Skip to main content


Healthy diet for a healthy microbiome

Feed your gut microbiota well

Scientists today agree that diet fundamentally impacts the equilibrium of the gut microbiota, which is in turn involved in general health and wellbeing.

Recent studies have shown that drastic lifestyle changes and modern diets result in a less rich and varied gut microbiota than in the past. Eating habits powerfully affect the gut microbiota, shaping its composition and activity. Short and long-term dietary changes can influence the intestine’s microbial profiles. The gut microbiota is fragile. In some situations, it loses its symbiotic character; this is called dysbiosis.

Diet is a natural and effective way to supply nutrients and energy, thereby helping to preserve one’s “health capital”.

Today, according to scientific consensus, the following dietary components alter the gut microbiota in a beneficial way:

  • fermented foods containing probiotics: “live active cultures”,
  • fibre,
  • prebiotics,
  • resistant starch,
  • fruits and vegetables,
  • breastfeeding.

Fermented foods containing probiotics

Consuming traditionally fermented foods such as sauerkraut, kefir, yogurt, and miso might be associated with several health advantages: reduced risk of type-2 diabetes and cardiovascular diseases, an improvement in the digestibility of foods, and/or reinforced vitamin synthesis or absorption.

Foods containing probiotics can also become a tool to enrich one’s diet with fibre that is beneficial to one’s health.

Fruits and vegetables

For many years, nutrition professionals have been promoting the health benefits of fruits and vegetables. We can now add improved intestinal health to the reasons for encouraging a varied consumption of these products. Fruits and vegetables, rich in polyphenols and fibre, probably contribute to giving the gut microbiota a profile more favourable to health by increasing lactobacilli and bifidobacteria.

Fibre and prebiotics

Some researchers claim that a lack of dietary fibre is the main reason behind changes in the gut microbiome and the increase in the number of chronic diseases.

Sources of fermentable fibre not only serve as a substrate for the growth of microbes but also increase the concentration of the products of bacterial fermentation, which are necessary for both intestinal and general health.

Prebiotics are another group of compounds used as a tool to modify the microbiota, primarily by providing growth substrates for intestinal micro-organisms. Currently, compounds considered to be prebiotics overlap with those in the category of dietary fibre – however, it’s important to note that not all forms of dietary fibre are prebiotics since they don’t all result in specific modifications of the gut microbiota.

Examples of foods rich in fibre:
almond, dry bean, apple, raspberry, kiwi, avocado, peas, broccoli, Brussels sprouts…

Resistant starch

Resistant starch is a form of dietary fibre that resists digestion in the small intestine and reaches the colon, where it is metabolied by the microbiota. At present, no specific recommendations exist for resistant starch, however it seems that 20g/day are necessary to improve intestinal intestinal

Resisting starchsources:
unripe bananas, pasta, legumes and potatoes, whole grain versions of products such as pasta, rice.

Breastfeeding infants

Human breast milk offers numerous benefits for infants beyond its effect on the microbiota. However, one of the main benefits it provides to the microbiota is due to its high content of oligosaccharides, which bifidobacteria feed on. Because of the complexity of human breast milk, its beneficial effects on the intestinal microbiome are not completely understood. Nevertheless, scientists believe that breastfeeding supplies infants with what they need to develop a healthier intestinal microbiome for better health.

Limit your consumption of highly processed foods

Scientists agree in recommending limiting our consumption of processed foods as much as possible.

It seems that the consumption of processed foods, characterized in particular by the presence of additives, has a deleterious impact on our gut microbiota. Indeed, a study examining emulsifiers (carboxymethylcellulose and polysorbate 80) in rodents showed that they had a negative influence on the gut microbiota and on the interaction of the latter with reduced thickness of the intestinal mucous membrane….

Indeed, the work of Benoît Chassaing and Andrew Gewirtz (Nature, 2015) has shown that emulsifiers, added to many processed food products in order to improve their textures and extend their lifespans, can modify the composition and location and composition of the gut microbiota, leading to chronic inflammation causing metabolic syndrome and chronic inflammatory bowel disease.

Chronic inflammatory bowel disease (IBD including Crohn’s disease and hemorrhagic colitis) are severe and disabling diseases affecting millions of people worldwide. Metabolic syndrome refers to all obesity-related problems, and is considered a precursor to severe diseases such as type-2 diabetes, cardiovascular disease and liver disease. The sharp increase in these diseases has occurred despite stable genetics, suggesting a key role played by one of the environmental factors, according to researcher Benoît Chassaing.

The addition of dietary emulsifiers to processed foods has correlated with the evolution of these diseases since the mid-20th century, and it had previously been shown that these additives favoured bacterial translocation of certain bacteria to epithelial cells. The work of Benoît Chassaing and Andrew Gewirtz demonstrates a major impact of these food additives on the functions of the gut microbiota, leading to the development of chronic diseases.

However, this research is currently highlighting that not all microbiota have the same sensitivity to the pro-inflammatory effects of dietary emulsifiers, some microbiota appear to be less impacted by the effects more deleterious than others. Further studies are required to better understand these differences, as well as the underlying mechanisms associated with them. Finally, several trials are underway in humans to determine the impact of these additives on human health.

Other food additives are currently being researched, and it has been observed, for example, that non-calorie artificial sweeteners (saccharin, sucralose and aspartame), administered to rodents, lead to intolerance to glucose when administered to rodents, via a mechanism here also involving the gut microbiota, much higher and were associated with an increased abundance of bacteria belonging to the genus Bacteroides and the order of Clostridiales in the intestine.

Data also accumulate on maltodextrin, polysaccharide used as an additive, with an impact on the microbiota and promotion of intestinal inflammation. Thus, these several particular additive sities characteristic of processed foods seem to harm the good health of our gut microbiota, promoting the development of chronic diseases.

The gut microbiota which is composed of more than 100 trillion microorganisms which, is specific to each individual, and only future research will be able to better define the components of a diet to improve the microbiota and health of everyone.