The Skin Microbiome is more Predictive of Age than the Gut Microbiome

The Skin Microbiome is more Predictive of Age than the Gut Microbiome

We all know that the first signs of aging can be visible in our skin. The appearance of fine lines in the face or dark spots on the hands is never welcome. However, our skin microbiome may be the key to future anti-aging discoveries.

Microbes, Biome, Microbiome, and Microbiota

You are not the only one who may get a bit dizzy when it comes to all these terms. We have heard them many times — it seems like they are everywhere — yet still, they can get a bit confusing. Let’s start from the beginning. 

Microbes are microorganisms, tiny living things. The human eye can not see them, but they are all around us. They are in the soil, the water, and even in the air we breathe. Trillions of microbes or microorganisms live within us. Bacteria, viruses, and fungi are the most common type of microbes. While some microbes can harm the body, others are crucial for human wellbeing. (1)

A biome is an ecosystem made up of flora and fauna. Biomes exist even within the ocean and soil. They are also present in the animal and plant kingdoms. Microbiome refers to the group of microorganisms that can not be seen by the naked eye. 

While microbiome and microbiota are terms often used as synonyms, there are significant differences between one and the other. They can better be described as one containing the other. Neuroscientist and researcher Miguel Toribio-Mateas explains “Although they’re often used interchangeably, microbiota is the actual bugs and microbiome is the bugs AND their genes.” (2)

Importance of Human Microbiome

In recent years scientists have focused their efforts on more in-depth studies about the human microbiome. Although the words virus, bacteria, or microbe may have bad connotations in our minds, they have proved beneficial. Like in the case of gut microbes, they help us to break-down the fibers we eat. Since the body does not produce enough enzymes for this laborious task, the gut microbiome helps the body to turn carbohydrates into beneficial vitamins, for example. 

Studying the microbiome in the human body grew to the point of the launching of The Human Microbiome Project by the National Institutes of Health (NIH) in 2007. This project was solely dedicated to the study of the human microbiome in different parts of the body such as skin, nose, digestive tract, mouth, and vagina. (3)

On June 13, 2012, researchers from 80 universities and scientific institutions published their findings over five years of studying the human microbiome. Among other things, scientists found out that the microbiome contributes with more genes for human survival than the human genome itself, a difference of 8 million to 22,000.

Moreover, the deficiency in the gut microbiome has been connected to illnesses like diabetes, obesity, autism, and anxiety. Also, recent studies had found a component on the skin microbiome that may help to protect against skin cancer. (4)

Skin Microbiome 

A diverse ecosystem of viruses, fungi, arthropods, and bacteria flourishes in the skin. This ecosystem is as unique as we are; like a fingerprint, no two are alike. Though, we do share some common traces. Other elements like genetics, what we eat, where we live, and even if we have pets, determines our own personal skin microbiome makeup. Furthermore, the skin microbiome differs all over the body. From the face, legs, or underarms, the microorganisms living there are not the same. 

The skin microbiome comes to life right after birth. Studies have shown that when babies are delivered naturally, their skin microbiome is the same as their mother vaginal’s microbiome. While when a cesarean section is used, babies’ skin microbiome is similar to their mother skin microbiome. (5)

The skin microbiome is the first layer of defense in the skin, contributing to the skin barrier. It helps to balance the pH as well as protecting the skin from harmful organisms. Recent studies had shown that imbalances in the skin microbiome possibly play the main factor in pathological and non-pathological skin conditions such as dandruff, acne, eczema, sensitive skin, dry skin, or irritated skin. (6)

Skin Microbiome Predicts Human Age 

Microbiomes all over the body evolved quite rapidly in the first three years of our lives and then not so much in adulthood. Studies have shed some light on how our gut microbiomes change as we age. Researchers have observed how some essential bacteria species disappear as we get older. These facts gave scientists the idea that by studying closely the human microbiome, they may develop more efficient anti-aging therapeutics.

For this purpose, a research team was assembled to find out if the human microbiome can accurately predict the age of its host. The team was led by Rob Knight and Zhenjiang Zech Xu at the University of California San Diego. They gathered data from subjects between 18 to 90 years old in the United States, United Kingdom, Tanzania, and China. Using machine learning software, they analyzed the microbiome from the gut, oral, and skin (hand and forehead). 

The research team learned that the skin microbiome was a better predictor of the age of the participants by 3.8 years. This compared to 4.5 years for the oral microbiome and 11.5 for the gut microbiome. 

These promising results by testing the accuracy of the skin microbiome predicting age in subjects have encouraged the scientific community for future investigations. They hope that one day a noninvasive microbiome-test can be used to check how the elderly are aging. Then they may be able to modify the aging process. (7)

The complexity of the human microbiome is an extensive subject of study. Sure, time and research may tell us more about it in the upcoming years. However, the studies done so far had shown the possible relation between the presence or absence of some human microbes and diseases. Microbiomes may be determinant to illnesses like irritable bowel syndrome, obesity, type II diabetes, and even certain types of cancers. (2)

Since the beginning of our existence, humans had lived together with microbes outside and inside their bodies. Thanks to research, we are getting a better understanding of the role of microbiomes in different areas of our lives. Let’s together (humans and microbes ) look forward to what is to come.  

Sources

1. What Are Microbes? Institute for Quality and Efficiency in Health Care (IQWiG); 2019.

2. Edermaniger, L. (2020, January 14). Microbiome vs Microbiota: What’s the difference for your gut bacteria? Retrieved November 19, 2020, from 

3. Human Microbiome Project. Nih.gov. Accessed November 19, 2020. 

4. Yu Y, Champer J, Beynet D, Kim J, Friedman AJ. The role of the cutaneous microbiome in skin cancer: lessons learned from the gut. J Drugs Dermatol. 2015;14(5):461-465.

5. Grice EA. The skin microbiome: potential for novel diagnostic and therapeutic approaches to cutaneous disease. Semin Cutan Med Surg. 2014;33(2):98-103.

6. Sfriso R, Egert M, Gempeler M, Voegeli R, Campiche R. Revealing the secret life of skin – with the microbiome you never walk alone. Int J Cosmet Sci. 2020;42(2):116-126.

7. Huang S, Haiminen N, Carrieri A-P, et al. Human skin, oral, and gut microbiomes predict chronological age. mSystems. 2020;5(1). doi:10.1128/mSystems.00630-198. Frontiers media – media bias/fact check. Mediabiasfactcheck.com. Published March 16, 2018. Accessed November 19, 2020.