Gut Microbiome, Butyrate, Long Covid and Vaccine Reactions






A recent study on ME/CFS looked at the microbiome of patients compared with healthy controls.

The results showed differences in species abundances and in short-chain fatty acid production in people with ME/CFS.

Here is the graphical abstract summing up the results.


There is a lot of overlap between ME/CFS and Long Covid / Long Spike. For many with ME/CFS, the symptoms began following a viral illness.

The bacteria in the gut produce short-chain fatty acids that are important in our health. Short-chain fatty acids, such as butyrate, help “support immunological tolerance and maintain inflammatory equilibrium”. [ref]

What about Long Covid?

In a study published in the BMJ journal Gut, researchers explained the results of a prospective study. They looked at the gut microbiome of 106 people before and after they got Covid, and then compared it with a similar group that didn’t get Covid.  The gut microbiome composition prior to Covid was predictive and associated with those who ended up getting long Covid.

From the conclusion: “Butyrate-producing bacteria, including Bifidobacterium pseudocatenulatum and Faecalibacterium prausnitzii showed the largest inverse correlations with PACS at 6 months.”

Another good review article explains that short-chain fatty acids are created in the gut and then can move through the intestinal wall and enter the circulation or be used by the intestinal cells. They can enter the intestinal epithelial cells either through diffusion or, more commonly, via active transport with MCT1 or sodium-coupled SMCT1.

In the intestines, short-chain fatty acids also are involved in the mucosal barrier integrity, which then impacts immune system homeostasis. Short-chain fatty acids help to limit autoimmune reactions by promoting the development of regulatory T cells (Tregs). They also decrease the pH which controls the growth of pathogenic bacteria and fungi. Butyrate specifically increases the mucin in the intestines and also promotes anti-inflammatory macrophage polarization (M2 macrophages instead of M1).[ref]

A placebo-controlled clinical trial investigated whether a ‘phytochemical-rich concentrated food capsule” would affect long Covid patients with gut dysbiosis. The results showed a 2-fold reduction in fatigue scores in the active arm of the trial. The researchers found that gastrointestinal symptoms improved with the supplement, which theoretically should have improved inflammation in the gut.

What about negative vaccine reactions (long Spike)?

Another placebo-controlled trial looked at the effects of a ‘novel oral microbiome formula’ that was taken within a week of the first covid-19 vaccine dose. Adverse health outcomes post-vaccine were significantly lower in the group taking the microbiome formula at one month and three months after vaccination. The results showed “Subjects who received SIM01 showed a significant increase in beneficial Bifidobacteria and butyrate-producing bacteria in faecal samples and strengthened the microbial ecology network.”


My takeaway:

For long Spike with gut microbiome or intestinal issues, increasing butyrate may be something to consider. Supplemental Sodium butyrate is available. Additionally, bifidobacteria probiotics along with increasing resistant starch in the diet may be something to consider.