to the cells of the colon.
Of relevance is that butyric acid
- is not known to be synthesised by any human cells, and
- seems not to behave as a fatty acid16 in our bodies, although known to do so in ruminants17.
Sufficiency in this substance, which I have tentatively labelled ‘vitamin M’, may have come naturally for humans tens of thousands of years ago. However, it is potentially a problem today.
Prior to eating a large proportion of our food cooked, hominids acquired most of their butyric acid by way of bacterial mutualism in the colon.
The process involved is that bacteria in the colon ferment plant fibre anaerobically. Among these are clostridia, which prefer the softest forms of fibre18 , and produce butyric acid instead of the lactic acid produced by the more familiar lactobacilli.
As long as the colon retains a healthy fermentation based on periodic consumption of plant fibre, our requirements for butyric acid were met.
However, cooking tends to diminish this mutualism, because it tends to convert the softest fibre into digestible starch, at the expense of the beneficial clostridia.
As a substitute, our hunting ancestors developed out-of-body fermentation systems, including both plant fibre and animal matter.
The result was diverse products such as kimchi (https://en.wikipedia.org/wiki/Kimchi) in Korea and igunaq (https://en.wikipedia.org/wiki/Igunaq) in the Arctic. However, these fermenting traditions have tended to disappear in the industrial world.
Within the last 10 thousand years, ruminants were domesticated for their milk. This can be a good source of butyric acid - which occurs in bovine milk at a concentration of about one part per thousand.
However, milk is in several ways a problematic food for adult humans. Furthermore, the butyric acid is part of the cream layer, which tends nowadays to be removed from milk in fear of its saturated fat content.
And the lactose in milk tends to be indigestible19 even to beneficial bacteria such as lactobacilli, fouling the colonic fermentation system and antagonising the supply of butyric acid that would otherwise be absorbed through the colon wall.
The following material requires some deep thinking but may be worth the effort.
Butyric acid and other volatile fatty acids as sources of energy, with a note on the chemical nature of acetic acid:
Volatile fatty acids, generated by anaerobic fermentation in the gut, can be used as an energy substrate by most plant-eating mammals. But how much energy do they yield?
(Please bear in mind that the energy value of organic molecules is generally indicated by their content of hydrogen.)
Well, in terms of kcal/g, recall that carbohydrates yield 4.1 and fats yield more than double this value, viz 9.4. As far as I can ascertain, the corresponding value for acetic acid is 3.5 kcal/g, propionic acid 5 kcal/g, and butyric acid 6 kcal/g.
It is interesting that butyric acid is energy-richer than acetic acid but overall these values are in line with carbohydrates rather than lipids.
Considering that the rumen of bovines and other ruminants generates acetic acid more than the other volatile acids, the weighted average energy content of volatile fatty acids must surely be about 4.5kcal/g, not much more than the value for sugar or starch, i.e. 4.1kcal/g.
This implies that when a ruminant uses volatile fatty acids to synthesise its own body fat, it must be putting energy into the process in order to boost the energy content of the lipid to >9 kcal/g. Not so?
In short, volatile fatty acids may be fatty acids but they’re a far cry from fat in their energy content. They may in some cases be building blocks of fat but to make fat out of them involves more than just cobbling them together; the bonds have presumably to be enriched with additional hydrogens.
There is an implication that I cannot recall ever reading anywhere, so it may be an original observation.
This is that when herbivores ferment complex carbohydrate in the form of cellulose (or resistant starch or hemicellulose), they are merely converting one fairly poor energy source (compared with fats/oils) to another slightly richer but still fairly poor energy source, the main gain being that something that was indigestible to the herbivore is now available to its metabolism.
And now for an implication, which again may be original: the fact that butyric acid is only modest in its energy content can be taken as support of a hypothesis that it is suited, at least in humans, to working as a vitamin more than as an energy substrate.
If the human body (beyond the cells of the colon wall, which do indeed use butyric acid as an energy substrate) use butyric acid mainly catalytically, and then excrete it intact, then my point is that the waste of energy is not a big deal. Sure, some fuel has been wasted, but considering the energy savings of catalysis this is not important, not so?
Now, let us express the energy values in kJ/g.
Volatile fatty acids generally contain about 18.5-20 kJ/g.
How does this value compare with other energy-containing food substances? Well, carbohydrates contain about 17 kJ/g, while fats and oils contain about 38 kJ/g. This confirms that the volatile fatty acids are closer to the carbohydrates than to the lipids.
Some other values for reference:
- wood (consisting mainly of cellulose) contains 13 kJ/g,
- charcoal (if pure carbon) contains 27-33 kJ/g,
- anthracite coal, despite its impurities, is compressed and so has a similar value to charcoal, i.e. about 32 kJ/g,
- crude oil (petroleum) contains 42-45 kJ/g, boosted to 46-47 in the form of petrol and diesel,
- ethanol contains 27 kJ/g.
Although hydrogen itself can hardly be described as ‘fuel’, its oxidation yields 143 kJ/g.
So, the bottom line is that volatile fatty acids are not nearly as energy-rich as the fats and oils to which they are chemically related.
As a footnote on the nature of acetate:
Acetate = CH3COO- (where the 3 is a subscript and the minus sign is a superscript) = what is left of acetic acid after DEPROTONATION. If you add H+ to acetate, you get CH3COOH = acetic acid.
So, acetic acid is just acetate plus a proton, and acetate is just acetic acid minus a proton.
Acetate is an anion, because it has a negative charge. It consists of two atoms of carbon, to the first of which are attached three hydrogen atoms and to the second of which are attached two oxygen atoms.
Acetic acid can be expressed as C2H4O2, or CH3COOH, or CH3CO2H, all are true (all the numbers are superscripts).
If one goes back to the molecular formula I described above, with the two carbon atoms: the carbon atom with the oxygens attached to it in acetate is the one which undergoes change in its bonds when coverted to acetic acid. In acetic acid, this carbon atom has a double bond with one atom of oxygen and a single bond with an OH. When water is added, this is converted to two single bonds with oxygen atoms, yielding a molecule of H3O. This reaction is of course reversible.
to be continued in https://www.inaturalist.org/journal/milewski/68580-butyric-acid-qualifies-as-a-previously-unrecognised-vitamin-part-2-differences-between-ruminants-and-non-ruminants#...
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Molecular formula of butyric acid:
https://en.wikipedia.org/wiki/Butyric_acid#/media/File:Butyric_acid_flat_structure.png
Other names for butyric acid, important in any literature search:
It is important to realise that this substance has many names. Please see under ‘Other names’ in the following: http://webbook.nist.gov/cgi/cbook.cgi?Name=butyric+acid&Units=SI
The paradoxical stink of a vital fatty acid:
Butyric acid (C3H7COOH and its precursors), which gives butter (the words ‘butyric’ and ‘butter’ have the same linguistic root), parmesan cheese, kimchi, durian (Durio) fruit and carob (Ceratonia siliqua) pod their characteristic aromas, is so valuable physiologically in small concentrations that functions like a human vitamin.
However, in greater concentrations its odour – familiar in vomit and Athlete’s foot (tinea pedis) – is repulsive enough to be used by many species as a deterrent or defence.
Butyric acid is used by the wolverine (Gull gulo) in its anal glandular secretions, by caterpillars (i.e. in the osmeterial secretion of the larvae of papilionid butterflies in reaction to attack by ants) to deter predatory insects, by apiarists to control the honey bee (Apis mellifera) during collection of honey, and by political protesters as a stink-bomb.
Furthermore, some of the butyric acid absorbed by the human body has ultimately been synthesised by clostridial bacteria, which are themselves ambivalent because they can cause botulism, gas gangrene and tetanus.
If butyric acid is a new vitamin, maybe hydrogen sulphide is too?
I have explored the possibility that butyric acid, one of the stinkiest substances known, is actually a vitamin.
Here is a new twist.
About seven years ago, there was a flurry of media releases (e.g.
http://www.dailymail.co.uk/health/article-2687696/Could-smelling-farts-GOOD-Potent-gas-flatulence-help-prevent-cancer-strokes-heart-attacks-claims-scientists.html)
on the scientific finding that cells make small quantities of hydrogen sulphide (rotten egg gas) in the interests of keeping the cells healthy, perhaps even acting as a self-generated anti-cancer medication of sorts.
This is interesting mainly because hydrogen sulphide is toxic. So the old adage applies, a medicine is a toxin in small amounts, but the news is that our cells actually make this potentially toxic compound for themselves.
The media, of course, put the spin on this that ‘smelling farts is healthy, ha ha’.
However, what seems to be overlooked here is that hydrogen sulphide, like butyric acid, could be effectively acting like a vitamin.
Like butyric acid, hydrogen sulphide is produced in large quantities by the colon bacteria. Presumably like butyric acid, some of the hydrogen sulphide is absorbed into the bloodstream. Perhaps like butyric acid, this may have a healthy regulatory effect in tissues far from the gut walls.
What has apparently been missed in this research is that the body has a ‘self-fumigation’ mechanism in which not one but two stinky gases, namely butyric acid and hydrogen sulphide, are produced by colonic bacteria, and then absorbed into the blood, in quantities that are salutary rather than toxic.
Were it merely that the body tolerates hydrogen sulphide and is adapted to it in the sense of hydrogen sulphide being part of the normal healthy biochemistry of the cell, there would be nothing much to explain. But the new discovery, that our cells actually make their own hydrogen sulphide, is the crucial fact leading to my speculation that butyric acid and hydrogen sulphide may have some parallels as ‘stinky vitamins’, and that, who knows, perhaps they even act in concert?
A way to test these ideas:
Can the human body actually suffer from a deficiency of hydrogen sulphide?
Good basic references to butyric acid in colonic health:
The reference below is a basic one w.r.t. the production and functions of butyric acid in humans, via the colon. There seems no doubt that butyric acid is valuable in inducing apoptosis. Butyric acid seems to prevent colonic cancer and the mechanisms include a) feeding the colon cells with suitable energy and b) inducing apoptosis in these cells.
http://www.ncbi.nlm.nih.gov/pubmed/16633129/
http://ar.iiarjournals.org/content/25/6B/4325.full.pdf
Effects of frying butter on butyric acid content:
Readers may wonder whether butyric acid is lost when butter is fried.
Perhaps, but I have not found any studies of this.
On one hand, butyric acid is a ‘volatile fatty acid’, implying that it evaporates easily, and perhaps heat hastens this evaporation considerably. And, after all, the smelliness of butyric acid proves that it volatilises easily.
On the other hand, butyric acid has a boiling temperature of 162 degrees Celsius, much higher than that of water. So, it would not necessarily boil off if butter was heated to boiling point.
However, I think the most important thing to bear in mind is that butyric acid does not occur as such, i.e. as the free molecule, in butter in the first place. Instead it occurs as the triglyceride, and it is only when this triglyceride goes rancid or is digested in the gut that the butyric acid as such is released.
So, my guess is that butter would lose only a minor proportion of its butyric acid when fried, and that frying hardly depletes ‘vitamin M’ in butter during cooking.
Implication that sugar is inimical to butyric acid system via candida in colon:
The following (http://www.wellnessresources.com/weight/articles/butyric_acid_improves_fat-burning_metabolism/) is the popular version of an article in the journal Diabetes.
As they say, the implication unstated in that article is that butter is good food to eat against insulin resistance. And there is also a hint that whatever causes candida (excess sugar in the diet?) also suppresses production of butyric acid in the colon because the unicellular fungus Candida can upset the healthy balance of colonic bacteria.
If true, this means that there are at least three antagonisms going on in most people on ‘normal’ diets, all of which might contribute to deficiency of vitamin M: lactose intolerance from drinking milk, too little fibre in the diet, and candida from eating too much sugar.
Clostridia can effectively turn lactic acid into butyric acid
See https://ift.onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2621.1989.tb04670.x and https://www.semanticscholar.org/paper/Butyric-Acid-Spoilage-of-Fermented-Cucumbers-Fleming-Daeschel/c9dbf39b6bedaaaed02374f16f0f341ca076cf04
Clostridia are well-known for generating butyric acid (although it is important to remember that many other anaerobic bacteria also generate butyric acid).
I have the impression that clostridia depend on neutral or only slightly acidic conditions and thus tend to be incompatible with the acidity generated by lactobacilli and vinegar-producing bacteria in extreme ferments such as the one (based on milk and cream) on my kitchen shelf.
However, bacteria are full of chemical tricks, both beneficial and detrimental from a human viewpoint. It is hard to keep track of it all, or to understand it well enough to predict much.
In this case, a nice lactic acid fermentation of cucumbers was ‘spoilt’ because somehow the lactic acid was converted not only to acetic acid but also in part to butyric acid.
The point is that this ‘spoilage’ occurred despite the pickle having the low pH of 3.7! (which is usually regarded as indefinitely self-preserving). Actually, no lactic acid remained after this ‘spoilage’ process!
Given all this complexity, I have realised the futility of trying to associate butyric acid with any particular ‘genus’ of bacteria (let alone any particular ‘species’).
Initially, I just assumed that the main anaerobic fermenters of a beneficial sort, e.g. lactobacilli, made the butyric acid. See
http://link.springer.com/article/10.1007/s002530051285.
Then I got caught up in the idea that clostridia are particularly valuable in this way, despite their otherwise deleterious effects (tetanus, botulism, colitis, gas gangrene, etc.).
Now, I realise that my initial assumption was right all along. So, I do not think one needs to bother much with ‘taxonomy’ in discussing the idea that butyric acid may constitute a human vitamin.
As a footnote: this pickle may have been ‘spoiled’, but I wonder if it was actually even healthier to eat after this spoilage, and despite what most people interpret as a foul stench?
Odd point about clostridum, w.r.t. vitamin M or butyric acid:
Vitamin M (butyric acid) is made by Clostridium, a bacterium that can also kill via tetanus. An odd fact about tetanus, which sounds significant although I do not know how to interpret it, is that it is the only vaccine-preventable disease that is not spread from person to person. Instead, it is spread by free-ranging spores of clostridia. What is the biological significance of being able to be immunised against a pathogen that is free-living as opposed to ‘infectious’ in the stricter sense?
It is also interesting that one of the ways people are killed by tetanus is shortly after birth, via infection of the cut umbilical cord. This is called neonatal tetanus and to this day kills 200,000 newborns per year in poor countries.
Can this be phrased this differently by saying that the spores of clostridia are somehow toxic or significant enough that the human immune system can generate antibodies not only against the bacteria, but in this case also against its spores?
Basic point about butyric acid availability:
Of all the viable dietary sources of butyric acid/vitamin M, the only one that is generally palatable is butter. Butter is unique as a good source, free of deleterious effects, of vitamin M.
To explain: all other dietary sources simply stink too much to be generally accepted by consumers, particularly the uneducated and quasi-educated who do not take an interest in the biochemistry involved.
I will not even go into the real stinkers such as bombay duck and the ferments produced by Inuit. However, this topic is important in evaluating everyday cheeses. For example, home-made cheeses like parmesan do contain butyric acid, but cheeses sold on an industrial scale are carefully formulated to lack butyric acid (which after all gives Athlete’s foot its stink) in the interests of a bland appeal to the public.
Sauerkraut is generally made today in such a way as to arrest the development of the clostridia that produce butyric acid. This makes a sauerkraut product which smells pleasantly sour, but is probably less healthy than the original types. At least in part, the Koreans still sensibly make their equivalent of sauerkraut in such a way as to stink nicely of butyric acid. Fact is, these ferments are healthiest for us when they stink of the same substance as vomit and old socks.
Even ghee, prepared in the Hindu tradition by clarifying butter, smells of butyric acid more than the original butter does – enough to put off some people.
And of course, that unique and wonderful fruit, durian, is among the few plant products rich in vitamin M, but once again it is only the smart consumer that recognises the real nature and value of the stink.
So, all the good dietary sources of vitamin M would tend to be perceived as speciality foods, so malodorous as to appeal to only niche markets, were it not for that simplest and most available of foods, butter. The existence of butter means that nobody needs to be deficient of vitamin M unless they’re misled.
I discount milk as a source of vitamin M, because its lactose content tends to outweigh the benefits.
For all intents and purposes in Western society, getting vitamin M from food means eating butter.
Vitamin M offers a good example of that deep and wonderful ambivalence in human affairs, between nature and nurture. Nature, because we need vitamin M. Nurture, because we have to be educated to accept what’s good for us in this case.
Fatty acid analysis of olive oil, again lacking butyric acid:
Please see http://www.essentialoils.co.za/olive-analysis.htm
for the fatty acid analysis of olive oil.
As in the case of tallow (beef fat), butyric acid seems absent.
Also please note that the essential unsaturated fatty acid linoleic acid constitutes up to a quarter of the fatty acid content of olive oil.
I infer that the health of people on the ‘mediterranean diet’, in which dairy products play a minor role (certain cheeses are eaten) is based on colonic fermentation of fibrous matter, which must be the source of butyric acid.
I accept that olive oil is a healthy oil in that it is less prone to rancidity than seed oils from herbaceous plants. However, I suspect that southern Europeans only get away with their emphasis on olive oil because their diet contains plenty of fibrous plant matter and some cheese. Without those dietary components, would they not run short of butyric acid?
Concentration of butyric acid in Ginkgo fruit-pulp:
See http://www.ucmp.berkeley.edu/seedplants/ginkgoales/ginkgo.html.
One of the oddest botanical facts is that the fruit-pulp of Ginkgo (https://www.inaturalist.org/taxa/64350-Ginkgo-biloba).
Thi species, itself one of the oddest of plants worldwide, is so rich in butyric acid that it smells repulsive to the human nose.
I presume that this acted as a reward to seed-dispersers, making Ginkgo apparently unique among all plants in using an essential saturated fatty acid in place of the usual combination of fructose, other sugars, and vitamin C offered by plants to frugivores in return for their mutualistic services.
Since ginkgos date from the time of the dinosaurs, I presume that this mutualism evolved originally with archosaurs. Ginkgos are medicinal plants and their seeds are eaten by people.
I think the medicinal values are largely in the leaves, which as far as I know do not contain butyric acid. I wonder if the seed-kernels themselves contain butyric acid.
(By the way, if parrots have a long and obscure history in China, this is even more so for Ginkgo, which only survives at all because monks in China have conserved it since about one thousand years ago.)
The abundance of butyric acid in ginkgo fruit-pulp proves that plants make this saturated fatty acid. Whether other plants make it is anyone’s guess. However, if so, then I suspect that it is used mainly in a quasi-hormonal role and would feature only in trace quantities in any analysis of plant matter (other than the fruit-pulp of ginkgos).
The seed-kernel of Ginkgo, unlike the fruit-pulp, seems to lack butyric acid: http://www.nutritionvalue.org/Nuts,_raw,_ginkgo_nuts_nutritional_value.html.
Butyric acid so stinky that it is used as a weapon:
See http://cocktailsandcologne.com/2010/11/19/the-ginkgo-problem-butyric-acid/.
Butyric acid is so stinky that it is used as a weapon by political activists.
Art of the reason why this substance is not recognised for the essential foodstuff that it is: it is associated with the colon, which is regarded as unwholesome, and it is associated with vomit.
I have experimented with 'hyperfermentation' of milk. My own ultra-sour, home-invented, something-beyond-clabber brew, made from milk by prolonged (yeasty) fermentation on my kitchen shelf, smells strongly of ‘vomit’, which I put down to butyric acid. By resorting to this extreme kitchen fermentation, I seem to have succeeded in getting rid of the galactose while boosting the concentration of butyric acid.
Kombucha tea is another ferment known to be rich in butyric acid. The fact that one can mix tea, water and sugar and come up with butyric acid, via microbial fermentation, is food for thought indeed. I now see that kombucha tea may be undersold, as a source of butyric acid for the dairy-averse. A particular application might be for e.g. colon-cancer sufferers who have had a colostomy and therefore can no longer ferment fibre in their gut?
Kombucha: “The culture transforms the tea into enzymes, vitamins and organic acids. The fermented mixture contains 0.5-1% alcohol, acetic acid, butyric acid, gluconic acid, glycuronic acid, L-lactic acid, carbonic acid, caprylic acid, citric acid, oxalic acid, usnic acid, vitamins B1, B2, B3, B6 and B12 and C, folic acid, amino acids, and other substances with antibiotic, antiseptic and detoxifying characteristics.”
Kombucha has many healing properties (blood thinner, blood cleanser, probiotic, skin improver, cancer treatment and more, as detailed in https://growyouthful.com/index.php.
A note on gamma aminobutyric acid or GABA:
A well-known neurotransmitter is gamma aminobutyric acid (GABA, https://en.wikipedia.org/wiki/%CE%93-Aminobutyric_acid).
This neurotransmitter is important for brain function. I assume that it is produced in the human body from butyric acid. Although it is, in a sense, an amino version of butyric acid, it is not regarded as qualifying as an amino acid (something parallel to our rejection of butyric acid as a fatty acid), because it is not actually incorporated into proteins in the way amino acids are.
GABA does not pass the blood-brain barrier, instead being synthesised in the brain cells themselves. The implication is that one of the functions of my hypothetically new vitamin, ‘vitamin M’, is to do with nervous function. This could perhaps help to explain Alzheimer’s disease?
It is well-known that omega-3 is essential for brain function, and indeed much of the matter (other than water) of the brain consists of essential fatty acids. Now, I am starting to see that, even in the tissues richest in omega-3, there may be an important role for 'vitamin M', a saturated quasi-fatty acid that is transformed into a quasi-amino acid effective as a neurotransmitter. However one regards GABA, it seems to corroborate to some extent the value of butyric acid in the human body.
Blood-sucking ticks use butyric acid to detect animals:
It is testimony to the smelliness of butyric acid that even the tiny amount emanating from the skin of mammals is enough to be used by blood-sucking ticks as a mechanism of detection and attraction.
Apparently experiments have been done in which balloons full of water have been smeared in butyric acid, and then placed near ticks. Provided the water in the balloon is suitably warm (to simulate mammalian body temperature), the tick is just as likely to drop off its grass perch on to the balloon and suck up the water! I.e. ticks virtually rely on butyric acid to tell them that an object is a real host.
However, I would like to go beyond anything available on the web, in reading between the lines of this observation. If we accept that the human body cannot make butyric acid, then the emanations of this substance from the skin (whether from sebaceous glands or in sweat) implies that butyric acid is poorly conserved by the body.
Whatever the physiological role of butyric acid in the human body, it ‘leaks’ out of the body intact, as opposed to being metabolised to some other substance. This in turn implies a quasi-catalytic role, as opposed to a role in which it reacts with some other chemical substance.
When I read, previously, that butyric acid has a brief ‘half-life’ in the body, i.e. is quickly used up, I imagined that it is rapidly broken down, or perhaps even incorporated into a larger molecule, in its various activities. Now I am starting to think that this brief passage through the body is partly because the stuff just leaks out through the skin and other surfaces. I wonder if any other vitamin behaves this way, i.e. is ‘excreted’ through the skin intact?
http://en.wikipedia.org/wiki/Jakob_von_Uexk%C3%BCll
http://www.bio-pro.de/magazin/wissenschaft/archiv_2007/index.html?lang=en&artikelid=/artikel/02099/index.html
http://books.google.com.au/books?id=5xfQffavYyUC&pg=PA85&lpg=PA85&dq=ticks+butyric+acid&source=bl&ots=jOFJFpRVhu&sig=R_arVtarPsSAhh_ao4FnwtH4EWw&hl=en&sa=X&ei=CY6JU4CpCoOllQX4sYHwCQ&ved=0CGoQ6AEwCQ#v=onepage&q=ticks%20butyric%20acid&f=false
Perhaps butyric acid works as a catalyst in the skin? After one has been sunbathing, the exposed skin takes on a different smell (apart from the smell of sweat or bacteria). This smell is quite strong and not particularly pleasant. It may be associated with the production of vitamin D from cholesterol by the sun.
Which types of carbohydrates are best for production of butyric acid in human colon?
The literature contains experimental results with gut fermentations of various carbohydrates. Although they are only indirectly relevant to humans (because done on rat and in vitro), they are indicative.
It is interesting to compare the proportions of butyric acid produced, bearing in mind the hypothesis (as per Paul Jaminet) that it is the resistant starches which most favour production of butyric acid = 'vitamin M'.
I note that the average proportion of butyric acid is about 15%, which happens also to be the figure for cellulose. So cellulose does generate some butyric acid, as I have suggested elsewhere.
However, the maxima are to be found in the cases of both starch (not necessarily resistant) and inulin.
We already know about ‘resistant starch’ generating butyric acid. However, it is interesting that the carbohydrate inulin seems equally suitable for this. Inulin occurs in tubers such as yam (Dioscorea), onion, artichoke, and chicory/dandelion root, as well as in the fruit of banana (plantain).
So, I would be hesitant to generalise that butyric acid is particularly associated with starches. It is also interesting to note that the proportion of butyric acid generated from fermentation of lactose is negligible: a mere 2%. This verifies that milk carbohydrates, which are often fermented in the colon instead of being digested in the small intestine (owing to ‘lactose intolerance), are no good for butyric acid.
I suggest that if one eats a range of fairly fibrous foods, emphasising various tubers but also including fruits and leaves, a healthy colonic microbial community will include clostridia and will generate sufficient butyric acid.
I suspect that what is more important for the vitamin M-generating system in the human colon, than focussing on resistant starch, is maintaining healthy conditions with the right pH (clostridia like mildly acid to neutral conditions, not extremely acid conditions) and rate of gaseous emanation. So, I still suspect that fermentation of lactose would reduce one’s uptake of butyric acid = vitamin M from the colon by two means at least, viz a) disrupting the activities of the healthy clostridia (as shown by swelling/gas/discomfort) and b) producing little butyric acid from the lactose. It is also possible that fermentation of lactose makes for an overly acidic colon, I do not know.
Butyric acid does partly function as fatty acid in bovine:
My suggetion to call butyric acid a vitamin, rather than a fatty acid, is based partly on an assumption that butyric acid is not a component of any lipid (fat or oil) in the human body.
However, it is important to note that butyric acid does function as a fatty acid in bovines. This is not only because ruminants can metabolise this compound as a source of energy, but also because they use it to synthesise at least one lipid: tributyrin, which is present in milk.
So, bovine milk contains butyric acid. This is not only in free form, but also as a component of tributyrin, which can presumably be broken down in the human gut into its components, namely three molecules of butyric acid and one molecule of glycerine. I suspect that, when butter goes rancid, the increased smell of butyric acid is at least partly owing to this breakdown.
Please see
https://en.wikipedia.org/wiki/Tributyrin.
Please note that tributyrin may sometimes be put in margarine, blurring any categorical denial of the value of margarine for vitamin M. The processed food industry uses butyric acid and related molecules to quite some extent, usually for what seem like the wrong reasons.
I cannot be sure that the human body is incapable of making tributyrin. If it can, we should perhaps revert to calling it an essential fatty acid rather than a vitamin, for humans. If not, a vitamin seems to describe it more aptly. A literature search is needed here.
The above thoughts affect my view of butyric acid as a hypothetical vitamin.
?The high energy content of fat versus acetic/propionic/butyric acid is important if they are being used for energy STORAGE.
?However, if they are being used to transport energy around the body or as cellular fuel, high energy content is not as important.?
Wolverine and lepidopterans are unlike skunks, in using a form of butyric acid:
The secretions of the anal gland of the wolverine (Gull gulo) contain butyric acid, at least in the form of methylbutanoic acid, which is similar in its chemical formula and odour.
The corresponding secretions of skunks (Mephitidae) do not contain butyric acid, instead containing thiols.
I take this as further evidence that the wolverine does not function as a skunk, despite the name ‘skunk bear’. The anal glands of the wolverine produce different substances from those produced by skunks, presumably for different functions (partly to do with scent-marking food items in the case of the wolverine).
Insects, including lepidopteran larvae, defend themselves with the stink of butyric acid, which can be toxic to ants:
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3032.1983.tb00346.x/abstract
Butyric acid repels honeybees: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3388969/
The following quote from Kendle Maslowski of the Garvan Institute of Medical Research, in a newspaper article in the West Australian on 18 Aug. 2010, gives a clue to the mechanism whereby butyric acid might operate as an anti-inflammatory:
“If we have low amounts of dietary fibre, then we’re going to have low levels of short-chain fatty acids. These have been known to be important for bowel health and have anti-inflammatory effects, in humans and mice, for some time, but the mechanisms were unknown. What our research showed is that the short-chain fatty acids actually bind to a gene that is expressed by our immune cells and functions as an anti-inflammatory receptor. This interaction between short-chain fatty acids and GPR43 proved to be essential for controlling inflammation, not only in the colon, but also in the lungs and joints. And we think this is the link between the increase in inflammatory diseases in Western societies compared to more traditional societies which eat high fibre and have a very low incidence of asthma, arthritis and colon cancers and diabetes.”
The link between butyric acid and vitamin D:
The article below suggests that butyric acid acts as an upregulator of the vitamin D receptor (a substance that occurs in various tissues). Apparently vitamin D, a form of cholecalciferol, does act against the proliferation of cancer cells; and butyric acid, particularly is supplied as tributyrin, enhances this effect.
Please note that butyric acid is rapidly ‘metabolised’ (implying respiration). I wonder if that is true, at least in humans. The fact that butyric acid emerges intact from the skin (contributing to body odour) suggests to me that this is not true, although it may be true in rats and/or pigs.
http://www.thedcasite.com/Butyrate_articles/Tributyrin_a_Stable_and_Rapidly_Absorbed_Prodrug_of_Butyric_Acid.pdf
http://en.wikipedia.org/wiki/Calcitriol_receptor
Butyric acid induces apoptosis and fights cancer:
http://www.thedcasite.com/Butyrate_articles/A_Phase_I_Study_of_Pivaloyloxymethyl_Butyrate_a_Prodrug_of_the_Differentiating_Agent_Butyric_Acid_in_Patients_with_Advanced_Solid_Malignancies.pdf
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