The colonies of microbes living on and in our bodies make up what is called our microbiome. The bacteria outnumber our own body cells by a ratio of ten to one. Your body is host to 100 trillion bacteria of at least 10,000 different species. Before you start to worry about that, most of the bacteria will not hurt you. More than that, you couldn’t live without a healthy microbiome.
Some bacteria are essential to make our immune system work to prevent infection. Others make it possible for us to digest the food we eat. Bacteria are on our skin, in our lungs, in our mouths, especially in our gut. Your digestive system needs a good balance of bacteria for proper digestion. Some medical experts think that an imbalance of gut flora (bacteria) leads to irritable bowel syndrome and Crohn’s disease.
There has been a boom in sales of probiotics in pills, liquids, and yogurts in recent years. These contain bacteria that may help your digestive system, but the amounts and types of bacteria may not necessarily be the ones needed for your system. Everyone has a somewhat different microbiome, and, as we recently posted, it all starts in our mother’s womb. Breastfeeding further adds beneficial bacteria to the baby’s flora.
When we take antibiotics, we can kill some beneficial bacteria resulting in digestive and other health problems. Science is trying to determine what is required for a healthy microbiome so that doctors can treat various issues that many times come from our poor choices regarding our health and diet. God designed a system that works, and we are just beginning to recognize that and learn how to take care of it.
The ancient Israelites’ diet consisted of very little meat, and most of that came from animals they raised. That was not true in the rest of the world. For many people in China and Africa, survival meant hunting animals and using them for food. We now know that many of the animals people ate were intermediate hosts for viruses. A virus can exist for many generations in a wild animal and mutate until it can jump to human populations, creating zoonotic diseases. The list of viral and bacterial diseases that have originated in wildlife grows constantly. A partial list includes SARS, MERS, Ebola, AIDS, Zika, Lyme Disease, rabies, swine flu, and COVID-19.
Wet markets, common in parts of Asia and Africa, are a significant source of zoonotic diseases. There animals, including rats, snakes, birds, bats, and monkeys, are kept in cages and killed when people purchase them for food. The filthy environment allows saliva, urine, and feces to become mixed with the blood of animals slaughtered on the spot. Experts say 376 wildlife species are known hosts to zoonotic pathogens, and at least 700,000 different viruses have the potential to jump to human populations. Christian Walzer, executive director of health for the Wildlife Conservation Society, calls wet markets “cauldrons of contagion.”
In Old Testament times, the Jews had very strict rules about what meat they could eat and how to prepare it. One of the priest’s jobs was to inspect the meat that people consumed to make sure it conformed to specific rules preventing zoonotic diseases. That was the world in which Christianity began, and early Christians benefitted from the rules they inherited. The instruction of the apostles was not to eat blood or animals that had been strangled. (See Acts 15:20,29 and Acts 21:25.)
In Acts 10:11-16, we read the account of God telling Peter, “What God has cleansed you should not call common.” The message was that all people are precious to God, but it also implied that there was no longer religious significance to eating the meat of various animals. The dietary laws that God gave Israel centuries before were “nailed to the cross” of Christ (Colossians 2:13-17). However, what is religiously acceptable is not always biologically advisable.
It seems that the battle of the 21st century may be zoonotic diseases caused by eating animals that carry viruses to which humans are not immune. There were good hygienic reasons for the instructions God gave to ancient Israel.
Bacteria are single-cell microorganisms that we do not think of as having social behavior. However, scientists are studying Myxococcus xanthus bacteria working together. They are rod-shaped bacteria that live in the soil and organize into structures of thousands of cells to hunt food or to survive when food is not available.
Myxococcus xanthus bacteria are predators that eat other microbes. When they organize into 3-D structures, they can be visible to the naked eye. In this complex form, they swarm toward their prey in a single mass of bacteria working together in “ripples.” You can see them on the left side of the picture.
To capture their food, the swarms of Myxococcus xanthus microbes secrete enzymes that kill and digest the prey and then take in their nutrients. These predator bacteria hunt together because individually they can’t produce enough of the antibiotics to kill the prey, but together they are deadly to other microbes.
When there is a food shortage, scientists still find these bacteria working together to survive. They form a structure called “fruiting bodies” as pictured on the right. In that form, they can survive for years if necessary. As single cells, they would not survive.
Studying how these microbes work can help scientists design new antibiotics or pest-resistant seeds for agriculture. Myxococcus xanthus rods are alive and can crawl, so their movement applies the laws of physics and the biological laws that govern living things. Studying these bacteria may help materials scientists gain new ideas for constructing liquid crystal display screens in electronic devices.
We learn much by looking at what is functional in the natural world. A wonder-working hand has moved before us and gives us tools for developing new materials to improve our lives. Also, bacteria working together can serve as a lesson to remind us that humans can accomplish more when we work together.
Many years ago in Alaska, I had a discussion with a biologist who was studying the Alaskan soils. His study revolved around the fact that Alaska has very little soil and what it does have is developing. The lack of soil in Alaska has limited plant growth and made the ecology dependent on migrating salmon. Soils are complex mixtures of organic matter, minerals, water, air, and billions of organisms that form over hundreds of years. Good soils are vital for survival. President Franklin D. Roosevelt once said, “A nation that destroys its soils destroys itself.”
Research has shown that plants are designed to “call” for nutrients from the soil. A plant will release molecules called flavonoids, which cause bacteria in the soil to migrate into the plant and form nitrogen nodules on the roots. The nitrogen nodules generate food for the plant. If ample nitrogen is already available for the plant, it will not release the flavonoids.
This “hunger” by plants is vital to understand because many natural and human-caused processes can deplete the soil. Forest and brush fires, hurricanes, pollution, and climate change can deplete soils’ nitrogen content and kill plants. Studies of the giant sequoias in California have shown that the soil under them has twice as many bacteria as the soil under nearby sugar pines. We all know that bacteria influence human health, but bacteria also affect plant health and growth.
As our population increases and world climates change, it will become increasingly important to understand how soil allows us to feed our growing population. God’s design of the Earth includes providing the soils necessary to produce food. Good soils are vital for survival.
One of the many things that make our planet uniquely well designed is the atmosphere. Our atmosphere has the right density to burn up the 10,000 plus meteors that speed into it every year. It’s also dense enough to scatter the cosmic rays and X-rays from space, so we are protected from this deadly radiation by our Earth’s atmospheric design.
Also very important, the atmosphere is thin enough to allow light to penetrate so plants can grow. It contains the proper mix of gasses for all living things to use. There is enough oxygen for us to breathe, but not enough to cause dangerous, uncontrolled combustion. It has the right amount of carbon dioxide to allow plants to live and give us the right amount of the “greenhouse effect.” This proper amount prevents too much heat from radiating off into space, keeping Earth at a temperature that promotes life.
The atmosphere is mostly nitrogen, which is relatively inert, but plants need it to grow. Because nitrogen is inert, it’s released to the soil by bacteria and certain plants, such as legumes or by lightning or tectonic activity. The atmosphere is topped off with a layer of ozone that absorbs ultraviolet energy from the Sun to keep us from being overexposed to the harmful effects of UV rays.
We usually think of bacteria as agents of infectious disease–“germs.” However, many types of bacteria are helpful to us. The truth is, we could not survive without bacteria.
More bacterial cells are living on and in your body than there are human cells in your body. Your body has more bacterial cells than there are people in the whole world! Even more amazing, the total biomass of all bacteria in the world is greater than that of all plants and animals in the world!
Bacteria in our digestive system allow us to digest the food we eat. Good bacteria even help us fight off their less-friendly cousins. Researchers recently discovered that a human skin bacteria (Staphylococcus epidermidis) protects against skin cancer. Those bacteria produce a compound nicknamed 6-HAP, which stops DNA formation in cancer cells, but not in healthy cells. The researchers hope to use this information to develop new treatments for skin cancer.
Bacteria live everywhere in soil, water, hot springs, the deepest part of the oceans, deep in the Earth’s crust, and even in radioactive waste. Bacteria break down waste materials, including sewage and oil spills, to help keep our world clean. Industry uses bacteria to produce cheese, yogurt, ethanol, vitamins, antibiotics, and prescription drugs.
Before humans or any form of animal life could live on the Earth, there had to be a full complement of the right kinds of bacteria. An intricate system of checks and balances had to exist for things to stay in a favorable condition. We have often paid the price for upsetting the balance of the microscopic world.
Don’t forget that we could not survive without bacteria. They feed us, clean up after us, and even fight the diseases some of their cousins cause. They also show us the wisdom and intelligence of the Creator who made us, and those microbes we can’t see.
There are many chemical wonders in our world, but few are as important and complex as the chemistry of nitrogen. Nitrogen makes up 78% of our atmosphere. It combines with oxygen to form nitrates and with hydrogen to produce ammonia, both of which are essential for growing our food. Nitrogen fixation, which is how nitrogen gets from what we breathe to what we eat, is an amazing demonstration of design.
First, let us review a little high school chemistry. The atoms of all elements have electrons which give them their properties for forming compounds. The electrons are arranged in pairs with their magnetic poles designed so that in a stable arrangement, one electron’s north pole is matched with its neighboring electron’s south pole. The electrons have various orbitals with different energy levels. The atom is stable and chemically inert if an orbital is filled with all the paired electrons it can hold. For example, neon has 10 electrons. The first two orbitals each have two paired electrons, and the last orbital has six electrons in three pairs. This pairing of electrons makes neon an inert gas which does not combine chemically with other elements.
Nitrogen has an uneven number of seven electrons. So how does nitrogen become chemically stable? The answer is that two nitrogen atoms share three electrons, giving them stability. The two nitrogen atoms bond together to form a diatomic molecule that cannot be easily pulled apart to bond with other elements. How strong is the bonding? To break up a nitrogen molecule into two nitrogen atoms requires temperatures of 400 to 500 degrees Celsius and pressures of 200 atmospheres. So with nitrogen as the dominant element in our atmosphere, the atmospheric gases are stable and inert. Also, nitrogen is not a greenhouse gas that could threaten our temperatures on Earth. How then has God built a system that takes these stable nitrogen molecules and breaks their triple bonds to produce nitrates and ammonia?
If you think this isn’t an important subject, ask yourself where your food comes from? The answer is that 50% of the American diet is produced using artificial fertilizers containing nitrogen, which has been “fixed.” Nitrogen fixation combines that inert gas with oxygen and/or hydrogen to supply the soil with the chemical needed to grow the plants we eat, and which the livestock eat to provide us with meat.
Bacteria accomplish God’s method of nitrogen fixation. The bacteria turn nitrogen into ammonia, which is a nitrogen atom sharing electrons with three hydrogen atoms instead of with another nitrogen atom. Plants known as legumes such as soybeans and peas, as well as bayberry and alder trees, attract bacteria which concentrate in nodules on the plant’s roots. The bacteria turn nitrogen gas into ammonia and nitrates the plants can use. Cyanobacteria in the ocean and cycad plants on the land are also major nitrogen fixers. Scientists are also discovering tropical plants that contribute to the wealth of nitrogen compounds in the soil.
Most of our fertilizers have nitrogen fixed by a method called the Haber-Bosch process. It uses massive amounts of energy to break the triple bonds of nitrogen gas. Producing 500 degrees and 200 atmospheres is expensive, and that is why you pay so much for the fertilizer you use in your garden. God’s methods are free. Scientists are trying to figure out how to recreate God’s nitrogen fixation method to save energy and produce more food.
Many bacteria are beneficial in various ways, and nitrogen fixation is only one of them. This is a great apologetic for God’s wisdom and design in preparing the Earth to provide food for us to eat.
The microbiome consists of trillions of beneficial bacteria that support our bodies in many ways. Some bacteria play an essential role in digestion and in separating the waste and processing it so that it can be excreted. Other bacteria play a role in our reproductive system. When I was a student at Notre Dame, there was a germ-free laboratory on campus where researchers raised animals with no bacteria. One of the complications of doing that was that even rabbits could not conceive if they were germ-free. For years, scientists have debated the question of the origin of our microbiome.
One interesting discovery that has come from prenatal research is that pre-born babies have their own microbiome separate from their mothers. For the past century, medical experts believed that babies acquired their microbiome at or shortly after birth. Research like that done at Notre Dame was thought to support the” sterile womb paradigm” hypothesis. Recent research has suggested that the origin of our microbiome may be from small amounts of bacteria built into the placenta. Discover magazine (June 2020, page 16) reviews the debate over when babies get their microbiome. Part of the problem is that it is very easy for contamination to get into the research specimens creating confusion over whether the bacteria were natural or if they came from contamination.
Our interest in this subject is not so much about the origin of our microbiome as to look at the implications of the data. Everyone agrees that the baby does not have its mother’s microbiome. Some microbes like E. coli are so common that they are found in all microbiomes. Beyond those, there is a unique makeup to each person’s microbiome, including newborns and pre-born babies.
Maintaining that a baby is an extension of the mother and therefore has no rights is to ignore the evidence. Morning sickness is caused by the mother’s immune system not recognizing a foreign object, the baby, and going into defensive mode. The baby growing inside the mother is a unique person with its own genetic makeup, awareness, and microbiome.
The abortion issue ignores the evidence and attempts to create a new vocabulary to make it seem less brutal, but taking a baby out of the womb and killing it is still infanticide. As tough as this issue is, we need to not shield the vile nature of this process by ignoring the evidence. Instead, we should look for solutions that recognize the value of life and the worth of every human being.
What if we could speed up time to test the concept of evolution? A scientist can’t wait millions or billions of years to study the process of natural selection as it creates new creatures. With that in mind, science must devise evolution experiments to study many generations in a much shorter time.
More than thirty years ago, Richard Lenski, who teaches at Michigan State University, began a project to study the evolution of the bacteria Escherichia coli, commonly known as E. coli. The project is called the Long-Term Evolution Experiment (LTEE). The scientist and his assistants carefully track the naturally-occurring random mutations in succeeding generations of E. coli. The environment for the bacteria is optimized for these one-cell creatures to grow and reproduce. Mutations are often harmful, but sometimes beneficial mutations lead to an improvement in the bacteria’s reproductive ability. Natural selection removes the bacteria with harmful mutations while those with beneficial mutations become more fit and reproduce. It’s what we call survival of the fittest.
Since 1988, the evolution experiment has continued, and scientists have kept careful records of the changes. Since the generation period of these bacteria is much shorter than that of humans, the study has gone through 70,000 generations. That is equivalent to more than 1.75 million years of human generations.
Through thousands of generations, there have been billions of mutations. Beneficial mutations that have lasted and accumulated amount to dozens. It is interesting that as time passes, successful mutations become increasingly rare. What the scientists are looking for is what they call “historical contingency,” which means a succession of small, almost inconsequential changes that accumulate to create significant changes.
So how has the E. coli changed after the 70,000 generations in this evolution experiment? The latest generation of E. coli can reproduce 70% faster than their ancestors. They are still bacteria. In fact, they are still E. coli bacteria. They have not mutated into some more advanced form of life. Dr. Lenski wants to see funding made available to continue the experiment for another 30 or even 300 years in the hope of seeing more dramatic results.
The LTEE has inspired other scientists to conduct evolution experiments. There is one at Harvard experimenting with yeast. Other scientists have experimented with fruit flies (Drosophila) to study the evolution of multi-cell creatures. They have bombarded the fruit flies with radiation and chemicals, changing light levels, and changing temperatures. After thousands of generations, the result has been mutant fruit flies with extra eyes or wings that didn’t function. They were still fruit flies.
The bottom line is that multi-generation evolution experiments have not resulted in new creatures or even greatly improved old creatures. The changes resulting from mutations and natural selection are either harmful or insignificant. God created animals to adapt and change due to environmental forces. Humans can change and sometimes improve animals by selective breeding. We see that very clearly in the many and very different breeds of dogs. But the evidence seems to indicate that only God can make a Canine or a Drosophila or an Escherichia—or a human.
One of the most interesting sites on the web is the “Astronomy Picture of the Day” produced by NASA. This website features a new picture every day, usually of objects in deep space with an explanation of the image. On August 18, 2019, there was a beautiful artistic rendition of a human with a star-filled background titled “Human as Spaceship.” (Because of copyright we can’t show you the picture, but you can see it HERE.) The opening line of the explanation is, “You are a spaceship soaring through the universe.”
The point of the presentation is that as we soar through the universe, we are not alone. We are the captains of our ships, our human bodies because we are not a singular living organism. There are a massive number of separate organisms that exist inside our bodies that do specific things for us. They help digest food, fight disease and infection, and carry vital materials on a liquid highway (your bloodstream) from one end of your body to the other. These organisms are the crew of this spaceship. They are bacteria, fungi, and archaea, and they actually outnumber your own cells. Science still doesn’t know what many of these organisms do, but they have their own DNA, and together they make up the human microbiome. You are a spaceship with a massive crew.
We sometimes seem to view God’s creation of the human body as a process similar to building a machine. To build a machine you would put together pre-manufactured parts in a prescribed way. To build a working and living human body requires a host of communities which do the jobs they were designed to do in ways that science is just beginning to understand.