A study published in the journal Nature on July 29 found that centenarians in Japan who lived more than a century ago harbor distinct groups of bacteria in their guts, which generate unique compounds that may prevent infection and other harmful environmental influences.

Genes are not the determining factor

Centenarians are generally considered to be less susceptible to chronic diseases, and they have been able, in one way or another, to overcome infectious diseases.

In their new study, researchers from Japanese and American universities attribute the reason for this unique ability to the gut microbiome, which is made up of billions of microorganisms that live in the digestive system.

Genes may be responsible for up to 30% of longevity (Getty Images)

The study was conducted on 160 centenarians from across Japan with an average age of 107 years, and compared the bacterial communities found in stool samples - collected over two years - with the gut microbiomes of 112 elderly people in their late 80s, as well as with samples taken From people younger than 47 years old.

Some may think that the secrets of long life are written in our genes, but scientific research has reported that genes may be responsible for longevity by no more than 30%, which leaves the door wide open for many other factors that change over time, including diet and bacteria. The intestines are also among many other factors.

Unique intestinal bacterial strains

As the report published on the Science Alert website notes, some centenarians showed typical signs of low-level inflammation, most of whom did not suffer from chronic diseases such as obesity, diabetes, high blood pressure and cancer.

The researchers found that centenarians have a unique mixture of bile acids, because they have a unique type of bacterial strains capable of synthesizing them.

But the study didn't take into account other lifestyle factors, such as diet, so we can't say exactly what contributed to these centenarians' unique microbiome profile.

Isoalu-lithocholic acid is able to inhibit the growth of the intestinal bacteria Clostridium difficile (Getty Images)

A comparative study has shown that the intestines of centenarians contain strains of bacteria called Odoribacteraceae that are responsible for the production of a bile acid called Isoallo-lithocholic acid.

The researchers found that this iso-lithocholic bile acid was able to inhibit the growth of in vitro cultured Clostridium difficile, a common intestinal bacterium that causes severe diarrhea and dangerous colitis.

When C. difficile-infected mice were injected with a dose of C. difficile-producing bacteria strains in centenarians, the researchers found that this treatment reduced the amount of C. difficile shed in the mice's droppings from levels before the treatment was applied.

Thus, the researchers concluded that this type of bacterial strain is able to resist infectious pathogens and maintain the health of the gut in old age.

Changes in diet can quickly change the composition of the gut microbiome within days (Getty Images)

future studies

The importance of studying the gut microbiome is that by figuring out what it looks like in a healthy person, scientists may be able to find ways to alter or correct bacterial communities to prevent disease and improve health in others.

Previous studies have shown that changes in diet can rapidly alter the composition of the gut microbiome within days, by favoring certain species.

Thus, more intensive studies are necessary about the effectiveness of intestinal microbiota treatment, and what bacterial species are appropriate as a type of treatment for modern diseases, in addition to how to produce them and maintain their activity within the intestine.