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Probiotic Strain Protects Aging Nerve Cells in Worms

A biofilm-forming probiotic strain protected aging nerve cells in roundworms, and a ginkgo extract boosted the effect further.

By Dr. Axe Editorial Team · October 28, 2026 · 1 source · Watch

A probiotic strain known for forming strong biofilms delayed age-related damage to nerve cells in roundworms, according to a study published October 16, 2026 in GeroScience.

Researchers screened multiple strains of the probiotic bacteria Bacillus subtilis for how well they form biofilms. They then fed roundworms (Caenorhabditis elegans) engineered so their cholinergic neurons glow green either the biofilm-strong strain, called B4U 50, or a standard laboratory strain, B. subtilis 168, for up to 15 days, with or without a standardized ginkgo biloba preparation added to the diet. Using fluorescence microscopy, the team tracked the worms' nerve fibers over several days, watching for knots and ruptures that typically appear as the animals age.

Worms fed the biofilm-forming strain had fewer of these structural defects than worms fed the standard strain, including worms switched onto the biofilm-forming strain later in life. Adding the ginkgo extract protected nerve fibers in worms on either bacterial strain, and the strongest protection came from combining the biofilm-forming strain with the ginkgo extract.

Cholinergic neurons rely on the chemical messenger acetylcholine and are among the nerve cells that decline with age, contributing to memory and movement problems. The authors describe their biofilm-forming strain as neuroprotective compared with a standard probiotic strain in this roundworm model. More broadly, bacteria that form strong biofilms may persist longer in the gut and influence the gut-brain connection; this study did not test that mechanism directly.

15days

Longest feeding period tested in roundworms before nerve fiber damage was assessed

GeroScience, 2026, Gong et al.

This is a roundworm study using an engineered worm and a lab biofilm test, not a study in people or any mammal. The abstract gives no sample size, and the comparison was against a standard lab strain rather than a placebo or untreated group.

Dr. Axe’s Take

The gut and the brain are in constant conversation, and this study adds a small piece to that picture. A probiotic strain that builds strong biofilms, the sticky colonies bacteria form on the gut lining, protected aging nerve fibers better than a standard strain, and ginkgo made that protection stronger. This was in worms, so I wouldn't chase this particular strain. What I'd do this week is feed your gut's diversity: fermented foods like kefir and sauerkraut, and plenty of fiber from vegetables, nuts and seeds.

— Dr. Axe

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Story summary

Who: Transgenic roundworms (C. elegans) with glowing cholinergic neurons; sample size not reported
Design: In vitro biofilm screening plus a worm feeding study, up to 15 days
Dose: B. subtilis strain B4U 50 or control strain 168, with or without a standardized ginkgo biloba preparation
Primary result: Fewer age-related nerve fiber defects (knots and ruptures) in worms fed the biofilm-forming strain vs. control strain
Secondary: Ginkgo extract reduced nerve damage with either bacterial strain; combining biofilm strain plus ginkgo gave the strongest protection; benefit held even when worms were switched to the strain later in life
Funding / conflicts: Funder listed in the journal record: Evonik Operations. Conflict statement in the PubMed record: too long to show here; see the source paper.
Date: Oct 16, 2026