Organic acids testing gives clinicians a window into metabolism, gut health, and microbial activity that standard bloodwork often misses. Two markers that frequently raise questions are arabinose and arabinitol. They sound almost identical, they are chemically related, and they appear side by side on the US BioTek panel. But they are not the same thing, and the difference between them carries important clinical meaning.
This post breaks down what each marker is, how they relate to one another, and why seeing both on a single organic acids profile gives practitioners more specific insight into fungal activity and sugar handling than either marker alone.
Arabinose is a simple five-carbon sugar, also called a pentose, found naturally in plant fibers and certain fruits. In the body, it is associated with the breakdown of plant fiber carbohydrates.
Here is the key point for interpretation. Humans do not produce arabinose on their own. Because of that, an elevation usually points to an outside source. In functional medicine, elevated arabinose is most often associated with yeast or fungal overgrowth, mainly Candida species.
When arabinose runs high, patients may experience symptoms such as:
| Leaky gut | Diarrhea |
| Bloating | Brain fog |
| Gas | Fatigue |
Because these symptoms are common and nonspecific, they are easy to attribute to other causes. That is part of why an objective marker is so useful in practice.
Arabinitol is derived from arabinose. Chemically, arabinose is reduced into a sugar alcohol, meaning an alcohol group replaces part of the original sugar structure.
Arabinitol is typically produced under low-oxygen or high redox pressure conditions. This chemical change makes arabinitol less reactive than arabinose, and as a result it tends to be stored within the body rather than cleared quickly.
In practical terms, arabinitol reflects a different slice of microbial and metabolic activity than arabinose. That is exactly why measuring both is valuable.
| Feature | Arabinose | Arabinitol |
| What it is | A simple five-carbon sugar (pentose) | A sugar alcohol derived from arabinose |
| Source in the body | Not produced by humans; tied to plant fiber breakdown and microbial activity | Formed when arabinose is reduced under low-oxygen or high redox conditions |
| Reactivity | More reactive | Less reactive |
| Behavior | Tied to active carbohydrate handling and fermentation | More stable, tends to be stored in the body |
| Main interpretive value | Flags carbohydrate fermentation and possible fungal activity | Adds specificity to fungal and microbial interpretation |
Measuring arabinose and arabinitol together gives a more specific picture of microbial activity than either one on its own. Both can point toward gut and fungal dysbiosis and toward altered sugar handling. The relationship between the two is what sharpens the interpretation.
Two patterns are especially useful for clinicians:
That distinction can change the direction of a treatment plan. One pattern steers toward antifungal and microbiome-focused strategies. The other points toward diet, digestion, and carbohydrate handling. Looking at the two markers in relation to each other helps avoid treating the wrong target.
Both markers are measured through an organic acids profile, a urine-based test that captures metabolic byproducts of microbial and cellular activity. Running arabinose and arabinitol on the same profile lets the lab and the clinician compare them directly, which is what makes the ratio interpretation possible.
Sample collection is designed to be straightforward for patients, with options that support at-home collection and minimal disruption to daily routines. As with any functional test, results are most meaningful when interpreted alongside patient history, symptoms, and the rest of the panel.
US BioTek brings years of functional laboratory experience to organic acids testing, with both arabinose and arabinitol included on the profile so practitioners get the full picture in a single panel.
What we offer:
Talk to our team to learn more about the Organic Acids Profile and how to use it in your practice.
Arabinose and arabinitol are closely related, but they tell different parts of the same story. Arabinose flags carbohydrate fermentation and possible fungal activity, while arabinitol adds the specificity needed to read fungal and microbial patterns with more confidence. Seeing both on one organic acids profile, and reading them in relation to each other, gives practitioners a more precise basis for treatment decisions. For clinicians working with gut health, dysbiosis, and sugar handling, that added clarity can be the difference between guessing and knowing where to start.
Arabinose is a simple five-carbon sugar that the body does not produce on its own, while arabinitol is a sugar alcohol formed when arabinose is reduced under low-oxygen or high redox conditions. Arabinitol is less reactive and tends to be stored in the body. Because they reflect different parts of microbial and metabolic activity, comparing the two adds clinical specificity.
Elevated arabinose is commonly associated with yeast or fungal overgrowth, mainly Candida species, because humans do not produce arabinose themselves. When elevated, it may also reflect carbohydrate fermentation or a dietary absorption issue, especially if arabinitol is not similarly elevated. Interpretation should always be paired with patient symptoms and history.
A higher level of arabinitol relative to arabinose suggests yeast or fungal overgrowth. This ratio is more specific than looking at arabinose alone, which is why both markers are valuable on the same profile.
Testing both gives a more specific picture of microbial activity than either marker on its own. Both can indicate gut and fungal dysbiosis and altered sugar handling, but the relationship between them helps distinguish fungal overgrowth from carbohydrate fermentation or dietary absorption issues.
High arabinose can be linked to leaky gut, bloating, gas, diarrhea, brain fog, and fatigue. These symptoms are common and nonspecific, which is why an objective marker is helpful for identifying the underlying driver.
Both are measured through an organic acids profile, a urine-based test that captures metabolic byproducts. Running them on the same panel allows the two markers to be compared directly.