Bunjil Holistic Health

Immune system and the gut

Our immune system is a complex network that incorporates multiple organs, cells, proteins and processes to defend the body against pathogens. The immune reaction to pathogens has seperate phases to it including recognition of pathogens, activation of immune cells and removal of the pathogen from the body. It is in these phases that we can feel the symtpoms of our body working in unison to remove the pathogen from the body.

We often find ourselves having more colds and flus than the average person for a number of reasons; autoimmune conditions, poor immune function and careers working in and around often sick people, to name a few. Though these reasons are multifaceted and there is no one-stop fix to improving immunity, looking at our gut health and diet can be a simple and really beneficial place to start.

With there being an estimated 70-80% of immune cells present within the
gastrointestinal tract there tends to be a big link between diet, microbiome,
and immune health (Wiertsema et al., 2021). Diets poor in nutritious foods or limited in what is consumed can have a negative effect on systemic immune function. Many vitamins and minerals such as vitamins A, C, D and zinc help to improve cell proliferation and differentiation, meaning they help the cell to reproduce and specialise as immune cells (Childs et al., 2019; Noor et al., 2021).

This is part of what makes a well-balanced, highly nutritious diet so
important in supporting proper immune cell function. This is especially true
during the winter months when we are getting less sunlight for vitamin D
synthesis and colds/flus are often more prevalent in the community.

It is also important to support the gut microbiome to help support immune
function. Not only will a poor microbiome potentially hinder the proper uptake of nutrients from the diet it can also lead to increased inflammation along with a broken first and second line of defence in the gut. This can lead to abnormal immune responses in the gut and potential gastrointestinal conditions such as IBD (Shi et al., 2017).

The gut microbiome can be supported by proper nutrition and a diet high in both probiotic and prebiotic food that will help to feed the beneficial
bacteria. Often high fibre foods, fruits, vegetables, and whole grains are high in prebiotics, so eating a well-rounded diet will help to support a good intake of these.

References:

Childs, Calder, & Miles. (2019). Diet and Immune Function. Nutrients,
11(8), 1933. https://doi.org/10.3390/nu11081933

Noor, S., Piscopo, S., & Gasmi, A. (2021). Nutrients Interaction with
the Immune System. Archives of Razi Institute, Online First.
https://doi.org/10.22092/ari.2021.356098.1775

Shi, N., Li, N., Duan, X., & Niu, H. (2017). Interaction between the gut
microbiome and mucosal immune system. Military Medical Research, 4(1),
14. https://doi.org/10.1186/s40779-017-0122-9

Wiertsema, S. P., van Bergenhenegouwen, J., Garssen, J., & Knippels, L. M. J. (2021). The Interplay between the Gut Microbiome and the Immune System in the Context of Infectious Diseases throughout Life and the Role of Nutrition in Optimizing Treatment Strategies. Nutrients, 13(3), 886. https://doi.org/10.3390/nu13030886