Exercise and dietary fiber shape gut microbiota – Supporting liver and whole-body health
The gut microbiota forms a central part of human metabolism by utilizing indigestible food and producing metabolites that affect the entire body – especially through the gut-liver axis. Imbalances in the gut microbiome are associated with the development of metabolic-dysfunction associated steatotic liver disease (MASLD).
Both prebiotics and physical activity promote microbial diversity and the growth of beneficial strains, and the metabolic products of microbes can mediate the health effects. The dissertation examined how exercise and nutrition change the metabolism of microbes and developed methods for combining microbiota data and metabolomics.
Exercise and prebiotics modify the chemical environment of microbes
A six-week endurance exercise program caused significant changes in both the composition of the gut microbiota and the metabolism of the entire body. In particular, an increase in free phospholipids in the serum and their breakdown products in the gut was observed. This appeared to correlate with the growth of beneficial Akkermansia bacteria. These changes suggest that exercise-induced lipolysis could promote the growth of health-promoting strains.
Adding xylo-oligosaccharide (XOS) fibers to the diet significantly reduced liver fat and inflammation observed in test animals, while the benefits varied among individuals. The intervention particularly reduced the amount of harmful amino acid metabolites in the gut, which was related to the decrease in bacteria strains that break down proteins. Individuals who responded best to the intervention had more of these metabolites and an imbalanced ratio of the bacterial genera Bacteroides and Faecalibacterium before the intervention.
Metabolic syndrome and related fatty liver disease are global health challenges, and there is no single medication for their treatment. The study supports the idea that a combination of diet and exercise can affect liver health through the gut microbiota. The results can be used to develop new nutrition and exercise strategies.
The public examination of Jukka Hintikka's dissertation “Associations of microbial metabolism with metabolic health and physical activity – The gut-liver axis in the focus of metabolomes and microbiomes” will take place on Friday, May 16th at 12:00 in room L304 at the Ģֱ. The opponent will be Professor Matej Orešič (University of Turku) and the custos will be University Lecturer, Docent Satu Pekkala (Ģֱ).
The public examination can also be followed remotely at
The dissertaton is available online at
More information:
Jukka Hintikka, doctoral researcher
Faculty of Sport and Health Sciences, Ģֱ
jukka.e.hintikka@jyu.fi, +358 40 8055162
