This special gut bacteria may be the secret to longevity?

World's oldest person, Japanese Tanaka Kane, dies at 119

Tanaka was born on January 2, 1903, and died on April 19, according to CNN.

According to the Guinness World Records, Tanaka became the world's oldest person at 116 years and 28 days old on January 30, 2019. She held the title for three years until her death last week.

01 Reasons for longevity

In recent months, Tanaka's family reported that she was frequently ill and in and out of the hospital, according to CNN.

116-year-old Kane Tanaka is recognized by the Guinness World Records as the world's oldest person. (Image source: Guinness World Records)

According to CNN, Tanaka was a two-time cancer survivor who worked at her family's store until she was 103. She married at 19 and had five children -- four biological and one adopted, according to the Guinness Book of World Records.

According to the National Institutes of Health (NIH), a person's lifespan is thought to be influenced by genetics, environment, and lifestyle. Scientists have been studying centenarians (people who live to age 100) and "supercentenarians" (people who live to age 110 and beyond) to better understand the factors that contribute to longevity.

According to the National Institutes of Health, some scientists speculate that lifestyle factors, including diet and exercise, play a major role in the first 80 years of life, after which genetic factors become increasingly important in keeping a person healthy as they age. Tanaka reportedly enjoys eating chocolate and drinking soda, NPR reported.

Genetic variants associated with longer lifespan include variations in the ABO, CDKN2B, APOE and SH2B3 genes, which have been found to be more common in centenarians than in people of average lifespan, Live Science previously reported.

After Tanaka's death, Guinness World Records confirmed that the world's oldest person is now Lucile Randon, also known as Sister André, of France, who is 118 years and 73 days old. She is also the oldest person to have survived COVID-19, Live Science previously reported.

02 Can intestinal bacteria fight infection?

People who live to 100 years old and beyond may have special gut bacteria that help ward off infection, according to new research from Japan.

The results suggest that these bacteria, and specific compounds they produce — called “secondary bile acids” — may contribute to a healthy gut and, in turn, healthy aging.

Still, more research is needed to understand whether these bacteria can extend lifespan. The current findings, published Thursday (July 29) in the journal Nature, only show an association between these gut bacteria and living past 100; they do not prove that these bacteria cause people to live longer, said senior author Ken Honda, PhD, a professor in the Department of Microbiology and Immunology at Keio University School of Medicine in Tokyo.

(Image source: Shutterstock)

It’s well known that the community of bacteria and other microorganisms that live in our intestines, called the gut microbiome, play a role in our health and change as we age. For example, less diversity in the types of gut bacteria has been linked to frailty in older adults. But researchers suspect that people who turn 100 may have special gut bacteria that contribute to good health. In fact, centenarians tend to have a lower risk of chronic disease and infection than those who haven’t reached that milestone.

In the new study, researchers examined the gut microbiota of 160 centenarians with an average age of 107. They compared the centenarians' gut microbiota with that of 112 people aged 85 to 89 and 47 people aged 21 to 55.

They found that the centenarians' gut microbes had distinct "signatures" that were not present in the other two age groups. For example, certain species of bacteria were either enriched or reduced in the centenarians compared with the other two groups.

The researchers then analyzed the gut metabolites (products of metabolism) of all three groups and found that the centenarians had significantly higher levels of so-called secondary bile acids compared to the other two groups.

Bile is a yellow-green fluid produced by the liver and stored in the gallbladder, according to the National Institutes of Health. Bile acids are compounds in bile that aid in digestion, especially of fats. After the liver produces bile acids, they are released into the intestines, where bacteria chemically modify them into secondary bile acids, according to a 2009 paper published in the journal Diabetes Care.

The researchers found particularly high levels of a secondary bile acid called isoallolithocholic acid (isoalloLCA) in centenarians. The authors did not know the metabolic process that bacteria used to produce isoalloLCA, so they set out to identify the pathway. They screened strains of gut bacteria from a 110-year-old with particularly high levels of secondary bile acids and found that bacteria belonging to a family called Odoribacteraceae produced isoalloLCA.

What’s more, isoalloLCA was found to have potent antimicrobial properties, meaning it can inhibit the growth of “bad” bacteria in the gut. In experiments in lab dishes and mice, the authors found that isoalloLCA slowed the growth of Clostridium difficile, a bacterium that causes severe diarrhea and colon inflammation. IsoalloLCA also inhibited the growth of vancomycin-resistant Enterococci, an antibiotic-resistant bacteria known to cause infections in hospital settings.

The findings suggest that isoalloLCA may promote gut health by preventing the growth of harmful bacteria.

They also suggest that these bacteria or their bile acids could treat or prevent C. difficile infections in humans, Honda said, although more research is needed to prove that.

If these bile acid-producing bacteria do contribute to gut health, they could one day be used as probiotics to improve human health, Honda said, noting that the bacteria appear safe because they do not produce toxins or contain antibiotic resistance genes.

It's unclear how centenarians acquire these beneficial bacteria, but both genetics and diet likely play a role in shaping the composition of people's gut microbiota, Honda said.

The study did not collect information on participants' diets, exercise habits or medication use, all of which could affect the gut microbiome and help explain the link, the authors said.

Future studies that track large numbers of people over time may further explore the link between these bacteria and longevity.

Source: Chongqing Tianji Network Co., Ltd.

Source: Live Science "World's oldest person dies in Japan at age 119" "People who live to 100 have unique gut bacteria signatures"

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