an autodidact meets a dilettante…

‘Rise above yourself and grasp the world’ Archimedes – attribution

Posts Tagged ‘blood

what is this thing called lymph?

leave a comment »

Canto: So in the last post, lymph glands, or nodes or whatever, got a passing mention, and I realise I’ve lived a pretty full lifetime without having much of an idea of this substance – is it a solid, liquid or gas, or is it delightfully ethereal, like qi?

Jacinta: Okay, let’s explore. The Better Health Channel, an Australian website, manages to give a point by point summary of the lymphatic system without really explaining what lymph actually is. For example, here are a couple of points that come close, but not very….

  • The lymph nodes monitor the lymph flowing into them and produce cells and antibodies which protect our body from infection and disease.
  • It maintains fluid levels in our body tissues by removing all fluids that leak out of our blood vessels.

From which we can deduce that it’s a fluid, since it flows.

Canto: The book we’ve been reading on CFS and its symptoms gives, en passant, this useful information on lymph nodes:

The lymph nodes are tender in multiple areas, such as in the front and back of the neck, armpits, elbows and groin…. One of the most characteristic symptoms is pain in the sub-auricular lymph nodes, the nodes located under the ear and behind the angle of the jaw.

Jacinta: Wow, they bin everywhere. And yes it does sound a bit like qi, some energy force that just needs to be needled at the nodes.

Canto: Time for some science. Lymph comes from Latin, lympha, ‘water’. So, very fluid. Here’s what Wikipedia says on its structure:

Lymph has a composition similar but not identical to that of blood plasma. Lymph that leaves a lymph node is richer in lymphocytes than blood plasma is. The lymph formed in the human digestive system called chyle is rich in triglycerides (fat), and looks milky white because of its lipid content.

Which sounds like the lymph nodes are where lymphocytes are produced. Lymphocytes are a type of leukocyte or white blood cell.

Jacinta: Well, here’s what I’ve come up with, to start things off.

The lymphatic system is the system of lymphoid channels and tissues that drains extracellular fluid from the periphery via the thoracic duct to the blood. It includes the lymph nodes, Peyer’s patches, and other organized lymphoid elements apart from the spleen, which communicates directly with the blood.

And what, you might ask, is the thoracic duct? Not to mention Peyer’s patches. The thorax, I think, is basically that part of the body covered by the rib cage, which includes the heart, the lungs and other organs, perhaps the spleen, perhaps the pancreas, the liver, the stomach, I’m very vague about it all. Anyway, the thoracic duct is an essential part of the lymphatic system, so here’s some more essential info about it:

The lymph from most of the body, except the head, neck, and right arm, is gathered in a large lymphatic vessel, the thoracic duct, which runs parallel to the aorta through the thorax and drains into the left subclavian vein. The thoracic duct thus returns the lymphatic fluid and lymphocytes back into the peripheral blood circulation.

So from this it’s clear that blood and lymph seem to circulate and work together in some respects.

Canto: It’s annoying that lymph is described as the ‘stuff of the lymphatic system’ or in the lymph nodes/vessels, etc etc. It reminds me of dormative virtue, somehow. Then again, it’s a bit like blood. What’s blood? It’s the stuff that comes out of us when we cut ourselves. Most people don’t know much beyond that – except for one key fact. It’s red, and it pools all over the floor in murder dramas. What colour is lymph? Have we ever seen a pool of it? Do we every lymph to death? Why can’t we turn lymph into a verb?

Jacinta: Okay, enough of the deepities. This really is a fascinating topic, and tracing the discovery of lymph, chyle, and the lymphatic system, starting with Hippocrates some 2400 years ago, would be the best, or at least the most interesting way to learn about the stuff, IMHO. I’ve found a recent series of pieces, The discovery of lymphatic system in the seventeenth century, which I’d love to read, but they’re behind a paywall, because we impoverished dilettantes need to be kept from accessing such things. They do give us access to the abstracts though. Here’s the abstract from part one:

The early history of lymphatic anatomy from Hippocrates (ca. 460–377 B.C.) to Eustachius (1510–1574). The presence of lymphatic vessels and lymph nodes was reported by ancient anatomists without any accurate knowledge of their true functions. Lymph nodes were described as spongy structures, spread over the whole body for the support of vulnerable body parts. Digestion was explained as being the resorption of clear chyle from digested food by the open endings of chyle vessels. The first insights into the place of lymphatic components within nutrition emanated from the medical school of Alexandria (fourth century B.C.) where vivisection was a common practice. Herophilus and Erasistratus described mesenteric veins [relating to the mesentery, a fold of membrane that attaches the intestine to the abdominal wall] full of clear liquid, air or milk. For Galen of Pergamum, (104–210) mesenteric lymph nodes also had a nutritional function. He described three different types of mesenteric vessels, namely, the arterial vessels, for the transport of spirituous blood to the intestines; the venous side branches of the portal vein, for the transport of nutritive blood from the liver to the intestines; and small vessels, from the intestines to the mesenteric lymph nodes (serous lymph vessels?). According to Galen, chyle was transported via the above-mentioned mesenteric venous vessels from the intestines to the portal vein and liver, where it was transformed into nutritive blood. This doctrine would be obliterated in the seventeenth century by the discovery of systemic circulation and of the drainage of chyle through a thoracic duct to the subclavian veins.

Canto: Hmmm. Chyle? Peritoneum? Subclavian?

Jacinta: Chyle’s a milky, fatty fluid (containing lymph), formed in the small intestine during digestion. It flows into those lymph vessels known as lacteals. These are special ‘lymph capillaries’ where the lipids ‘are colloidally suspended in chylomicrons’ My guess is that ‘chylomicrons’ are itty-bitty chyle bits. Colloidal suspension is ‘a stable phase showing little tendency to aggregate and separate from the aqueous phase’, according to ScienceDirect. The peritoneum is ‘the serous membrane that lines the abdominal cavity’. Other serous membranes are the pleura and the pericardium. They are two-layered membranes ‘lubricated by a fluid derived from serum’. The subclavian veins (and arteries) are those running from the neck down the left and right arms.

Canto: Serum?

Jacinta: Comes from the blood, and rich in proteins.

Canto: So it seems that lymph, or the lymphatic system, has a few functions. Three in particular are highlighted by a NIH website relating to cancer. First, it returns interstitial fluid – fluid that leaks from blood capillaries into the spaces between cells – to the venous blood. This is a sort of recycling process – a regular leakage and a regular return. The returned fluid is called lymph. The second function connects it to the digestive system. Fats and fat soluble vitamins are absorbed and transported to the venous circulation. This happens through those aforementioned lacteals. The small intestines are lined with villi, little finger-like projections, in the centre of which are blood capillaries, and lacteals, aka lymph capillaries. The blood and the lymph thus act together, with the blood capillaries absorbing most of the nutrients and the lymph capillaries absorbing the fatty stuff. And this high fat content lymph is called chyle. And the third function – the most well-known function according to my source – is immunological:

Lymph nodes and other lymphatic organs filter the lymph to remove microorganisms and other foreign particles. Lymphatic organs contain lymphocytes that destroy invading organisms.

Jacinta: A reasonably good dummies intro to lymph and the lymphatic system, IMHO, and it’s not really surprising that it took a while to work out what it was all about. We certainly don’t know ourselves, but we know a bit more than we did.

Canto: Yes, much more to learn, about lymphoid tissue, capillaries, vessels and that big thoracic duct. And since much of this info comes from the National Cancer Institute (in the US), the connection with cancer, positive or negative, might be worth exploring….

References

David Bell, The disease of a thousand names, 1991

https://en.wikipedia.org/wiki/Lymph

https://en.wikipedia.org/wiki/Lymphocyte

https://www.ncbi.nlm.nih.gov/books/NBK27092/

https://www.ncbi.nlm.nih.gov/books/NBK10759/def-item/A3018/

https://www.ncbi.nlm.nih.gov/books/NBK10759/def-item/A3298/

https://en.wikipedia.org/wiki/Mesentery

https://www.sciencedirect.com/topics/engineering/colloidal-suspension

https://training.seer.cancer.gov/anatomy/lymphatic/

https://training.seer.cancer.gov/anatomy/lymphatic/components/

Written by stewart henderson

March 31, 2023 at 8:30 pm

covid19: autopsy analyses, biomarkers, von Willebrand factor

leave a comment »

von Willibrand factor, a multimeric blood protein which plays a central role in blood clotting

Canto: So we’re working hard to get through what has been reported on medcram update 95, even though it’s taking us further behind the times in terms of what’s happening in the fight against this virus – there’s been some controversy on convalescent plasma recently for example – because it’s important to get the most out of every report before going onto the next one.

Jacinta: Yes, which means we need to work harder and faster. So in this study of a number of fatal cases of covid19 they found ‘no endothelial abnormalities on microscopic review, in alignment with previous studies’, which suggests that evidence of endothelial damage just doesn’t seem to be there, but they couldn’t rule out pro-coagulant endothelial dysfunction in the absence of ‘histopathological evidence of cell activation or erosion’, and they referred to another autopsy study with specialised equipment which ‘demonstrated ultrastructural endothelial damage’. So it seems they’re struggling with causes.

Canto: What they call the precise aetiology of the disease. 

Jacinta: Yes that’s what we’re after. So they do mention elevated troponin in covid19, which appears to be found regularly. Troponins are ‘a group of proteins found in skeletal and cardiac muscle fibres that regulate muscular contraction’. As the update tells us, troponin tests measure cardiac-specific troponin in the blood as a sign of heart injury. This Australian site tells us more:

For patients who are hospitalised with COVID-19, mild elevation of troponin is common (19.7%) and frequently correlates with disease severity, acting as a marker for cardiac injury. The cause of troponin elevation in serious infection is multifactorial.

In the study under discussion, they consider that the elevated troponin has to do with ‘thrombosis of the microvasculature and cardiac veins’. This cardiac vein finding is apparently important – they found, they believe for the first time, that thrombosis of a cardiac vein can cause myocardial infarction. They also write about renal findings in their subjects, to ‘shed light on the pathogenesis of acute kidney injury in covid19’. They found virions in proximal tubular cells. A virion is essentially a full, active molecule of a virus (there’s still some disagreement about these definitions, it seems). The proximal tubules are components of nephrons, the most important functional units of kidneys. They found acute tubular necrosis and other damage, and noted that this was common to other covid19 autopsy findings, perhaps unsurprisingly as these tubular cells present ACE2, the receptor for the virus. Dr Seheult then goes on to another study from Switzerland. This study looked at 639 critically ill covid10 patients, to determine which factors were most associated with survival or otherwise. So in general they found that this group suffered a ‘moderate’ mortality rate of 24%. To understand the findings will require quite a bit of medico-immunological knowledge, but here goes: they found that ‘PCT and IL-6 levels remained similar in ICU survivors and non-survivors throughout the ICU stay’. PCT is procalcitonin. According to Medscape:

Procalcitonin (PCT) is a biomarker that exhibits greater specificity than other proinflammatory markers (eg, cytokines) in identifying sepsis and can be used in the diagnosis of bacterial infections. Procalcitonin is also produced by the neuroendocrine cells of the lung and intestine and is released as an acute-phase reactant in response to inflammatory stimuli, especially those of bacterial origin. This raised procalcitonin level during inflammation is associated with bacterial endotoxin and inflammatory cytokines.

IL-6 is interleukin-6. An opinion article in Frontiers in Microbiology  entitled ‘The Role of Interleukin-6 During Viral Infections’ describes IL-6:

IL-6 is a pleiotropic cytokine produced in response to tissue damage and infections…  Multiple cell types including fibroblasts, keratinocytes, mesangial cells, vascular endothelial cells, mast cells, macrophages, dendritic cells, and T and B cells are associated with the production of this cytokine….

Pleiotropic cytokines – a cytokine is a type of small protein – affect the activity of multiple cell types. The complex pleiotropic nature of IL-6 unsurprisingly implicates it in both pro-inflammatory and anti-inflammatory effects. So, PCT and Il-6 levels remained similar for these study subjects, but ‘CRP, creatinine, troponin, D-dimer, lactate, neutrophil count, P/F diverged within the first seven days.’  Okay, C-reactive protein (CRP) is produced in the liver, from which it enters the bloodstream, and its levels ‘start to increase very soon after any inflammation or infection affects the body’, according to Australia’s healthdirect website. Creatinine is a waste product found in everyone’s bloodstream, and it’s produced by muscle metabolism. It’s generally filtered out by the kidneys. Too much blood creatinine may be a sign of kidney dysfunction. D-Dimer, the fibrin degradation product, always contains ‘two D fragments of the fibrin product joined by a cross-link’. I won’t try to explain much further at present. Neutrophils, remember, are infection-fighting white blood cells, and P/F ratio, aka PaO2/FiO2 ratio, is, briefly, an assessment of lung function. So with that, and some more, the study looked at levels of different markers most associated with mortality. To quote from the study: 

In contrast to risk factors in hospitalised patients reported in other studies, the main mortality predictors in these critically ill patients were markers of oxygenation deficit, renal and microvascular dysfunction, and coagulatory activation. Elevated risk of bloodstream infections underscores the need to exercise caution with off-label therapies. 

Canto: That last point seems important- it’s all about the blood. Or mostly..?

Jacinta: They presented a number of graphs which Dr Seheult interprets for us, but basically they are all likely to mark higher levels of microthrombi in the patients who died, and this seemed more clearly so in the D-dimer levels. High lactate levels are a sign of anaerobic metabolism, a problem with oxygenation. Ischemic heart disease was also measured, and this has to do with narrowing of the arteries. So blood oxygenation, or lack thereof, and coagulation, which can happen just about anywhere, seems to be happening early, leading to a wide range of symptoms, especially in patients with comorbidities, some of them previously undetected. 

Canto: So we’re moving on to update 96, which starts again with thrombosis due to endothelial damage causing increased production or release of von Willibrand factor (VWF).

Jacinta: Yes, and they’re apparently finding that different blood groups or types – and that’s a topic we could spend a lot of time on – affect the level and activity of VWF. As do other factors, according to Russian researcher Anna Aksenova:

The level and activity of VWF in the blood in people can be different. The lowest values are associated with von Willebrand disease. It is a hereditary blood disease that is characterized by spontaneous bleeding. Additionally, it differs markedly among healthy people. For example, it is higher among: African Americans than among Europeans; in men than in women; in adults than in children; and in the elderly than in middle-aged people. Also, academic papers have described the VWF and blood group relationship—its level is lower among people with blood group 0, and is higher among those with blood group A. The different amount and activity of VWF in people with different blood groups has a very interesting explanation: this protein is modified by oligosaccharide chains of antigenic determinants of the AB0 system (one of the blood group systems), and this affects its stability and activity.

She points out that ‘to date, the way in which the level of VWF is regulated in the blood has not yet been fully studied’, and then she describes some of what we do know, that it’s stored in special organelles (Weibel-Palade bodies) from where it’s secreted in multimeric form. She argues that, in order to determine the level of involvement of VWF in the progress of covid19, ‘large scale and comprehensive research’ needs to be carried out. Another article which is looking at emergency covid19 treatment has the title ‘targeting raised VWF levels and macrophage activation in severe covid19: consider low volume plasma exchange and low dose steroid’. It points out that VWF is such a large protein that it can only really be removed from the body through plasma exchange. This may be a way to reduce thrombosis in serious cases. Another interesting commentary piece is titled ‘microthrombotic complications of covid19 are likely due to embolism of circulating endothelial-derived ultralarge von Willebrand Factor (eULVWF) decorated-platelet strings’. 

Canto: An embolism being a blockage, caused by an embolus. That embolus could be a blood clot (a thrombus) or a fat globule or an air or gas bubble. 

Jacinta: Yes, and VWF can come in these long strings of platelets. In fact the platelets adhere to the strings. Anyway, that’ll do for now. We’ll go on about ivermectin and the Moderna vaccine trials next time. 

References

Coronavirus Pandemic Update 95: Widespread Clotting on Autopsy; New COVID-19 Prognostic Data

Coronavirus Pandemic Update 96: RNA Vaccine; Ivermectin; von Willebrand Factor and COVID-19

https://labtestsonline.org/tests/troponin#:~:text=Troponins%20are%20a%20group%20of,to%20help%20detect%20heart%20injury.

https://www1.racgp.org.au/ajgp/coronavirus/cardiovascular-conditions-and-covid-19#:~:text=Elevated%20biomarkers%3A%20Troponin%20and%20natriuretic,a%20marker%20for%20cardiac%20injury.&text=The%20cause%20of%20troponin%20elevation%20in%20serious%20infection%20is%20multifactorial.

https://www.medscape.com/answers/2096589-179642/what-is-procalcitonin-pct

https://www.frontiersin.org/articles/10.3389/fmicb.2019.01057/full

https://www.medicinenet.com/script/main/art.asp?articlekey=26197

https://www.healthdirect.gov.au/c-reactive-protein-CRP-test

https://medicalxpress.com/news/2020-07-complications-covid-von-willebrand-factor.html

Written by stewart henderson

September 6, 2020 at 1:44 pm

want to live to 100?

leave a comment »

… It may destroy diseases of the imagination, owing to too deep a sensibility, and it may attach the affections to objects, permanent, important, and intimately related to the interests of the human species.

Humphry Davy,  on the value of science, in ‘Discourse introductory to a  course of lectures on chemistry’, 1802

il_340x270.643224959_qav7

A great many of us would like to live a long and healthy life, with a greater emphasis on health than length. But both please, if possible, thanks.

I’ve been reading the issues of New Scientist: the collection as they come out. The first issue dealt with the Big Questions, namely Reality, Existence, God, Consciousness, Life, Time, Self, Sleep and Death. Bit of a roller coaster ride, leaving me dizzy, confused, but often enlightened, and sometimes even exhilarated. So, better than a roller coaster. The second issue, entitled The Unknown Universe, took me far out beyond multiverses, quantum loops, energetic dark matter and the eventful horizons of black holes, and essentially taught me that modern cosmology is a mess of competing theories, often competing, it seemed, to be the most egregious ideas that are compatible with mathematical possibility. However, it may be that the studious avoidance of scary maths in these essays/summaries may have made them seem more loopy (or strangulatingly stringy) than they are.

The third issue was more down to earth, and not only earth but me, and you, dear reader. It’s entitled The scientific guide to a better you, and it’s all about longevity, health and success.

So what’s the secret, at least for the first two? Basically, eat healthily, with not too much meat, make sure you have good genes, don’t be too much of a loner (too late for me, I’ve been a loner for 40 years, and that’s unlikely to change, but I’l try, as I always say), be intelligent, active and exploratory. That’s the message of the first half of this issue anyway.

What interested me, though, was the detail. Measurements. Blood sugar, cholesterol, heart rate and many other factors and parameters, most of which I didn’t know I had to be concerned about. The various essays are peppered with these measures of health or lack thereof, but how does your average Jo like me get a measure of these things without pestering doctors on a weekly basis about wellness instead of sickness?

So, for fun, I thought I’d look into these ways of measuring ourselves and see if we can manage them from home. A sort of practical guide to centenarianism and beyond.

1. Body mass index (BMI)

Your BMI is a very rough-and-ready guide to whether or not you’re a healthy weight for your height. Various websites can calculate this for you instantly if you know your height and weight. My current BMI is 26, according to the Heart Foundation, which it regards as ‘overweight’, though very close to the borderline between ‘overweight’ and ‘healthy’. About three years ago my BMI was 29, well into the overweight category, in fact getting close to obese. I decided to eat less, without fasting or ‘going on a diet’, and to try to up my exercise, and over a 2-year period I brought my BMI down from 29 to 23, well into the healthy range. Since then it has crept back up to 26, and I’m struggling to get it back down again. I just need to lose a couple of kilos, and keep them off. The myriad other ways of measuring your health these days might make the old BMI seem outmoded – it doesn’t measure your fat to muscle ratio, for example, or the amount of fat around your heart and other organs – but I find it a useful guide for me, and the cheapest available.

2. Heart rate/blood pressure

Measured in beats per minute, your heart rate naturally varies with exertion, and also with anxiety, stress, illness, drug use and so on. The normal resting heart rate for an adult human ranges from 60 to 100 bpm. You can measure your own heart rate (your pulse) at any time by finding an artery close to the surface. The radial artery on the wrist, the one you see heading in the direction of the thumb, is commonly used due to ease of location, but don’t try it with your thumb which has its own strong pulse. I’ve just located my own wrist pulse and measured it as 62bpm. That’s the first time I’ve ever done it. However, I imagine it would be harder to measure after a bout of HIIT (high intensity interval training), which I sometimes indulge in, or after a moderately strenuous bike-ride. It would be even harder while you’re in the middle of exercise, so that’s where heart rate monitors, including those that can be worn on the wrist, come in handy. A quick google-glance tells me that such wrist devices are selling at $100 to $150. However, caveat emptor, as doubt is being cast on their accuracy. Electrocardiographs (ECGs, or EKGs), which measure the electrical activity of your heart, provide a much more accurate record than heart rate monitors, which are apparently only really effective when you’re at rest. One of the problems is that these optical monitors use light to track your blood, and to get an ‘accurate’ reading, you need to be very still, which sort of defeats the purpose. Reporter Sharon Profis, with the help of cardiologist Jon Saroff of Kaiser Permanente medical center in San Francisco compared various wrist monitor brands with the gold standard EKG measurements, and found them well off-beam especially at over 100 bpm. However, the Garmin Vivofit chest strap monitor, which measures electrical activity, was very accurate. This device can be bought for around $150 in Australia.

3. Cholesterol

Cholesterol’s an essential organic molecule, a sterol, a structural component of our cell membranes. It’s biosynthesised, mainly by our liver cell, often as a precursor to such vital entities as steroid hormones and vitamin D, and researchers have tracked the 37-step process of its synthesis. Cholesterol is transported through the blood within lipoproteins, and that’s where you get HDL (high-density lipoprotein) and LDL (low-density lipoprotein) cholesterol, of which the former is the one that causes problems. Some 32% of Australian adults have high blood cholesterol, the primary cause of atherosclerosis, leading to clogging of major blood vessels. Ways of lowering your LDL levels include not smoking, avoiding transfats, regular moderate exercise, and healthy eating including fruit, veg, grains and pulses and sterol-enriched foods. But of course you know all that. The big question is, can you measure your cholesterol from home? The current answer appears to be no, according to the Harvard Medical School (though I note that their article is 11 years old). The problem is that home testing kits can’t separate the ‘good’ HDL cholesterol from the ‘bad” (LDL). Measuring your overall cholesterol levels might be useful, but the real issue is the proportion that is LDL, not to mention that cholesterol can also be carried by other molecules such as triglycerides.

 4. Blood sugar/glucose

Glucose is a vital source of energy for the body’s cells, and its levels are associated with the hormone insulin, produced by the pancreas. Blood glucose levels naturally vary throughout the day, and having a level regularly above normal is termed hyperglycemia. Hypoglycemia is the term for low levels. Diabetes (technically Diabetes mellitus) is the disease most commonly associated with high blood sugar. General symptoms are frequent urination, hunger pangs and increased thirst.  The mean normal blood sugar level is around 5.5 mM (millimolars). That’s the international standard measure – the Americans measure it differently, which causes the usual confusion. Not surprisingly, considering the global rise in diabetes, blood glucose meters for use at home are readily available, but they’re mostly specially devised for use by diabetics, supervised by healthcare professionals. You can of course buy one and DIY but you must learn to be inured to pricks, and unless you’re at risk, which I’m not, as I don’t have much of a sweet tooth, don’t have particularly high cholesterol, and have never evinced any diabetic symptoms, it’s probably not worth the investment. The essential test associated with ‘pre-diabetes’ or hypoglycaemia is a glucose-tolerance test (GTT).

5. Sequence your genome

According to the Australian government’s National Health and Medical Research Council (NHMRC):

Rapid advances in DNA sequencing technologies now allow an individual’s whole genome to be sequenced. Although this is still relatively expensive, it is likely that in the near future it will become affordable and readily available.

Ah, that other country, the near future. But it is a fact that the price is coming down, from $10 million in 2005 to a mere $1 million in 2007 when James Watson’s genome was sequenced. The going rate in 2012 was under $10,000, and this year (2014) the Garvan Institute of Medical Research in Sydney became one of only three institutes in the world to deliver whole sequenced genomes at under $1000. However, there’s a problem. Your genome will mean nothing to you without expert analysis and interpretation, at a hefty price tag. So what would be the purpose, from a health perspective, of ‘doing your genome’? If you’re already quite healthy, do you want to spend up to $1000 only to find out that you carry a gene which may pre-dispose you to a disease that’s currently non-preventable? Our genome is very complex, so much so that current thinking on the subject, and especially on the introns, the sections that don’t code for proteins, has become more cloudy than ever. We know, or think we know, that the number of introns an organism has is positively correlated with that organism’s complexity, but that’s about all we know for sure, and  considering the enormous complexity of the interaction between genetics and environment, together with our lack of knowledge of the role of so much of our genome (over 98% of which is non-coding DNA), the question of whether it’s worth sequencing at this time is a live one. Of course if the price comes down to $100, or the price of a latte (which will soon be up around that figure) then it’d be well worth it; you would have it there awaiting scientific breakthroughs on all that non-coding stuff.

6. microbiome

If you’ve been paying attention to the world of human health, you’ll know that the microbiome is all the rage at the moment. the term was coined by Joshua Lederburg, who defined it thus, according to Wikipedia:

A microbiome is “the ecological community of commensal, symbiotic, and pathogenic microorganisms that literally share our body space.”

You may well have heard the impressive statistic that you have ten times more bacterial cells (and, most interestingly, archaean cells) growing on or in you than bodily (eukaryotic) cells, though this might become less impressive when you learn that the combined weight of those cells amounts to only a few hundred grams. Still, recent research on the microbiota has turned up some interesting results, especially for health. One finding, which may make it difficult to assess your own microbiome, is that different sets of microbes appear to perform the same function for different people. So you won’t just need to know the genetic content of your microbiome, but its function. Still, we can learn a lot already from our microbiome, according to Catalyst, the ABC science program. For example, we inherit a lot of bacteria from our mothers, via her breast milk, not only directly but because the sugars in breast milk encourage the growth of particular types of bacteria. Most of this gut bacteria does its work in the large intestine or bowel region. They’re anaerobic beasties, so they die when exposed to air. However, recent technological developments (and how often can that story be told) have allowed us to learn far more about them, by sequencing their genes inside the gut. From this we’ve learned that our gut bacteria are vital components of our immune system. And since these bacteria rely on our own diets for their nourishment, the kind of microbiome we have is profoundly related to what we eat. A diverse microbiome results, apparently, from eating a high-fibre diet, and low-fibre processed food, and the ingesting of antibiotics, is reducing that diversity, and contributing to multiple health problems. It appears that a less diverse microbiome finds itself under stress, leading to inflammation, an immune response that can damage our own tissue. As a sufferer from bronchiectasis, a chronic (and incurable) inflammation of the airways due probably to early childhood damage, I’m particularly concerned to limit the extent of inflammation through diet and exercise, so this is probably the aspect of my health I’m most concerned to monitor. And there’s also the relationship between gut bacteria and obesity. Some 62% of Australians are overweight or obese, and I’m one of that majority, and trying not to be.

It has been shown clearly, in mice at least, that a high-fibre diet reduces bronco-constriction, improving resistance to asthma and other airways conditions such as COPD. This is mainly due to the production of short-chain fatty acids by particular bacteria. The short-chain fatty acids are produced though the digestion of dietary fibre. Interestingly, acetate, found in vinegar, is a short-chain fatty acid, and a natural anti-inflammatory, so that’s something I should include regularly in my diet.

Finding out what your particular microbiome is, and how it might align with your health, is a simple if rather unpalatable and ‘intimate’ process. You can apply for a kit from the American Gut Project, an organisation dedicated to researching microbiota. The kit is for obtaining a sample of your ‘biomass’ as they call it, which you then send back to the AGP for analysis. All of this was spelt out in the above-linked Catalyst program, but since that program was aired two months ago, the AGP has been inundated with more biomass than it can deal with, so there’s been a backlog of logs, as it were. I plan to send for a kit anyway. The AGP sends back the results, apparently, with hopefully an analysis of the microbiome easy enough for a layperson to understand.

 

So there’s six areas to look at, either independently or with the help of your GP or other professionals, in terms of measuring how you’re going in terms of overall health, and there are many more aspects of your bodily chemistry and physiology to check up on – hormones, neurotransmitters, bone density, sight, hearing, lung capacity and so forth. Or you can follow the standard advice on diet and exercise, try to avoid stress and hope for the best. And above all don’t stop laughing and dancing, otherwise life would hardly be worth living.

Written by stewart henderson

November 1, 2014 at 6:36 pm