Chronic Obstructive Pulmonary Disease (COPD) is a term used to describe a group of respiratory diseases that cause airflow blockages and breathing difficulties. COPD is associated with chronic inflammation of the airways and includes emphysema and chronic bronchitis [1]. The World Health Organization (WHO) estimates COPD to be the 3^rd leading cause of death worldwide, causing more than 3 million deaths in 2019 alone [2]. In the United States, an estimated 16 million people are diagnosed with COPD [3].

Recent studies have discovered that our gut and lungs communicate bi-directionally via the gut-lung axis. Gut health and microbiota are involved in respiratory diseases such as COPD through this gut-lung axis. Read on to find out more about how a healthy and balanced gut microbiota may improve our respiratory health and reduce the risk factors for COPD.

Gut Health and Gut Microbiota

Our gut consists of trillions of such microorganisms, including bacteria, viruses, fungi and protozoa species. This set of gut microbiota is unique to everyone and varies due to several factors including environmental, lifestyle, dietary habits, and consumption of medications such as antibiotics[4].

This innate set of gut microbiota (the set that we are born with) is thought to be the most optimum for oneself. This optimum composition deteriorates as we age. Along with poorer modern-day diets lacking in prebiotics (food for the good gut bacteria) as well as increased use of medications, the composition and amount of good gut bacteria decrease even faster.

An optimum gut microbiota consists of a healthy balance of both good and bad gut bacteria species, which leads to good gut health.

Risk Factors for COPD

Smoking is the biggest risk factor for COPD. Approximately 90% of COPD cases are caused by smoking [5]. Other risk factors for COPD include:

• Air pollution exposure
• Secondhand smoke
• History of childhood respiratory infections
• Diet: dietary fiber intake is inversely related to COPD incidence [6]

Gut Health and COPD

A study published in the medical journal Gut in 2022 described the role of gut microbiota in COPD [7]. The study highlighted that dysbiosis (alteration of the gut microbiota) plays a role in influencing the pathogenesis of COPD. An increased abundance of Lachnospiraceae species in COPD patients may have contributed to chronic inflammation and worsening COPD. An increase in Lachnospiraceae species has also been observed in other chronic inflammatory diseases such as inflammatory bowel disease (IBD) [7].

The lung microbiota is known to play key roles in COPD [8]. Gut dysbiosis leads to increased gut permeability, leaking toxins and bacteria into the bloodstream which travel to the lungs, causing lung dysbiosis and possibly worsening COPD [8]. Increased gut permeability also leads to chronic systemic inflammation which worsens COPD.

Supporting our respiratory health

For prebiotics which are dietary fibers, they also support healthy lung functions. By modifying our diets and increasing our intake of prebiotic fiber, we can potentially decrease our risk of COPD.

Prebiotics are food for our good gut bacteria. By supplementing our diets with prebiotics, we allow good gut bacteria to grow, and in turn crowd out bad ones. This establishes a healthy and balanced gut microbiota which helps support our respiratory health.

Good gut bacteria feeding on prebiotics also produce metabolites such as short-chain fatty acids (SCFAs) that confer health benefits. SCFAs are known to have anti-inflammatory effects and thus have the potential to reduce the risks of COPD [9].

Conclusion

The existence of the gut-lung axis suggests that improving our gut health supports our respiratory system and can potentially reduce the risks of lung diseases such as COPD. The use of prebiotics to induce positive changes to our gut microbiota and improve our gut health is one option we can consider to improve our respiratory health and reduce the risk factors for COPD.

Related articles

Introduction to the Gut-Lung Axis

Prebiotic: Gut Microbiota, Gut Health, and Beyond

References

1. Centers for Disease Control and Prevention (CDC). Chronic Obstructive Pulmonary Disease (COPD). What is COPD?
2. World Health Organization (WHO). Chronic obstructive pulmonary disease (COPD).
3. National Heart, Lung, and Blood Institute (NHLBI). COPD National Action Plan. Key Facts about COPD.
4. Rutsch A, Kantsjö JB., Ronchi F. The Gut-Brain Axis: How Microbiota and Host Inflammasome Influence Brain Physiology and Pathology. Immunol. 2020;11.
5. American Lung Association (ALA). COPD Causes and Risk Factors.
6. Varraso R, Willett WC, Camargo CA Jr. Prospective study of dietary fiber and risk of chronic obstructive pulmonary disease among US women and men. Am J Epidemiol. 2010 Apr 1;171(7):776-84.
7. Lai HC, Lin TL, Chen TW, et al. Gut microbiota modulates COPD pathogenesis: role of anti-inflammatory Parabacteroides goldsteinii Gut. 2022 Feb;71(2):309-321.
8. Qu L, Cheng Q, Wang Y, et al. COPD and Gut-Lung Axis: How Microbiota and Host Inflammasome Influence COPD and Related Therapeutics. Front Microbiol. 2022 Apr 1;13:868086.
9. Vinolo MA, Rodrigues HG, Nachbar RT, Curi R. Regulation of inflammation by short chain fatty acids. Nutrients. 2011 Oct;3(10):858-76.