Early nasal colonizers of piglets as nasal probiotics

The nasal microbiota plays an important role in the respiratory health of piglets, mainly through pathogen exclusion and early stimulation of the immune system. The balance of this microbiota can be altered by various factors, causing dysbiosis or a microbiota with low bacterial diversity, which facilitates pathogen invasion and subsequent disease.

One of the factors influencing the composition of the microbiota is antibiotics. When administered to mothers, they have an effect on the nasal microbiota of piglets that lasts longer than when administered directly to piglets. This leads us to emphasize the importance of mothers in transmitting a healthy microbiota in the first days of life to piglets. In addition, it is interesting to highlight that inoculation of nasal colonizers obtained from healthy piglets appears to have a stabilizing effect on the microbiota of young piglets and may be useful in reversing dysbiosis, especially those caused by antibiotic treatment.

Keywords: nasal microbiota; antibiotics; probiotics; polyserositis; nasal colonization.

Early nasal colonizers of piglets as nasal probiotics

The nasal microbiota plays an important role in the respiratory health of piglets, mainly through pathogen exclusion and early stimulation of the immune system. The balance of this microbiota can be altered by various factors, leading to dysbiosis or low microbiota diversity, which promotes pathogen invasion and subsequent disease.

One of the main factors influencing the composition of the microbiota is antibiotics. These molecules, when administered to sows, have an effect on the nasal microbiota of the offspring that lasts even longer than when the antibiotic is administered directly to piglets. This fact highlights the importance of sows in transmitting healthy microbiota to piglets at an early age. It is also interesting to note that inoculation of nasal colonizers obtained from healthy piglets appears to have a stabilizing effect on the microbiota of young piglets and may be useful in reversing dysbiosis, especially those caused by antibiotic treatment.

Keywords: nasal microbiota; antibiotics; probiotics; polyserositis; nasal colonization.

Nasal microbiota of piglets as an early prognosis

Living microorganisms that live and coexist in a symbiotic relationship with the host are called microbiota. These microbial communities are essential for regulating homeostasis and immunological functions of the host. Different bacterial communities are located in different parts of the body, which are closely related to the health of animals by performing specific functions. It has been known for decades that the gut microbiota is essential for maintaining animal health due to many specific functions, such as fermentation of ingested food and production of vitamins, as well as its important role in the maturation of the immune system. system. . The role that microbiota plays in other parts of the body has also recently been studied and proven to be important.

The respiratory microbiota consists of communities with specific functions that act as guardians or gatekeepers protection against penetration of respiratory pathogens3. Its role in protection against pathogens and early stimulation of the immune system is very important. When these communities are disrupted, resulting in loss of diversity and compositional imbalance, they lead to a state of dysbiosis, which often has a cascading effect on the immune system, creating an advantage for the emergence of pathogens.

The nasal microbiota is considered to be the first barrier that these pathogens encounter when colonizing and/or entering other niches and has proven to be important when it comes to preventing or controlling various diseases. Therefore, its proper creation and development is important. In pigs, the composition and diversity of the nasal microbiota has been shown to change dramatically from birth to the end of the transition period, with weaning being a critical time when the established microbiota is associated with the susceptibility of piglets to disease later in life. in life.life. Thus, it has been shown that the diversity of the nasal microbiota at weaning in animals that subsequently develop diseases such as Glässer’s disease or diseases associated with Mycoplasma hyorinis or Streptococcus suis lower than those who remain healthy until the end of the transition period. Moreover, the nasal microbiota of transitional animals already has an altered composition at the time of weaning, and these changes appear to be specific to the pathogen that will subsequently cause clinical cases. This opens up the possibility of using the acquired knowledge to develop a prognostic method that allows for monitoring animals in order to determine their susceptibility to various diseases of respiratory origin and to be able to take appropriate preventive measures.

Changes in the nasal microbiota.

The formation of the microbial community inhabiting the nasal cavity of piglets is dynamic and includes various microorganisms. Colonization begins immediately at birth, and the transfer of colonizers from mothers to piglets is essential for the development of a healthy microbiota. Within these early colonizers, not only commensal bacteria are found, but also opportunistic microorganisms capable of developing various pathologies (pathobionts). Typically, early colonization occurs when piglets are still protected by maternal immunity, and therefore there is a balance between pathogen colonization and immunity. But if this balance is disturbed, these pathobionts can spread to other internal organs and thus cause associated disease. For a long time, attention was paid only to the level of antibodies acquired through colostrum (maternal immunity). While it is true that after weaning maternal immunity reaches its lowest level and the protection it provides disappears, we cannot remove the effect of colonization from the equation. This colonization can be modified by reducing the transfer of beneficial colonizers from the mother or by actions in the piglet that can cause dysbiosis.

There are various factors that can change the nasal microbiota, including the environment, food and, most importantly, the treatment used. Bacterial diseases are usually controlled with antibiotics, especially when commercial vaccines are not available. Mothers are the main reservoir of pathogens and therefore one way to control these harmful microorganisms on farms is to treat pregnant and/or lactation mothers with antibiotics. This treatment of mothers is aimed at preventing the transmission of pathogens to piglets, which are immunologically more immature. Alternatively, piglets are treated with antibiotics at an early age for the same purpose of stopping colonization by these potential pathogens. In a study published in 2019, we demonstrated that treating suckling piglets with antibiotics may have detrimental effects on the normal development of the nasal microbiota. Perinatal treatment resulted in decreased microbiota diversity at weaning, predisposing them to later disease development. In addition, we observed that after discontinuation of perinatal treatment, the animals showed better health status, as evidenced by improved farm performance.

This article appears in issue 204 (January-February 2024) of the journal. Suis. Subscribe here for full access to this and other magazine content.