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Short-Chain Fatty Acids (SCFA)

What are short-chain fatty acids?

Short-chain fatty acids (SCFA) contain 2-5 carbon (C) atoms. They are mainly produced during fermentation of the soluble dietary fiber by beneficial large intestinal bacteria. They include [2]:

  • Acetic acid (2 C atoms)
  • Propionic acid (3 C atoms)
  • Butyric acid (4 C atoms)

SCFA Functions

SCFA are considered the main nutrients for the large intestinal lining cells; they also increase the blood flow, muscle activity and water absorption in the colon [1,2]. SCFA are partly used as food for beneficial bacteria and partly they are absorbed and metabolized – this is why soluble dietary fiber, from which colonic bacteria produce SCFA, has 1-3.8 Calories per gram [1].

SCFA Food Sources

The following soluble dietary fiber produces most SCFA in the large intestine [2,3]:

Butyrate in Dairy

Butter, certain cheeses and cow’s milk contain considerable amounts of butyric acid in the form of butyrate (a compound of butyric acid and glycerol) [4]; note that these foods are also high in saturated fats.

In rancid butter, butyric acid appears in the free form–not bound to glycerol as in normal butter–and causes unpleasant odor.

SCFA (Butyrate) Supplements

Short-chain fatty acid supplements, mostly butyric acid salts, such as sodium, potassium, calcium and magnesium butyrate, are available without prescription (over-the-counter).

Butyrate supplements are–like other fatty acids–absorbed in the small intestine, so they cannot promote the growth of beneficial colonic bacteria or clean the large intestine (colon), as advertised. There is no scientific evidence about their effectiveness as liver or biliary tree cleansers, or ammonia or neurotoxin detoxifiers.

Possible Short-Chain Fatty Acids (SCFA) Benefits

  • Adding resistant starches (which generate SCFA in the colon) to oral rehydration solution (ORS) may help to reduce acute diarrhea in small children [5], including diarrhea in cholera [1]. Cooked green bananas (high in resistant starches) or pectin (which is a soluble fiber), which both generate SCFA in the colon, may help to relieve chronic diarrhea in children [6].
  • When feeding by mouth is not possible for certain periods of time, like after a gastrointestinal surgery, colonic lining may undergo a rapid degradation (atrophy). Short-chain fatty acids (SCFA) used in intravenous infusion help to nourish colonic lining and thus prevent its degradation [7].

There is INSUFFICIENT EVIDENCE about the effectiveness of short-chain fatty acids (SCFA) in the prevention or treatment of colorectal cancer [2,8,9], ischemic stroke, treating obesity, high blood cholesterol, diabetes type 2, sickle cell disease, Crohn’s disease and ulcerative colitis [10,11,12,13], post-infectious irritable bowel syndrome (IBS) [7], increasing calorie delivery in cystic fibrosis [14], prevention ammonia or toxins absorption from the intestine, constipation, antibiotic-associated diarrhea.

The role of SCFA produced by the intestinal bacteria in immunity is not clear yet: they may either promote or inhibit inflammation in the body [17,18,19].

Ethyl Butyrate, Methyl Butyrate, Propionate

Ethyl butyrate and methyl butyrate are esters of butyric acid and ethanol or methanol. They have a fruity odor, so they can be used as food flavors added to orange juice, other fruit products or alcohol beverages, such as martini. Butyric acid is industrially produced by fermentation of starch by the bacterium Bacillus subtilis.

Propionic acid is also produced by bacteria from the genus Propionibacterium and is responsible for a specific flavor of Swiss cheese [15]Propionic acid (E-number = E280) and its salts sodium propionate (E281), calcium propionate (E282) and potassium propionate (E283) can be used as food preservatives or flavorings; they are Generally Recognized As Safe (GRAS) by the U.S. Food and Drug Administration (FDA) [16].

Another short-chain fatty acid that is different than above ones is alpha-lipoic acid.

  1. Corman ML, Colon and Rectal Surgery, 5th Edition, p.34
  2. Topping DL et al, 2001, Short-Chain Fatty Acids and Human Colonic Function: Roles of Resistant Starch and Nonstarch Polysaccharides  Physiological Reviews
  3. Rossi M et al, 2005, Fermentation of Fructooligosaccharides and Inulin by Bifidobacteria: a Comparative Study of Pure and Fecal Cultures  PubMed Central
  4. Foods high in butyric acid  Wholefoodcatalog.info
  5. Binder HJ, 2010, Role of colonic short-chain fatty acid transport in diarrhea  PubMed
  6. Rabbani GH et al, 2004, Green banana and pectin improve small intestinal permeability and reduce fluid loss in Bangladeshi children with persistent diarrhea  PubMed
  7. Berni Canani R et al, 2011, Potential beneficial effects of butyrate in intestinal and extraintestinal diseases  PubMed Central
  8. Wong JM et al, 2006, Colonic health: fermentation and short chain fatty acids  PubMed
  9. Hinnebusch HN et al, 2002, The Effects of Short-Chain Fatty Acids on Human Colon Cancer Cell Phenotype Are Associated with Histone Hyperacetylation  The Journal Of Nutrition
  10. Hallert C et al, 2006, Increasing fecal butyrate in ulcerative colitis patients by diet: Controlled pilot study  Wiley Online Library
  11. Breuer RI et al, 1997, Short chain fatty acid rectal irrigation for left-sided ulcerative colitis: a randomised, placebo controlled trial  PubMed Central
  12. Vernia P et al, 2000, Combined oral sodium butyrate and mesalazine treatment compared to oral mesalazine alone in ulcerative colitis: randomized, double-blind, placebo-controlled pilot study  PubMed
  13. Di Sabatino A et al, 2005, Oral butyrate for mildly to moderately active Crohn’s disease  PubMed
  14. Vaisman N et al, 1992, Short-chain fatty acid absorption in patients with cystic fibrosis  PubMed
  15. Drake SL et al, 2007, Sources of umami taste in Cheddar and Swiss cheeses  PubMed
  17. Renan Corrêa-Oliveira R et al, 2016, Regulation of immune cell function by short-chain fatty acids  PubMed Central
  18. Kim HC et al, 2014, Gut Microbiota-Derived Short-Chain Fatty Acids, T Cells, and Inflammation  PubMed Central
  19. Park J et al, 2016, Chronically Elevated Levels of Short-Chain Fatty Acids Induce T Cell-Mediated Ureteritis and Hydronephrosis
    PubMed Central

17 Responses to "Short-Chain Fatty Acids (SCFA)"

  1. Glenda says:

    Current research points to short-chain fatty acids promoting T cell production, thereby promoting immune health.

  2. Jose says:

    There is SUFFICIENT evidence to say that SCFAs directly impact on immune cells of the gut polarizing the T cells from th1/th17 (inflammatory populations) to a th2 profile (antiinflamatory), and THIS HAS BENEFITS.
    Treatment with SCFAs obtained by an enriched diet in a model mouse of Multiple sclerosis (the EAE mice) direclty protects it and ameliorates the course of this inflammatory disease. Here is the reference, from 2015, nature paper ;).


    • Jan Modric says:

      This is an experimental study in mice. The Nutrients Review reviews the evidence of health benefits of nutrients in humans.

  3. Anna says:

    How do we know if SCFAs would promote or inhibit inflammation. What would we look for in humans? Whether we are Th1 or Th2 dominant? Thanks.

  4. Anna says:

    Thanks. I did check the resources. They seem to indicate that SCFAs can be inflammatory and also they can be helpful. Does nobody know? What type of research needs to be done to further understand this?

    • Jan Modric says:

      The problem is that SCFAs may be inflammatory or helpful depending on the amount consumed (or produced by the normal colonic bacteria) and eventually by the relative amounts of other fatty acids or other nutrients. A suggestion for initial search site:gov SCFA “systematic review” (+ inflammation, immunity..)

      • Ivan Blazquez says:

        That is correct. Too much SCFA production can be problematic and can be obesogenic via increased energy harvest. This can happen from caloric excess. But in moderate normal amounts, they predominantly appear to be beneficial.

  5. Barbara says:

    I believe, after lengthy studies and personal illnesses and healings, the bottom line is that your whole body needs to be considered and kept healthy. SCFAs are only a part of the solution. The body is extremely complex and composed of more than our organs. You may take SCFAs or probiotics, but if one or the other is lacking, the secondary item will not help. . . and, in fact, may cause more harm. The answer, I believe, is in finding a way to provide ‘all’ your body needs to heal.

    Let me back track a bit. Two younger sisters died of autoimmune diseases. I, now 74 yrs old, have lived with IBS and a host of allergies and intolerances my entire life. To make this brief, I was quite ill, on and off, the last two years. One Dr. diagnosed me as having an immune system that was out of control. By the time I met with my Allergist, he told me to keep doing what I was doing, as it looked like I had overcome the ailment. (That was last year.) This past January, I was diagnosed with Rosacea and a blood test prescribed by a dermatologist showed I might have Lupus, but needed further testing. (My appointment with a Rheumatologist is this May.}

    Once I was diagnosed with Rosacea I started gathering information on the computer and made an appointment with an additional physician that dealt with integrative medicine. That day, I was introduced to ‘root soup’ while visiting a health store with a soup bar. I found I craved this soup. So, I bought the basic ingredients, such as, rutabaga, kale, carrot, parsnip, onion, garlic and a touch of apple cider vinegar. (I added the ‘ acv’ the last hour or so into the slow cooker. Sometimes I add chicken stock from an organic chicken cooked with skin and bone. I ate this soup 3 times a day for a week and once a day thereafter. (I never would have made this soup as I am not fond of kale on its own and garlic causes stomach upset. But the already made soup smelled and tasted so good!!!) And, like I said, I craved it! (As I kept gathering information, I found these vegetables were providing me natural, God provided (organic) SCFAs.)

    But, there’s more. The day I was in the health store, I was also in need of probiotics, so that was also a part of my routine. I am also a fan of flax and flax oil.

    Several weeks after visiting the integrative medicine physician, I took my blood test, which involved 14 vials (I think).

    One showed negative for Lupus (but not conclusively). One showed I had Epstein Barr in the past, which was a surprise. Made me think of long periods of fatigue in the past with no help from my physicians Another test said I lacked’ lactobacillus’. When I reread the probiotic I was taking, it was shy of lactobacillus. Since then, I purchased another probiotic with that in mind. I really started to feel my health improve, that is, intestines, sinuses, bones and joints. I still have some issues that come and go, but with less severity and less often.

    I was tested for allergens about 1 week ago and was told that the results were the best ever. I only reacted to dust mites. When I walk outside (on mo meds), I start to develop a bit of congestion, but It disappears in about 5-10 min.So far, so good.

    Hope this helps.

    • Linds Baker says:

      Hi Barbara! Could you please send the soup recipe that you use?

    • RoseMary Wells says:

      Is there a specific recipe for the root soup? Amount of water or chicken broth to amount of each root vegetable? Can you get the ingredients all year or just seasonally? I am very interested in finding out more about this soup and its preparation/seasoning. Thank you!

  6. Barbara says:

    I forgot to mention the root soup tastes better yet if you add a can or two of diced tomatoes at the same time you add the apple cider vinegar.

  7. Jan says:

    Yea, I am also very interesting if you can publish the recipe.

  8. Tom says:

    Did anyone ever get the recipe ? If so , please post.

  9. Chris Lotito says:

    Just stumbled across this post. I am also wondering if someone has the root soup recipe?

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