Altered microbiome composition in individuals with fibromyalgia, 2019, Minerbi et al.

I was a bit underwhelmed by this as there's maybe 1000 species of bacteria in the gut microbiome, so odds were that there'd be plenty that happened to be in greater or lesser quantities than in the microbiomes of controls. But the finding does seem a bit more robust than that.

Abstract:
Fibromyalgia (FM) is a prevalent syndrome, characterised by chronic widespread pain, fatigue and impaired sleep, that is challenging to diagnose and difficult to treat. The microbiomes of 77 women with FM and that of 79 control participants were compared using 16S rRNA gene amplification and whole genome sequencing. When comparing FM patients to unrelated controls using differential abundance analysis, significant differences were revealed in several bacterial taxa.

Variance in the composition of the microbiomes was explained by FM-related variables more than by any other innate or environmental variable and correlated with clinical indices of FM. In line with observed alteration in butyrate metabolising species, targeted serum metabolite analysis verified differences in the serum levels of butyrate and propionate in FM patients.

Using machine learning algorithms, the microbiomecomposition alone allowed for the classification of patients and controls (ROC AUC 87.8%). To the best of our knowledge, this is the first demonstration of gut microbiome alteration in non-visceral pain. This observation paves the way for further studies, elucidating the pathophysiology of FM, developing diagnostic aids and possibly allowing for new treatment modalities to be explored.

I haven't read the full article but it is open-access.

 

Yes.

This 2016 paper from Maureen Hanson's team found lower levels of bacteria that produce butyrate in a ME/CFS cohort and note IBD and IBS research finding the same. That IBD and IBS research also found lower levels of butyrate in the gut, corresponding to the lower levels of the butyrate-producing bacteria.

Reduced diversity and altered composition of the gut microbiome in individuals with myalgic encephalomyelitis/chronic fatigue syndrome

I don't know what later ME/CFS studies have found.

 

https://www.ncbi.nlm.nih.gov/pubmed/29986139
Dietary Fiber Increases Butyrate-Producing Bacteria and Improves the Growth Performance of Weaned Piglets.

The study investigated the impact of dietary fibers on the performance, fecal short-chain fatty acids, nutrient digestibility, and bacterial community in weaned piglets with the control group (CON) and dietary supplementation of 5% corn bran (CB), 5% wheat bran (WB), or 5% soybean hulls (SB). The piglets in CB and WB groups showed greater weight gain and feed efficiency ( p < 0.05) in comparison to piglets in CON and SB groups.

Fecal samples from piglets in CB, SB, and WB groups contained greater ( p < 0.05) butyrate levels than fecal samples from piglets in the CON group. The fecal samples from piglets in CB or WB groups contained greater ( p < 0.05) abundances of Actinobacteria and Firmicutes or Fibrobacteres than the fecal sample from piglets in the CON group, which could promote fiber degradation and the production of butyrate.

In summary, dietary CB or WB may enhance the growth performance of weaned piglets via altering gut microbiota and improving butyrate production, which shed light on the mechanism of dietary fiber in improving gut health.
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I'm off to eat some celery.

 

Ha, I should have learned by now to not just read the abstract. I was a bit concerned that the abstract didn't actually say whether the butyrate producing bacteria and the butyrate levels were up or down. Here's the relevant section:

Consistent alterations in the abundance of butyrate-metabolism-related bacteria were observed:F. prausnitzii and B. uniformis were found in lower relative abundance in FM patients, while higher relative abundance was observed for Intestinimonas butyriciproducens, Flavonifractor plautii, Butyricoccus desmolans, Eisenbergiella tayi and Eisenbergiella massiliensis.

To explore the possible metabolic effect of these alterations, a targeted metabolite approach was used to measure the serum concentrations of butyric acid, isobutyric acid, propionic acid and lactic acid.

Serum levels of butyric acid in FM patients (n=73) were higher compared to unrelated controls (n=46, p=0.005), while levels of propionic acid were lower (p=0.006) and a trend towards lower levels of isobutyric acid was also observed (p=0.056). No significant differences in the serum levels of lactic acid was observed (Figure 4B). Multivariate analysis showed a significant between-group difference (Pillai’s Trace, F=8.97, p<0.0001).
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So FM patients actually had higher levels of butyric acid in their serum, with just a trend to lower levels of isobutyric acid. And levels of butyrate-metabolism-related bacteria were a bit all over the place at the species level. And there was no difference in the fibre-intake between the FM cohort and the controls.

As usual, it seems that it's complicated...

When considering the nineteen specific species identified as significantly differentially abundant between FM patients and unrelated control participants, there was a broad range in how well- characterised these species were. Those species putatively depleted (lower in relative abundance) in FM were relatively well-characterised and included Faecalibacterium prausnitzii, Bacteroides uniformis, Prevotella copri and Blautia faecis.

Faecalibacterium prausnitzii is one of the most abundant and well-studied butyrate producing bacteria in the human gut [46]. This species has been reported to be depleted in multiple intestinal diseases and was therefore suggested as a potential marker for gut disorders. Within the gut, F. prausnitzii has been reported to exert anti- nociceptive as well as anti-inflammatory effects [58,79] and to enhance the intestinal barrier function [46]. Similar to our observations, F. prausnitzii was also reported to be depleted in patients with CFS [61].

Bacteroides uniformis, is one of several species which have recently been reported as having altered relative abundance in patients with inflammatory arthritis, along with H. parainfluenza,P. copri and others [96]. B. uniformis and H. parainfluenza were detected in synovial tissues of osteoarthritic joints, whereas P. copri and H. parainfluenza were detected in rheumatoid arthritis synovial fluid. P. copri is thought to mediate inflammatory response via Th17 activation [37,43], and was also shown to induce arthritis in an animal model of arthritis-prone mice [51]. In this study, these species were found in lower abundance in FM patients. Although FM is often considered to be a rheumatologic disease, it seems that at least some species previously found at higher abundance in inflammatory rheumatic diseases are depleted in FM.​

In contrast to the depletion of butyrate producers F. prausnitzii and B. uniformis in FM patients, we observed significant higher relative abundance of a number of other known intestinal butyrate producers: Intestinimonas butyriciproducens, Flavonifractor plautii, Butyricoccus desmolans,Eisenbergiella tayi and the recently identified Eisenbergiella massiliensis . Alterations in butyrate and propionate metabolizing species were further supported by alterations in serum levels of these short chain fatty acids. Coherent with this putative shift in the butyrate producing community of FM patients, Parabacteroides merdae was also significantly higher in relative abundance in FM patients.

Recently, P. merdae has been reported by Olson et al. to be one of two key mediators of the anti-epileptic effect of the ketogenic diet [64]: in a mouse model, ketogenic diet can drive an increase in the abundance of P. merdae, which in turn, by regulation of amino acid γ-glutamylation leads to an increase in hippocampal γ-aminobutyric acid (GABA)/glutamate ratio. The increase in the inhibitory to excitatory neurotransmitter ratio in the brain is thought to protect against seizures. The second key mediator species of the ketogenic diet effect on seizures reported by Olson et al. was Akkermansia muciniphila, which in our cohort was also found at higher abundance in FM patients, although this observation did not reach statistical significance (p=0.042, Benjamini-Hochberg FDR=0.27).​

It's interesting stuff, although clearly early days.

The study looks to have been well done as far as a quick skim by someone unqualified to judge can tell. Canadian researchers. Perhaps worth encouraging them.

 

So this study of FM patients found Faecalibacterium prausnitzii to be depleted. And they reference a 1979 study that found lower levels of F. prausnitzii in people with CFS.

They don't reference the much more recent Hanson study (mentioned above) that found the same thing.

I wonder if the two research groups are aware of each other.