Her Research Journey into the ‘Mucobiome’ continues as Sjöberg Jabbar joins WCMTM

In November 2024, Karolina Sjöberg Jabbar joined the Wallenberg Centre for Molecular and Translational Medicine (WCMTM) to continue connecting findings of basic research with benefits to clinic and patients. 

“I am very excited and grateful for this opportunity that will allow me to continue to focus on research together with a very talented team,” Karolina Sjöberg Jabbar says.

At the core of her research lies the gut mucus barrier—a vital shield that trillions of bacteria in our bodies rarely overcome. This barrier mediates interactions between the microbiome and our immunity, as well as between bacterial immunity and their own viruses, known as phages. Karolina calls this dynamic ecosystem within the mucus the ‘mucobiome’.

I want to be there in my research because it’s where so many exciting things happen

What do bacteria do without fibers?

In her current research at the Wallenberg laboratory, Karolina aims to combine insights from her prior studies of mucus and the microbiome, as she focuses on the role of the ‘mucobiome’ in cardiometabolic disease.

“It is common knowledge that fiber intake protects us against cardiovascular diseases,” says Karolina, “although we cannot digest or absorb them.”  Instead, our gut bacteria can produce beneficial compounds from fiber fermentation, but these also mostly act locally in the gut and can barely be detected in blood.

So, Karolina thinks that perhaps the key question is not what bacteria do with the fibers, but what they do without them.

“Other dietary components are absorbed higher up in the intestines. This means that, in a shortage of fiber, the large population of bacteria that live in the final parts of the colon may have to turn to their human hosts for nutrition instead. Mucus and its mucin glycoproteins would be one abundant source.”

Production of harmful metabolites

Karolina thinks that excessive microbial degradation of gut mucosal components, including mucus, could cause production of harmful metabolites and weakening of the gut barrier, promoting systemic inflammation. These effects may then converge on increased risk of cardiometabolic disease. 

Now she is excited to explore how the triangular relationship of human cells, bacteria and phages in the gut mucus niche is associated with fiber intake and cardiometabolic disease.

“Being part of the WCMTM carries major potential for collaboration in the translational research field and exchange of expertise with the other fellows in the program, and I hope my research projects will open many doors for collaboration both locally and nationally.” she concluded.