What is the Microbiome?

WHAT IS THE MICROBIOME

The term “good bacteria” is by now familiar, and probiotic supplements and foods have been found on supermarket shelves for some time.  Humans are colonized by trillions of microorganisms that include bacteria, fungi, viruses and protozoans.¹ The microbiome refers to all the microorganisms, and their DNA, living within the human body.  The manner in which this community of microbes living in each human host affects development, immunity and susceptibility to diseases is being explored now more than ever.

HOW DOES THE MICROBIOME AFFECT YOUR ALLERGIES OR ASTHMA?

Clinical observations about the link between the microbiome and the development of allergic diseases have been documented since the 1980s.  The hygiene hypothesis proposes that reduced exposure to bacteria early in life increases risk of developing allergic diseases, including eczema and asthma.  For example, children in larger families had less allergic rhinitis and eczema compared to children in smaller families.  In Europe, children raised on farms and exposed to stables and raw milk, especially in the first year of life, had lower rates of allergic diseases.  Other studies linking early exposure to microbes and decreased risk of allergic diseases include exclusive breast-feeding for the first 4 months of life, furry pets in the home during infancy, lack of maternal antibiotic use during pregnancy and vaginal delivery.²

Recent scientific advances have allowed for analysis of the bacterial communities within the microbiome, including their DNA and metabolism.  Such information helps us understand how they are associated with allergy, asthma and food allergy.  Investigations have detailed that specific microbes reside on the surface layers of the skin, lungs and gut.  The variety of species and abundance of microbes present along with the balance of “good” versus “bad”, or pathologic, species all impact your tendency toward allergic diseases, severity of disease and response to treatment.³ The microbiome varies between individuals and is impacted by factors such as diet, medication exposure and infection or illness.²

MAKING THE MOST OF YOUR MICROBIOME

A healthy microbiome can decrease the occurrence or severity of allergic disease including eczema and asthma.  So how can you restore a healthy microbiome to your body and maintain it?  You can begin with the right dietary choices.  Foods that have fiber and complex carbohydrate like vegetables, nuts, seeds, fruits and legumes increase the growth of beneficial bacteria.  Such foods are metabolized by the microbes into short chain fatty acids which reduce allergic inflammation.² In addition, probiotic supplements restore balance to the microbiome by adding beneficial bacteria.  Many supplements are available with different bacterial strains and strengths.  The more common supplements typically contain Lactobacilli and Bifidobacterium found in raw or unpasteurized milk and yogurts. Less common strains are soil-based probiotics of the Bacillus species which may be even more important in giving us a diverse microbial exposure that mimics life on a farm. Dr. Herrscher and his team at AIR Care can direct you to the best probiotic to meet your needs.

Sources:  ¹ Gensollen, PhD, T. “Correlation between early-life regulation of the immune system by microbiota and allergy development.” JACI. 139 (4) 1084-1091.

² Huang, MD, Y. “The microbiome in allergic disease:  Current understanding and future opportunities-2017 PRACTALL document of the AAAAI and EAACI”. JACI. 139 (4) 1099-1110.

³ Chung, MD, K. “Airway microbial dysbiosis in asthmatic patients:  A target for prevention and treatment?” JACI. 139 (4) 1071-1081.