Did you know that a considerable portion of human breast milk is indigestible by the nursing infant? Does that issue have a purpose? Yes. It is a system that has evolved over millennia to actually help the baby. Specialized sugars in mother’s milk cannot be digested in the small intestine or stomach. Rather than feeding the infant, they provide food for bacteria living inside the baby’s large intestine.
The gut microbes are crucial for the baby’s long-term health. There is a sophisticated system for delivering and maintaining them. This includes inoculation by healthy bacteria in the birth canal, microbes in breast milk, and bacteria transferred from the mother’s skin around the nipple to the infant.
What’s more, research suggests that microbes from the mouth of the nursing baby convey information to the mom about the baby’s health needs.
These are several amazing functions of our microbiome, which is composed of bacteria, viruses, and yeasts that live in and on us. Some experts estimate that humans have outsourced up to 90 percent of their day-to-day metabolic functions to the microbiome.
We have co-evolved with microbes, and they are found everywhere in our environment. Researchers are gaining new insights into how crucial they are for the health and balance of all ecosystems and their inhabitants.
The human microbiome is considered so crucial to human health that the National Institute of Health launched the Human Microbiome Project in 2007 with the explicit goal of analyzing the genomes of all the microbes that live in the human body. By 2020, over 200,000 genomes from the human gut microbiome alone have been cataloged and published, along with 170 million protein sequences from 4,600 bacterial species.
However, over 70% of the bacterial species have not been cultured in a lab. Scientists are still investigating what their activities are, a fact that shows just how rich and diverse the human microbiome is. In addition, recent studies reveal that the human microbiome is susceptible to environmental effects and can change quickly as a result of outside influence.
The soil microbiome is considered to be richer and more diverse than the human microbiome. It promotes soil fertility and plant health. Proponents of regenerative agriculture count on a healthy soil microbiome to accomplish a significant amount of carbon sequestration, which is removing excess carbon from the atmosphere to mitigate the impact of climate change.
The risks of genetically engineered microbes
Previously, we altered the genome of living organisms such as crops and livestock through natural breeding methods. The changes were limited by combinations and mutations that occur naturally through reproduction. With today’s genetic engineering technology, scientists can now create or insert entirely new DNA sequences, in order to produce desired traits for the genetically modified organism.
Since its inception, however, the technology sometimes caused unintended consequences, collateral damage to the genome and organism. Recent research shows that even the recently developed gene-editing methods can produce random genetic changes in a relatively uncontrollable manner.
Genetically modified microbes can have unintended mutations, deletions, and additions that could impart unintended new traits. In addition, these unintended genetic elements can interact with the rest of the genome in unpredictable ways or make the genetically modified microbes more susceptible to further mutation. These genetically modified microbes can also interact with other microbes in the environment – in the microbiome – and transfer some of these novel genetic elements to them, potentially causing new complications.
In addition, microbes know no boundaries. They cross national and international borders with ease. They can travel on people who are traveling or moving goods. In our modern society with air, sea, and land travel, a microbe will eventually spread worldwide.
Typically, this isn’t a problem. Most microbes are harmless to humans. If a genetically modified microbe is released in the U.S., it will spread globally. Even if that microbe were beneficial or benign to our environment, it may enter new ecosystems with disastrous consequences. That new environment includes the human body.
Many beneficial microbes are vital to our continued existence. However, we are still learning about them and their role in our sophisticated ecosystem. Millions of species exist symbiotically with humans – either in our bodies or in the soil. Still, scientists cannot define what a healthy microbiome looks like. They do know that the slightest disruptions can produce significant negative consequences like disease or ecosystem collapse.
Genetic modification of microbes often results in random unwanted genetic alterations with unpredictable consequences, especially when interacting with other microbes. Therefore, when we consider releasing genetically modified microbes into the environment, we should consider this: how equipped are we to accurately evaluate the risks and the potential consequences? Today’s health and environmental risk analyses do not even account for the microbiome’s pivotal role, its complex relationships, or the tendency for microbes to travel and swap genetic material across species.
It’s possible that scientists in the future may have adequate knowledge about the microbiome to accurately predict the impact of new genetic combinations. We will know with confidence that a genetically modified microbe designed to remediate soil in midwest farmland won’t interfere with the health of an infant’s microbiome on the other side of the planet.
Since microbes travel the world, laws governing releases may need to be global. However, we can start here and lead the way. We don’t want an altered microbe to ultimately alter mother’s milk.