Researchers at the University of Copenhagen studied the Intestinal Bacteria of 176 healthy Japanese centenarians to determine whether their gut microbiome had any influence on their longevity. “Previous research has shown that the intestinal bacteria of old Japanese citizens produce brand new molecules that make them resistant to pathogenic — that is, disease-promoting — microorganisms,” says Joachim Johansen, a postdoc and first author of the study. What these researchers discovered was that these centenarians had a unique combination of intestinal bacteria and bacterial viruses. In fact, one of the study’s findings was that specific viruses in the intestines can have a beneficial effect on the gut microbiome. “Our intestines contain billions of viruses living of and inside bacteria, and they could not care less about human cells; instead, they infect the bacterial cells,” says Simon Rasmussen, a University of Copenhagen professor and last author of the study. The researchers also found high biological diversity in the gut bacteria of the centenarians, which is usually associated with a healthy gut microbiome. This better protects them against aging-related diseases, Johansen notes. 

The researchers designed an algorithm to map the intestinal bacteria and bacterial viruses of the centenarians. “We want to understand the dynamics of the intestinal flora,” Rasmussen says. “How do the different kinds of bacteria and viruses interact? How can we engineer a microbiome that can help us live healthy, long lives? Are some bacteria better than others?” The researchers hope to use the algorithm to describe the balance between viruses and bacteria and determine what that optimal balance should be to protect the body against disease. The obvious next step, Rasmussen says, is to find out whether only some or all of us have this combination of bacteria and viruses. “Intestinal bacteria are a natural part of the human body and of our natural environment. And the crazy thing is that we can actually change the composition of intestinal bacteria. We cannot change the genes – at least not for a long time to come. If we know why viruses and intestinal bacteria are a good match, it will be a lot easier for us to change something that actually affects our health. 

If you want a gut full of diverse bacteria, a great way to start is by diversifying your diet. A couple of years ago, researchers at Stanford School of Medicine found that a 10-week diet high in fermented foods boosted microbiome diversity and improved immune responses. According to those researchers, their findings are an example of how a simple diet change can remodel the microbiota. Fermented foods are “foods made through desired microbial growth and enzymatic conversions of food components.” Traditional Japanese cuisine focuses heavily on fermented foods like fermented bean paste (natto), tempeh, soy sauce, miso, rice vinegar and pickled vegetables. In fact, some type of fermented food is included at almost every meal. Could this be the link to their longevity? Fermented foods are considered superfoods, so it certainly makes sense.