A resilient immune system has a positive effect on lifelong health
Immune fitness is a state where an individual’s immune system is resilient, having an inbuilt capacity to adapt to challenges by establishing, maintaining and regulating an appropriate immune response. Resilience is the capacity of the immune system to return to homeostasis – a healthy state of wellbeing – after an external challenge.
An appropriate response of the immune system is to eliminate a harmful agent, such as bacteria and viruses, but tolerate harmless ones, like food. This immune response should be of an optimal strength: not too weak, which will increase the risk of infections, or too strong, potentially resulting in allergy, chronic inflammation, or autoimmune disorders.
The immune system has influence over most of our physiological functions and so factors that impact our immune development can also have an impact on our health, both in the long and short term.
• Short-term: our immune system is responsible for tolerating foods and other non-harmful stimuli such as pollen and dust. When our body overreacts to such stimuli, it is an early sign of inflammation, or poor immune fitness. Those suffering from allergic reactions now count for 30-40% of the world’s population1,contributing to the epidemic in non-communicable diseases (NCDs). Cow’s milk allergy is the leading cause of food allergy in infants and young children, with an incidence of around 5%.2
• Long-term: having an allergy early in life predisposes a person to having other, secondary allergies later in life (the ‘allergic march’). Allergies and other NCDs (e.g. obesity, diabetes, cancer) have in common an underlying low-grade inflammation3 and our immune systems will influence their development.4,5 A fit immune system is more able to cope with external factors and so can protect the body against the development of NCDs.
What contributes to Immune Fitness?
Early life presents a unique window of opportunity to influence the development of the immune system, including training it to elicit the appropriate immune response to external stimuli.
As well as family history, there are a number of external factors related to modern life that can challenge the developing immune system by causing a gut microbiota dysbiosis. These include C-section deliveries, overuse of antibiotics, as well as westernised diets and air pollution.
An imbalance of gut microbiota is associated with inappropriate immune responses like allergic diseases, (chronic) inflammation and the development of NCDs.6 Conversely, a healthy gut microbiota is associated with improved health later in life, fewer NCDs, including a reduced risk of allergies and a lower persistence of allergic diseases.7
Nutrition is a key factor in training towards Immune Fitness
Nutrition is one of the most important environmental factors that can positively influence gut microbiota composition and therefore the development of a healthy immune system, which in turn improves immune fitness and optimises future health.8
Nutritional ingredients such as specific pre- and probiotics to can positively influence the immune system directly9 and indirectly via modulation of the gut microbiota9–13 creating the optimal conditions for the immune system to be fit.
Prebiotics already have been shown in multiple clinical studies to have a positive impact on the gut microbiota composition11, 14–19and the immune system 20–23 As an example, in high-risk infants, a six-month intervention with partial hydrolysed protein (pHP) and prebiotics showed a reduced allergenicity by means of reduction in sensitisation marker CM-IgG1. This persisted up to three years, indicating immune training and long term effects of nutritional interventions in early life.24,25
Synbiotics were shown to restore the colonisation of the gut microbiota of infants born by C-section
Synbiotics also have been shown in multiple clinical studies to have a positive impact on the gut microbiota composition and the immune system.26,27, As an example, in infants born by C-section, a 12-week intervention with specific synbiotics (prebiotics + Bifidobacterium breve M-16V) was able to re-establish the delayed colonisation these infants.28
Learn more about the study here.