Archaea: Hot springs, the Dead Sea, and your intestines

It’s a peculiar situation.

Bacteria are obviously primitive organisms. They are ubiquitous in the human body, occupying virtually every nook and cranny, crack and crevice. But there’s another class of microorganisms that inhabit the gastrointestinal tract of most humans that, if their proliferation goes unchecked, can wreak havoc: Archaea.

Archaea are fascinating. Evolutionarily, Archaea pre-date bacteria and lack such features as having a cell nucleus. Archaea are sometimes called “extremophiles,” as they have evolved the ability to survive in extreme environments, such as the boiling water temperatures of hot springs (“thermophiles”) or the toxic levels of salt in the Dead Sea (“halophiles”). You can also find them in the guts of ruminants and insects where they assist with digestion. You can even find them at the bottom of the ocean and in Antarctic ice. In other words, they are extremely adaptable, able to survive in conditions that few other organisms can. Some scientists believe that, if we are to discover life on places like the moon or Mars, they are likely to be something like Archaea.

I don’t believe that we can classify the human gastrointestinal tract as an extreme environment, though certainly one I would not want to live in. Most humans harbor Archaea in their digestive tracts where they may provide some benefits, such as consuming hydrogen gas produced by bacteria, consuming toxic metabolites resulting from bacterial protein fermentation, and reducing trimethylamine intestinal content. And, despite the many human diseases caused by bacteria—tuberculosis, pneumonia, urinary tract infections, etc.—Archaea are largely benign and appear to not typically cause human diseases. In other words, they seem less opportunistic than bacteria or viruses, benign co-inhabitants in creatures like mammals.

This is why it is surprising that evidence is mounting associating the proliferation of Archaea such as Methanobrevibacter smithii, so-called because it produces methane gas rather than hydrogen gas, with a form of small intestinal bacterial overgrowth, SIBO, called methanogenic SIBO. Because methane gas has been shown to slow intestinal propulsive activity in the intestinal tract, the red flag for methanogenic SIBO is constipation.

Now, recall that gliadin-derived opioid peptides can be responsible for constipation, as are other opioids, a fact that the ever-enterprising pharmaceutical industry puts to advantage. Gliadin-derived opioid peptides can also be responsible for severe, unremitting constipation, “obstipation,” an awful situation in which sufferers move their bowels every several weeks, partial and temporary relief provided by mega-dose laxatives and enemas. Banishing all gliadin-containing wheat and related grains can therefore provide dramatic relief to many cases of constipation.

But Archaea can also cause constipation, often labeled IBS-C or irritable bowel syndrome with constipation. But why? Why would a class of organisms that are largely quiet inhabitants of the human gastrointestinal tract proliferate and cause problems?

Nobody has the answer. Preliminary observational and experimental evidence suggests that methanogenic SIBO and/or higher methane levels may lead to increased potential for:

• Colon cancer—Most people with colon cancer have
• Obesity
• Diverticular disease—diverticulosis and diverticulitis
• Brain abscess
• Gingivitis

A provocative observation was made recently in which our old friend, Lactobacillus reuteri, the bacteria that we put to work in making our L reuteri yogurt that smooths skin, restores youthful muscle and libido, and turns the clock back 10 or 20 years, exerts a potent suppressive effect on Archaea. In a small study, L reuteri 100 million CFUs per day for four weeks reduced breath methane by over 50% with 11 participants experiencing complete eradication of methane. Is methanogenic SIBO therefore yet another aspect of the changing human microbiome that includes progressive loss of L reuteri? And does the higher bacterial counts of our yogurt, given the unique fermenting process we use—prolonged fermentation in the presence of prebiotic fibers—eradicate methanogens?

Stay tuned for more on this fascinating topic as we dive deeper into Archaea, methanogenic SIBO, and related conditions in our Undoctored Inner Circle.