23 May 2026
The gut–joint axis: a closer look at the emerging research
For a long time, osteoarthritis was explained almost entirely as wear and tear. That explanation is being broadened. One of the studies most often cited in that shift was published in Science in 2025. It's a good piece of research — and a good example of why it's worth reading past the headline.
What the researchers did
The research team combined several kinds of evidence.
Study at a glance: The GLP-1–mediated gut–joint axis in knee osteoarthritis
Study type: Human observational studies plus laboratory experiments in mice
Who was studied: Blood metabolites in 1,868 people across two cohorts; stool samples from 981 people; health records of 5,972 people; mouse models of knee osteoarthritis
What it found: People with knee osteoarthritis had lower levels of a bile acid called GUDCA, and lower levels went with more severe disease. A gut bacterium, Clostridium bolteae, tracked closely with GUDCA and was less common in people with osteoarthritis. In mice, acting on a bile-acid sensor in the gut (FXR) raised GLP-1 and altered cartilage outcomes in the mouse model
What it does not establish: That this pathway works the same way in people, or that diet, probiotics or supplements can change it. The human findings are associations
Did it test LYVA Flex: No
Yang Y et al. Osteoarthritis treatment via the GLP-1–mediated gut-joint axis targets intestinal FXR signaling. Science 2025;388:eadt0548. doi:10.1126/science.adt0548
The researchers also looked at health records for people taking UDCA, a prescription drug used for some liver conditions. Those taking it had a lower rate of knee replacement for osteoarthritis than similar people who weren't. That is an observational finding: the absolute difference was small, and it doesn't prove the drug caused it. UDCA is a medicine and should only be taken on a doctor's advice.
Why it matters
The study is important because it brings together human data and a worked-out biological mechanism. The authors describe it as evidence for a "functional and targetable gut–joint axis" — though the functional part was shown in mice.
A 2026 review in Nature Reviews Rheumatology, from the same research group, summarised the wider field the same way: gut changes are associated with osteoarthritis in human studies, animal work points to several possible pathways, but "evidence supporting therapeutic strategies that target the gut–joint axis remains limited".
What it doesn't tell us
- It doesn't show that osteoarthritis is caused by the gut.
- It doesn't show that changing your gut bacteria will protect your joints.
- It doesn't show that any food supplement — including ours — works through this pathway.
- The human findings come from specific populations and may not apply to everyone.
Where LYVA stands
Research like this is why we think the gut–joint axis is worth taking seriously, and why LYVA Flex is being developed with the gut environment in mind. But an interesting mechanism is not the same as proof that a supplement improves a medical condition. LYVA Flex is a food supplement for healthy movement. It is not a treatment for osteoarthritis, and it hasn't been tested in a clinical trial.
Further reading
Yang Y et al. (2025). Osteoarthritis treatment via the GLP-1–mediated gut-joint axis targets intestinal FXR signaling. Science 388:eadt0548. doi:10.1126/science.adt0548
Wei J et al. (2026). The gut–joint axis in osteoarthritis. Nature Reviews Rheumatology 22(6):345–361. doi:10.1038/s41584-026-01378-2
Explore how we are developing LYVA Flex: read the science or join the waitlist.
This article is for general information only. It is not medical advice. LYVA Flex is a food supplement, not a medicine. If you have a joint condition or take medication, speak to your GP or physiotherapist.
— William Tyler-Street, Founder