Rifaximin Alters Intestinal Microbiota and Prevents Progression of Ankylosing Spondylitis in Mice

pattismith

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Front. Cell. Infect. Microbiol., 04 March 2019 | https://doi.org/10.3389/fcimb.2019.00044

Rifaximin Alters Intestinal Microbiota and Prevents Progression of Ankylosing Spondylitis in Mice


Lianjun Yang
1†,
Bin Liu1†,
Junchi Zheng1†,
Jincheng Huang2,
Qinghao Zhao1,
Jinshi Liu1,
Zhihai Su1,
Min Wang1,
Zhifei Cui1,
Tingxuan Wang1,
Weicong Zhang1,
Qingchu Li1 and
Hai Lu
1*
  • 1Department of Orthopedic Surgery, Orthopaedic Hospital of Guangdong Province, Academy of Orthopedics of Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou, China
  • 2Department of Orthopedics, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, China
Recently, accumulating evidence has suggested that gut microbiota may be involved in the occurrence and development of ankylosing spondylitis (AS). It has been suggested that rifaximin have the ability to modulate the gut bacterial communities, prevent inflammatory response, and modulate gut barrier function. The goal of this work is to evaluate the protective effects of rifaximin in fighting AS and to elucidate the potential underlying mechanism. Rifaximin were administered to the proteoglycan (PG)-induced AS mice for 4 consecutive weeks. The disease severity was measured with the clinical and histological of arthritis and spondylitis. Intestinal histopathological, pro-inflammatory cytokine levels and the intestinal mucosal barrier were evaluated. Then, western blot was performed to explore the toll-like receptor 4 (TLR-4) signal transducer and NF-κB expression. Stool samples were collected to analyze the differences in the gut microbiota via next-generation sequencing of 16S rDNA. We found that rifaximin significantly reduced the severity of AS and resulted in down-regulation of inflammatory factors, such as TNF-α, IL-6, IL-17A, and IL-23. Meanwhile, rifaximin prevented ileum histological alterations, restored intestinal barrier function and inhibited TLR-4/NF-κB signaling pathway activation.

Rifaximin also changed the gut microbiota composition with increased Bacteroidetes/Firmicutes phylum ratio, as well as selectively promoting some probiotic populations, including Lactobacillales.
Our results suggest that rifaximin suppressed progression of AS and regulated gut microbiota in AS mice. Rifaximin might be useful as a novel treatment for AS.


Introduction
Ankylosing Spondylitis (AS) is a chronic systemic autoinflammatory disease mainly affects sacroiliac joints and axial skeleton. To date, a lack of knowledge regarding the precise molecular mechanisms underlying AS progression limits the ability to halt the progression of this disease. Although human leukocyte antigen B27 (HLA-B27) is estimated to be linked to 90–95% of AS cases (Martín-Esteban et al., 2017), the relationship between HLA-B27 and AS has not been fully elucidated. The cause of AS cannot be fully explained by a genetic predisposition alone, explaining the ongoing need to identify additional predisposing factors. The consensus is that AS is caused by coaction of heredity and environmental factors (Yang et al., 2016).
Changes in the commensal intestinal microbiota has been associated with several autoimmune diseases, including multiple sclerosis (Mestre et al., 2018), inflammatory bowel disease (IBD) (Sheehan et al., 2015), and type 1 diabetes (Meijnikman et al., 2018). Many studies have shown that AS and IBD share similar genetic risk factors and etiopathogeneses (Rashid et al., 2013). Studies based on next-generation sequencing technology, and bioinformatics suggest a significant relationship between the pathogenesis of AS and dysbiosis of intestinal microbiota. Wen et al. (2017) demonstrated that intestinal microflora in AS patients were enriched in Prevotella melaninogenica, Prevotella copri, and Prevotella sp. C561, along with a lower level of Bacteroides spp. In a similar study, in the terminal ileum, AS patients had significantly increased levels of five bacterial families and reduced levels of two bacterial families, when compared to healthy controls (Costello et al., 2014). In animal experiment, HLA-B27 transgenic rats housed in a germ-free environment do not appear features of spondyloarthritis (SpAs). However, HLA-B27 transgenic rats when transferred to a conventional rat colony, these rats appeared AS-like symptoms including colitis and arthritis (Rath et al., 1996). This suggests that intestinal flora takes a critical role in the pathogenesis of AS, and gut microbiota may therefore become a potential target for AS treatment.
Using antibiotics to manipulate gut microbiota may represent a potentially effective treatment option for AS. Previous research has shown that AS patients treated with moxifloxacin, a fourth-generation fluoroquinolone, presented with significantly reduced inflammatory symptoms (Ogrendik, 2007). Rifaximin is a gastrointestinal selective antibiotic that is almost no absorption into the blood with less adverse reaction (Ponziani et al., 2017). Rifaximin acts by inhibiting bacterial DNA-dependent RNA polymerase. While the full effect of rifaximin on gut flora remains limited. Previous studies have shown that rifaximin can alter intestinal flora, inhibit bacterial attachment, prevent intestinal inflammation, and modulate gut barrier function (Xu et al., 2014; Lopetuso et al., 2018). This special feature distinguishes rifaximin from other systemic antibiotics. Most studies up to now have focused on evaluating the effect of rifaximin on gut-liver axis or gut-brain axis (Ponziani, 2015; Wang et al., 2018). However, it is not clear whether orally administered rifaximin can prevent the development of AS by down-regulation of the inflammatory response triggered by gut microbes. In this research, we have evaluated the effects of rifaximin on the severity of AS, inflammatory response, and the changes in intestinal flora. To our knowledge, it is the first study to evaluate the effect of rifaximin on the gut-bone axis in AS.

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ljimbo423

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Thank you for tagging me @pattismith.:)

Yet another study showing the far reaching consequences of a disrupted microbiome in the development of many diseases.

Changes in the commensal intestinal microbiota has been associated with several autoimmune diseases, including multiple sclerosis (Mestre et al., 2018), inflammatory bowel disease (IBD) (Sheehan et al., 2015), and type 1 diabetes (Meijnikman et al., 2018).
Stool samples were collected to analyze the differences in the gut microbiota via next-generation sequencing of 16S rDNA. We found that rifaximin significantly reduced the severity of AS and resulted in down-regulation of inflammatory factors, such as TNF-α, IL-6, IL-17A, and IL-23.
Notice that by reducing levels of gram negative bacteria in the gut and therefore lipopolysaccharies (LPS). This Lowered the amount of LPS getting into the bloodstream from the gut and causing inflammation and ankylosing spondylitis (AS).

By lowering the level of LPS in the gut and getting into the bloodstream. The Rifaximin also reduced the pro-inflammatory cytokines TNF-α, IL-6, IL-17A, and IL-23. Which cause chronic inflammation and chronic inflammation has been found to be behind almost all chronic diseases.

There is little doubt in my mind that the gut microbiome is becoming the frontier of researching and battling chronic disease and this idea is growing more and more every year.:):thumbsup:
 

ryan31337

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This hits very close to home for me. I've taken Rifaximin for recurrent SIBO previously, and more recently had the onset of Axial Spondyloarthritis (AxSpA, essentially the precursor to AS).

It took a lot of effort but I do have a clinical diagnosis of AxSpA now. My presentation is not standard but there was enough suspicion according the AS expert Rheumy i saw and I'm due to start biologic therapy straight away because I can't tolerate NSAIDs.

In my mind there is and has always been, for over 20 years, a very clear link between my gut, joint and fatigue issues. Only in the last 2 years has it progressed enough to show objectively, with GI bleeding and post-inflammatory lesions on my spine. But despite those, I still don't meet the regular criteria for AxSpA/AS or Crohns.

I can't help but wonder if my explorations into Rifaximin and long-term low-FODMAP/ketogenic diets have held back the progression. Certainly a good subset of established AS patients do much better when initiating low-carb diets, it doesn't surprise me considering the microbiome impact of such a diet.
 

pattismith

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@ryan31337
glad you finally got the diagnosis. Let us know how you are doing with biologic therapy!

AS was the first disease I thought of in my case, because of my spine and pelvis pain, but rheumis always ruled it out (I am HLAB27 negative, and no blood nor xray sign of rheumatologic disease).

Azithromycin is efficient in my case, and I found one chinese study about azithromycin being efficient in AS patients, so I keep an eye on this disease. Some docs agree they might be atypical cases.
 

ryan31337

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Have you had an MRI @pattismith? Radiographic (x-ray) changes take a very long time to develop and in many cases never do (e.g. AxSpA that never fully progresses to AS), MRI is a lot more sensitive.

Even on MRI i've seen stats suggesting only 7/10 with AxSpA will show active inflammation. I'm in that 3/10 with a diagnosis on clinical grounds only, though I do show some lesions on MRI that probably reflect previous inflammatory changes. Perhaps if I was scanned at the right time it would've been more obvious.

B27 negativity will make most Rheumy's discount the possibility, but there are quite a few B27 negative patients with clear AS in a group I belong to - so it shouldn't be completely dismissed. I guess you would probably need some other clear signs like uveitis, enthesitis (particularly ankle/heel & ribs), peripheral arthritis, psoriasis, IBD etc. to be taken seriously for SpA. I have mild elements of all of these and wonder if I'd be better classified as an undifferentiated spondyloarthritis...
 

pattismith

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Have you had an MRI @pattismith? Radiographic (x-ray) changes take a very long time to develop and in many cases never do (e.g. AxSpA that never fully progresses to AS), MRI is a lot more sensitive.

Even on MRI i've seen stats suggesting only 7/10 with AxSpA will show active inflammation. I'm in that 3/10 with a diagnosis on clinical grounds only, though I do show some lesions on MRI that probably reflect previous inflammatory changes. Perhaps if I was scanned at the right time it would've been more obvious.

B27 negativity will make most Rheumy's discount the possibility, but there are quite a few B27 negative patients with clear AS in a group I belong to - so it shouldn't be completely dismissed. I guess you would probably need some other clear signs like uveitis, enthesitis (particularly ankle/heel & ribs), peripheral arthritis, psoriasis, IBD etc. to be taken seriously for SpA. I have mild elements of all of these and wonder if I'd be better classified as an undifferentiated spondyloarthritis...
Yes I had one ankle arthritis one time, and occasional swelling of finger's joint.
Ultrasound also noticed tendinitis with microcalcifications in my shoulders (I don't know if it could be labeled enthesitis or not), but it seems it wasn't enough for the rheumi.
I had also MRI of my lumbar and sacroiliac joints.
 

ryan31337

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Sounds like you're quite similar to me @pattismith. My lumbar/SIJ MRI is clear, the fatty romanus lesion is on thoracic spine and was only spotted because I had a full spine MRI.

Radiology here refuses to scan more than lumbar/SIJ in their MRI inflammatory back pain protocol, which is bullshit. Its contentious how to classify someone with FRLs and no sacroiliitis, but there's still plenty of evidence for SIJ sparing in some AxSpA patients. I guess they take the opinion that someone without sacroiliitis but with multiple FRLs is going to get a clinical diagnosis of AxSpA regardless... but that didn't happen in my case because the 2x Rheumy's I saw first were either unwilling or unable to make a clinical diagnosis. Third Rheumy was an AS expert and didn't hesitate based on B27++, ESR, inflammatory back pain & peripheral arthritis. The equivocal romanus lesion, skin complaints and gut problems probably helped convince her too.

I was pretty skeptical of the spondyloarthritis diagnosis until recently. Lots of very short flare ups (few days at a time), often mild, plus a hypermobility diagnosis clouding the water. But then last autumn I got hit with a 3x month severe flare that hit my thoracic spine again and thumb DIP in tandem. They got better gradually this year but are still tender now, 10 months on. Its obviously not AxSpA/AS in the classic aggressive sense, but there is definitely an inflammatory process going on so hopefully biologics will help. NSAIDs really helped but my gut had a meltdown after a week on them :(
 

pattismith

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@ryan31337 ,
fortunately you have some specific lesions that really help the diagnosis, and are relevant to spondylitis, I mean the romanus lesion, the high ESR and skin lesions, and you are a man and you are HLA B27 positive if I understood well.
I have none of these, so the hypothesis is still just very hypothetic for me.

Do you have Fibro? I read in recent studies that people with Spondylitis + Fibro doesn't often improve their fibro when they have the anti TNF alpha treatment, even when their spondylitis improves.
If Fibro is the result of the spinal stenosis produced by the spondylitis (I believe ME and Fibro are often triggered by spinal stenosis, after recent studies showing improvement of fibro and ME following spinal surgery), it is not surprising that the medical treatment for spondylitis is not enough to cure the fibro...
 

ryan31337

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Yes, you're right, I do register higher suspicion generally I think. That said, we haven't been able to replicate the raised ESR (though it isn't expected to always track with symptoms) and plenty of healthy people can have 1 or 2 romanus lesions from other causes. The B27 status would certainly be a sticking point for many docs though.

That said, its often noted that women have a less classic presentation, milder onset with less SIJ and more neck involvement - but its getting into the territory of needing a Rheumy that specialises in spondyloarthritis to get anywhere with that I feel.

I haven't got a diagnosis of Fibro. Probably because the pain & fatigue fit the post-viral/CFS label for a long time, then subsequently a hypermobility label. Had I seen a Rheumy early on I expect I would've been lumped into the Fibro group, but I don't really know how relevant that would've been. I've also had Small Fibre Neuropathy confirmed recently and from what I gather that seems at the root of a lot of Fibro diagnoses too.

Interesting about the spinal stenosis thoughts. My father suffers quite badly from that, but is otherwise the absolute normal healthy opposite to myself and my mothers CFS/autoimmune riddled side of the family.
 

pattismith

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just what we were talking about in this 2019 study

"Conclusion
The diagnostic delay in axSpA is still unacceptably long. Patients who are female, young at symptom onset, HLA-B27 negative or have psoriasis have a longer diagnostic delay. Specific referral strategies might be necessary in order to decrease the diagnostic delay in patients presenting with these characteristics."

and this other about gut microbiome role in AS:

HLA alleles associated with risk of ankylosing spondylitis and rheumatoid arthritis influence the gut microbiome

2019

Objectives

HLA alleles affect susceptibility to more than 100 diseases, but the mechanisms to account for these genotype‐disease associations are largely unknown. HLA‐alleles strongly influence predisposition to ankylosing spondylitis (AS) and rheumatoid arthritis (RA). Both AS and RA patients have discrete intestinal and faecal microbiome signatures. Whether these changes are cause or consequence of the diseases themselves is unclear. To distinguish these possibilities, we examine the effect of HLA‐B27 and HLA‐DRB1 RA‐risk alleles on the composition of the intestinal microbiome in healthy individuals.

Methods

568 samples from 6 intestinal sites were collected from 107 otherwise healthy unrelated subjects and stool samples from 696 twin pairs from the TwinsUK cohort. Microbiome profiling was performed using sequencing of the 16S rRNA bacterial marker gene. All patients were genotyped using the Illumina CoreExome SNP microarray, and HLA genotypes were imputed from these data.

Results

Association was observed between HLA‐B27 genotype, and RA‐risk HLA‐DRB1 alleles, and overall microbial composition (P=0.0002 and P=0.00001 respectively). These associations were replicated in the TwinsUK cohort stool samples (P=0.023 and P=0.033 respectively).

Conclusions

This study shows that the changes in intestinal microbiome composition seen in AS and RA are at least partially due to effects of HLA‐B27 and –DRB1 on the gut microbiome. These findings support the hypothesis that HLA alleles operate to cause or increase the risk of these diseases through interaction with the intestinal microbiome, and suggest that therapies targeting the microbiome may be effective in their prevention and/or treatment.