Updated: Nov 4
The name intestinal “microbiota” signifies in Latin mikrós – “little” and bio – “living”, which represents the total of microorganisms living in the intestine. Intestinal bacteria make up 99% of this microbiota, affecting us – their host - in many ways. The remaining 1% of this small universe consists of archaebacteria, viruses and eukaryotes.
Where are most of our bacteria located?
Among all the microbiota of our body, the gut microbiome is the most diverse in microbes and is the most studied. 90% of our bacteria are located in our intestine, partly due to its favorable pH and its richness in mucus. Then, a fairly large part reigns on our skin, in our mouth and, for women, in the vagina. On the other hand, most of these microorganisms cannot be cultured, since they are anaerobic, and remain unknown to humans.
There are around 1 to 100 trillion bacterial cells of 1000 to 1500 species in the intestine, i.e., 10 times more in number than all human cells; weighing around 1.5 kg when fully developed. This mature microbiota is reached as early as 2-3 years of age, when the first bacteria develop following maternal contact as well as through the baby's environment.
What does it do? Why is it important?
The microbiota is responsible for the metabolism of elements of our diet, like fiber or amino acids; compounds originating within our body, like bile acids or hormones. Microbiome composition has been proven to correlate with numerous diseases, ranging from, Crohn’s disease, diabetes or IBS, to types of cancer, skin diseases and even neurodegenerative diseases like Parkinson’s or Alzheimer's; and neurodevelopmental diseases such as autism.
The relationship between the gut microbiome and the organism hosting it is largely bidirectional. On one hand, numerous studies have shown that this community of microorganisms, notably through the production of short-chain fatty acids (SCFAs), enhances our immune and digestive system functionality, and influences our cognitive abilities through the production of hormones, such as 95% of the body’s serotonin and 50% of its dopamine; and certain peptides. On the other hand, we can promote a healthier physiology of this mysterious “organ” with careful management of our stress levels, physical activity, nutrition and other lifestyle factors.
Why care about having a diverse microbiome?
Oftentimes, a microbiota lacking diversity in terms of microorganisms is linked with dysbiosis, which is a state of microbial disequilibrium. This “invisible inner force” has the potential of becoming a strong biomarker, modulator and even contributor to the reversal of disease.
Sex hormones, age and health span all influence the composition and biodiversity within the gut microbiome. The microbiome also influences sex hormone levels. Future blogs will address these connections in more detail with a specific focus on menopause.
What can I do to optimize my microbiome health and diversity?
Here are a few nutrition and lifestyle recommendations that can help with that. Investing the energy now and making changes will help you prevent potential physical and mental challenges in the future. Those efforts are worth your time!
Consume in moderation: Avoid the excessive consumption of specific food types - especially those that tend to induce inflammations, such as ultra-transformed foods, as this could induce an immoderate development of certain bacterial strains, that could then suppress competitive advantages of more beneficial bacteria. For instance, an excessive consumption of animal products can lead to a decreased microbiota diversity.
Prioritize diet diversity: A diverse diet nourishes a larger selection of bacterial strains, promoting a functional variety.
Eat prebiotics to feed your gut: Fiber-rich foods - containing different types of prebiotics - like vegetables, legumes, fruits, nuts, and whole grains promote the bacterial production of SCFAs, such as butyrate, which benefit the host’s gastro-intestinal health, immunity and cognitive function. Resistant starch, such as that found in potatoes, peas, and bananas (especially unripe ones), is another example of a prebiotic source that nourishes our gut. Prebiotic supplements can also be beneficial, since they tend do contain especially valuable, uncommon types of fiber or nourish specific types of bacteria.
Augment your probiotic intake: Strains like Bifidobacterium and Lactobacillus have been shown to protect the intestinal barrier and promote the secretion of calming messenger substances for the brain. These bacteria can be found in foods or beverages like yogurt, and kefir; and fermented foods like sauerkraut and kimchi, as well as in probiotic supplements.
Avoid ‘destructive’ products: Limit the consumption of alcohol, preservatives, and pesticides, which can “blindly” destroy the gut bacterial community.
Meditation, breathing, and other relaxation methods: Early research suggests these practices may augment the quantity of beneficial bacteria, like Lactobacillus strains, and reduce harmful ones, while minimizing stress levels that could lead to inflammation.
Balanced work-life: Achieving an adequate work-life balance can significantly reduce nervous tension and therefore promote a healthier gut composition.
Exercise consistently: Regular physical activity has been shown to have a positive impact on the gut microbiome and can help alleviate stress, improve sleep quality.