It all sounds like voodoo until you can find the sense (science) to understand it.
A Working Goal of my blog: Inspiring all people, but particularly parents with school-aged children, to understand that it is a true medical necessity to return our diets to a whole foods diet, free of processed foods, and lower in overall sugar (sugar, honey, maple syrup, agave, juice, corn syrup, date sugar, rice sugar, we-can-make-sugar-out-of-anything-sugar, and we-can-make-anything-taste-good-with-enough-sugar sugar).
What the upcoming series of posts will be about and why it is important to you: The upcoming series of posts is going to be about butyrate. It is a very important chemical that our body needs to function properly. You probably haven’t heard about it, but it is important. I guess if I had to try to compare it to something that you did know about, I’d liken its importance to vitamin C. I am not saying it is vitamin C, but I am trying to relay the importance of the stuff. The best source of butyrate comes, not from food, but from bacteria in the colon working on vegetable and plant matter. It comes from bacteria that live naturally in your colon which ferment vegetable and plant matter and turn it into butyrate, which your body in turn uses to maximize health and function in many splendid ways.
Butyrate, then, is one specific retort to the statement and question: “I don’t like vegetables. Why do I have to eat my vegetables?” You now have something concrete to say besides, “They’re healthy.”
Try this for a change: “Aw, sweetie. I know you don’t. But the bacteria in your colon do! And they will gobble them all up for you and turn them into butyrate.”
Or, “Tough. I don’t care. Eat them anyway. Your bacteria do (like them). You’ll be low on butyrate if you don’t.”
Short Chain Fatty Acids Overview
Recap from Part 1 (Part 1): Yesterday we talked about how we need the bacteria in our colon and how we want to help keep the “good” bacteria thriving. Plant matter, like vegetables and fruits, feed the good bacteria and allow them to make important substances, like butyrate, which we absolutely depend on, see “Butyrate is Important for YOU.” Sugars and processed carbohydrates can feed the growth of “bad” bacteria in our colons. Bad bacteria are more likely to make chemicals that can be harmful to us, like ammonia, methane, hydrogen sulfide, and others. Butyrate is a short chain fatty acid made by favorable strains of bacteria in the colon. This series is honing in on butyrate because it seems to be a strong healer of the GI tract. (1,2)
Butyrate is a short chain fatty acid: There are several types of short chain fatty acids (SCFAs) besides butyrate, and each SCFA, in its own way, looks vitally important to the positive functioning of our bodies. The most important way we get SCFAs is by eating food that comes from plants. The “plant food” itself doesn’t give us SCFAs! The bacteria ferment the plant-based food to make SCFA. (Later we will learn that SCFAs are made best from certain types of plant foods, but for now we will just lump it all together.) A brief explanation of digestion is needed to later understand which foods butyrate can be made from. Allow us to deviate.
Brief explanation of digestion of carbohydrates up through the small intestine: For butyrate’s purposes, we are concerned with carbohydrate digestion (even though butyrate is a fatty acid—forget that for now). Let’s look at an apple. Bite apple. Chew apple. Your saliva starts working on digesting the apple. Swallow apple. Apple goes to stomach. Apple moves to small intestine where the bulk of digestion is done. The apple has some simple sugars (fructose, glucose, sucrose), a small amount of starch (starch is an energy form for the plant and is made up of glucose strings), and some fiber (and other stuff, but we’re focusing on the carbohydrate component for the purpose of this butyrate series).
- The sugars of fructose and glucose get completely absorbed in the small intestine by most people. The apple’s intrinsic sucrose sugar is broken down and then completely absorbed. (Simple. Simple sugars!)
- The starch needs to get worked on by an enzyme called amylase, which is made by the salivary glands and pancreas. The pancreas dumps its amylase into the small intestine (specifically the duodenum). The amylase breaks down the apple starch into smaller units so it can be made into glucose by more small intestine enzymes. The glucose is then absorbed by the small intestine. Nearly all of the starch in the apple will be broken down and converted to glucose to be absorbed. More complex, eh? Complex carbohydrates! (Even more complex is the fact that not all starches get completely digested and absorbed, although we used to learn that they did! That will be explored later and is very important.)
- Any kind of fiber in the apple (pectin and cellulose for example) doesn’t get broken down or absorbed. We don’t have enzymes to do anything to the apple fiber. It moves into the colon (large intestine) for the bacteria to feast on and make SCFAs.
The lovely colon (Aside: I see it like a Star Wars world down there.): After the small intestine absorbs what it can, leftover foodstuff travels to the colon for further processing. The colon was not designed to function alone; it was designed to work in concert with billions of bacteria that naturally and ideally live there. (You are not alone…) The bacteria make many products that we humans absolutely rely on, such as B vitamins and vitamin K, but here today we will be looking at SCFAs. The colon’s bacteria ferment what they can of the leftover foodstuff; that’s a fancy way of saying they eat the leftovers and turn it into energy for themselves. They like to ferment starches, sugars, and fiber the best. When they “eat” the fiber or starch, they make the necessary SCFAs for us to use and the colon absorbs them. (The bacteria do care about us, by the way. Don’t think they don’t. Without us they’d die. Is the feeling reciprocal? I’m poking. Grin.)
(Key point: We have to have SCFAs, and we get them from the bacteria in our colons who make them best from plant-based foods.)
Summarizing through highly sophisticated pictures:
“Sillily” simple structures: SCFAs possess simple, simple structures that any high school chemistry student could draw, but their functions are so complex that even our most trained professionals are challenged to give us answers about them!
(Please note: I STILL have not had time to upload the figure with the corrected structures for the SCFAs. The structures you see are the alkanes. Correct structures should show the final carbon on each as a carboxyl group, which is a COOH.)
No, you can’t just eat sugars and make these wonderful SCFAs: Now I know at this point you’re thinking, “Whoo-ha! Free ticket to eat sugar and starches. She just said the bacteria like sugars and starches (oh, yeah—and fiber) the best!”
(Shout) “NO!” Because if you remember when we talked about the digestion of carbohydrates in the small intestine, I told you that most sugar and starch is broken down and completely absorbed by the small intestine. So most of the processed foods, candy, soda pop, donut, what-have-you—those sugars and starches are for you. They provide your calories (which many of you don’t want), not the helpful bacteria’s calories. And, by chance, any simple sugars that do make their way down the intestines, they promote the overgrowth of “bad” bacteria and a decline of “good” bacteria.
Fate of the SCFAs after they are made by the bacteria: Each SCFA has its own path once absorbed by the body. Acetate mostly goes to the liver and to the blood to be circulated on to the peripheral tissues of the body. Propionate gets sent to the liver. Butyrate is immediately used as fuel and support for the lining of your colon (colonocytes; epithelial layer) and is also sent to the liver. (I am focusing on butyrate because it is so vital to the maintenance and restoration of the GI tract.) Valerate and caproate have not been quite sorted out yet. We do know that valerate is poorly recovered in fecal matter, and so it may be highly used up like butyrate in the colon. (3)
(Key point: SCFAs have different destinies in the body, and they are all important. However, I’m focusing on butyrate because studies show that it hugely affects the function of the gut. It may help so much more in the body, though!! What starts in the gut–benefits or detriments elsewhere! Acne, headaches, reflux, skin rashes, food intolerances, yada, yada, yada, can all be a sign of a disordered gut!!!)
Stop: Okay. We’re stopping here today. The next post will discuss why a person would be low in SCFAs and butyrate and discuss some problems with this. Then we’ll talk about how to get butyrate from food. Which will lead us to resistant starch. Thank you for reading. Butyrate–it’s great. 🙂
Sources: All of these are available free on-line in full text. Let me know if the links don’t work.
(1) Targeting Enteric Neuroplasticity: Diet and Bugs as New Key Factors. deGiorgio and Blandizzi. Gastroenterology. May 2010. 138(5): 1663-1666. http://www.gastrojournal.org/article/S0016-5085(10)00377-X/abstract
(2) Review article: the role of butyrate on colonic function. Hamer, Jonkers, Venema, et al. Alimentary Pharmacology and Therapeutics. 2008. 27: 104-119. http://www.ncbi.nlm.nih.gov/pubmed/17973645
(3) http://arno.unimaas.nl/show.cgi?fid=16226 Chapter 3 page 62