**Author details**

*Thymus*

probiotics have ability to increase the intestinal integrity by enhancing the gene expression in tight junction signaling. These probiotics decrease the adhesion

the cortex representing the subsequent impacts on the thymus.

autoimmune diseases, infections, and aging.

The thymus is a part of primary immune organs, having excellent example of connection between the cellular organization and function. Not like other wellorganized organs, the microstructure of the thymus parenchyma has the very complex meshwork, where T cells differentiate, proliferate, and die. Disorganized thymic architecture of the elderly and disease thymus added cavitation and FCT proliferation and atrophy. Moreover, defects in the thymus caused to lesser the production of T cells and the interruption of self-tolerance. This may result in worsening the development of disease. Consequently, the thymus is declared as one of the most significant organs in maintaining immunity and safeguard the host against progression of age and development of ailments. Subsequently, this gland acts a crucial part in health and disease. The size, architecture, and function of this gland decreases with progression of age. There are some possible pathways to modify the thymus microarchitecture and function, in order to progress the physiology during

entero-invasive *E. coli* in HT29 and Caco-2 cells by the maintenance (actin and ZO-1) or enhancement (actinin and occludin) of cytoskeletal and tight junctional protein phosphorylation. Antimicrobial peptides produced by probiotics are now considered as the future of the new class of therapeutics because it produces lesser resistance and have a specific antimicrobial activity to protect the host. Different kinds of antimicrobial peptides like lysozyme, secretory phospholipase A2, defensins, defensin-like peptides (elafin and SLPI), and cathelicidins are produce from the paneth cells. These are the characteristics epithelial cells of the small intestinal which is located at the bottom of the intestinal crypts. The probiotics *B. subtilis* was found in improvement of the thymus microarchitecture in broilers [25]. Prebiotics are those high fibrous non-digestible food particles that are used as a source of energy for the beneficial bacteria like bifidobacteria and lactobacteria and symbiotic is the combination of the probiotics and the prebiotics. It modulates the host immune system and usually effect the intestinal microflora and regulate the immune system directly and indirectly. When symbiotic are administered during the embryo it enhances the proliferation of the lymphocytes by causing decrease in the cortex/medulla ratio of the thymus gland. In a research, a number of prebiotics like inulin (Pre1), Bi2tos (Pre2), and also a symbiotic composed of inulin and *Lactococcus lactis* subsp. lactis IBB SL1 (Syn1), a symbiotic composed of Bi2tos and *L. lactis* subsp. cremoris IBB SC1 (Syn2), is administrated in the early chick embryonic life in order to check its effect on the lymphoid tissue activity. B. longum and a prebiotic (Synergy 1) when administered into the body, can enhance the release of defensins from epithelial cells and they have antimicrobial activity. The outcomes of the research come in the form of enhance lymphocytes proliferation. When the Bi2tos were administered with *L. lactis* subsp. cremoris (Syn2) they caused reduction of the thymic cortex to medullary ratio [26]. This indicates the more spreading of the medulla without the effect on

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**11. Conclusion**

Arbab Sikandar\*, Shahzaib and Naeem Ullah Sub-Campus, Jhang, University of Veterinary and Animal Sciences, Lahore, Pakistan

\*Address all correspondence to: arbab.sikandar@uvas.edu.pk; drarbab786@gmail.com

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
