Nutrition and immunology in relation to the gut microbiome – prebiotics and probiotics
The immune system has a vital role to play in maintaining health, but there is also a careful balancing act required to maintain homeostasis. The immune system needs a strong and protective response to infections by pathogenic bacteria but must be extremely selective to ensure it can tolerate normal exposures, such as food proteins. Disorders of immune function can result in health conditions, commonly seen in the form of an allergy or inflammatory disease. There is a wide range of demographic and lifestyle factors that can affect how our immune system functions, such as age, gender, previous exposure to infections or whether we smoke.
As we age, our immune function declines. This decline is associated with impaired vaccination responses and an increased risk of adverse outcomes following infection or injury. This is seen often in primary healthcare; in an elderly individual, illness and disease can be much more difficult to recover from as a result of less efficient immune response. Nutrition can also heavily influence immune health; diet is one of many factors which affect our immune system. The food we eat provides the energy and building blocks required by our immune cells to function correctly.
Increasingly, we look to the gut microbiome to support better immune health. Probiotics and prebiotics are functional foods which can affect the types of bacteria within the gut. Probiotics add more beneficial bacteria to the gut, while prebiotics nourish the ‘good’ gut bacteria that are already present, encouraging them to increase in number. Changes to the type of bacteria in our gut can influence the activity and function of the gut associated lymphoid tissue. There is a strong body of evidence that functional foods such as probiotics and prebiotics have a role in immune function beyond the gut.
Research conducted by Dr Childs investigates the potential of dietary prebiotics in exerting microbiome independent effects upon immune cells. These direct interactions between dietary components and immune cells could yield important therapeutic benefits to those with inflammatory bowel disease, obesity or non-alcoholic fatty liver disease. In addition, the global Covid-19 pandemic has brought a focus to modifiable factors which could be used to support optimal immune function, and the roles of diet and the gut microbiome are likely to be a crucial mediator of health and immunity as we look further into the future.