Who would ever think that these three things can be intimately related to one another? In fact, allergies or asthma symptoms can worsen or come to the surface as the gut microbiome or leaky gut problems worsen. (For information on leaky gut please refer to our previous newsletters). Findings suggest leaky gut can lead to leaky lung.

As a reminder, about 70- 0% of your immune system is embedded in the lining of your digestive tract. However, the lining of your sinuses, throat (trachea), bronchioles and lungs also have many immune cells embedded within. There is very interesting “communication” or link between the gut and lungs and more research is revealing this close relationship. We will explore some of these connections in this newsletter and help to identify possible solutions.

A Quick Review on Leaky Gut

Image 1: The image illustrates the two main routes of intestinal barrier penetration by antigens

The lining of the digestive tract, more specifically the small intestines, plays a very important role by determining what substances should be absorbed and which ones are harmful.To accomplish that task, it is essential that the single cell lining of your gut, represented by the purple cells above, remains healthy and structurally intact.

The lining of the gut not only acts as a selective barrier but permits a “chemical cross-talk” between the bacteria and other microorganisms (microbiome) found along the lining of the gut and the embedded immune system found throughout the digestive tract.

In the diagram above you will notice how foreign proteins and other compounds (antigens) may pass through when the lining is compromised or damaged. When this occurs, it is known as Leaky Gut. These antigens then react with the immune system which is often referred to as the gut associated lymphatic tissue (GALT). Additionally, there are specialized nodular areas called Peyer’s patches that contain a higher concentration of immune cells.

Furthermore, the immune cells can enter the blood stream or lymphatic system and spread throughout the body causing health issues. The immune cells can also produce several chemical messenger proteins/glycoproteins called cytokines or interleukins. These immune cells and/or chemical messengers can spread throughout the body and negatively affect organs and tissues such as your sinuses, nasopharynx, throat, larynx, trachea, bronchioles, and lung tissue.

How Does Leaky Gut Lead to Leaky Lung?

This is still a very active and relatively new area of research. Below are a few ways leaky gut can lead to respiratory problems such as allergies, asthma, and other respiratory issues, even some forms of chronic obstructive pulmonary disease (COPD) have been implicated.

The “release” of immune cells and cytokines from the digestive tract into the blood and lymphatic system can have a direct effect on that portion of the immune system that lines the respiratory tract. Therefore, it can influence how your respiratory tract responds to airborne antigens such as pollens, weeds, trees, dust, animal dander, fungal/mold spores, bacteria, viruses, volatile chemicals, and air pollutants. In a sense you become hypersensitized to substances you normally should not react to.

The release of various cytokines can influence the integrity of the respiratory membranes lining the sinuses, nasopharynx, larynx, throat, trachea, bronchioles, and lung. The cytokines often result in an inflamed and weakened membrane lining. Thus, subjecting you to additional reactions to airborne irritants. This is what you may refer to as Leaky Lung. There is also a group of immune cells called mucous associated lymphoid tissue (MALT) that are activated improperly by these cytokines and traveling immune cells. This results in further respiratory irritation and sensitivity.

In the case of a severe Leaky Gut, some bacteria and/or microorganisms may pass through the gut lining only to be transported to the lungs and other parts of the respiratory tract via the blood and/or lymphatic system. This is known as translocation.

Irritation of the digestive lining can stimulate an important nerve called the vagal or vagus nerve. This nerve can relay sensory information from the digestive tract back into your brain stem and “reroute” information to the various parts of the respiratory tract resulting in changes in the lining and immune response. This potentially can result in excessive mucous production and/or inflammation.

Image 2: Bidirectional Gut-Lung axis. The metabolites like SCFAs produced by gut bacteria move through blood stream to stimulate immune response in lung and different factors from lung effect gut immune response. Apart from metabolites, the immune cells induced by multitude of antigens move through lymphatic duct between both these organs which leads to modulation of immune response in both organs.

Reasons Why the Microbiome is Important to the Immune System

One of the key things to address is making sure you have a healthy and diverse microbiome. Briefly, the microbiome consists mostly of bacteria. These bacteria play an extremely important role in keeping the gut healthy. Below, I have listed examples of how bacteria support gut health:

Assist in the breakdown of food and harmful compounds
Important in the production of Vitamin B1, B2, B12, Vitamin K and amino acids. All these vitamins can impact immune responses
Prevents overgrowth or attack by unfavorable organisms
Supplies essential nutrients to the lining of your digestive tract, called short chain fatty acids (SCFA). They are derived from various fibers in our diet. An important one is called butyrate
Properly process and remove various hormones to assist in hormonal balance in the body. Many hormones influence immune responses
Produce compounds that pass through the lining of the digestive tract or have direct communication (dendritic cells) with the various immune cells. The immune cells also send chemical compounds back to the microbiome and to the lining of the gut to maintain a healthy active environment.
Affects metabolic function and weight gain
Can potentially impact moods, behavior, and neurotransmitters. Many of the immune cells can be influenced by neurotransmitter imbalances

Image 3: Schematic representation to depict assimilation of dietary nutrients by gut microbiome and their impact on distal organs.

Factors that Contribute to Leaky Gut and Leaky Lung

Usage of antibiotics
Usage of Nonsteroidal anti- inflammatories (NSAIDS)– Aleve, Ibuprofen etc.
Usage of medications for gastric reflux, heartburn, esophagitis, and gastritis. Some examples: Zantac (recently removed as it may cause cancer), Tagamet, Pepcid, Dexilant, Nexium, Prilosec, Protonix, Prevacid, and Aciphex
Diet high in refined carbohydrates and low in natural fibers
Excessive consumption of alcohol and caffeinated products
Excessive consumption of animal products and lack of vegetable and fruit products

Factors that Help the Microbiome and Decrease Leaky Gut and Leaky Lung Issues

Utilize different probiotics
Add to your diet: indigestible carbohydrates and fibers such as inulin, resistant starches (i.e., beans), gums, pectin’s and fructooligosaccharides. However, be cautious about adding a lot of these to your diet in a short period of time because doing so can result in excessive bloating and digestive distress. Go slowly! Be aware of lectin and gluten sensitivities!
Additional foods to include in your diet: garlic, onions, leeks, asparagus, Jerusalem artichoke, dandelion greens, other greens, bananas, and seaweed
Fermented foods to add to your diet: Kefir, yogurt (with live cultures), pickled vegetables, tempeh, kimchi, sauerkraut, miso and kombucha. However, proceed with caution if you have an overgrowth of Candida

Testing the Health of the Microbiome, Leaky Gut and Leaky Lung

There are several tests that can evaluate the integrity of the lining of the gut. One of the tests can measure the formation of antibodies in your blood from damaged components that come from the lining of the gut such as, zonulin and occluding (refer to first diagram above). The test can also measure antibodies formed from certain bacteria components (lipopolysaccharides) that can result in inflammation. For more information you can reference our previous newsletters about this testing, leaky gut, and lipopolysaccharides, or visit our website under laboratory testing.

Another great test known as the GI MAP Test utilizes a stool sample that can measure the quantity of numerous viruses, bacteria, yeasts, and other microorganisms. This test can also check for “good, bad, or neutral” bacteria that can lead to Leaky Gut and Leaky Lung. Additionally, the stool test can also evaluate the health of the digestive tract and detect gut lining damage.

The above-mentioned tests are available in our office. If you are interested in learning more about either test or would like to order one, please contact our office. Additionally, we will elaborate more on these tests and the microbiome in future newsletters.

As always, we are here and happy to help you balance your microbiome, improve your gut, and help with any respiratory issues! To make an appointment contact our office at (480) 732-0911. For more information check out our articles and videos online under our Health Blog. We hope this information is helpful in your journey to optimal health.

References:

Image 1:

Image 2:

Diet, Microbiota and Gut-Lung Connection – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Schematic-representation-to-depict-assimilation-of-dietary-nutrients-by-gut-microbiome_fig1_327748052 [accessed 31 Jul 2025]

Image 3:

Diet, Microbiota and Gut-Lung Connection – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Bidirectional-Gut-Lung-axis-The-metabolites-like-SCFAs-produced-by-gut-bacteria-move_fig2_327748052 [accessed 31 Jul 2025]