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How Two Gut Organisms Can Cause Digestive Distress

Woman sitting on a bed with stomach painBalance of bacteria and organisms in your gut matters more than you may think.

When the bacteria are out of balance, you may experience many bothersome symptoms, such as
  • Bloating
  • Cramping
  • Gas
  • Belching
  • Constipation
  • Diarrhea

There are two types of organisms in the gut.

One group is bacteria, the other is an archaea—a one-celled organism like bacteria that also inhabits the gut. An overgrowth of archaea that produces methane gas causes constipation, while overgrowth of hydrogen sulfide producing bacteria causes diarrhea.

Archaea can also cause gastroparesis, a condition in which the signals to the digestive system decelerate, which slows down the digestive processes.

The Vicious Cycle Inside Your Gut

If you have diarrhea-related Small Intestinal Bowel Overgrowth (SIBO), you have an overgrowth of hydrogen-producing bacteria in your small intestine. Bacteria produce hydrogen gas as a byproduct of carbohydrate fermentation in the gut.

An overgrowth of bacteria also produces toxins that irritate the gastrointestinal lining that causes diarrhea. Most of these toxins overload the TRPV1 receptors in our gut, greatly increasing water concentration and gut movements (peristalsis), which cause diarrhea as a defensive mechanism to protect the body from the toxins and bacteria.

If you experience constipation, you likely have an overgrowth of archaea. Archaea in the digestive system feed off of hydrogen that other bacteria produce during the fermentation of carbohydrates in our gut. Archaea then produce methane as a byproduct of their digestion.

The more fermentation and hydrogen gas that occurs in the intestines, the more methane archaea can produce. Methanobrevibacter smithii seems to be the most dominant of the archaea species in the gut, compromising at least 90 percent of the archaea gut flora.

Increased hydrogen-producing bacteria and poor lactose absorption have been associated with an overgrowth of archaea in the gut, gastroparesis (slowing of digestive activities) and constipation.

Decreased migrating motor complex function (or MMC, the process by which the digestive system eliminates waste) also leads to an increase of hydrogen (feeds archaea) and methane concentrations in the gut, which causes excessive bloating. People suffering from archaea overgrowth also have significantly lower colon pH, which can help protect the bacterial overgrowth from immune elimination.

How does archaea dysbiosis further hinder MMC function to the point of chronic constipation? Serotonin (5-HT3 / 5-HT4) is one of the biggest neurotransmitters in the gut associated with regulating proper gut function. Lower amounts of serotonin in the gut lead to reduced function and chronic constipation in methane-dominant SIBO.

Reduced activation of the serotonin receptors in the ileum greatly slows down both gastric emptying of the stomach, which can cause gastroparesis symptoms, and emptying of the small intestine, which can lead to SIBO.

Stopping the Cycle

Bacteria and archaea in the gut feed off each other, so how do you stop the back and forth of bacterial or archaeal overgrowth?

Taking a full-spectrum probiotic while following the FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) diet is usually the best way to maintain balance of the gut bacteria.

Address Your Digestive Distress

If you suffer from diarrhea, constipation or other digestive conditions, we want to help you. Contact us today to schedule an appointment.

3 Join the Conversation

  1. Dean Brockner says
    Aug 05, 2023 at 1:39 PM

    So what is the best way to control the bad archaea in the gut. Judging by the systems it looks like I may have a bad infestation causing my gasroparesis. I am a 65YO male and I've tried all the so called natural laxatives. All sorts of probiotics with multiple strains of bacteria, Miralax, citrocel, increasing fiber and water intake. Nothing has worked and most of them have caused worse bloating. I am gaining weight and losing patients. Once a week or so I use a stimulant to relieve the pressure of a backed up digestive pressure. It is a vicious cycle. I have been taking a product called Emma and it seems to be starting to work. I think it says it may take three weeks or more to kick in. Any insights would be appreciated.

    • says
      Aug 07, 2023 at 2:43 PM

      Hi Dean, It could be that your problems are from dominance of archaea overgrowth. However, archaea also consume hydrogen from hydrogen sulfide-producing bacteria. So often, the SIBO is more complicated than a single species overgrowth. But, there are a few herbal supplements that have been studies specifically targeting methanogens. One of my favorites is Atrantil by KBS Research - 2 capsules before meals. If the problem has been going on for a long time, you may need to take multiple months of herbs. If this does not at least make a little bit of improvement, I highly recommend working with a skilled practitioner and getting breath testing and still testing to determine what else might be going on because it's often become a problem of multiple species overgrowth and changes to the migrating motor complex.

  2. Shane Alexander says
    May 21, 2024 at 7:22 AM

    I had colorectal cancer 10 yrs ago. I had all the cancer removed but my bowel movements have been an all consuming factor since then. I now have IBS and I'm sure, gut parasites. With each passing year, there are new food groups my gut just won't tolerate. It's easier to list the foods I can eat than the laundry list of those which I can't. Is IBS just a catch all term for gut bacteria and parasites?

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