Fermented Foods May Increase Microbiome Diversity
- Researchers have shown that the gut microbiome is linked to overall health and that diet can alter the microbiome.
- In a recent small-scale preliminary study, researchers compared the effects of two diets on the gut microbiome.
- They found that a fermented diet increased the diversity of the gut microbiome and reduced markers of inflammation.
In a new proof-of-concept study, consuming fermented foods increased the diversity of participants’ gut microbiomes and reduced markers of inflammation.
In contrast, participants who ate a high-fiber diet did not see an increase in the diversity of their gut microbiome.
The research, published in the journal Cell, lays the groundwork for further research to further explore how different dietary interventions can positively affect a person’s gut microbiome.
The human microbiome describes the various bacteria and other microorganisms that exist in and on the human body. A person’s gut microbiome is a particularly diverse location of these microbes relative to other parts of the body.
Over the past 10 years, there has been a a significant increase in the amount of research scientists have conducted on the gut microbiome and its links to human health.
Researchers showed that the gut microbiome plays an important role in health. The makeup of the microbiome can affect the development of many chronic non-communicable diseases, such as gastrointestinal disorders, metabolic diseases, and some types of cancer.
A person’s gut microbiome generally remains fairly stable over the course of their life. However, some factors, including environmental factors, medications, and eating habits, can significantly affect he.
Considering the links between the gut microbiome and health, scientists are interested in precisely how to change a person’s gut microbiome.
This is an urgent problem, as researchers have argued that Western diets tend to reduce the diversity of people’s gut microbiomes, which has negative effects on people’s health.
For example, in a 2018 article in the journal Nutrients, Marit K. Zinöcker, of the Department of Nutrition at Bjørknes University College in Oslo, Norway, and Inge A. Lindseth of the Department of Clinical Sciences at the University of Bergen, Norway, argue that the ultra-processed foods that predominate in Le Western diet has altered people’s gut microbiome.
As a result, they suggest that these alterations promoted chronic inflammation, which is an underlying factor in many chronic noncommunicable diseases.
Knowing that diet can affect the microbiome, the researchers behind this study were interested in determining the effects of specific dietary interventions.
If scientists can show that specific dietary interventions positively alter a person’s gut microbiome, then these could, in the future, be included in recommendations for a nutritious and well-balanced diet. If more people had healthy gut microbiome, it could help reduce chronic noncommunicable diseases. According to the World Health Organization (WHO), these diseases represent
In the current study, researchers looked at two dietary interventions: a fermented food diet and a high fiber diet.
The study involved 36 participants, 73% of whom were female and 81% were Caucasian. They were all generally in good health.
The researchers collected blood and stool samples from the participants for 3 weeks to serve as a baseline.
They then randomly assigned participants to one of the two plans. The first diet was high in fermented foods, such as yogurt, kimchi, and kombucha, while the second was high in fiber.
Participants slowly increased their intake of fermented foods or fiber, depending on their group, over 4 weeks. After that, they followed the high fiber or high fermented food diet for another 6 weeks.
The fermented food group increased their intake from an average of 0.4 servings to 6 servings per day. The high-fiber group increased their daily intake from 21.5 grams (g) to 45.1 g.
Finally, participants had 4 weeks during which they could continue the diet if they wished. Throughout each step of the study, the researchers continued to collect blood and stool samples.
The stool samples allowed them to identify any changes in the participants’ gut microbiome, while the blood samples revealed any fluctuations in key biomarkers of inflammation and general health.
After analyzing the data, the researchers found that the diversity of the gut microbiomes of participants who followed a fermented diet increased dramatically.
According to Dr. Justin Sonnenburg, Ph.D., associate professor of microbiology and immunology at Stanford University, Calif., And corresponding author of the study: “This is an amazing finding. It provides one of the first examples of how a simple change in diet can reproducibly reshape the microbiota in a cohort of healthy adults.
The researchers also found that for people who ate a fermented diet, 19 inflammatory proteins were reduced and four types of immune cells were less activated.
Another corresponding author, Professor Christopher Gardner, Ph.D., Professor at Rehnborg Farquhar and Director of Nutrition Studies at the Stanford Prevention Research Center, states: “Diets targeted to the microbiota can alter immune status, providing a promising way to reduce inflammation. in healthy adults.
“This result was consistent across all study participants who were assigned to the highest fermented food group.”
– Prof. Christopher Gardner, Ph.D.
In contrast, participants of the fiber diet saw no change in the diversity of their gut microbiome and no decrease in 19 inflammatory proteins.
Dr. Erica Sonnenburg, Ph.D., senior scientist in basic life sciences, microbiology and immunology at Stanford and corresponding author of the study, notes: “We expected the high fiber content to have an effect. beneficial more universal and increases the microbiota. the diversity. Data suggests that increasing fiber intake alone over a short period of time is insufficient to increase microbiota diversity. “
The researchers noticed that participants of the high-fiber diet had more carbohydrates in their stool samples. This suggests that the participants did not have the right gut microbes to completely break down fiber.
For Dr. Erica Sonnenburg, “It is possible that a longer intervention would have allowed the microbiota to adapt adequately to the increased fiber consumption. Alternatively, the deliberate introduction of fiber-consuming microbes may be necessary to increase the microbiota’s ability to break down carbohydrates.
As a result, other research that tracks the effects of a high-fiber diet over a longer period or examines a diet high in fiber and fermented foods may provide more information on how doctors can positively alter the gut microbiome of a person.
In addition, future studies would benefit from a larger and more diverse sample size.