Gut microbiome

The human microbiome is a general term for the bacteria and other microorganisms present in and on the human body. For example, the gut microbiome is a community of diverse microbes present in the gut.

Over the last decade, there has been an increase and a significant one in the number of research conducted on the gut microbiome and its relation to human health.

Studies have shown that the gut microbiome is associated with human health. For example, the microbiome makeup affects the development of some types of cancer, metabolic disease, gastrointestinal disorders, and other non-communicable chronic diseases.

It is important to note that the human gut microbiome is usually stable during a person’s lifetime. However, several factors such as medications, environmental factors, and even diet can significantly alter one’s gut microbiome.

The issue is a pressing one, as nutritionists and medical researchers have argued that the diversity of the gut microbiome has been negatively affected by Western diets, resulting in poor health.

For instance, a 2018 study published in the journal Nutrients argued that processed food which makes up a greater percentage of the Western diet, has severely altered the gut microbiome in humans.

According to the study, these alterations greatly increase chronic inflammation, a primary causative factor of many noncommunicable chronic ailments.

Knowing that the microbiome can be affected by diet, the researchers sought to determine the effects of dietary interventions.

If it can be proven that specific dietary interventions can alter an individual’s gut microbiome positively, then these could be recommended as components of a nutritious, balanced diet in the future. In addition, an increase in the number of people with a healthy gut microbiome will translate to a decrease in the number of non-communicable disease cases. The World Health Organization reports that at least 71% of deaths globally are attributed to noncommunicable chronic diseases.

Is everyone susceptible to inflammation?

Inflammation is the natural response from your immune system.

When your body is stressed, for instance, from injuries and infections, your immune system will release proteins and antibodies alongside increased blood flow. This will help your body to heal.

Short-term inflammation can heal the body, but prolonged inflammation can affect healthy tissues, resulting in damage.

When your immune system causes excessive damage, you may develop a chronic inflammatory disease.

How do fermented foods help?

A July 2021 study published in the Cell found that fermented food increases microbiome diversity and decreases markers of inflammation.

In the study, 36 healthy adults were assigned a 10-week diet that included high-fiber or fermented foods.

In the group assigned fermented food, four types of immune cells showed less activation.

There was also a decrease in the blood levels of 19 inflammatory proteins. Analysis of the results revealed that a simple change in the diet could significantly affect the gut microbiome and the immune system.

The study found that fermented foods caused less activation of immune cells involved in chronic inflammation.

The evidence from this study lends credence to the already established relationship between the gut microbiome and the immune system. This relationship has been implicated in health conditions such as inflammatory bowel disease and celiac disease and non-GI conditions like cancer and rheumatoid arthritis.

The study found that kefir, yogurt, fermented cottage cheese, vegetable brine drinks, kimchi, and kombucha tea greatly increased gut microbiome diversity.

Takeaway

It is worth knowing there’s no specific cure for inflammation. However, short-term inflammation contributes to the healing process.

Recent studies suggest that modifying one’s diet with fermented foods prevents unwanted inflammation by acting on the gut microbiota.

Further research on the links between the diet-microbiota-immune system pathway may help treat various inflammatory conditions.

References

Wastyk HC, Fragiadakis GK, Perelman D, et al. Gut-microbiota-targeted diets modulate human immune status. Cell. 2021;184(16):4137–4153.e14. doi:10.1016/j.cell.2021.06.019

Farré-Maduell, Eulalia & Casals-Pascual, Climent. (2019). The Origins of Gut Microbiome Research in Europe: From Escherich to Nissle. Human Microbiome Journal. 14. 100065. 10.1016/j.humic.2019.100065.

Hills Rd, Pontefract BA, Mishcon HR, Black CA, Sutton SC, Theberge CR. Gut Microbiome: Profound Implications for Diet and Disease. Nutrients. 2019; 11(7):1613. https://doi.org/10.3390/nu11071613

Shreiner, Andrew B; Kao, John Y; Young, Vincent B. The gut microbiome in health and disease, Current Opinion in Gastroenterology: January 2015 — Volume 31 — Issue 1 — p 69–75 doi: 10.1097/MOG.0000000000000139

Zinöcker MK, Lindseth IA. The Western Diet–Microbiome-Host Interaction and Its Role in Metabolic Disease. Nutrients. 2018; 10(3):365. https://doi.org/10.3390/nu10030365

Wastyk HC, Fragiadakis GK, Perelman D, et al. Gut-microbiota-targeted diets modulate human immune status. Cell. 2021;184(16):4137–4153.e14. doi:10.1016/j.cell.2021.06.019