How is my gut actually doing? This question is more relevant than ever, as the microbiome of our gut is increasingly coming into our awareness and is now being held responsible for many mechanisms in our body. Whether we live to an old age is determined by many factors, over which we likely have more influence than previously thought. Recent research indicates that the gut flora plays a significant role in how long we live and what diseases we will develop.
In this article, we will show you the current state of research on the topic of microbiome, whether microbiome tests are worth it, and what short-chain fatty acids, such as butyrate, have to do with health.
What is the microbiome?
To start, we need to briefly clarify what the microbiome actually is. Strictly speaking, we have different microbiomes. Everywhere bacteria, viruses, and fungi are present, we can speak of a microbiome. These are z.B. the gastrointestinal tract (especially the intestines), the skin, the mouth, the respiratory tract, and the urogenital system.
In this article, we will mainly focus on the microbiome of the intestines, our gut flora.
The functions of the microbiome
The human microbiome represents an inexhaustible field of research that produces new scientific discoveries every day. We are learning more about the inhabitants of our gut flora, the gut-brain axis, and how diseases may potentially be treated through the microbiome. Without the symbiosis of our bacteria and the body, we would most likely not survive at all. The microbiome is z.B. essential for the assimilation of certain nutrients from food.The human body alone does not possess the entire spectrum of enzymes necessary for the breakdown of every nutrient.
Waste products and gut feeling
The term microbiome is used synonymously with gut flora and refers to the totality of microorganisms that inhabit our intestines. What is often regarded as "waste" for the human organism, such as fiber, serves as an essential food source for the gut flora. The microbial digestion of these substances is not only vital for the bacteria themselves but also results in the production of metabolites that are highly beneficial for human health, including secondary bile acids, vitamins, amino acid derivatives, and short-chain fatty acids.
Moreover, there is a significant connection between the microbiome and the enteric nervous system – an extensive network of neurons that runs through the entire gastrointestinal tract. This is often referred to as the "second brain" or the physical manifestation of the "gut feeling."
Did you know?
Artificial sweeteners are suspected of playing a role in insulin resistance, a precursor to diabetes mellitus. Initially, it was hoped that artificial sweeteners could provide the sweet taste without the negative effects of sugar. However, this does not seem to be the case. In this study , researchers were able to show that sweeteners alter the microbiome and thus may contribute to the development of the disease.
Research on the Microbiome
The field of microbiome research is still quite young. This is partly because many bacteria in our gut are strict anaerobes. This means that when they come into contact with oxygen, they almost immediately die. To circumvent this problem, there are various methods that researchers have devised. One of them is the Human Microbiome Project.
Human Microbiome Project (HMP) – the starting signal for the exploration of the microbiome
The Human Microbiome Project (HMP) was a groundbreaking initiative aimed at understanding the complex microbial communities that inhabit the human body and exploring their role in health and disease. Launched in 2007 by the National Institutes of Health (NIH) in the United States, it was one of the first major research programs to systematically address the human microbiome.
Goals of the Human Microbiome Project
The main goal of the HMP was to create a reference database of the microbiota that inhabit various parts of the human body, including the gut, mouth, skin, and urogenital tract.Through the use of cutting-edge genomic technologies such as 16S rRNA sequencing and metagenomics, the project aimed to catalog the genetic diversity of microbial communities and understand their functions, interactions, and impact on human health.
Key Findings
One of the central findings of the HMP was the realization that the human microbiome exhibits enormous diversity and represents a significant genetic resource that is essential for human physiology.The project revealed that microorganisms are involved in many important biological processes, including:
- Digestion and metabolism of nutrients
- Development and function of the immune system
- Protection against pathogenic microorganisms
- Influence on brain function and behavior
Furthermore, the HMP showed that changes in the microbiome are associated with a variety of diseases, including chronic inflammatory bowel diseases, obesity, diabetes, cardiovascular diseases, and even psychiatric disorders such as depression
Did you know?
The colonization of the gut flora is a lifelong process that begins at birth and only ends with death.In a study published in "Nature Metabolism", the gut flora of 9000 people aged 18 to 101 years was compared. The researchers found that not only does the human body age, but so does the gut microbiome. In healthy subjects over 77 years old, changes in the gut flora were observed, where rare bacterial species dominated and the usual microbiome pattern decreased. In less healthy subjects, this uniqueness was absent.
Microbiome Test – what options are available?
From the HMP, the desire for reliable microbiome tests also developed.In the project, a complete genome sequencing, also known as Whole Genome Sequencing (WGS), was applied for microbiome analysis. The advantage is that everything is analyzed, and that is also one of the disadvantages. True to the saying, "not seeing the forest for the trees," a WGS can provide too much information that we, as of today, cannot yet categorize. Perhaps in the future, it will be possible to better evaluate this wealth of information with the help of artificial intelligence. Another disadvantage of complete genome sequencing is the high costs, both financially and in terms of labor.There are also other microbiome tests available on the market:
Bacterial Strain Analysis
The bacterial strain analysis, often performed using 16S rRNA sequencing, focuses on the identification and quantification of specific bacterial species or strains in a sample. The 16S rRNA gene sequencing targets a highly conserved region in the bacterial genome, allowing for the differentiation between various bacterial strains. Think of it like a barcode. Each bacterium has such a barcode (the 16S rRNA), and for each bacterial species, this barcode varies slightly. This allows researchers to distinguish between different bacterial species.
Did you know?
Just a quick clarification of terms.Bacteria are divided into families and into strains. The first part of the word represents the family name, Bacillus, and the second part of the name represents the strain, in this case, Bacillus subtilis. Even though this name sounds more like a pathogen, Bacillus subtilis is extremely important for our health. It was even chosen as the "Microbe of the Year 2023." You can learn more about this fascinating bacterium in our article on QBIOTIC. Further microbiome tests In addition to those already mentioned, there are a few more tests. Commonly used are the shotgun metagenome sequencing and metaproteomics. The former offers the advantage over 16S rRNA gene sequencing that other organisms, such as viruses or fungi, are also included. In metaproteomics, one does not look at genetics, but at the produced proteins. This field of research, also called proteomics , is one of the most exciting in the field of personalized medicine and longevity. In comparison to epigenetics, where markers on the DNA are measured, proteomics looks at the proteins produced. This is also the basis of the latest test from MoleQlar, with which you can learn about your molecular profile.In collaboration with the renowned LMU Munich, we offer you a deeper insight into your molecular self.
Discover your proteome with the Molecular Profile Test from MoleQlar. Learn more now.
It’s not just the genes
The field of microbiome research is highly complex and shaped by many influences. An interesting example is the bacterium Eggerthella lenta (E. lenta) DSM 2243, a bacterium that occurs in the human gut. E. lenta has an interesting interaction with the heart medication Digoxin. Digoxin has often been used to treat certain heart conditions such as heart failure and arrhythmias. It works by improving the efficiency of the heart muscle and regulating the heart rate.Currently, it is rarely used for the therapies of these diseases. One of the reasons was the difficult dosage of the medication. For some people, even the smallest amounts of digoxin worked, while others needed a much higher dose. A possible explanation is likely hidden in our gut.
How the microbiome influences medications
Certain strains of E. lenta are capable of metabolizing and inactivating digoxin, which reduces the effectiveness of the medication in the body. This microbial metabolism occurs through the enzyme cardiac glycoside reductase, which converts digoxin into a less active form. And here comes another factor into play, making the whole connection more complex. Colleen Cutcliffe, a molecular biologist, mentioned in Peter Attia's podcast that it makes a difference whether E.lenta has a copy of the gene that codes for the enzyme, or five genes. People who have a E.lenta form with five genes for the inactivation of digoxin seem to respond significantly worse to the medication. If we can learn more about these interactions in the future, it is another step towards personalized medicine.
How can one strengthen the microbiome?
Now that we have learned a lot about testing and the background of the microbiome, we will explore the question of what we can do to build or strengthen the microbiome.
Before we dive deeper into the topic, we need to define a few terms: If you want to know more about the individual topics, you can simply click on the word and you will be taken to a detailed article:
- Probiotics: These are preparations that z.B.Contains live intestinal bacteria. Probiotics are often used to make the intestinal flora more diverse again, or to restore the balance between "good" and "bad" bacteria
- Prebiotics: Prebiotics are substances, mostly indigestible carbohydrates such as inulin, fructooligosaccharides (FOS), and galactooligosaccharides (GOS), which selectively promote the activity or growth of health-promoting microorganisms in the gut. In food, you find them as dietary fibers and they serve as "food" for your gut bacteria
Did you know?
The German Society for Nutrition (DGE) recommends a daily intake of at least 30 grams of dietary fiber for adults. These substances are found exclusively in plant products, z.B.in whole grain products, fruits, and vegetables. A high fiber content in the diet ensures that the bacteria in the gut receive enough nourishment. However, most people eat less than the recommended 30 grams per day.
- Synbiotics: Synbiotics are products or dietary supplements that contain a combination of probiotics and prebiotics . The idea behind this is that the prebiotics serve as a nutrient source for the living microorganisms provided with the probiotics, which can improve their survival, colonization, and effectiveness in the gastrointestinal tract.
- Postbiotics: Postbiotics are bioactive compounds produced by the metabolic activity of probiotic microorganisms in the gut.This includes short-chain fatty acids (such as butyrate, propionate, and acetate), bacteriocins, enzymes, vitamins, and other metabolites. These substances can have positive effects on the host by supporting the gut barrier function, having anti-inflammatory effects, and modulating the immune system.
Through all these means, you can strengthen your gut flora. The simplest way is probably to adjust your diet by increasing fiber intake. If you are currently not consuming many fibers per day, it is best to gradually increase the amount, as otherwise, it may lead to bloating or gastrointestinal issues. You can find more on the topic in our article on building gut flora.
The Butyrate Metabolism – not only important for gut health
The butyrate metabolism refers to the biochemical process in which certain microorganisms in the human gut ferment indigestible carbohydrates (especially fiber) and produce short-chain fatty acids (SCFAs) such as butyrate. Butyrate is of particular interest because it has various positive effects on our health, including promoting gut health, strengthening the gut barrier function, anti-inflammatory effects, and potential protective mechanisms against metabolic diseases such as type 2 diabetes.
Butyrate production in the gut
The butyrate production occurs through the fermentation of dietary fibers by anaerobic bacteria in the colon. These bacteria, which include genera such as Faecalibacterium, Eubacterium, Roseburia, and Butyrivibrio, utilize the fibers as an energy source and produce SCFAs, including butyrate. Butyrate then serves as the main energy source for the intestinal mucosal cells (colonocytes) and supports their health and function. By the way: The intestinal mucosal cells are the only cells in the body that can use butyrate as an energy source.
Did you know?
Perhaps you know the "miracle weight loss drug" Ozempic, also known as the weight loss injection. In fact, it is a medication for diabetes mellitus that mimics a hormone in the body.To be precise, the GLP-1 (glucagon-like peptide-1). You can learn more about it in the article on berberine. But back to the microbiome. The butyrate produced by the bacteria can stimulate the L-cells in the intestine, which in turn produce the hormone GLP-1. Therefore, a diet rich in fiber can indirectly increase GLP-1 secretion by stimulating butyrate production and thus have positive effects on glucose metabolism and appetite regulation.
Bioavailable Berberine with Chromium and Zinc in the Mineral Complex Berbersome
The Role of Bacillus subtilis
Bacillus subtilis, often cited as a probiotic bacterium, plays a somewhat different role in the microbiome than the direct producers of butyrate. B. subtilis is a gram-positive, soil-dwelling bacterium that can also be found in the human gut. It is known for its ability to form robust endospores, allowing it to withstand harsh environmental conditions. Although B. subtilis is not directly involved in the production of butyrate, it can still have indirect effects on butyrate metabolism and overall gut health:
- Promoting a healthy gut flora: B.B. subtilis can support the growth and activity of butyrate-producing bacteria in the gut by promoting microbial diversity and ecological balance.
- Stimulation of the immune system: B. subtilis can modulate the immune response and contribute to the integrity of the gut barrier, which can indirectly improve the environment for butyrate production.
- Competition with pathogenic microorganisms: Through its antimicrobial properties, B. subtilis can inhibit the growth of harmful bacteria, thereby supporting a healthier gut flora that in turn promotes butyrate production.
All these properties have contributed to B.subtilis being named Microbe of the Year in 2023.
The microbiome and its role in longevity
The older we get, the more our microbiome loses diversity. In the worst case, a symbiosis becomes a dysbiosis. The changes in the microbiome can be so severe that they have been recognized as one of the hallmarks of aging . These describe the molecular changes that accompany aging. The hope is that if we manage to reverse these hallmarks, we can also stop aging.
Conclusion
“...an unhealthy gut is the root of all evil...,” Hippocrates already knew. An intact gut is extremely important for our health and a long life. Understanding the molecular composition of the gut flora is a challenge that we must now face. Our microbiome is a highly complex and exciting field of research. Through the newer methods of gene analysis and proteomics, we have come a step closer to better understanding our gut flora. In the future, personalized medicine could also go hand in hand with the microbiome.
