Welcome to the fourth and final installment of our animated series on the digestive system.
Fittingly, this episode will be focussing on the end of the digestive system – the colon. We will look at the genesis of colon cancer, as well as a little molecule scientists like to call ‘butyrate’, and the influence it has on colon health.
The colon, otherwise known as the large intestine, is one and a half metres long. It primarily extracts water and micronutrients (such as salts) from our faeces. The first half of the following video describes the colon, its structure and function in glorious, animated detail.
Colon cancer (colorectal or bowel cancer) is the third most common cancer, accounting for around 10% of cancer cases. After the colon, the second half of the video describes the anatomy and mechanisms of colon cancer.
The second video describes the formation of colon cancer (known as colon carcinogenesis):
Butyrate is a small molecule created by the bacteria in our guts. Butyrate is formed when these bacteria breakdown resistant starch and is involved with up-keeping colon health. Recent research suggests that butyrate might be important in staving off the formation of colon cancer.
That’s it for our series on the microbiome.
Just like your breakfast from yesterday, our journey through the digestive system had to come to an end. We have come a long way through the alimentary canal, there has been lots of information to digest, lots to ruminate upon. There were simmering facts about the stomach, ups and downs through the tortuous mess of intestines, and sobering descriptions of colon cancer. And also like yesterday’s breakfast, we too emerged on the other side of the journey, changed. Over the last 4 weeks, we hope you learned as much about the alimentary canal as we did.
Butt – it’s not over. For the back catalogue of microbial madness, here are our previous blogs on the (faecal) matter. And for more anatomical animations, check out the writer, animator, and narrator’s YouTube channel.
9th February 2015 at 8:20 am
Awesome illustrations and synthesis of information!
6th February 2015 at 8:05 pm
I have not had yet the chance to see – sometimes the computer doesn’t let me see or hear anything nor send comments – the video/animation part nor have read the previous three articles which I will as I was most interested and best at gastroenterology perhaps because I do have a big gut myself alas.
I even did my electives on cholelithiasis in young Indian women nowadays called first nations people. I never thought it had anything to do with genetics or race but change in diet from natural wild foods to North American processed poverty junk food. And later radiological signs of acute pancreatitis. And much later reading about and finally meeting in Halifax in person the greatest man who ought to have received the Nobel Prize in medicine not for Burkitt’s lymphoma but for the colon cancer and other GI maladies connexion with bowel transit times and HIGH FIBER diet in Ugandans which protected them from all these GI maladies. For he realized that it is not not so interesting why some people develop certain diseases but why others almost never do. High fibre went out of fashion not because it was wrong but because it was misunderstood.
At the first illustration of this article I said here we go again nineteenth Cy medicine Wirchow and all that cellular pathology and hematoxylin eosinophilic stains mitoses and meiosis and nucleoli and all that but the second illustration redeemed itself about histones acetylation methylation DNA uravelling etc. Not yet quad DNA supported by four guanines as cancer cells wave goodbye to Watson and Crick double helix and hello quadruple and triple stranded DNA and even more adieu the exclusivity of mRNA tRNA and rRNA and and bonjour iRNA and ten thousand other small RNAs which are probably how epigenetics work.
Which is of course the defeat of half of Darwinism the inheritance of acquired characteristics whereby Lamarckism rears its ugly head. For it seems that iRNA a and a myriad others is the means by which non genetic changes occur as DNA sequence itself is unalterable but its function and expression must be alterable and that is done by reverse transcriptase and epigenetics of iRNAs etc.
Needless to say the evolution half of Darwinism is simply unassailable as Dobzhansky said without evolution nothing makes any sense. But inheritance of acquired characteristics is another matter. In Canada we say another kettle of fish brrr it’s -29.
Then there is the matter of chenodeoxycholic acid and lithocolic acid and the enterohepatic circulation of bile acids. Another theory of bowel cancel is that altered gut flora due to lack of Burkitt’s fiber and William Davis’s evil gluten and wheat starches of refined steel ground (Painter Taylor Cleave Yudkin) and 1939 New York World’s fair extruded pulp odious white presliced fake bread dough ugh! alters the bacterial biome of the colon and chenodeoxyxholic acid is manufactured into the aptly named lithocholic acid by gut flora though now they are protists not plants – please don’t insult the goddess of spring – which then causes gallstones and ultimately and more sinisterly bowel cancer by inserting itself into the DNA chains causing mutations and the growth of cancer cells.
So this is where epidemiology meets cellular biology and pathology and histology and carcinogenesis and oncology and biochemistry and organic chemistry.
Which brings us to sulphoraphane Raphanin sulforafene glucoraphanin from Raphanus sativa the active ingredient of radishes extracted by two Hungarian chemists or MD’s in 1947. The formula is H3C-S=O-CH=CH-CH2-CH2-N=C=S. Cannot be given as a drug as it is highly toxic and has a sulphurous netherworldly smell but is highly desirable in food plants of the cruciferae family being antiviral antibacterial antifungal? anticancer preventing spinal chord injuries and neurodgenerative diseases and maybe the metabolic syndrome which stands now at thirty + disease count!
Raphanin occurs in bok choy chinese cabbage Chinese broccoli mustard horseradish RADISH probably even more in black radish which is just a variety of, the lowly turnip being a miracle food!? cabbage esp. red cabbage kohlrabi kale broccoli Brussel sprouts watercress cauliflower. Allyl iso thio cyanate AITC CH2=CH-CH2-N=C=S you can see the similarity to raphanin occurs in mustard radish horseradish.
The speculation is that these molecules with the S end turn into H2S hydrogen sulfide inside the cell and outside the mitochondrion as all this nefarious activity of synthesis of endogenous carcinogens and cancer promoters occurs in the very synthetic endosymbiont mitochondrial DNA not in the nuclear cytosolic DNA methylation and histones or not and this noxious gas H2S destroys the mitochondria of the cancer cells?
So now we have to stop eating a hundred pounds of wheat bran a month because of Dr William Davis’s Wheat Belly but we can continue to get our fiber from pulse/legumes beans peas chick peas and lentils.
I still go for oats rye and barley for their low glycemic index unless you are suffering from gluten enteropathy non tropical sprue.
Either way unless you get a cast of your colon every morning you are deficient in Burkitt’s fibre.