Nutritional Strategies for Reducing the Symptoms of EMS (plants and functional foods)
Management of EMS is largely through nutritional management and exercise, understanding how foods interact with the physiology of the horse especially as relates to metabolism is key to comprehending the benefits of adding certain food items.
Bioactive Peptides
Bioactive peptides are potent signaling molecules with positive effects on the body, only small amounts are needed to make a difference to help in
reducing insulin resistance
reducing adipose tissue
reducing/regulating blood glucose
Bioactive Peptides are safe and effective biological molecules with multiple functions in a living organism or cell. They are found mostly hidden in protein structures.
A chain of bioactive compounds is made up of proline, arginine and lysine. Some bioactive compounds are found in nerve and immune system cells, (made naturally by the horse) and others are derived from foods. Food-derived bioactive peptides have short sequences of 2–50 amino acids being inactive when ingested as part of dietary protein intake and then activated by gastric enzymes or other art of the digestive processes.
Bioactive compounds have different physiological activities, they are more easily digested and bioavailable than proteins, and have less allergenic effects (less able to cause an allergy), making them very attractive as therapeutic compounds, especially for metabolic dysregulation.
Foods Containing Bioactive Compounds
Foods containing bioactive compounds are cereal grains such as oats, barley and wheat, others are found contained within legumes such as peas and beans. A particularly rich supply can be found in cultivated seeds such as quinoa, chia, buckwheat and linseed, plus wild seeds such as grass, thistle, and nettle. The cultivated and wild seeds contain protein fractions of albumin, globulin, cross-linked prolamin, b-prolamin and glutelin, plus high percentages of essential amino acids including cysteine and methionine.
Plant bioactives are highly bioavailable to animals and humans with only small amounts needed each day and all have positive effects on health and physiology. They are especially effective on metabolism including the ability to reduce plasma glucose, preventing the absorption of carbohydrates in the gut, and increasing tissue sensitivity to glucose uptake.
Bioactive peptides isolated from the hydrolysates of plants have been reported to have a crucial role in energy homeostasis, insulin signaling, and insulin resistance. Though insulin dysregulation is one of the hallmarks of EMS it is preceded or accompanied by high postprandial (after eating) glucose levels, one of the most effective methods (in humans) of controlling the amount of glucose is to inhibit an enzyme called dipeptidyl peptidase 4. DPP4 enzyme, in particular, is responsible for the inactivation of GLP-1 associated with insulin insensitivity. In a study on food grains, peptides released from oat, buckwheat, and barley proteins both inhibited the DPP4 enzyme with the barley peptides having the highest value.
Plant-based bioactive compounds also influence the hormones that control satiety.
Appetite is regulated by gut hormones and neuronal peptides and bioactive peptides derived from functional foods; many plants contain thousands of such compounds with appetite-regulating effects. Physiologically, there should be a balance between energy expended (exercise and maintenance) and energy intake (food eaten). One of the rules for feeding horses is to feed according to body weight and workload, one of the changes in horse management in the last 20-30 years is a decrease in the levels of exercise and an increase in access to high-calorie foods (fertilised monoculture grass/hay and foods containing more sugar), plus an increase in rugging and stabling horses which reduce the metabolic reset mechanism many horses, (especially natives and their cross breeds) seem to need. The result is an increase in obesity and horses and an increased risk of developing EMS, reducing calorie intake without understanding the effect of bioactive peptides on appetite creates long-standing dysbiosis of the gastrointestinal microbial population.
Obesity can be defined therefore as an imbalanced diet with a series of physiological alterations that include changes and deficits in gut hormone secretion altering the pathways that control satiety (the feeling of being full). An imbalanced diet causes the loss of beneficial bacteria, good gut bacteria are the police force of the microbiome, once these have been reduced the pathogenic bacteria increase causing health problems including systemic inflammation.
The use of antibiotics and anthelmintics and environmental factors (exposure to glyphosate) cause these changes to a greater extent than the components of the diet.
Bioactive Compounds and the Gut -Brain Axis.
The signaling/ messaging system by the gut to the brain and back again is complex, it uses blood circulation and cranial nerves as the medium to speak through, the process starts with hormones being released by the enteroendocrine system.
The stimulation of the hormones from the enteroendocrine system is through and by macronutrients namely amino acids (L-Lyseine, L-Arginine, and L-Ornithine), aromatic amino acids (phenylalanine, tyrosine, tryptophan and histidine) and peptones (amphopeptone, antipeptone, and hemipeptone).
Once stimulated, the hormones then travel to the brain through the bloodstream, where they influence the satiation mechanism (the feeling of fullness), accessing the brain by way of special receptors. The hypothalamus is the location of the most important satiety response, and it contains two types of neurons-
1. Neuropeptides that promote the feeling of fullness/ satiety - neuropeptides (central signals) including pro-opiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART)both activate melanocortin 2. (MC3) and 4 (MC4).
3. Neuropeptides that stimulate food intake/hunger- neuropeptides Y (NPY) and agouti-related peptide (AgRP) together with POMC neurons at the nucleus tractus solitarius (NTS).
The nerves or neural pathways make up a separate pathway to the bloodstream, this pathway is also bi-directional through the vagus nerve and works to produce satiety by the release of hormones and the transport of metabolites from the gut.
Obesity and metabolic dysregulation cause a change in the hormone released from the gut, causing a lower satiety rate and hungry horse syndrome!
Macronutrients and Satiety
Proteins and Peptides
Proteins as eaten or manufactured internally by the horse are digested in the small intestine helped by pancreatic enzymes and peptidases. These are transported across the gut wall membrane into the bloodstream. Proteins are commonly known as the building blocks for protein synthesis, but they are also precursors (substances that help form others) of different metabolites (chemicals) that interact with the lining of the gut wall and the gut bacteria. Proteins are transported across the gut wall from the duodenum to the ileum and are the densest in the jejunum. Proteins mix together with the gut bacteria, these microbes degrade the protein and also make new proteins for the benefit of the host.
In the hindgut, bacteria are more numerous and the transit time is slower any leftover undigested proteins are degraded but cannot be absorbed in this area of the gastrointestinal tract, but are instead used to form other useful products such as short-chain fatty acids and organic acids to be used for energy and substances to maintain the health of the gut wall.
EquiBiome Biome Food Seven (EMS) and a Pack of Polyphenols both contain a wide range of bioactive peptides.