Health May Depend on Good Viruses and Microbes
There is still much to learn about the human body. Some of our best friends may not even share our own genes.
Scientists have tended to characterize microbes of the kingdom Archaea, thought to be the most ancient life forms, as extremophiles – cells that live predominantly in extreme environments, like hot springs. What’s coming to light now is that we have numerous archaeans in our bodies. How did they get there, and what do they do? Science Magazine gave a run-down on this frontier of human ecology. In “Survey of archaea in the body reveals other microbial guests,” Elizabeth Pennisi says,
When you think of archaea—perhaps the most ancient life forms—extreme locations such as hot springs, alkaline lakes, and wastewater treatment plants likely come to mind. But these microbes are also at home, sometimes in large numbers, in the human nose, lungs, gut, and on the skin, microbiologists reported last week.
Their survey, published in mBio, is part of a growing push to look beyond the bacteria that make up the much-discussed microbiome to find other microbes that naturally inhabit the human body and may influence health and disease (see p. 982). “It is very exciting to know the existence of such a rich repertoire of archaea in humans,” says Jean-François Brugère, a molecular biologist at the University Clermont Auvergne in Clermont-Ferrand, France. “Human microbiotas should not be limited to bacteria.”
This diversity was just here, on and within us, and we did not know it.
Another researcher found archaea in “surprising abundance” everywhere she looked, even in hospitals and spacecraft “clean” rooms. She began looking at the human body and found them in human skin, lungs, noses, and guts. At this point it is not clear how they influence our health. Their “tissue specificity” (preferred locations) seem to suggest healthful interactions. One researcher marveled, “This diversity was just here, on and within us, and we did not know it.”
Even smaller than archaea, beneficial viruses called bacteriophages (phages for short, rhymes with pages) may also play key roles in human health. As the name implies, bacteriophages “eat” bacteria. Off the cuff, that sounds like a good thing. In Science Magazine, Giorgia Guglielmi asks, “Do bacteriophage guests protect human health?” If so, they are wanted guests. Here’s some background on their discovery:
A century after they were discovered killing bacteria in the feces of World War I soldiers, the viruses known as bacteriophages, or simply phages, are drawing new attention for the role they might play within the human body. Phages have been found most everywhere, from oceans to soils. Now, a study suggests that people absorb up to 30 billion phages every day through their intestines.
The fact that healthy humans are flooded with archaea and phages would indicate they help us out somehow. Some health organizations have suggested that ingesting more phages might help control parasites or work other benefits. “There have been some compelling success stories, but phage therapy has struggled to become a dependable treatment,” Guglielmi cautions. Work on classifying the “phageome” of the body is just beginning. Phages appear most abundant in mucus membranes, which tend to be exposed to the environment where harmful bacteria are likely to accumulate. New work shows that they can also spread into our tissues. Some research provides clues of beneficial functions for our minuscule guests:
If phages do get into our tissues, what—if anything—do they do there? Only a few studies address the issue. In 2004, researchers led by Dąbrowska reported that a specific type of phage can bind the membrane of cancer cells, reducing tumor growth and spread in mice. A few years later, Dąbrowska’s graduate adviser, phage expert Andrzej Górski, showed that phages can affect the mouse immune system when injected, ramping down T-cell proliferation and antibody production. In mice, they can even prevent the immune system from attacking transplanted tissues.
Phages may also reduce inflammation and regulate the immune system. It may take decades to figure out what the “phageome” does for us (or to us), but initial indications are positive.
There’s plenty of work to do in human physiology. Since neither of these articles mentioned Darwinism, apparently nothing in archaea biology or phage biology made sense in the light of evolution. We suggest an intelligent design approach, like Paul Nelson’s quip, “If something works, it’s probably not happening by accident.” Look at these new fields of study without the Darwin blinders on. You might find additional support for beneficial functions that are irreducibly complex.