Firmicutes:Bacteroidetes Ratio

High Firmicutes and low Bacteroidetes (resulting in a high F/B ratio) suggest microbial imbalance which may be related to:

- increased caloric extraction from food,

- fat deposition and lipogenesis,

- impaired insulin sensitivity,

- and increased inflammation.

Potential causes: 

- Poor diet

- Dysbiosis

- Maldigestion or hypochlorhydria

Therapeutic Approaches & Considerations

- Balance commensal bacteria using the 5R Protocol (see this Blog article)

- When Firmicutes phyla is high, consider using Bifidobacteria probiotics and Saccharomyces boulardii primarily.

- Lactobacillus spp. and Bacillus spp. (found in probiotics) can elevate Firmicutes

- Optimize the diet; a lower fat diet may help to normalize the F/B ratio

- Address all other imbalances on the GI-MAP

An abnormal result in one or both of these phylum suggest imbalanced normal microbes in the GI tract.

Gram-negative Bacteroidetes and grampositive Firmicutes are bacterial phyla that dominate the entire human digestive tract, including the mouth, nose, throat, and colon.