It is estimated that the average person will generate approximately 0.6 to 1.8 liters (L) of gas every day. People with SIBO or dysbiosis will produce even more gas than average.
So, what exactly is this gas composed of?
To understand this, we have to first look at the sources of our intestinal gas, as well as the different ways in which the elements within our body interact with these chemicals to produce some not so pleasant effects that everyone should be familiar with.
Intestinal gas can either come from swallowed air, which is termed exogenous gas, or from the bacteria that reside within our gastrointestinal tract which is called endogenous gas.
The major components of it include oxygen, nitrogen, carbon dioxide, hydrogen, and methane. Typically, air that is swallowed will remain in the stomach until it gradually moves through the digestive system through peristalsis. The movement of these gases does not cause us any pain or discomfort, and will eventually be released in small amounts.
In the colon, there are numerous bacterial species that thrive on poorly digested foods such as starches and sugars (carbohydrates). As the bacteria within the colon ferment these foods, hydrogen and carbon dioxide gases are released during the process.
However, it is important to note that bacteria within the colon can also consume gases, particularly hydrogen, to release gases like methane and certain sulfur-containing gases like hydrogen sulfide that account for the foul odor we associate with gas.
In addition to colon bacteria, people with SIBO can have too much bacteria in the small intestine (where there should only be a small amount) which can ferment carbohydrates and also produce these gases.
In people with SIBO, there is usually an overproduction of certain types of gases like hydrogen, methane, and hydrogen sulfide in the small intestine. There are a number of different reasons why this could occur. One of the most common causes is altered intestinal motility due to nerve damage.
Currently, breath tests are the most useful diagnostic test for examining the type and amount of gas produced in the gut.
Despite the usefulness of breath testing, it is important to realize that some patients with SIBO may also have too much hydrogen sulfide (H2S) in their bodies, which is not a type of overgrowth that is detectable by traditional breath tests yet. In H2S SIBO, the hydrogen sulfide producing bacteria compete with the methane-producing bacteria in consuming hydrogen gas.
Hydrogen sulfide is a colorless gas that has a characteristic smell of rotten eggs. Outdoors, H2S is naturally present in crude petroleum, natural gas, volcanic gases and hot springs.
Additionally, H2S can also result from the bacterial breakdown of matter, and can therefore be produced by humans and animals in their waste and gas. Bacteria found in your mouth and gastrointestinal tract produce hydrogen sulfide from decomposing materials that contain vegetable or animal proteins.
Remember, with any case of SIBO, it is extremely important to rule out other underlying causes that could be contributing to bacterial overgrowth, such as decreased digestive motility. In the case of hydrogen sulfide SIBO, it may also be worthwhile thinking about helping your sulfur metabolism.