Butyric acid – What is it and what properties does it have?

kwas masłowy

Contrary to its name, butyric acid is not part of butter at all. This compound, which is essential for the proper function of the intestines, is produced by the bacteria present there. Butyric acid deficiency can be associated with many unpleasant symptoms, and its supplementation supports the treatment of certain diseases. What is butyric acid, what properties does it have and when is it worth supplementing?

Butyric acid – What is it?

Butyric acid is a natural compound belonging to short-chained fatty acids (SCFAs), produced through fermentation by bacteria present in the colon – the longest and most important section of the large intestine. Together with acetic acid and propionic acid, butyric acid accounts for about 83% of the SCAFs present in the large intestine, in the respective proportions of 60 : 25 : 15 (acetate : propionate : butyrate).

Although in terms of proportions, butyric acid represents the smallest share of the total SCAFs’ concentration in the intestinal lumen (variable in the range of 60-150 mmol/kg), it acts as the most important substance, providing energy to intestinal epithelial cells. Furthermore, many newer possibilities for its use in treatment, nutrition and disease prevention have been discovered since research on the role and properties of butyric acid began in the 1980s; and these are not only related to the function of the gastrointestinal tract.

Butyric acid or sodium butyrate?

Butyric acid is a compound that poses some problems in its use as a medicine or supplement. These are mainly related to its unpleasant odor, reminiscent of rancid butter, and low chemical stability. After oral administration, butyric acid is quickly taken up and utilized by the epithelium of the upper gastrointestinal tract, which prevents the full dose from reaching the desirable site of action, i.e. the large intestine. To avoid these problems, it is usually administered in the more stable form of a sodium salt – sodium butyrate, which dissociates in the body into a butyrate anion and sodium. In addition, the active ingredient can be protected against too early absorption and degradation by encapsulating it in pellets and micro-encasements.

Butyric acid – Properties

The vast majority of butyric acid is utilized at the site of its production, providing beneficial effects on the colon’s epithelium. The effects of butyric acid on the gut, however, are associated not only with its energy function, but also with numerous biological effects that improve human health. At the intestinal level it constitutes:

  • An energy source for colonocytes (colon epithelial cells);
  • A compound with nutritional, regenerative and cytoprotective action;
  • An agent strengthening and sealing the intestinal barrier;
  • An immunomodulator;
  • An anti-inflammatory;
  • An antioxidant;
  • It also influences intestinal motility
  • and visceral sensitivity,
  • as well as participates in the trans-membrane transport of water and sodium.

In other words, butyric acid is the main source of energy for the cells of the intestinal epithelium; has a nourishing effect on its mucosa and promotes its healing and regeneration; seals the intestinal walls, which protects against the entry of bacteria into the bloodstream; and at the same time exhibits immunomodulatory, anti-inflammatory and antioxidant effects.

Butyric acid – Applications

Butyric acid’s properties are used clinically in diseases such as ulcerative colitis, Crohn’s disease, irritable bowel syndrome (IBS) and other inflammatory and functional bowel diseases. However, its benefits can also be of use in milder conditions. It reduces discomfort associated with diarrhea, constipation or digestive problems (indigestion, bloating, abdominal pain), regulates intestinal function, improves gastrointestinal motility and has a protective effect during the use of steroids (both taken medicinally and for building muscle tissue) Importantly, and unlike popular home remedies for improving digestion, butyric acid can also be used in treatment of peptic ulcer disease. It not only relieves its symptoms, but also promotes epithelial regeneration.

Butyric acid – Not just for the gut

Although butyric acid is a compound that acts primarily in the intestines, it also shows beneficial extraintestinal actions. Its small amounts absorbed into the bloodstream affect other tissues and organs, including by:

  • Sensitizing cells to the action of insulin;
  • Immunomodulation;
  • Influencing neurogenesis and reducing the risk of stroke;
  • Stimulation of leptin production, and so affecting the hunger/satiety mechanisms;
  • Inhibition of lipolysis and having a beneficial effect on adipose tissue;
  • Inhibition of fat storage in the liver.

These multidirectional properties and applications of butyric acid make it worth considering its supplementation, not only for therapeutic purposes – to relieve unpleasant intestinal and gastrointestinal symptoms, but also preventively – to use it similarly to multivitamins to support the proper functioning of the body. Supplementation of butyric acid is particularly recommended in the elderly (as its production decreases with age), in systemic diseases leading to gradual cachexia (cancer, immune diseases and immune disorders), as well as when taking immunosuppressive and steroid medicines. Thanks to the described parenteral effects, the benefits of taking butyric acid will also be felt by those at risk of developing lifestyle diseases such as obesity and insulin resistance.

Butyric acid – Hazards and harmfulness profile

An important advantage of butyric acid is that it is a low-harm compound, very safe for the body. It causes no significant side effects or adverse reactions, and its use is permitted in all age groups without any significant contraindications. As a compound characterized by very low toxicity, it can be safely incorporated into the diet, bringing numerous benefits to the proper functioning of the body. A prophylactic dose, with an average intestinal content production of 3-4 l/day, is 300 mg of butyric acid (sodium butyrate) per day. For visible results, the treatment should be continued for at least 3 months.

Sources of butyric acid

As already mentioned, butyric acid is produced in the human body primarily by sugar fermenting bacteria present in the intestines. These include the microorganisms: Clostridium spp., Eubacterium spp., Fusobacterium spp., Butyrivibrio spp. Megasphaera elsdenii and Mitsuokella multiacida. However, for the fermentation process to occur, we need to consume foods containing specific ingredients. The main sources of indigestible carbohydrates and hexose oligomers with varying degrees of polymerization used by the bacteria include:

  • Resistant starch;
  • Oats;
  • Wheat bran;
  • Partly ground cereal grains;
  • Seeds;
  • Vegetables.

Small amounts of butyric acid are also present in products consumed every day – milk and milk products, hard cheeses, fermented products (e.g., sauerkraut, cucumbers in brine, fermented soybeans). However, due to the low chemical stability of this compound and its low content in these products, they do not have any major impact on the human intestinal epithelium.

Thus, to supplement butyric acid deficiencies, one must rely on physiological bacteria or nutritional supplements available from shops. Just do not decide to consume the liquid butyric acid that is on the market today – it is used in fishing to create ground bait and has a very strong, unpleasant odor.


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