Intestinal physiology

The physiological characteristics of the intestine are the digestion and absorption of nutrients, as well as being a physicochemical and immune barrier against biological and chemical agents, preventing systemic damage. Among the cells that make up the intestine, mainly enterocytes, goblet cells, and cells that produce antimicrobial peptides can be observed. Although enterocytes perform nutritional and protective functions efficiently, they are still vulnerable to damage from infections, inflammation, and metabolic dysregulation leading to enteropathies with malabsorption conditions ^(1-3). The intestine, being the largest mucosal tissue in the body, plays an important role in immune homeostasis; for example, mucus secretion by goblet cells is important in reducing the spread of pathogens and the action of mycotoxins ^(4,5). Therefore, maintaining or improving intestinal health implies the optimal health of the organism.

Contaminated feed: source of pathogenic and cytotoxic agents

The poultry diet is one of the main sources of exposure to toxic and biological chemical substances capable of generating various forms of enteritis that can lead to systemic dysfunctions, which are generated mainly during the processing and preparation of feed. Among these cytotoxic agents are pathogens (bacteria, fungi and viruses) that produce even more dangerous cytotoxic compounds such as mycotoxins; it is also possible to find other cytotoxic agents such as pesticides, heavy metals and other synthetic compounds commonly used in poultry farming.

Mycotoxins. Several reports mention that feed ingredients are susceptible to mycotoxin contamination, leading to various enteric and non-enteric toxicity conditions in poultry. Mycotoxins are secondary metabolites of fungi mainly from the genera Aspergillus, Alternaria, Fusarium, Cladosporium, Claviceps and Penicillium. The most frequently detected mycotoxins are aflatoxins (B1, B2, G1 and G2); fumonisins (B1 and B2); trichothecenes (deoxynivalenol and T-2 toxin); and ochratoxin A (OTA) ^(6-8).

Contamination of feed with mycotoxins causes illness and even death of the animal, which translates into millionaire losses for the poultry industry, since it is difficult to achieve adequate control and good storage free of contamination. The high humidity, high temperature and poor ventilation of most of the geographical areas dedicated to this exploitation are factors that increase the contamination of the feed by mycotoxins ^(9,10).

One of the most studied mycotoxins, due to its importance in animal health, is OTA, which is capable of inhibiting the absorption of nutrients such as glutamate by reducing the expression of the glutamate/aspartate transporter and the glutamate transporter on the cell surface. In addition, many studies have shown that OTA can destroy the integrity of the intestinal barrier in broilers by suppressing tight junction (TJ) proteins, which would increase intestinal permeability and allow translocation of bacteria. Another study indicates that contamination of poultry feed with OTA induces villus thinning, epithelial denudation, reduced villus/crypt ratio, and loss of intestinal histomorphology, which reduces nutrient absorption and decreases the number of globet cells, which makes the intestine more susceptible to infection ^{(11-13 )}.

Bacterial infection. Bacterial enteritis is one of the most frequent infections in the poultry industry, and within this classification we find necrotic enteritis caused by Clostridium perfringens as one of the most frequent. The high pathogenicity of C. perfringens is due to the high toxicity of its toxins, which in the case of broilers is more frequently the presence of α-toxin of C. perfringens Type A (CPA) and netB-toxin of C. perfringens Type G ⁽¹⁴⁾. Cytotoxic concentrations of CPA can cause extensive plasma membrane degradation and release of lactate dehydrogenase (LDH), which is a marker of cell necrosis ⁽¹⁵⁾. Subtoxic concentrations of CPA are associated with the activation of the MEK/ERK kinase pathways and the generation of reactive oxygen species (ROS), which in certain amounts can cause oxidative stress in cells and activate intrinsic mechanisms of apoptosis, inducing the activity of the caspase-3 ^(16,17). It has also been reported that C. perfringens begins to secrete harmful substances, which play an important role in the development of enteritis, such as perfrin that inhibits the growth of beneficial bacteria producing intestinal dysbiosis ⁽²⁾. While NetB toxin-producing strains are capable of forming pores in target cells causing cell lysis and destruction of the intestinal mucosa ^(18,19).

Pronutrients of botanical origin

The main way to control the different enteric pathologies is directed to the use of synthetic compounds such as antibiotics, especially as growth promoters or as therapeutic agents, but overuse or abuse of these compounds can lead to antimicrobial resistance of pathogens. In addition, it may happen that manure residues, which contain antibiotics, spread in the environment and contribute to the spread of pathogens with antimicrobial resistant genes ⁽²⁰⁾.

For this reason, the poultry industry has been developing reliable and effective alternative solutions to the use of antimicrobials, without compromising productivity and animal welfare. Among these new antimicrobial reduction or substitution strategies are the use of plant extracts, polyphenolic acids, chemically defined secondary metabolites, organic acids, probiotics, prebiotics, essential oils and exogenous enzymes ^(21-23).

Botanical alternatives are the most encouraging because of their safety and no residual effect, and within these alternatives BIOVET has developed pronutrient compounds of botanical origin and chemically defined botanical metabolites. Initially, pronutrients were defined as micro-ingredients present in the diet and with effects that improve the animal’s physiology, and which could be of microbiological, botanical and mineral origin ⁽²⁴⁾. However, this classification has “evolved” due to the current conditions of the industry and legislation, assuming that pronutrients have more complex effects such as intestinal conditioners, immunodulators, among others ^(25-28).

A pronutrient compound derived from plant extracts is Alquernat Nebsui, whose chemical composition presents a high concentration of plant pronutrients that promote intestinal growth, the rapid regeneration of enterocytes, the improvement of intercellular junctions (tight junctions) strengthening the intestinal cytostructure and increasing the absorption surface, which will finally allow optimal absorption rates, and a better use of the feed with desired values in the productive indexes ⁽²⁹⁾. A comparative trial was conducted in which Alquernat Nebsui was administered to broilers for 42 days with antibiotic growth promoters (APCs) and another group with APCs only, the results showed that the diet containing Alquernat Nebsui produced a marked improvement in zootechnical parameters such as mortality reduction, weight improvement and feed efficiency compared to the control group ⁽³⁰⁾.

On the other hand, Alquernat Zycox is a plant pronutrient with high intestinal immunostimulant capacity that activates polymorphonuclear cells, improving the molecular expression of cytokines such as IL-1, IL-12 and IL-18, which in turn activate the response of Nk cells, macrophages and lymphocytes-T, thus increasing a greater immune response against coccidiosis ^{(27, 31)}. Experimentally, Alquernat Zycox was evaluated in broilers for 13 days (8-21 days of life) at a dose of 0.5 kg/T, showing that it controlled the occurrence of coccidiosis, improved production parameters and reduced mortality by up to 50%. Similarly, Alquernat Zycox was administered to pullets for 4 weeks (from 19 weeks of age) at a dose of 0.5 kg/T to control the occurrence of coccidiosis and was shown to improve zootechnical parameters, reduce mortality, increase average weight and production percentage ⁽³⁰⁾.

Compounds synergistic to pronutrients

Pronutrients are active botanical biomolecules with the capacity to improve cell physiology. Likewise, this capacity could be improved by reducing the load of biological and non-biological contaminants in the feed or in the digestive system ^(27,28). In this sense, other compounds of plant (cimenol) or mineral (silicates) origin could be used as synergistic or complementary agents to the action of pronutrients.

BIOVET has developed a cymenol ring-and-citric acid formulation, Alquermold Natural, whose active ingredient is cymenol, which is a monocyclic monoterpene hydrocarbon commonly found as a major compound in the essential oils of several aromatic plant species, including the genus Artemisia (Asteraceae), Protium (Burseraceae), Origanum, Ocimun, Thymus, and Eucalyptus (Mirtaceae) ^(32,33). Cimenol has demonstrated a wide variety of properties, with its antimicrobial effect being the most recognized. In addition, in vitro studies have shown that cimenol can be used as an antibacterial agent against Gram-positive and Gram-negative bacteria ⁽³⁴⁾. Therefore, Alquermold Natural has been used effectively in the poultry industry as a natural biocide in feed and cereals, and as an intestinal microbiocide; moreover, it has a broad spectrum and can be effective for up to 6 months without generating residues ⁽³⁵⁾.

Pronutrients have a very complete synergy, as they are able to improve all physiological and immunological conditions of the digestive system by acting on contaminated feed and on a digestive system overloaded with metabolic stress. Another compound that would help to improve physiological conditions is Alquerfeed Antitox, a compound derived from silicates capable of significantly reducing the presence of mycotoxins and pathogens that, if they entered the digestive system, would generate greater stress to which the digestive system is already subjected ⁽³⁵⁾.

References:

1. Snoeck V, Goddeeris B, Cox E. 2005. The role of enterocytes in the intestinal barrier function and antigen uptake. Microbes Infect. 7: 997-1004.
2. Timbermont L, Haesebrouck F, Ducatelle R, Van Immerseel F. 2011. Necrotic enteritis in broilers: an updated review on the pathogenesis. Avian Pathol. 40: 341-347
3. Miron N, Cristea V. 2012. Enterocytes: active cells in tolerance to food and microbial antigens in the gut. Clin. Exp. Immunol. 167: 405-412
4. Johansson ME, Hansson GC. 2016. Immunological aspects of intestinal mucus and mucins. Nature Reviews, Immunology. 16: 639-649
5. McGuckin MA, Hasnain Z. 2017. Goblet cells as mucosal sentinels for immunity. Mucosal Immunology. 10: 1118-1121
6. Njobeh PB, Dutton MF, Åberg AT, Haggblom P. 2012. Estimation of Multi-Mycotoxin Contamination in South African Compound Feeds. Toxins. 4:836–848. doi: 10.3390/toxins4100836.
7. Akinmusire OO, El-Yuguda AD, Musa JA, Oyedele OA, Sulyok M, Somorin Y, Ezekiel CN, Krska R. 2018. Mycotoxins in poultry feed and feed ingredients in Nigeria. Mycotoxin Res. 35:149–155. doi: 10.1007/s12550-018-0337-y.
8. Kemboi DC, Ochieng PE, Antonissen G, Croubels S, Scippo ML, Okoth S, Kangthe EK, Faas J, Doupovec B, Lindahl JF. 2020. Multi-Mycotoxin Occurrence in Dairy Cattle and Poultry Feeds and Feed Ingredients from Machakos Town, Kenya. Toxins. 12: 762. doi: 10.3390/toxins12120762.
9. Okoth S, De Boevre M, Vidal A, Di Mavungu JD, Landschoot S, Kyallo M, Njuguna J, Harvey J, De Saeger S. 2018. Genetic and Toxigenic Variability within Aspergillus flavus Population Isolated from Maize in Two Diverse Environments in Kenya. Front. Microbiol. 9:57. doi: 10.3389/fmicb.2018.00057.
10. Kana JR, Gnonlonfin BGJ, Harvey J, Wainaina J, Wanjuki I, Skilton RA, Teguia A. 2013. Assessment of Aflatoxin Contamination of Maize, Peanut Meal and Poultry Feed Mixtures from Different Agroecological Zones in Cameroon. Toxins. 5: 884–894. doi: 10.3390/toxins5050884.
11. Zhai S, Zhu Y, Feng P, Li M, Wang W, Yang L, Yang Y. 2021. Ochratoxin A: its impact on poultry gut health and microbiota, an overview. Poult Sci. 100(5): 101037. doi: 10.1016/j.psj.2021.101037.
12. Wang W, Zhai S, Xia Y, Wang H, Ruan D, Zhou T, Zhu Y, Zhang H, Zhang M, Ren W, Yang L. 2019. Ochratoxin A induces liver inflammation: involvement of intestinal microbiota. Microbiome. 7: 151.
13. Yang S, Li L, Yu L, Sun L, Li K, Tong C, Xu WX, Cui GY, Long M, Li P. 2020. Selenium-enriched yeast reduces caecal pathological injuries and intervenes changes of the diversity of caecal microbiota caused by Ochratoxin-A in broilers. Food Chem. Toxicol. 137: 111139.
14. Cooper KK, Songer JG, Uzal FA. 2013. Diagnosing clostridial enteric disease in poultry. J Vet Diagn Invest. 25(3): 314–327.
15. Flores-Díaz M, Alape-Girón A, Clark G, Catimel B, Hirabayashi Y, Nice E, Gutiérrez JM, Titball R, Thelestam M. 2005. A cellular deficiency of gangliosides causes hypersensitivity to Clostridium perfringens phospholipase C. J. Biol. Chem. 280: 26680–26689. doi: 10.1074/jbc.M500278200.
16. Monturiol-Gross L, Flores-Díaz M, Pineda-Padilla MJ, Castro-Castro AC, Alape-Giron A. 2014. Clostridium perfringens phospholipase C induced ROS production and cytotoxicity require PKC, MEK1 and NFκB activation. PLoS ONE. 9: e86475. doi: 10.1371/journal.pone.0086475.
17. Manni MM, Valero JG, Pérez-Cormenzana M, Cano A, Alonso C, Goñi FM. 2017. Lipidomic profile of GM95 cell death induced by Clostridium perfringens alpha-toxin. Chem. Phys. Lipids. 203: 54–70. doi: 10.1016/j.chemphyslip.2017.01.002.
18. Yan XX, Porter CJ, Hardy SP. 2013. Structural and functional analysis of the pore-forming toxin NetB from Clostridium perfringens. mBio. 4(1): e00019–13.
19. Savva CG, Fernandes Da Costa SP, Bokori-Brown M. 2013. Molecular architecture and functional analysis of NetB, a pore-forming toxin from Clostridium perfringens. J Biol Chem. 288(5): 3512–3522.
20. Osterberg D, Wallinga D. 2004. Addressing externalities from swine production to reduce public health and environmental impacts. Am J Public Health. 94(10): 1703-1708. doi: 10.2105/ajph.94.10.1703.
21. Diaz-Sanchez S, Souza DD, Biswas D, Hanning I. 2008. Botanical alternatives to antibiotics for use in organic poultry production. Poultry Science. 94: 1419–1430. doi: 10.3382/ps/pev014
22. Huyghebaert G, Ducatelle R, Immerseel FV. 2011. An update on alternatives to antimicrobial growth promoters for broilers. The Veterinary Journal. 187: 182-188. doi: 10.1016/j.tvjl.2010.03.003
23. Pliego AB, Tavakoli M, Khusro A, Elghandour MY, Salem AZ, Rivas-Cáceres RR. 2021. Beneficial and adverse effects of medicinal plants as feed supplements in poultry nutrition : a review. Animal Biotechnology. 1-23. doi: 10.1080/10495398.2020.1798973.
24. Rosen GD. 1997. Future prospects for pronutrients in poultry production. In: Proceedings of the 16th Scientific Day, 16 October, University of Pretoria, Pretoria, Republic of South Africa, pp. 60–79.
25. Borrell J. 2006. Benefits Of The Use Of Natural Pronutrients In Veterinary. Thepoultrysite.com.
26. Borrell J. 2012. El uso de los Pronutrientes. com
27. Borrell J. 2005. Uso de pronutrientes de origen natural en veterinaria. Real Academia de Ciencias Veterinarias de España (RACVE).
28. Borrell J. 2014. De los proplastos a los pronutrientes. Academia Peruana de Ciencias Veterinarias (APCV)
29. Borrell J, Domenech C, Martin N, Tesouro A. 2016. Pronutrients use in poultry nutrition. The Proceedings of XXV World’s Poultry Congress 2016 Abstract S1- 0224. Beijing-China.
30. Diaz A. 2018. XXXI Simposium Internacional de Biovet. Tarragona, Catalunya.
31. Díez D. 2021. Programas de control de la coccidiosis basados en pronutrientes optimizadores intestinalis. Actualidad Avipecuaria.
32. Philis JG, 2005. The S1← S0 spectrum of jet-cooled p-cymene. Spectrochim. Acta. A. Mol. Biomol. Spectrosc. 61: 1239–1241.
33. Santana MF, Guimaraes AG, Chaves DO, Silva JC, Bonjardim LR, Lucca Júnior W, Ferro JN , Barreto E, Santos FE, Soares MBP. 2015. The anti-hyperalgesic and anti-inflammatory profiles of p-cymene: Evidence for the involvement of opioid system and cytokines. Pharm. Biol. 53: 1583–1590.
34. Balahbib A, El Omari N, Hachlafi NE, Lakhdar F, El Menyiy N, Salhi N, Mrabti HN, Bakrim S, Zengin G, Bouyahya A. 2021. Health beneficial and pharmacological properties of p-cymene. Food Chem Toxicol. 153: 112259. doi: 10.1016/j.fct.2021.112259.
35. https://biovet-alquermes.com/producto/