Butyric Acid: The Real Deal
As the era of “Antibiotic Ban” approaches, we can see that many new antibiotic alternatives have risen but all these products have one core component – that is Short Chain Fatty Acids (SCFA). Antibiotics use in feed has been extremely effective because it firstly reduces the bacteria count in the gut.
Decreasing the amount of nutrients being used by these bacteria allows more nutrients to be utilized by the animal leading an to increase in feed efficiency. Secondly, antibiotics can thin the mucosal layer in the gut, allowing for nutrients to be absorbed rapidly, also leading to an increase in feed efficiency.
The saying “You are what you eat” is not far from being true for animals as it is for humans. But what if the gut is unable to fully absorb what is eaten? How to enable the gut to fully absorb what is eaten so it can be utilized by the body? Well, gut microbiota is a major player in gut function, therefore, cultivating a healthy gut microbiota is key to creating an efficient and healthy gut. SCFA are organic acids produced naturally by the body as by-products when dietary fibre and indigestible saccharides in the large intestine are fermented by the microbiota – bacteria that colonise the gastrointestinal system. These acids are not only absorbed by the gut cells but used by the microbiota themselves. Therefore, to cultivate a healthy gut microflora we could supplement them with short chain fatty acids (SCFA).
The Roles of Butyric Acid
Butyric acid is one of the important SCFAs. Although butyric acid only constitutes 15% of total SCFA produced, it can be taken up by the epithelial cells and provides a source of ATP without going through the tricarboxylic acid cycle (also known as the citric acid cycle or the Krebs cycle). This energy produced drives a sodium pump which maintains osmotic balance in the gut, allowing water to be absorbed producing a more solid faecal matter. Besides that, butyric acid is also bactericidal and bacteriostatic. The energy production of butyric acid consumes oxygen and produces carbon dioxide, leading to a hypoxic (low oxygen) environment, favouring anaerobic bacteria such as the Clostridium butyricum. Besides that, endogenously supplementing butyric acid can decrease pH of the intestinal lumen supressing growth of certain bacteria such as salmonella. Furthermore, as it is also being utilized by the gut microbiota, the population of Clostridium butyricum, Rothia, lactobacillus, etc. would increase, allowing for increased fibre fermentation and increased butyric acid production forming secondary acidification in the gut.
Figure 1: Functions of Butyric Acid
The gut is the largest immunologically active organ dealing with large numbers of pathogens daily as the first line of defence. It is important to appreciate that SCFAs not only aids in maintaining intestinal homeostasis but also animal immunity. They contribute to many cellular processes such as gene expression, cell proliferation (cell multiplication) and cell apoptosis (cell death). Butyric acid has been shown to increase the proliferation of gut cells and intestinal epithelium, a defensive barrier, and increasing villi length, allowing increased surface area for nutrient absorption. The studies available on butyrate on gut integrity is vast. It has also been found that butyric acid plays an anti-inflammatory role by modulating cell cytokine production. Gathering the benefits of butyric acid, it definitely plays a crucial part in maintaining healthy microbiota and immune system in the face of challenge when the antibiotic ban comes into play.
Applications of Butyric Salt
Butyrate salt on its’ own is hygroscopic (it readily absorbs moisture). When used in animal feed, it readily dissociates in the gut allowing for improved epithelial cell proliferation and repair. However, butyric acid has an iconic rancid odour which although loved by mammals, is not very acceptable by humans. Therefore, coated forms of butyrate can reduce the rancid odour, provides protection needed to get past the acidic stomach and allow for continuous slow release of butyric acid throughout the gut, yielding its full effects in the entire gastrointestinal tract. Being coated also makes the product easily handled, prevents hygroscopicity and that the butyrate salt does not readily react with other feed ingredients. When embedded in a lipid matrix, butyrate is protected in the foregut and gradually released in the small intestine where the lipolytic activities are present, making it a good stomach/rumen by-pass butyrate option. Manuka Biotech’s butyrate product series (BTR-), is coated with different materials depending on the product. These include water-soluble coating, fat-soluble coating and a series of other beneficial products that work synergistically with butyrate forming 7 generations of product evolvement meeting the various needs of farmers and producers.
By Kayla Wong, Technical Specialist, Manuka Biotech