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

The majority of the bacteria that live in our gut are anaerobes, or unable to live in oxygen. Both Bacteroidetes and Firmicutes are anaerobes. Researchers observe a higher ratio of Firmicutes to Bacteroidetes in obese humans, while in leaner humans, a higher ratio of Bacteroidetes to Firmicutes can be found.

- One recent study [L] linked/associated a low Firmicutes level in the gut microbiota with depressed patients:

[...] This study found that there is a significant disorder of gut microbiota in the patients with depression, in which the Firmicutes decreased significantly. Defects of the Firmicutes may lead to the depression in short-chain fatty acids, which could account for the physiological basis of low-level inflammation of depression.[...]

- Other data suggests that lower Firmicutes have generally been related to a lower BMI (=Body Mass Index).

Possible causes:

- Poor diet

- Dysbiosis

- Maldigestion

- Hypochlorhydria

Possible therapeutic Approaches & Considerations:

- Balance commensal bacteria

- 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 Firmicutes levels