Ankylosing spondylitis and your vagina and urinary tract

Ankylosing spondylitis (AS) is a chronic inflammatory condition affecting the spine and joints with no known cause. AS is understood (in theory) to be an autoimmune disease and a form of reactive arthritis. There is evidence that the gut microbiome and intestinal inflammation is closely linked to this condition.

AS and bugs

While AS tends to affect men between the ages of 20 and 30, it also affects women. Symptoms range from lower back pain, stiffness, with fusing of bone, alongside a positive genetic marker. There are close associations with the microbiome, immune reactivity and inflammation, but any deciding factor or cure remains elusive. Females are more likely to experience gut symptoms than males, but gut dysbiosis with markers of inflammation was found in almost 90 per cent of a group of men with AS​1​.

There have been various considerations of causes of symptoms, including Klebsiella bacteria, a bacteria closely linked with genitourinary tract infections. Ankylosing spondylitis is also associated with vaginal and urinary tract infections generally​2​ and sexual dysfunction​3​ with suggestions that infection may be the trigger for the development of AS​2​, in the presence of the positive genetic marker test.

Meaning, if you are positive for HLA-B27 and get a vaginal or urinary tract infection, it could trigger AS that wasn’t showing symptoms previously.

Interestingly, as early as 1953 there were associations drawn between AS and male genitourinary infection, with observations of increased urogenital infections in male patients with AS. Vaginal studies have shown links to bacteria.

Although now an old study​2​, Lange et al found genitourinary infection was found significantly more frequently in female AS patients.

Understsanding ankylosing spondylitis and HLA-B27

HLA-B27 is a blood test looking for a protein found on the surface of white blood cells, human leukocyte antigen B27 (HLA-B27). HLAs are immune proteins that help determine self and foreign substances. HLA-B27 is made via instructions from a gene passed on from our parents.

HLA-B27 may shape the gut microbiota or alter how the antigen behaves in some people. Subclinical gut inflammation is found in up to 60 per cent of AS patients. There is a growing association between the gut microbiome and autoimmune disease. ​4​

A positive HLA-B27 test indicates a higher risk for developing specific autoimmune disorders, whereby the HLA-B27 mistakes our own cells for invading pathogens or foreign substances. The result is the destruction of healthy tissue, and what’s known as spondyloarthritis. Just testing positive does not mean you have these conditions.

Spondyloarthritis is broken down into sub-groups:

  • Ankylosing spondylitis
  • Crohn’s disease or ulcerative colitis-related arthritis
  • Psoriatic arthritis (related to psoriasis)
  • Reactive arthritis
  • Sacroilitis (sacroiliac joint inflammation)
  • Uveitis (eye inflammation)

Klebsiella and AS – what’s the connection?

AS can occur after infection with Klebsiella in an HLA-B27-positive person. There appears to be molecular mimicry between HLA-B27 and Klebsiella​5​, though this theory is still developing. Increases in faecal Klebsiella has been found in Europe and North American patient stool samples, while antibodies to Klebsiella have been found in AS patients in England and Finland.

We still don’t know for sure if this association exists between AS and HLA-B27-positive people, but it does seem clear that microbes may be playing a role. Namely, the innate immune system and gut microbes may interact resulting in inflammation. K. pneumoniae, a species of Klebsiella, has been implicated as at least an exacerbating agent for AS.

K. pneumoniae are surrounded by polysaccharide-rich capsules, an essential part of its virulence. In those living with AS, immune responses to specific serotypes appear to trigger higher antibody levels in HLCA-B27-positive AS patients compared with other K. pneumoniae serotypes.

Results of studies into AS and K. pneumoniae have been conflicting and we don’t know what the relationship is between K. pneumoniae antibodies and AS. We do know that antibiotic therapy has shown improvements in AS disease activity.

Treatments for AS


The western medical model for treating AS is the use of pain killers, glucocorticoids and immunosuppressive drugs. These drugs are usually not fully effective in preventing the progression of disease though they can provide symptom relief. Long-term use of drugs is associated with bone and muscle wasting and cardiovascular issues.


Diet establishes and maintains the human intestinal microbiome, with various nutrients impacting the structure of the microbial communities and offering up substrates for microbial metabolism. Indigestible carbohydrates are fermented by gut microbes and produce short-chain fatty acids which are known to regulate immune function​6​ and intestinal hormone production. The gut is the largest endocrine (hormone) and immune organ in the body, so addressing the digestive tract in autoimmune disease is a pragmatic and prudent first step.

Altering the diet to alter the gut microbiome to reduce intestinal inflammation could be useful. A study has shown that those on a high carb/low protein diet had 40 per cent greater numbers of K. pneumoniae than those on a low-carb/high protein diet. A low-starch diet thus may decrease inflammatory activity and stop disease progression in AS and potentially other reactive arthritis conditions.

A low carb/high protein diet can be used in conjunction with drugs with or without antimicrobial therapy, which could come in the form of targeted herbal medicine or antibiotics.

There are many diet regimes that are known to be beneficial in autoimmune disorders, such as the autoimmune protocol (AIP), gluten-free, dairy-free, paleo, low-FODMAP and others. The exact mechanism through which diet modifications create change is not fully understood but thought to be the result of reducing irritants, allergens and ‘unfriendlies’ from the digestion to reduce immune responses and inflammation. If you have been diagnosed with AS, diet is a great place to start your journey.

Herbal antibiotics

There are many alternatives to drug antibiotics. Please see an experienced naturopath or herbalist for comprehensive treatment.


  1. 1.
    Klingberg E, Magnusson MK, Strid H, et al. A distinct gut microbiota composition in patients with ankylosing spondylitis is associated with increased levels of fecal calprotectin. Arthritis Res Ther. Published online November 27, 2019. doi:10.1186/s13075-019-2018-4
  2. 2.
    Lange U, Berliner M, Ludwig M, et al. Ankylosing spondylitis and infections of the female urogenital tract. Rheumatology International. Published online February 27, 1998:181-184. doi:10.1007/s002960050031
  3. 3.
    Akkurt H, Yilmaz H, Yilmaz S, Parlak L, Ordahan B, Salli A. Evaluation of Sexual Dysfunction in Females With Ankylosing Spondylitis. Arch Rheumatol. 2015;31(1):41-47. doi:10.5606/ArchRheumatol.2016.5697
  4. 4.
    Zhang L, Zhang YJ, Chen J, et al. The association of HLA-B27 and Klebsiella pneumoniae in ankylosing spondylitis: A systematic review. Microbial Pathogenesis. Published online April 2018:49-54. doi:10.1016/j.micpath.2018.02.020
  5. 5.
    Ebringer A. Ankylosing spondylitis is caused by Klebsiella. Evidence from immunogenetic, microbiologic, and serologic studies. Rheum Dis Clin North Am. 1992;18(1):105-121.
  6. 6.
    Smith PM, Howitt MR, Panikov N, et al. The Microbial Metabolites, Short-Chain Fatty Acids, Regulate Colonic T            reg            Cell Homeostasis. Science. Published online August 2, 2013:569-573. doi:10.1126/science.1241165

Jessica Lloyd - Vulvovaginal Specialist Naturopathic Practitioner, BHSc(N)

Jessica is a degree-qualified naturopath (BHSc) specialising in vulvovaginal health and disease, based in Melbourne, Australia.

Jessica is the owner and lead naturopath of My Vagina, and is a member of the:

  • International Society for the Study of Vulvovaginal Disease (ISSVD)
  • International Society for the Study of Women's Sexual Health (ISSWSH)
  • National Vulvodynia Association (NVA) Australia
  • New Zealand Vulvovaginal Society (ANZVS)
  • Australian Traditional Medicine Society (ATMS)