Qu'est-ce que votre microbiome intestinal ?

Qu'est-ce qu'un microbiome ?

The human microbiome is a collection of microorganisms - such as fungi, bacteria and viruses - which live inside their very own ecosystem in various parts of your body. Each part contains a one-of-a-kind network of microbes, working together for the good of your health. These unique little systems are constantly changing and reacting to what you eat, how you exercise and the medicines you take.

Dr Saurabh Chatterjee, Professor of Environmental and Occupational Health, UC Irvine's Program in Public Health, explains that there are trillions of bacteria, viruses and fungi living inside your gut, colonising different areas.

"They each have assigned behaviours and functions that help keep the body healthy," he says.

The gut microbiome is one of the most talked about microbiomes because of its effect on human health. The microbes in your gut (microbiota) help balance your good and bad bacteria. They break down complex foods such as fibre that your body can't digest by itself, transforming them into short-chain fatty acids (SCFAs) which feed your gut cells. They also make some vitamins - such as vitamin K - and digestive enzymes to help your body function.

Up to 70% of your système immunitaire also lives in your gut. Your gut microbiome plays a major role in immune function, sending messages to your immune cells to ward off harmful organisms (pathogens).

Comment savoir si mon microbiome intestinal est sain ?

Plusieurs facteurs peuvent affecter la santé de votre intestin, y compris le régime alimentaire, la génétique et les antibiotiques. Si les microbes de votre intestin deviennent déséquilibrés, cela peut entraîner des conditions telles que l'obésité, la maladie inflammatoire de l'intestin (MII) et le diabète.

Chatterjee says: "Many diseases such as cancer, IBD, liver disease, and even brain inflammation have been associated with an imbalanced gut microbiome."

Dr David D. Clarke, President, Association for the Treatment of Neuroplastic Symptoms (ATNS), warns that an unhealthy gut microbiome (dysbiosis), can cause digestive issues.

Changes in the gut microbiome have also been associated with weight gain, tiredness, skin conditions, immune dysfunction, food intolerance, and mood disorders.

"These symptoms can be persistent and might fluctuate in intensity," says the board-certified gastroenterologist. "However, in some cases they may be caused by something else, such as past or present life stress."

Antibiotiques

Prendre des antibiotiques peut nuire aux bactéries amicales de votre intestin. Ils peuvent créer un déséquilibre entre les bonnes et les mauvaises bactéries, rendant plus difficile pour votre corps de combattre les infections à long terme.

Dr Pamela Young, Action Rehab, drug detoxification and mental health specialist, explains that antibiotics are sometimes a necessity. However, some aren’t advanced enough to understand the difference between good and bad bacteria.

"Some antibiotics can target the necessary bacteria, but many harm the ones we need to stay healthy," she says.

Chatterjee adds that too many antibiotics can cause your friendly bacteria to build up resistance, meaning they won't work as well. Since you need your good bacteria to stay healthy, you should use antibiotics as they are prescribed and finish the course. You shouldn't overuse antibiotics.

Alcool

Drinking too much alcohol also throws your gut bacteria off balance. It can weaken your gut lining, letting harmful organisms leak out, causing liver inflammation.

Clarke conseille que la consommation excessive d'alcool peut réduire les bactéries amicales telles que Lactobacillus et Bifidobacterium, et augmenter les bactéries nocives comme Proteobacteria.

Stress

Votre intestin communique constamment avec votre cerveau. Il permet au cerveau de contrôler la digestion et la fonction immunitaire dans l'intestin, et aux microbes intestinaux d'influencer le cerveau. Le stress peut perturber cette communication, ce qui peut modifier le mélange de bonnes et mauvaises bactéries dans l'intestin. Cela peut, à son tour, affecter la façon dont le corps réagit au stress.

Clarke says stress can affect the gut ecosystem in two ways. It can increase or decrease the muscle contractions in the gut and lead to changes in the quantity and quality of your nutrition - including alcohol consumption.

"Tous ceux-ci peuvent nuire à l'écosystème intestinal," dit-il.

Studies have shown there's a two-way street between your gut microbiome and mood. The types of bacteria in your gut may influence your susceptibility to dépression and anxiety. Those with a wider variety of gut bacteria are generally happier and less anxious.¹

Dr Raj Dasgupta, Chief Medical Advisor for NCOA explains there is a growing body of research connecting our gut microbiome's state to mental health through what's called the 'gut-brain axis'.

"Imbalances in gut bacteria have been increasingly associated with mental health conditions such as depression and anxiety," he says.

According to Clarke, many chemical messengers that carry signals from nerve to nerve (neurotransmitters) are produced in your gut. This includes serotonin, which plays a key role in mood regulation.

Chatterjee ajoute que des problèmes de santé tels que la démence, l'autisme et des affections telles que Parkinson et Alzheimer ont montré un microbiome intestinal altéré - bien que les études soient en cours.

How you treat your gut microbiome is important for digestion, immunity, and your mood. Having a well-balanced and varied diet - along with a healthy lifestyle - is essential for a happy gut and overall wellbeing.

Here are some important ways to keep your gut microbiome thriving.

Fill your plate with prebiotics

Les aliments d'origine végétale tels que les fruits, les légumes, les légumineuses, les grains entiers et les noix sont riches en fibres spéciales appelées prébiotiques. Les prébiotiques sont des glucides non digestibles qui nourrissent vos bonnes bactéries intestinales. En nourrissant ces bonnes bactéries, vous pouvez maintenir l'équilibre de votre intestin.

Dr Lynn Bry, Directrice, Massachusetts Host-Microbiome Centre, déclare : "Vous avez peut-être entendu parler de manger un arc-en-ciel pour inclure divers fruits et légumes - qui contiennent tous des fibres végétales. Un microbiote sain est un microbiote diversifié et qui a accès à des nutriments variés grâce à ce que nous mangeons. Une partie de la raison d'inclure des fibres dans notre alimentation est qu'elles nourrissent notre microbiote intestinal."

Herbs and spices

Whole herbs such as basil, cilantro and mint - along with spices such as black pepper, cumin and ginger - have been shown to have a prebiotic effect on the gut.²

Power up with probiotics

Fermented foods which contain live bacteria and yeasts. Often found in yoghurt and supplements, these microbes can restore balance by feeding the good bacteria in your gut.

Put aside processed foods

These tend to be low in fibre and filled with unhealthy fats and sugars. This disrupts the balance of good bacteria, which could damage the lining of your gut, causing it to leak. Leaky gut has been linked to inflammation throughout the body, which may contribute to diseases such as diabetes and heart disease.³

Cut back on sugar

Certain foods with too much sugar can fuel the growth of bad bacteria. Chose natural sweeteners and limit your intake of sugary drinks.

Tackle stress and sleep well

Consider relaxation techniques such as yoga, meditation, or deep breathing to manage stress effectively. Getting a good night's sleep can also help balance your gut microbiome.⁴

Drink plenty of fluids and move your body

Make sure you drink 6-8 glasses of water a day. Keeping your body hydrated helps gut digestion run smoothly, meaning your body can absorb nutrients more efficiently.

Regular physical activity is good for your gut. Exercise improves circulation, which supports your digestive system and growth of good bacteria. For best results, get at least 30 minutes of exercise a day, over five days a week.