Microbiota Gut test

The amount of bacterial cells in the gut has been estimated at 10¹¹ to 10¹³ per gram which makes the intestinal tract one of the most densely populated microbial habitats on earth. The gut microbiome encodes over 3 million genes producing thousands and thousands of metabolites.

The dominant gut microbial phyla are Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria, Cyanobacteria, Fusobacteria, and Verrucomicrobia, with the two phyla Firmicutes and Bacteroidetes representing 90% of gut microbiota, followed by Actinobacteria and Cyanobacteria. They are represented differently depending on the basis of age and geography.

In particular, Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria, and Cyanobacteria represent the cornerstones of the intestinal ecosystem being involved in the 3 main physiological duties:

1. Trophic
2. Metabolic
3. Immunological

A disbalance, or dysbiosis, of these phyla, can cause gut microbiota physiological variations followed by huge implications in intestinal and extra-intestinal disorders. This dysbiosis is often defined as an alteration of gut microbiota composition and a cause or a consequence of disorders. A chronic change of these fine and interconnected phyla abundances by external stimulation may be stressful and disruptive for this ecosystem.

Firmicutes and Bacteroidetes are the two major and dominant bacterial phyla in human gut microbiota. The Firmicutes to Bacteroidetes ratio (F/B ratio, conventionally around 1) has been extensively examined in the past in human and mouse gut microbiota as a marker of weight gain or loss, but recent discoveries have associated F/B ratio to many metabolic disorders and chronic diseases. This ratio is influenced by diet and age. The Firmicutes/Bacteroidetes ratio undergoes an increase from birth to adulthood and is further altered with advanced age. This ratio appears applicable in highlighting variations between infants, adults, and the elderly. It can be linked to overall changes in bacterial profiles at different stages of life.

F/B ratio can also be used to evaluate the metabolic absorption of the intestine, which can influence the intake of calories or a predisposition to lose or gain more calories, when the ratio is below or above 1, respectively. Of course, these measurements should be done longitudinally, and in particular useful to follow the trend of the gut microbiota during a slimming diet or the use of foods rich in sugar.

Microbial diversity (or Biodiversity) describes the number of different species of microbes present and their distribution in the gut. A reduction in diversity causes a microbial imbalance or dysbiosis. Gut microbial diversity generally decreases when people age, which is likely due to changes in physiology, diet, medication, and lifestyles. Decreased diversity is considered to be an indicator of an unhealthy microbiome, and it has been linked to different chronic conditions. Reduced microbial diversity has been in fact observed in various chronic health conditions, including inflammatory bowel disease and Crohn’s disease, type 1 and 2 diabetes, psoriatic arthritis, cardiovascular disease, obesity, allergies, and many immunological disorders.

The determination of microbial diversity involves sequencing data from 16S rRNA genes amplified from gut microbial samples which, with the use of computational analysis and dedicated software platforms, allows to determine the microbial diversity richness and the distance between bacterial clusters (Alpha or Beta-diversity analysis or other metrics are generally used).

The gut microbiota plays a huge role in maintaining overall health (it is even connected to other organs such as; the brain, skin, oral, vaginal, respiratory tract, etc), particularly as it relates to inflammatory disease. According to the recent literature, the gut microbiome influences the balance of pro-and anti-inflammatory responses in our digestive system and throughout our immune system. In particular, the specific microbial clusters can influence the gut and other organs’ inflammatory responses.

We know now that there is an association between the gut microbiome in the promotion of inflammation. This can be triggered from animal-based food, processed food, grain-based foods, alcohol, and sugar can promote some diseases:

• heart disease
• inflammatory bowel diseases
• systemic lupus erythematosus
• rheumatoid arthritis
• diabetes
• gut, skin, and brain disturbances

That’s why it is important to know the bacteria that are able to protect from or promote inflammation, respectively. Recognize and identify “opportunistic” microbes that, after the intake of certain foods, can be also very relevant to avoid or decrease the inflammation processes.

Examples of bacteria that have links with inflammation are; Clostridium, Prevotella, Alistipes, etc. whose growth is also facilitated in individuals that consume a cluster of meats, french fries, mayonnaise, and soft drinks.

Examples of “friendly” bacteria having anti-inflammatory properties are; Bifidobacterium, Lactobacillus, Akkermansia, etc. Their presence in the gut is related to a qualified Mediterranean diet.

When an imbalance occurs, it may influence a diverse range of inflammatory-mediated conditions.

Many tests actually proposed by labs, pharmacies, etc, may not have a sufficient degree of scientific validity and therefore should be avoided. The only tests with a minimum of reliability are those that genetically analyze the microbiota (genomic map) by using skills, DNA sequencing tools, and bioinformatic interpretation of high proficiency. The interpretation of the Microbiota genetic map needs to be performed by a Clinical Microbiota Expert, which is of fundamental importance.

Prof. Lorenzo Drago, a Microbiota Expert, reports “Metagenomic analysis of microbiota is a big and complex screenshot of thousands of microbial genetic information. Before carrying out a test for the Microbiota, it must be realized that investigating in advance the healthy status of subjects or patients is mandatory. This is where it must start if we want to understand the correlation between the state of the microbiota in those subjects who suffering from any disturbance and the alterations of the intestinal bacterial flora. Many stages of research are at the beginning, but we can do a lot about the possibility of treating or preventing certain diseases through the manipulation of the microbiota. Using the right food, diet, prebiotics, and/or probiotics is not child’s play, but it requires high competence and specialization in the field. We should try do not to give false interpretations and expectations to the patient, but only aim towards presenting correct suggestions based on true scientific concepts and internationally accepted literature.”