What Is The Association Between Asthma And Autism?

In our body, lungs are where oxygen in carbon dioxide exchange occurs. 

Asthma is a chronic/reversible (there’s a lot of debate as to whether asthma is a chronic disease or reversible disease), just know that in the literature it is described as both. So asthma is a chronic/reversible, episodic obstructive airway disease caused by hyperactivity of the bronchial tree to a variety of stimuli, thus allowing less air into and out of the lungs. 

Symptoms are:

  • coughing
  • wheezing
  • shortness of breath
  • chest tightness

The majority of children who develop asthma do so before the age of five. Asthma is the leading cause of school absences in children younger than 17. And, boys are twice as affected as girls until adolescence. 

Asthma triggers are:

  • exercise
  • smoke
  • cold air
  • pollen
  • insects
  • chemicals
  • pollution
  • pets
  • stress

Studies have suggested that several co-morbidities might be associated with autism, including immune mediated disorders such as asthma, allergy, and skin disorders, such as atopic dermatitis and eczema. 

Interesting. Huh? The immune system really gets involved.

Asthma And The Immune System

Many asthma symptoms are due to an apparent expansion of Th2 lymphocytes that secrete cytokines. Cytokines are small, secreted proteins released by cells that have a specific effect on the interactions and communications between cells. So cytokines basically are information from one cell telling another cell what to do or what’s going on.

Asthma is heterogeneous in clinical presentation, progress, and response to therapy. So as you saw, there are many different triggers for asthma. So asthma is quite heterogeneous in clinical presentation, progress, and response to therapy, just like autism. 

Autism And The Immune System

Immune abnormalities were first described in individuals with autism in 1977 that’s pretty shocking. 1977 that’s 40 years ago. It is well-documented that individuals with autism have altered immune profiles that are correlated with deficits in behavioral profiles. So that goes even a step further.

Research has identified many immune functions that are atypical in autism, but not surprisingly, the findings are often as heterogeneous as the behavioral phenotypes, which make up autism. So that pretty much says just because one study finds a particular immune function to be, let’s say, hyperactive, another research study might find that same immune function to be normal, and another study could be, could find it less occurring. 

That’s really what’s been some of the difficulties with studying autism is that the research done on autism, it’s not always conclusive. There are really great threads of truth of scientific truth. You have to be willing to read a lot of research to really understand the trends in autism,

Asthma And Autism 

Asthma affects about 9.5% of children in the US. The National Health Interview Survey revealed that 21.6% of children with autism were reported to have asthma. That’s quite profound. So one immune factor that has been suggested to have contributed to the immune-mediated disorders, including asthma, allergies, and autoimmunity is the inflammatory T cell cytokine, interleukin-17. 

Interleukin 17 (IL-17) is a cytokine that elicits protection against extracellular, bacterial and fungal infections, and is important in inflammation. However, when produced an excess, interleukin-17 contributes to chronic inflammation associated with many inflammatory and autoimmune disorders. 

Interleukin-17 is a cytokine that elicits protection against extracellular, bacterial and fungal infections, and there’s so much research coming out about the different microbiota of those with autism compared to those without. 

Cytokines are small secreted proteins released by cells that have a specific effect on the interactions and communications between cells. 

Recent research reported that interleukin-17 was increased in children with autism who also had asthma compared to controls with asthma. That’s a good study.

The Lung Microbiota

I know when everyone says the word microbiota, you automatically think the gut, but that’s not the only place where bacteria thrive, as well as are needed. 

Research is ongoing to understand the importance of microbes in the lower airways, basically our lungs. Many more microbes have been detected than previously thought to inhibit the lungs. The lungs were initially thought to be sterile. Just like the stomach was initially thought to be sterile. Turns out neither is true. 

Lung microbiota research is constrained by the fact that most sampling techniques are quite invasive and that limits the sampling and research. Obviously our lungs are quite protected and it’s not very easy to just take a little sample, so it is a little bit invasive. In healthy people. bacteria enters the lungs, your lower airways, mainly through inhalation, and it’s cleared by a combination of mucus and the innate immune system. 

Failure to remove bacteria rapidly may allow colonization and infection to occur.

Asthma And The Lung Microbiota

Results published in 2010 from 24 adults in 19 children show that the bronchial tree contains the characteristic microbiota. Their analysis suggests that the microbiota is disturbed in asthmatic airways. 

The relative abundance of particular families of bacteria (Comamonadaceae, Oxalobacteraceae, Sphingomonadaceae) was also correlated to bronchial hyperresponsiveness.

Proteobacteria were found to be at higher levels in children with asthma. Lung microbiota is extremely important to overall health.

Gut Microbiota And Asthma

We’re talking about two different kinds of things here. We have microbiota in the gut and we have microbiota of our lungs, right? They’re not connected. Right.

The increase in asthma rates has been linked epidemiologically to the rapid disappearance of Helicobacter pylori. H pylori is considered a bacterial pathogen that persistently colonizes the human stomach. 

I’m sure many of you have heard about the hygiene hypothesis that pretty much says that early life microbial exposure is critical for our proper immune system maturation and function.

Mechanistic studies performed in mouse models of allergic asthma showed that early life colonization with H pylori in the stomach prevents allergic asthma through the recruitment of pulmonary T egulatory cells and impaired dendritic cell maturation. 

Absolutely amazing how a considered bacterial pathogen that persistently colonizes the human stomach can actually confer protection against allergic asthma. That’s in our lungs.

The human body is absolutely amazing and this is how special diets are that powerful gut health is extremely important to overall health, especially those with autism.