- The microbes in your gut play a role in the development of allergies
- This is especially true in the early years of life – and even in the womb
- Exposure to good bacteria can help strengthen a child's resilience to allergies
From food allergies to springtime sniffles to skin sensitivities, the reason could lie in your gut.
Science has shown over and over again how the microbial ecosystems that thrive in our bodies are important for our health, fighting off contagions, keeping inflammation levels in check and digesting certain foods.
Just as they prevent disease, these microscopic armies can also help prevent the development of allergies – if you are exposed to a variety of microbes early in life both in your environment and diet.
Sterilised, urban environments
According to research, Western, urbanised societies are exposed to far fewer microbes than before the Industrial Revolution, and have since then been affected by a steady rise in allergies.
The exposure to microbes in the first year of an infant's life can determine immune development, but it's a delicate balance. Colonisation by certain bacteria before babies are six months old could make them more allergic, whereas, after that, their system is better equipped to deal with the introduction of new microbes.
In adults, those with allergies, especially to nuts and seasonal pollen, also have low diversity of microbes and an imbalance in their gut microbiota, according to a study.
Exposure in pregnancy
Dr Vincent Ho, gastroenterologist and author of The Healthy Baby Gut Guide, told Australian radio programme Life Matters that children are growing up in more sterile environments and aren't exposed to good bacteria any more.
And this exposure can even start in the womb. Studies in Sweden found that pregnant women exposed to farm life, especially dairy farms, have babies that are far less likely to develop allergies due to their exposure to bacteria that comes with rearing animals.
A similar situation can also be found in households with pets. Dogs and cats have more microbial diversity in their dust, which can help prevent pet-related allergies.
On the other hand, exposure to farm bacteria later in life can actually cause allergies, highlighting the importance of establishing microbial resilience early in life.
You can also have more diversity in gut microbes if you have a larger your family, as siblings can influence each other's microbial colonies, according to Ho. This is further added to by their peers at school, but with the pandemic and physical distancing, the limited exposure to microbes might mean more allergies in the future. Only time will tell.
Fighting food allergies
When it comes to food allergies, it can be daunting to start babies on solids without knowing what their body might reject. Ho recommends that you should breastfeed until six months – itself an important source of good bacteria – and then introduce allergenic foods during the first year of life.
The key is to have a consistent plan, giving your baby small amounts of allergenic foods during the day so that you can monitor if there are any reactions, slowly increasing the amounts if everything seems fine. This method could also help prevent the development of food allergies at a later stage.
Another method is also being investigated. In 2019, scientists discovered certain microbial strains that can protect against food allergies, and their introduction to manage allergies could be an alternative to desensitisation.
It's also not just gut microbiota that can impact allergies. These ecosystems also populate respiratory tracts and the skin, working together to keep their host healthy and thriving. A review even suggests that pre- and probiotics could help rebalance the system to reduce allergic reactions.
While there is no catch-all prevention or cure for allergies, it's important to keep the gut and its inhabitants in mind to help stem the development of allergies in future generations.
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