The human microbiome corresponds to all microorganisms that have colonized the human body and inhabit organs such as the skin, mouth, nose, digestive tract or vagina. The intestinal microbiome is the largest microbiome in the human body, both in terms of weight and composition, and refers to the dense population of bacteria in the gastro-intestinal tract and particularly the colon.
What is the intestinal microbiome?
- The intestine contains 100 trillion bacteria! Living in a complex ecosystem, this dense microbial population is called intestinal microbiome or intestinal commensal flora.Its first elements are acquired at birth; it matures during the first three years, and further evolves all along life with lifestyle, food habits and environments in which we live.
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3 to 10times more bacteria than cells in the body1,000+different strains of bacteria1.5 kgof bacteria
As heavy as an organ!
Why is diversity of the intestinal microbiome important?
The key role of a healthy intestinal microbiome is everyday more and more ascertained. It contributes to many aspects of human health via the metabolic activities of the several hundred species of which it is composed. Acting as a barrier against many harmful bacteria, a healthy and diverse microbiome plays a crucial role in prevention of life-threatening infections. It also contributes to the digestion of certain foods, the regulation of host metabolism, and increasingly appears as a precious ally to ensure optimal activity of the immune system.
Antibiotics and other drugs impacting the microbiome
When we take antibiotics orally, part of the dose is not absorbed and reaches the gastro-intestinal tract; similarly, a part of the antibiotic dose taken by injection is recycled through the liver, and excreted into the intestine with the bile. When those antibiotic residues reach the colon, they provoke a serious disruption of the intestinal microbiome: several bacterial populations are decimated whereas others (sometimes pathogenic and resistant to antibiotics) proliferate; this state is called dysbiosis. The intestinal microbiome balance is hence disturbed and may take weeks to months to fully recover, i.e. return to its original equilibrium. Other drugs are also known to disrupt the microbiome such as some anti-cancer chemotherapies.
Similarly to a damaged organ, a disrupted microbiome can no longer fulfil its physiological functions, leading to many adverse consequences including:
- Colonization by pathogenic and resistant bacteria, leading to an increase of severe infections
- Impaired host immune response, leading to a decreased efficacy of cancer treatments
- Altered metabolism with increased risk of inflammation, metabolic syndrome, obesity…
- Emergence and dissemination of antibiotic resistance
Protecting the microbiome
- The medical community has well acknowledged today that preserving the microbiome balance and diversity during antibiotic treatments could prevent serious medical conditions. Maintaining a healthy microbiome is a driver for long-term health, and could also be essential for better survival of cancer patients treated with therapies such as immune checkpoint inhibitors. Maintaining the microbiome equilibrium will also prevent the selection and colonization of multi-resistant bacteria, and therefore limit the emergence and spread of antimicrobial resistance and prevent subsequent life-threatening infections. Da Volterra develops innovative healthcare products with demonstrated benefits in protection of the intestinal microbiome during antibiotic treatments.
