Intestinal protection starts immediately after birth
The first weeks of life are crucial for the intestine to build up a working defense against bacteria. Researchers at the University of Gothenburg have shown that both the mucus barrier and certain protective cells in the intestine mature quickly—and that this process is driven by the bacteria that colonize the gut early on.
The results are published in Journal of Experimental Medicine and are based on studies in mice.
Right after birth, the intestine begins to fill with bacteria from the surrounding environment. At the same time, the body needs to rapidly build up protection against these microbes.
"We show that a functional mucus barrier develops just a few days after birth, but only if the gut is colonized by microbes," says George Birchenough, Associate Professor at Sahlgrenska Academy, University of Gothenburg, and one of the researchers behind the study.
Mucus cells that detect bacteria
Once the mucus barrier is in place, a special type of mucus-producing goblet cell begins to develop. These “sentinel goblet cells” work like sensors, able to detect bacteria trying to pass through the barrier. When that happens, they respond immediately by releasing extra mucus to stop the bacteria from reaching the intestinal wall.
The researchers also discovered that an enzyme called Duox2 plays an important role in activating this defense. The enzyme is influenced by the bacteria in the gut and is essential for the protective cells to work properly.
Early life inside the gut
Although the study was done in mice, the findings may also be relevant for humans.
"Even though this research was done in animals, we believe that similar processes happen in humans. This may help explain why children who are born prematurely or receive antibiotics early in life face a higher risk of intestinal diseases later on," says George Birchenough.
The next step for the researchers is to explore whether it’s possible to support the development of gut protection in newborns who don’t have a fully functioning microbiota.
"We want to find out if we can help build up the mucus barrier in children where it doesn’t develop properly," says George Birchenough.
The study highlights how important early contact with bacteria is for the immune system to develop as it should—and the active role the intestine’s cells play in that protection.
Article: Neonatal microbiota colonization primes maturation of goblet cell–mediated protection in the pre-weaning colon; https://doi.org/10.1084/jem.20241591
