Yes, Parkinson's is a disease that effects nerve cells in the brain, leading to tremors, stiffness, speech changes and more, according to Mayo Clinic. However, there is growing evidence that the degenerative disorder actually begins in the GI tract and then travels to the central nervous system—which has led to more research on how nutrition and gut health affect cognitive decline. One such new study suggests that taking the B vitamin biotin could protect the brain from Parkinson's disease.
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How are gut health and Parkinson's connected?
A Sept. 2024 study published in the journal JAMA Network Open asked the question: "Is upper gastrointestinal mucosal damage associated with increased risk of subsequent Parkinson disease (PD) diagnosis?"
Researchers analyzed the health data of 9,350 patients with no prior history of Parkinson's and found that those with upper gastrointestinal mucosal damage (injury, such as ulcers, to the esophagus, stomach, or upper part of the small intestine) had a 76 percent higher chance of developing the disease.
"Many people who get Parkinson’s disease experience GI symptoms like constipation and nausea for years — even decades — prior to developing motor symptoms like difficulty walking or tremors. Our lab has been trying to better illuminate this 'gut-first' pathway of Parkinson’s disease because it can open new avenues for early intervention and treatment strategies," said corresponding author Trisha S. Pasricha, a neurogastroenterologist and director of Clinical Research at the Institute for Gut-Brain Research at BIDMC, in an interview with The Harvard Gazette.
Vitamin deficiencies have been previously linked to Parkinson's.
A May 2024 study published in the journal npj Parkinson's Disease looked at a different connection between Parkinson's and the gut. Specifically, researchers sought to "identify gut microbial features" in those with the disease.
The meta-analysis considered fecal samples from 94 Parkinson's patients and 73 control people in Japan, comparing these results with five previously reported datasets from the U.S., China, Taiwan, and Germany.
As Best Lifepreviously reported, "According to the study, those with Parkinson's disease were found to have a noticeable lack of bacterial genes that could contribute to the potential deficiency of two important B vitamins, riboflavin (B2) and biotin (B7)."
Riboflavin—which is found most commonly in eggs, organ meats, lean red meat, milk and yogurt, and fortified cereals and oats—"improves oxidative stress, mitochondrial dysfunction, neuroinflammation, and glutamate excitotoxicity," all of which are inversely related to Parkinson's disease, the study authors wrote.
Likewise, biotin—found in organ meats, eggs, canned salmon, pork chops, ground beef, sunflower seeds, and sweet potatoes—"produces anti-inflammatory substances and decreases inflammation, which leads to the relief of allergy, immunological symptoms, and inflammatory bowel disease," they note.
RELATED: 5 Surprising Benefits of Taking a Biotin Supplement.
Now, more research shows the protective benefits of biotin.
The authors of the previous study concluded that B vitamin supplementation could help protect against developing Parkinson's, and now research takes that hypothesis a step further.
Published on Jan. 21, 2025, in the journal Science Signaling, this new study suggests that biotin may protect the brain from "manganese-induced damage."
Manganese is a mineral found in trace amounts in the body, mainly in the bones, liver, kidneys, and pancreas, notes Mount Sinai. Among its other functions, it is "necessary for normal brain and nerve function," the hospital says.
"Abnormal concentrations of manganese in the brain, especially in the basal ganglia, are associated with neurological disorders similar to Parkinson's disease," Mount Sinai adds.
The most common ways people are overly exposed to the mineral is through fumes at steel mills and mines or rural drinking water.
Using model systems and human nerve cells, the researchers concluded that "biotin may have a protective effect, potentially mitigating manganese-induced damage," according to a press release.
However, since biotin is synthesized by gut bacteria before enhancing dopamine production in the brain, this further supports the importance of gut health in Parkinson's prevention.
"Biotin supplementation shows potential as a therapeutic strategy to mitigate manganese-induced neurodegeneration, and the safety and tolerability of biotin in humans make it a promising candidate for further exploration,” said Sarkar Souvarish, PhD, an assistant professor at the University of Rochester Medical Center (URMC) Departments of Environmental Medicine and Neuroscience and lead author of the study. "Biotin-rich prebiotics or biotin-producing probiotics could provide non-pharmacological intervention options, but more studies have to performed."
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The takeaway:
Growing evidence supports the theory that Parkinson's disease develops in the gut before attacking the central nervous system and brain. To this point, two studies suggest that B vitamins, specifically biotin, and riboflavin, could protect against Parkinson's when taken as supplements.
