What we analyze

We turn laboratory measurements into clear, actionable insights. The Gut Health Test uses 3 quantifiable biomarkers and turns them into 5 actionable health markers.

What we measure (quantifiable values)

We measure three blood metabolites and derive three ratios. All concentrations are shown in µM in your results. 

• IPA (indole-3-propionic acid) – a microbial metabolite linked to gut barrier support and antioxidant activity. Higher is better. 
• KYN (kynurenine) – a tryptophan metabolite that reflects immune activation. Lower relative to TRP is generally better. 
• TRP (tryptophan) – an essential amino acid and the substrate for both IPA (microbiome) and KYN (host). 

Ratios displayed on your page:

1. IPA:KYN – Microbiome Immune Support (shown as %, higher is better) 
2. IPA:TRP – Gut Microbiome Efficiency (shown as %, higher is better) 
3. KYN:TRP – Immune Stress (shown as %; lower is better) 

Sample type & comparability to research. We collect dried blood spot (DBS) samples for convenience and stability. To ensure your numbers are comparable with values reported in scientific literature (typically plasma/serum), we apply a validated DBS-to-plasma  conversion factor during analysis. The factor is proprietary but validated; it does not change your category boundaries—only the unit equivalence. 

How we set the cutoffs

We define Low, Moderate, Medium-high, and High using Zinzino reference groups and patterns consistent with published dietary fiber tertiles. Higher fiber intake and a better omega-6:3 balance are linked to improved metabolic and immune-stress profiles. Although fiber intake was self-reported, it’s a robust proxy: studies associate higher fiber intake with elevated IPA and more favorable tryptophan ratios (higher IPA:TRP, lower KYN:TRP). By combining dietary (fiber intake) and biochemical (BalanceTest Protection %) indicators, our low fiber/low protection vs high fiber/high protection groups represent realistic ends of the lifestyle–diet–health spectrum in our population.

As our dataset grows, these targets are subject to change.

• High (green) reference group: High fiber intake and high protection from the BalanceTest. 
• Low (red) reference group: Low fiber intake and low protection from the BalanceTest.

We then set the threshold rules below, using medians and 75th percentiles from those groups: 

IPA 

• Medium-high: Median of the high fiber / high protection group. 
• High: 75th percentile of the high fiber / high protection group. 
• Low: Median of the low fiber / low protection group. 

IPA:TRP and IPA:KYN

• High: 75th percentile of the high fiber / high protection group. 
• Low: Median of the low fiber / low protection group. 

KYN:TRP (lower is better) 

• High (green) cutoff: Median of the high fiber / high protection group. 
• Low (red) cutoff – conservative rule: 75th percentile of the low fiber / low protection group, so only the worst quartile in this “least healthy” group shows red. 
Rationale: KYN:TRP is often discussed in disease contexts; our approach is tailored to preventive health and the distribution seen in healthy populations. 

This framework keeps categories anchored in real-world data rather than theoretical targets. 
 

How scoring works (and what it’s used for)

You will always see your measured values (µM or %) and their color band. 
Separately—and only for calculating the overall Gut Health Index—we convert each marker to an internal 0–100 subscore: 

• 0 if the value is in the red Low zone 
• 100 if the value reaches the High zone 
• Linear scaling between cutoffs 
• Inverted for KYN:TRP (lower values score higher) 

These sub-scores are not shown as standalone “grades” for each marker. They exist solely to combine markers fairly into one summary score for the Gut Health Index. 

The Gut Health Index (overall %)

We combine the sub-scores using a weighted model to provide a reliable snapshot of your overall balance: 

• IPA level – 45% of the index 
• Immune Stress (KYN:TRP) – 30% 
• Microbiome Immune Support (IPA:KYN) – 15% 
• Gut Microbiome Efficiency (IPA:TRP) – 10% 

Target ranges shown on your result page

For practical context we also display target ranges in the table at the bottom at the result page. These come from participants who achieved High on IPA:KYN; within that favorable subset, we show the 25th–75th percentile for each marker target value.

Quality controls & intended use

• Analyses are run by accredited laboratories with calibration standards and internal quality controls. 
• Only quantifiable laboratory values enter the calculations. 
• Unit harmonization uses a validated DBS conversion factor to align with plasma/serum literature. 
• The test is designed for wellness and preventive health and does not diagnose disease. 

Quick summary

We quantify IPA, KYN and TRP, compute meaningful ratios, and map results to population based cutoffs from defined lifestyle reference groups. We score markers only to build the Gut Health Index, with heavier weight on IPA and KYN:TRP. DBS results are converted using a validated conversion factor so the numbers you see are directly comparable with findings in the scientific literature.