Microbial endocrinology: strategies to improve animal health

On this article we will introduce several concepts that will ultimately help us put the missing parts together on the coming articles to see how we can influence the microbiome to act on our benefit to have better welfare, health and production

Stress

Stress is an inevitable aspect of swine production, whether due to transportation, housing, social or environmental factors, as it is present at every stage we can use it as a focal point in microbiome research as its impact on the microbiome can have far-reaching consequences. The microbiome can be used to enhance their animal welfare, health and productivity. By doing this we will use microbial endocrinology to enhance animal health.

Microbial Endocrinology

But before we start let’s introduce an interesting concept, microbial endocrinology. Microbial endocrinology is the interception of microbiology and neurobiology, providing an evolutionary understanding of how hosts and microbe communicate via stress related neurochemicals. They will mediate the interaction of stress and nutrition in influencing disease, behaviour and other aspects of physiology crucial to have healthy animals. Microbial endocrinology can have a focus on the gastrointestinal tract, but because there is an evolutionary understanding for how neurochemicals mediate host microbiome interaction, it is not limited to the gut, we can apply to other systems like the respiratory tract.

Neurochemicals:

Neurochemicals are a big class of compounds that can have different actions. As we are talking about stress related neurochemicals we can focus on the fight or flight monoamine neurochemicals such as norepinephrine, epinephrine, dopamine, serotonin within others. Something interesting is that Dopamine in pigs (and other species) as an example is structurally identical to dopamine found in plants and bacteria. Therefore, neurochemicals are interkingdom messengers of stress.

How are these related:

Stress alters the production of host neurochemicals such as norepinephrine and serotonin, which influences microbial populations and behaviour. Mitigating stress through environmental enrichment, optimized handling, and dietary interventions can help maintain microbial stability. Feed additives such as prebiotics and probiotics have emerged as effective tools in counteracting stress-induced dysbiosis. For example, supplementing diets/animals with specific bacterial strains has been shown to improve gut barrier function and reduce pathogen load under stressful conditions.

Last, but not least, we might think about stress as an expression of fear, environmental discomfort, transport, weaning or other stages of production, but they are not the only sources. A ”hidden” source of neurochemicals are plants, as we mentioned they produce the exact same molecules, thus if they are under stress and more neurochemicals are available on feed there will be an interaction with the animal microbiome.