How can flavonoids improve gut health?

February 15th, 2023

Flavonoids are important polyphenols that can exert beneficial effects in the body. Due to their antioxidative properties and metabolism, they can improve gut health and change the gut microbiome. In this article, we will describe how flavonoids, and especially hesperidin and naringin, can change the gut microbiome composition, increase gut barrier function, enhance the immune system, and altogether improve gut health.


What are flavonoids?

Flavonoids are a group of phytonutrients (chemicals of plants) that are found in almost all fruits and vegetables. Flavonoids give color to fruits and vegetables, but are also found in cacao, coffee and tea. There are more than 6,000 types of flavonoids.

Since there are many types of flavonoids, they also have a wide range of beneficial effects, such as reducing chronic inflammation, and reducing risks associated with cancer and cardiovascular diseases (1, 2). Thus, implementing different flavonoids in your daily diet could be beneficial your health.

Flavonoids and gut health

Gut health and the gut microbiome have gained a lot of interest in the past years, since the gut microbiome and its metabolites are recognized as important regulators of host health.

The gut barrier is an important barrier because it acts as a physical defence against toxins and microorganisms. This barrier should remain intact to function properly.

Flavonoids may improve intestinal barrier function via inhibition of inflammatory proteins such as nuclear factor-kappa B (NF-κB), and via reduction of oxidative stress.

Flavonoids also contribute to the preservation of the intestinal tight junction barrier and structure, which is important for remaining the physical barrier for pathogens (3).

Flavonoids can stimulate short-chain fatty acids to increase gut health

Additionally, it is found that flavonoids can increase faecal short-chain fatty acids (SCFAs), which may be a result of increased SCFA production in the gut. SCFAs have different beneficial effects on the host and gut health. These benefits include serving as energetic fuel for intestinal epithelial cells, and improving intestinal barrier function (4, 5).

An important SCFA for gut health is butyrate. It can bind to G-protein-coupled receptors. Upon binding, different anti-inflammatory signalling pathways can be promoted in macrophages and dendritic cells, which are important in the immune system of the colon (6).

Thus, flavonoids can increase gut barrier function and SCFA production, and enhance the immune system via butyrate. Therefore, they are beneficial for gut health and it’s also shown in human studies that they can be used for inflammatory bowel diseases! (3)

Two flavonoids for gut health; What are hesperidin and naringin?

Hesperidin and naringin are flavanones, a subclass of flavonoids. These flavanones are mostly present in freshly prepared juices of citrus fruit, such as grapefruit, oranges and lemons. But it’s worth noting that hesperidin can be obtained in higher concentrations than naringin. Both compounds are even more abundant in the peels of these citrus fruits.

After oral consumption, hesperidin and naringin reach the colon almost completely intact, because they are difficult to degrade by the enzymes in the stomach and the small intestine.

This means the gut microbiota can digest them. They do this by releasing α-rhamnosidase, which converts hesperidin and naringin to hesperetin and naringenin. These metabolites are more bioavailable to the body, resulting in higher uptake by the gut into the blood, meaning they can be used by other tissues (7).

Hesperidin and naringin can feed specific bacteria, meaning they can influence the microbiome. It was shown that naringin could reduce microbial dysbiosis caused by a high fat diet in mice. This means that harmful bacteria were reduced and there was an increase in beneficial bacteria (8). The same was shown for hesperidin in rats (9).

Hesperidin and naringin also play a role in immune system regulation. They can inhibit gut inflammation and oxidative stress by increasing antioxidant levels. By bringing gut inflammation down, the gut barrier stays intact as a physical defence against pathogens.

That hesperidin and naringin reduce gut inflammation was not only shown for them individually, but also when they were combined in mice.

Hesperidin and naringin: Hero flavonoids of MicrobiomeX®

Hesperidin and naringin are the focus of many clinical trials done by BioActor, as the product MicrobiomeX® is a natural extract from Citrus sinensis & paradisi, consisting of both flavonoids.

In vitro simulations of the human colon with the TIM-2 system showed that MicrobiomeX® could increase butyrate-producing bacteria Roseburia spp. and acetate-producing bacteria B. eggerthii (9). As mentioned before, butyrate is an important SCFA for gut health.

Besides in vitro studies, clinical trials have also been done on the butyrate-increasing properties of MicrobiomeX®. All clinical trials are available in the MicrobiomeX® White Paper.

It has also been found that by consuming MicrobiomeX® calprotectin levels went down, which could indicate that MicrobiomeX® helps to bring gut inflammation down.

MicrobiomeX® combines the benefits of the flavonoids hesperidin and naringin and is therefore an ideal ingredient for gut health support.