Having a second brain – The GUT
Yes, you have read the title right – Having a second brain. This second brain is none other than our gut. The link between our brain and our “second brain” is called the gut-brain axis (GBA).
The GBA consists of bidirectional communication between the central nervous system and the enteric nervous system. The GBA was discovered in the 1960s and 1970s when several peptides were discovered to occur in both the brain and the gut allowing further studies of the relationship between gut microbiota and the brain (Figure 1).
Figure 1: Microbiome gut-brain axis structure
Source: https://bit.ly/2S4krgD (NCBI Resources)
Role of Gut Microbiota in GBA
Both clinical and experimental evidence suggests that enteric microbiota has an important impact on GBA, interacting not only locally with intestinal cells and enteric nervous system (ENS) but also with central nervous systems (CNS) through neuroendocrine and metabolic pathways. An absence of gut microbiota negatively affects gut sensory motor functions such as delayed gastric emptying therefore reducing feed intake and negatively impacting growth. Besides that, animals also show increased stress reactivity when a healthy gut microbiota is absent. When using probiotics, stress-induced release of cortisol is reduced. Gut microbiota has been associated with the restoration of intestinal barrier and tight junction integrity and mucosal immune regulation.
Since it is clear that gut microbiota health affects the physiological condition of animals, we should be careful when formulating feed so that optimal gut microbiota health can be achieved. We should be careful to where animal feed consists of increased amounts of undigested protein and carbohydrates and consider the addition of crude fibre. Soluble fibre is degraded to smaller molecules via enzymatic reactions and are used by the gut microbiota to produce short chain fatty acids allowing for improved epithelial and immune target cells, regulation of ENS and behaviour through the GBA, stimulation of mucous production and cell proliferation, anti-inflammatory and antimicrobial effects. Furthermore, the usage of antibiotics, although banned in many countries, is still common in some countries. Antibiotics not only inhibits the growth of pathogenic microorganisms, but also affect gut microbiota symbiosis.
Improving Gut Health and Development: 1 Reduction 3 Stimulation
1 Reduction: Reducing Intestinal Pathogens
1. Providing animals with highly digestible diets
Carbohydrates and digestible fibre are broken down by microbes into SCFA and polyphenols which enables animals to produce anti-inflammatory components and balance gut microbiota. Undigested protein and fat are broken down by gut microbiota to produce harmful endotoxins which damages the host microbial barrier and causes gut dysbiosis.
Research has shown that poorly digestibly protein in diets are the main reason that E. Coli in intestines turn into pathogenic E. coli. Therefore, formulating feed based on amino acid digestibility, together with the addition of cellulase and protease, enables less amino acids to reach the hindgut.
2. Supplementing Enzymes
Enzyme supplementation is not uncommon in animal feed. Enzymes such as glucanase and xylanase has been shown to improve gut microbiota and increases fibre fermentation and breakdown. It has also been suggested that enzymes can improve environmental pollution.
3. Supplementing Organic Acids
Another popular choice to reduce intestinal pathogens is by using organic acids. Acidifying drinking water allows for a decrease in pH in the foregut. However, pH usually becomes higher later in the hindgut compared to control groups. This indicates that animals have an internal pH balancing mechanism.
4. Supplementing Zinc
Zinc has been used for centuries and has been proven to promote animal growth, reduce inflammation and reduce diarrhoea by regulating gut permeability and gut normal function. However, due to concerns that zinc pollutes the soil, many countries have banned or controlled zinc usage.
1. Stimulating Digestive Function
Often times, animals have poor small intestine integrity due to the nature of modern intensive farming systems. Feed additives such as butyrate salts, prebiotics and organic acids can improve intestinal morphology and intestinal integrity.
2. Stimulating Immune Response
Fatty acids such as n-3 polyunsaturated fatty acids (PUFA) have strong anti-inflammatory effects. Diets rich in n-6 PUFA (such as vegetable oils) can increase plasma tumour necrosis factor (TNF) compared to animals fed n-3 PUFA. When n-6:n-3 PUFA ratio is less than 5:1, inflammation will be alleviated. Besides PUFA, medium chain fatty acids (MCFAs, i.e. lauric acid) are also effective against gram-positive bacteria (i.e.clostridium)
3. Stimulate beneficial microflora
Since there is an interaction between gut microflora and the brain. When animals are under stress, it will also affect the balance of gut microbes, leading to a decline in immunity. The microflora of pigs and poultry are different, the intestinal microflora of animals in different growth stages are also different.
Here at Manuka Biotech, we carry a range of products, such as BTR Benz and BTR MCL that could help you maintain animal gut microbiota symbiosis thus producing healthy animals and a sustainable business. Do contact us for more information.
By Kayla Wong, Technical Specialist, Manuka Biotech