The Key to Longevity Lies in Your Gut
by Ashleigh Feltham,  Accredited Practising Dietitian and Accredited Nutritionist.

Living a longer and healthier life is something that most of us strive to work towards. While there are many products and theories that claim to help you live longer and healthier, there is no one single key.

Factors, such as genetics influence how long you will live, but lifestyle choices play a larger role. Your choices, such as if and how much you exercise, your mental health, social and family connections, sleep, diet and drugs you may take, can all influence your lifespan.

Diet is one component which can influence your longevity and health. Your diet promotes the health of your cells and influences your gut microbiome – the types and amounts of different microbes that live in your gut. These gut microbes play a role in influencing the health and function of almost every part of your body and consequently may impact your lifespan.

The types of gut microbes living in your gut may promote a longer life. One study found that the Firmicutes, Lactobacillus and Bacteroidetes strains were found in greater abundance in those individuals who were living longer.

People with exceptionally low levels of chronic diseases and a longer lifespan have a more diverse variety of microbes. This brings out the importance of not having one or two health promoting microbes in vast numbers, but a variety, which may help protect your body from illness and disease in different ways.

Researchers found that people living into their hundreds had a greater number of microbes known to support metabolic health and immunity. These included the strains Proteobacteria, Actinobacteria, Verrucomicrobia, Akkermansia, Christensenellaceae and Lactobacillus.

Key dietary habits of these individuals were including three varied meals each day. This is a key factor to help you to meet 30 different plant foods a week to promote an optimal amount and variety of prebiotic fuel sources. This allows the health promoting microbes in your gut to exist and stay alive.

The major fuel sources of the health promoting microbes comes from plant-based foods; wholegrains, nuts, seeds, legumes, beans, fruit and vegetables.

When the health promoting microbes eat the prebiotic fuel, they create short chain fatty acids. These short chain fatty acids play many key roles in promoting longevity and good health. This includes reducing inflammation and carcinogenesis.

Gut microbes also help to regulate bile acid. Bile acid allows your body to digest fat. In excess, bile acid can cause DNA damage, mutation and oxidative stress. Hence, it is essential that bile acid is regulated.

Your health-promoting microbes also support a healthy gut lining. If it is not healthy, it can cause leakage of proinflammatory molecules outside the gut and cause damage to other parts of your body in many ways, including promoting chronic inflammation.

Seventy percent of your immune system lies in your gut. A suboptimal immune system impairs the removal of senescent cells; cells that stop multiplying, but do not die off as they should. Instead, these cells continue to release chemicals that induce inflammation. These senescent cells can also damage healthy cells in your body.

The number of senescent cells you have increases with age. An increase in senescent cells reduces your body’s ability to stay well and recover from stress or illness. It is evident that your gut microbiome plays many roles that directly or indirectly impact your health and longevity.

Take home message:

While there is no “one single elixir” for a long and healthy life, your gut microbiome may play a key role in promoting your longest and healthiest life. A lifestyle of healthy choices nurtures a healthy gut microbiome. Recognise the importance of your lifestyle choices as a whole rather than any one single factor.

References:

1. Boyajian JL, Ghebretatios M, Schaly S, Islam P, Prakash S. Microbiome and Human Aging: Probiotic and Prebiotic Potentials in Longevity, Skin Health and Cellular Senescence. Nutrients. 2021; 13(12):4550.
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3. Kong, F.; Hua, Y.; Zeng, B.; Ning, R.; Li, Y.; Zhao, J. Gut microbiota signatures of longevity. Curr. Biol. 2016, 26, R832–R833.
4. Krautkramer, K.A.; Fan, J.; Bäckhed, F. Gut microbial metabolites as multi-kingdom intermediates. Nat. Rev. Microbiol. 2021, 19, 77–94.
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6. Does cellular senescence hold secrets for healthier aging? National Institute on Aging. July 13,2021.