Phocaeicola

What does this bacterium look like?

The shape of this bacterium is somewhat between a sphere and a rod, depending on the species. The spheres are usually smaller than 1 micrometer, while rods can be up to 6.5 micrometers long. That is small when you know that 1,000 micrometers fit into one millimeter.

Some species are motile because they have flagella. A flagellum is nothing more than a tail that rotates very quickly to propel the bacterium forward. This is similar to the propeller of a submarine. 😉

The name Phocaeicola literally means “inhabitant of Phocaea”. It was in this place in ancient Greece that Phocaeicola abscessus (the most important species of this genus) was first isolated.

What does science already know about this bacterium?

Not much yet. The genus Phocaeicola was first described in 2009. Several species were originally classified under the genus Bacteroides, but this was revisited by researchers. As a result, the genus Phocaeicola expanded further. Phocaeicola does not tolerate oxygen well and is therefore difficult to grow in the lab. We do know that there are several species in the gut, such as Phocaeicola vulgatus, Phocaeicola dorei and Phocaeicola faecicola.

We also know that the genome of Phocaeicola varies from about 2.5 to 6 million base pairs with more than 2,000 genes. This means that this bacterium can produce more than 2,000 different substances.

What is this bacterium doing in my gut?

Phocaeicola can process undigested food residues and thus produce useful substances such as acetate and propionate. These are short-chain fatty acids with numerous benefits. For example, they can provide energy to your intestinal cells and thus contribute to a stronger intestinal wall (or intestinal lining). As a result, harmful substances are less likely to leak through the intestinal wall.

But that’s not all! Certain gut bacteria can in turn use these beneficial substances and convert them further. Consider Faecalibacterium, for example, which uses acetate to produce butyrate. In this way, gut bacteria work together in a network and help each other.

Butyrate is also a beneficial short-chain fatty acid that provides energy to intestinal cells, resulting in a stronger intestinal wall. Butyrate is also able to reduce inflammation. In this way, intestinal bacteria also strengthen your immune system and maintain peace in your gut.

Did you know that vitamin B2 or riboflavin also plays an important role here? Some Phocaeicola species can produce riboflavin themselves. This vitamin can then be released into the gut environment, where it contributes to the vitamin balance and where it can be shared with other bacteria. Riboflavin plays a central role in our VIAB2L study, allowing us to investigate this further. Interesting! 🙂

Get to know a few more interesting facts from recent research (compiled in this article):

• Different strains within the Phocaeicola dorei species also appear to have different health effects. For example, they are associated with lower cholesterol levels, milder flu symptoms and less inflammation. Important to know: these are correlations that have been found in scientific research, but they are not yet proven effects of adding these bacteria to your diet, for example. Much more research is needed to confirm these correlations and understand exactly how they work.

• Different strains within the Phocaeicola vulgatus species appear to have very different effects on your health. For example, some studies show links to reduced inflammation and arteriosclerosis and regulation of cytokine levels (which are messenger molecules of your immune system). These effects are often linked to the production of butyrate and special sugars on the cell wall of these bacteria.