According to the University of Sydney, a pre-clinical study found that a high-protein diet changes the gut microbiota, an event that causes an immune response. This study contributes to the comprehension of how diet affects the gut and immune system. Intestinal bacteria exposed to high concentrations of luminal succinate suffer cellular stress which activates the production of ROS. This stress helps in vesicle formation and enhances the levels of bacterial extracellular vesicles.
Associate Professor Laurence Macia from the University’s Charles Perkins Centre and Faculty of Medicine and Health said: “Our research is looking at how gut microbiota the billions of bacteria living in our gut influences the immune system. Our long-term aim is to look at how bacteria can be manipulated for the benefit of health and we do know that food is one of the simplest ways to change the bacteria .”
Traditionally, researchers believed that dietary fiber benefits the digestive system of the human body. However, the team from the Charles Perkins Centre utilized computational modeling for the first time in this study published in Nature Communications to explain the impact of 10 diets containing different proportions of protein lipids and carbohydrates on mice. They found that increased protein consumption altered the nature and function of the microbiota.
Mice fed with a high protein diet had increased bacterial extracellular vesicles which contain bacterial information such as DNA and proteins. This activity was seen by the body as a threat and led to the recruitment of immune cells into the gut wall. “We are beginning to understand the relation between diet, gut health and immunity, especially on the protein that influences the gut microbiota,” said Associate Professor Macia.
Although this research is seemingly applicable to humans, the researchers observe that immune system stimulation can be beneficial as well as detrimental. The lead author and post-doctoral researcher Jian Tan said, “There could be enhanced protection against such pathogens as salmonella through increased antibodies in the gut, but an activated immune system would also mean a higher vulnerability to conditions like colitis, which is an inflammatory bowel disease, or autoimmune diseases such as Crohn’s disease.”
The study therefore brings to a realization of the implications of modern diets, with western countries experiencing reduced incidences of gastrointestinal infections but increased prevalence of chronic diseases. This advancement in knowledge would not have been possible other than by the interdisciplinary approach for which the Charles Perkins Centre is well known. The study adopted the principles of the geometric framework for nutrition introduced by Professors Stephen Simpson and David Raubenheimer.
Responding to questions from Professor Simpson, the Academic Director of the Charles Perkins Centre said, “Nutritional geometry can be used to map foods, meals, diets or dietary patterns according to their nutrient profile which helps researchers to notice other patterns in relation between some diets, health and disease.”
According to Associate Professor Macia, this concept can be implemented in immunology by the Charles Perkins Centre and he said, “The future possibilities are thrilling.”
