Our body is home to billions of bacteria that are not without consequence for our health. One of these bacterial colonies in particular seems to play a determining role: the set of micro-organisms present in our colon, called the « microbiome », better known as « gut flora » or « intestinal flora ». This microbiome is composed of both pathogenic bacteria and commensal bacteria — the former can be the origin of various inflammations and diseases, while the latter fulfil functions of protection and regulation.

When there is an imbalance in the flora in favour of pathogenic bacteria, called « dysbiosis », many disorders can appear: inflammatory digestive pathologies, food intolerances, overweight, diabetes, poor mental health and depression, Parkinson’s disease, cardiovascular diseases, cancers, allergies…

All this in part because an imbalanced intestinal microbiome:

• Produces little propionate, an acid that reduces appetite and the risk of glucose intolerance through slowed gastric emptying, and little butyrate, an anti-inflammatory agent.
• Reduces the thickness of the intestinal wall that acts as a protective barrier against unwanted passage into the blood, such as endotoxins or pollutants.
• Degrades amino acids such as tyrosine and tryptophan, thereby causing poor control of our impulses and psychological discomfort.
• Metabolises more calories.

Harmful consequences for our body and our ageing, but also for our intellectual faculties, our mood, and our behaviour.

Several factors influence microbiome diversity

Various factors affect the composition of these colonies of bacteria living in our gut, such as the bacterial environment, diet, additives, medications (particularly antibiotics), pollution, birth method and breastfeeding of the newborn, and stress.

For example, children born by caesarean section or who were not breastfed have a less diverse and less balanced microbiome and are therefore more exposed to allergies, intolerances, metabolic diseases, and overweight. Overweight in an individual can be predicted with 90% accuracy through a study of their microbiome. Studies have also demonstrated close relationships between our gut microbiome and glucose intolerance, leading to diabetes.

The industrial diet that dominates our current societies, consisting mainly of simple sugars, saturated fats, and animal proteins, also generates a poor and unbalanced microbiome. There would notably be an obvious link between industrial diet and a significant increase in autism.

How to take care of your intestinal flora?

Our microbiome feeds on what we give it to eat. Our diet is therefore one of the foundations of our good health. Fruits and vegetables, fibres, zinc, and omega-3s are beneficial for our commensal bacteria, unlike many other elements, such as:

• Meat, saturated fats (butter, cheese, palm or coconut oil, etc.)
• Simple carbohydrates (sweets and other treats)
• Caffeine, excess alcohol
• Choline (egg yolks, meats, fish, seafood, etc.)
• Aggressive spices (black pepper, harissa, etc.)
• Industrial foods, supplements, and medications containing additives and sweeteners…

Probiotic supplementation can be a short-term aid, but a deep transformation of the diet is necessary for lasting results. Durably modifying our diet to primarily eat foods that are beneficial for our microbiome significantly renews it.

Currently, many studies are on the verge of deepening our knowledge of these phenomena, such as those conducted by Dr Patrice Cani, specialist in intestinal microbiome at UCLouvain. It appears, for example, that ingesting the commensal bacterium Akkermansia muciniphila in pasteurised form, as a food supplement, has a positive impact on cardiovascular diseases, cholesterol levels, pre-diabetes risk, and also weight.

References:

• Dr CURTAY, J.-P., « Be the good gardener of your gut flora — it’s vital! », in Les dossiers de Santé & Nutrition, January 2017, no. 64.
• DEPOMMIER, C., EVERARD, A., DRUART, C. et al. « Supplementation with Akkermansia muciniphila in overweight and obese human volunteers: a proof-of-concept exploratory study », in Nat Med 25, 1096–1103 (2019).
• Dr MOSCA, A., « Dysbiosis of the intestinal microbiome: multiple consequences. Pathologies associated with intestinal microbiome imbalances. »

If you want to take care of your microbiome, I offer consultations in Liège and online. ⟶ Further reading: Functional Health and PERMANUTRITION · Satiety: Physiology and Hormones · Night Sweats: Physiological Causes · Boosting Your Immunity · Understanding and Treating Candidiasis