A 2026 rodent study investigated effects of inulin intake:
“This study investigated whether the prebiotic inulin could improve vascular cognitive impairment (VCI) by restoring medial prefrontal cortex (mPFC) GABAergic function via the gut-brain axis. The medial prefrontal cortex (mPFC), a hub for executive functions such as working memory and decision-making, is particularly vulnerable to vascular insults.
Clinical and preclinical evidence consistently implicates mPFC dysfunction as a critical contributor to cognitive deficits in VCI. Inulin reversed VCI-induced reductions in GABAergic synaptic transmission and GABA levels, which positively correlated with elevated colon short-chain fatty acid (SCFA) levels.
While prior work has established that direct SCFA administration or fecal microbiota transfer can mitigate brain injury in hypoperfusion models, our data advance the field by identifying a simple dietary intervention that can initiate this protective cascade.
We propose that SCFA-GPR41/43 signaling enhances the presynaptic GABAergic machinery, thereby strengthening inhibitory tone. This restored inhibition was associated with a reduction in neuroinflammation and oxidative stress, effects that were reversed upon GABAergic blockade, suggesting that the reinstated GABAergic activity may actively suppress glial activation and promote a synaptic environment conducive to plasticity.“
https://link.springer.com/article/10.1186/s40168-026-02469-8 “Inulin alleviates vascular cognitive impairment by restoring prefrontal GABAergic function via microbiota-SCFA-GPR41/43 axis”
Despite this rodent study’s biological plausibility, there are all sorts of problems translating it into human results that will show cognitive improvement. The primary obstacle is that inulin is unpatentable, and no pharma company can make big money off of running trials for it.
We can wait around to see clinical trial results such as those due in 2027 with the https://clinicaltrials.gov/study/NCT06433037 “Gut-brain Health Effects of PREbiotics in Older Adults With Suspected COgnitive DEcline (PRECODE)” trial (chicory inulin and other fibers for 26 weeks in older adults with subjective cognitive decline) testing working memory, fMRI, and gut-brain markers. But that trial won’t specifically test inulin for alleviating relatively common vascular cognitive impairment.
