What does this bacterium look like?
Blautia is a coccobacillus: its shape is something between a sphere and a rod. This bacterium is usually about 1 to 3 micrometers in size. That is small when you know that 1,000 micrometers fit into one millimeter. The name of this bacterium honors Michael Blaut, a German microbiologist who studies gut bacteria.
What does science already know about this bacterium?
Not much yet. This bacterium was first described in 2008 as a new genus when it was separated from other cocobacillus-shaped gut bacteria, namely Clostridium and Ruminococcoides. Blautia does not tolerate oxygen well and is therefore difficult to grow in the lab. We do know that there are different species in the gut, such as Blautia faecis, Blautia intestinihominis and Blautia intestinalis.
The amount and composition of Blautia in the gut varies from person to person. So it is quite possible that you have more or less Blautia in your gut than your mum, neighbor, good friend, and so on. What else? Different species and strains might be there. There can be various reasons for this variation, such as different dietary habits.
We also know that the average genome size of Blautia varies between 3 and 6 million base pairs with more than 3,000 genes. This means that this bacterium can produce more than 3,000 different substances.
What is this bacterium doing in my gut?
Blautia can process undigested food residues and subsequently produce useful substances such as acetate. This is a short-chain fatty acid with various benefits. For example, acetate can provide energy to your intestinal cells and thus contribute to a healthy, strong 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 acetate and convert it into butyrate (another short-chain fatty acid). Think of Faecalibacterium, for example. 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 inhibit inflammation. This way, gut 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? Blautia can produce riboflavin itself and uses it as a building block for enzymes (proteins with a specific function) that help break down complex carbohydrates. What else? Riboflavin is released into the intestinal environment, where it can be shared with other bacteria and your own body. This vitamin is even involved in activating a certain type of immune cells (also known as MAIT cells) that train your immune system. And that’s a good thing, because it teaches your body how to distinguish between “friend” and “foe”. This means that only the real enemies are tackled and the beneficial bacteria are left alone. In this way, Blautia helps to maintain peace in your gut. In our VIAB2L study, the Isala daughter study with a central role for vitamin B2, we want to investigate whether we can further enhance these beneficial effects, and we are doing this by supplementing riboflavin itself or lactobacilli that produce riboflavin to healthy women!
But there’s more! Blautia is not only interesting for fundamental research, this bacterium is also coming onto the radar as a “next-generation probiotic” or “Live Biotherapeutic Product” (LBP). What are probiotics again? Probiotics are live microorganisms that confer a health benefit on the host when administered in adequate amounts. Recent research, for example, shows a negative correlation between Blautia and food addiction, suggesting a possible role for this bacterium in the gut-brain axis and the regulation of the food reward system. But this is only a correlation! It has certainly not yet been proven that consuming more Blautia or eating foods that promote Blautia will reduce cravings. But it is certainly an intriguing link that warrants further study. 🙂
Does this bacterium occur elsewhere?
Blautia feels most at home in your gut. When this bacterium moves outside its familiar environment, it cannot survive very well because it is very sensitive to oxygen. Researchers have also found this bacterium in other mammals, where it also prefers to reside in the intestines.