A string of discoveries over the past few years alone have uncovered interesting links between the microbial communities that call the human body home and its overall health. These bunches of bacteria and the metabolites they produce have been linked to obesity-related depression, PTSD and Alzheimer’s, diabetes and autism, and a team of researchers at the University of Melbourne looked to expand on this by investigating their links with the immune system.

More specifically, they sought to learn how the microbiome can drive the development of memory T cells, which are immune cells that have evolved to quickly recognize dangerous pathogens that threaten the body and swiftly spring into action to kill them off.

“We were trying to understand how the microbes that live in and on us influence our ability to form killer memory cells,” associate professor Sammy Bedoui explains to New Atlas. “We addressed this question in preclinical mouse models, where we compared mice that did to those that did not have microbiota. We found that in the absence of microbiota, killer T cells failed to survive as memory cells. The reverse was true in mice with microbiota that we fed a high-fiber diet, akin to eating All-Bran or muesli. Here we found that more production of particular metabolites by the microbiota enhanced the ability of killer cells to survive and form memory cells.”