Bacteroidetes is a large bacterial phylum, a classification containing many different organisms. You may also see the newer name Bacteroidota. GI-MAP uses the familiar Bacteroidetes label; a high value describes a broad group, not one disease-causing species.
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Why a phylum result is broad
A phylum sits above genus and species in bacterial classification. Bacteroides fragilis is a much more specific target. Individual members can have different ecological roles, so a phylum total cannot identify which strain or function explains a symptom.
What GI-MAP reports
The panel reports Bacteroidetes and Firmicutes separately and includes their ratio. Read the units and reference range on the actual report. A DNA quantity is not interchangeable with the relative-abundance percentages often used in research. [1]
Why high does not mean unhealthy
Research relating these broad groups to body weight has been inconsistent. The Firmicutes:Bacteroidetes ratio is not a reliable individual diagnostic shortcut for obesity or “dysbiosis.” A high Bacteroidetes number cannot establish inflammation, insulin resistance or the diet you need. [2]
A low result is similarly nonspecific. Neither direction identifies a missing nutrient or justifies trying to eliminate or increase an entire phylum. Review the clinical reason for testing before setting a target for the number.
What to compare before drawing conclusions
Check whether earlier testing used the same laboratory, assay and units. Consider collection timing and recent illness or medicines. A change in a broad group is not automatically a meaningful change in symptoms or health.
Common questions
Is Bacteroidetes the same as Bacteroides?
No. Bacteroides is a genus within a much larger classification. A result for one cannot substitute for the other.
Can high Bacteroidetes predict weight loss?
No. Group-level microbiome associations cannot predict an individual’s weight response from this stool result.
Sources and review
Sources checked October 7, 2026. Manufacturer material describes the test; clinical guidance and research support the interpretation limits.
- Diagnostic Solutions Laboratory: GI-MAP interpretive guide (manufacturer specifications)
- The Firmicutes/Bacteroidetes ratio: a review of the evidence, 2020
Medical review of this article is pending. For a correction or source question, contact GI MAP Test.