Gut Bacteria Diversity and Longevity

By now, it's common knowledge that our gut bacteria play a big role in the state of our health. Many of us know now that a healthy composition of gut bacteria can improve our digestion, prevent embarrassing symptoms related to poor digestion and even prevent infections such as colds and flu. But did you know that they can also affect aging and longevity?

Research shows that as we get older, both our gut bacteria counts and the number of species declines. This is not just an inconsequential symptom, as a decline in microbiome (the "ecosystem" of bacteria inside our digestive system) quality can raise the risk of digestive, immune and even neurological conditions. You may also not know that there are now many people over the age of 100 (known as "centenarians") who are healthy and vital enough to live independently. Studies on them have shown too that independent centenarians have a higher diversity in their gut microbiomes than centenarians living in aged care homes or other assisted living facilities. Of course, worse off still are those who haven't lived to this age.

Kimchi. Source: Alan Chan (CC 2.0)

So how can we increase the diversity of our microbiome? One way is to become more in touch with nature, as urban environments cut off our exposure to many beneficial, commensal microbes. This may be a reason why "green" and "blue" spaces are linked with improved mental and cardiovascular health, as well as reduced mortality rates. When you are spending time inside, indoor plants can make your environment much healthier.

Traditional fermented foods are another way to improve our intestinal microbiome. In a small trial, prediabetic patients were instructed to consume either 1-day or 10-day fermented kimchi, which is a traditional Korean food. Both types of kimchi significantly reduced the average body weight, waist circumference and BMI. However, the 10-day fermented kimchi also decreased insulin resistance, and of course, increased insulin sensitivity. Only 9.5% of people eating 1-day old kimchi saw improved glucose tolerance, compared to 33.3% in the 10-day fermented group. Blood pressure also dropped significantly in the 10-day group, which has its own benefits. More general dietary advice is to eat a wide variety of foods; as different bacteria have different food sources, this can boost the diversity of your microbiome. However, it is important to avoid the foods you are intolerant or allergic to, and to get tested if you suspect any sensitivity. Gut inflammation can disrupt the microbiome and its communication with the immune system. Overall, you don't have to rely on "luck" or "fate" to live a long, healthy life. The secrets to longevity are hidden in plain sight.