For over a decade I suffered from bursitis in both my feet (large toes), plus mild plantar fasciitis. The standard podiatrist-recommended treatments included shoe inserts, Medieval taping, and dry heat were completely ineffective. But when I took a broad-spectrum probiotic as a digestive aide I noticed the pain almost completely disappeared after a week! Since I wasn't expecting this outcome, it's unlike to be a placebo effect. Two years later I am still essentially pain free (while the occasional residual flare-ups are minor).

It's likely your body contains more foreign microbes (in the form of bacteria and viruses), than human cells. They sometimes control our mood, metabolism and disease response. There is some evidence microbes can reduce inflamation.

Although the medical literature rarely considers the link between neuropathy and the biome worthy of study, here are two papers of interest:

Clinical Evidence for the Microbiome in Inflammatory Diseases

Microorganisms are crucial in maintaining gastrointestinal homeostasis and can potently modulate systemic immunity, and differences in the microbiota have been observed in patients with inflammatory diseases compared to healthy controls. There is a growing amount of clinical research being done to better understand the role that the microbial community can play in inflammatory diseases,

Benefits of Probiotics in Rheumatic Diseases

Concerning probiotics, the results of the RCTs discussed above are still limited to firmly conclude their effect in improving disease activity or progression, and even less in preventing disease development. However, their promising anti-inflammatory and immunomodulating properties are worth to be investigated by larger population studies, in order to identify their possible functional interest in supporting standard therapies and disease activity control in rheumatic diseases.

The probiotic brand I took for a month that inadvertently eliminated my chronic toe pain is

https://wholesome-wellness.com/product/raw-probiotics-100-billion-cfu/

Originally, I had hoped these microbes would permanently colonize my biome, so additional treatment would be unnecessary. But entirely stopping their consumption slowly increased pain levels, while two capsules a week reduced or eliminated any discomfort.

Of course, the therapeutic dose is unknown, and I assume only one or two of the species on the ingredients list are responsible. For a host of reasons one should take claims of superfoods, vitamins and natural cures skeptically- their overall track record is quite poor. Careful double-blind studies are imperative.

Your mileage may vary.