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Microbiome, overweight and obesity

Overweight and obesity affect 42.5% of the Italian adult population. Excess weight is not the only characteristic of these conditions: both go hand in hand with changes in the population of microbes that live in the gut (the gut microbiota). Not only that, alterations in the intestinal microbiota (the so-called dysbiosis) are also associated with an increased risk of complications typical of obesity, such as diabetes.

The microbiome analysis makes it possible to identify dysbiosis and to implement strategies aimed at correcting those changes that increase the risks to health due to excess weight.

Microbiota and excess weight

The link between intestinal microbiota and obesity depends in part on the role played by the bacterial flora in regulating the energies obtained from food.

In fact, the bacteria that live in the intestine are responsible for the fermentation of food components (dietary fibers) that otherwise would remain undigested. This fermentation increases the energy that is obtained from a meal, increasing it by 2 Kcal for each gram of fiber.

The fermentation of fibers is not a negative phenomenon; on the contrary, a diet rich in fiber promotes the growth of a health-friendly microbiota. However, dysbiosis associated with excess weight can lead obese people to absorb more energy than slender people. Furthermore, the fermentation of fibers leads to the production of short-chain fatty acids, which inhibit the degradation of fats while stimulating their accumulation, that of triglycerides and the production of adipocytes (the cells of adipose tissue).

Microbiota and complications of obesity

Alterations in the gut microbiota also affect the risk of health problems closely associated with obesity.

  • La riduzione dei clostridi e l’aumento dei lattobacilli sono associati alla resistenza all’insulina, anticamera del diabete.
  • The reduction of clostridia and the increase in lactobacilli are associated with insulin resistance, the antechamber of diabetes.
  • The decrease in the richness of the microbiota is associated with both insulin resistance and an alteration in the fat and cholesterol levels in the blood.
  • The communication between the intestine and the brain and the signals directed towards the adipose tissue are also altered by intestinal dysbiosis.
  • The changes in the gut flora typically associated with obesity alter the production of hormones and other molecules by the cells of the gut.

Characteristics of the microbiota associated with obesity

The main intestinal dysbiosis associated with obesity is the increased ratio of Firmicutes to Bacteroidetes. The other variations include:

  • reduction of microbiota diversity
  • increase in microbiota richness
  • increase in Blautia hydrogenotrophica, Coprococcus catus, Eubacterium ventriosum, Ruminococcus bromii, Ruminococcus obeum, Lactobacillus reuteri
  • reduction inBacteroides faecichinchillae, Bacteroides thetaiotaomicron, Blautia wexlerae, Clostridium boltae, Flavonifractor plautii, Methanobrevibacter smithii and several Bifidobacterium, Lactobacillus


The MICROBALANCE test by the Bioscience Institute allows you to carry out a targeted microbiome analysis to identify dysbiosis associated with excess weight and plan corrective interventions based on nutrition and possibly on the intake of food supplements.

To obtain more information and request the kit for the collection, contact us by emailing or fill out the following request form to be contacted without obligation by one of our trusted biologists.

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