A recent scientific breakthrough suggests an unlikely ally in the fight against Alzheimer’s disease: hydrogen sulfide, the notorious gas your body releases when you pass wind.
Researchers at Johns Hopkins Medicine discovered that this compound, typically associated with its distinctive rotten egg odor, may actually shield aging brain cells from the devastating effects of neurodegeneration. The findings, published in The Proceedings of the National Academy of Sciences, reveal how declining hydrogen sulfide levels in the brain could contribute to cognitive decline as we age.
The research carries significant weight given that approximately 500,000 Americans receive an Alzheimer’s diagnosis annually. Scientists have long searched for ways to slow or reverse the condition’s progression, and this discovery offers a promising new direction.
“Our new data firmly link aging, neurodegeneration and cell signaling using hydrogen sulfide and other gaseous molecules within the cell,” says Bindu Paul, Ph.D., faculty research instructor in neuroscience at Johns Hopkins University School of Medicine and lead corresponding author on the study.
The human body produces small quantities of hydrogen sulfide naturally to help manage various biological processes, from cell metabolism to blood vessel expansion. This gas functions as a cellular messenger, particularly important in brain activity. However, as we age, our ability to generate this compound diminishes, potentially leaving neurons more susceptible to damage.
To investigate these effects, the research team worked with genetically modified mice designed to replicate Alzheimer’s disease in humans. The animals received injections of NaGYY, a specially developed compound that gradually releases hydrogen sulfide throughout the body over time.
After 12 weeks of treatment, the results proved remarkable. Behavioral assessments revealed that hydrogen sulfide improved cognitive and motor function by 50% compared with untreated mice. The treated group demonstrated better memory recall when locating platform exits and displayed notably higher activity levels than their counterparts.
“The results showed that the behavioral outcomes of Alzheimer’s disease could be reversed by introducing hydrogen sulfide,” the research team said.
But the scientists wanted to understand the underlying chemistry at work in the brain. Their investigation uncovered changes to glycogen synthase kinase beta, a common enzyme that normally functions as a signaling molecule in the presence of adequate hydrogen sulfide levels.
When hydrogen sulfide concentrations drop, however, this enzyme becomes overly attracted to a brain protein called Tau. This interaction transforms Tau into a form that tangles and accumulates inside nerve cells. As these clumps expand, they obstruct communication between neurons, eventually causing cellular breakdown.
“This leads to the deterioration and eventual loss of cognition, memory, and motor function,” the researchers explained.
“Understanding the cascade of events is important to designing therapies that can block this interaction like hydrogen sulfide is able to do,” says Daniel Giovinazzo, M.D./Ph.D. student and first author of the study.
Collaborator Matt Whiteman, Ph.D., professor of experimental therapeutics at the University of Exeter Medical School, emphasized the significance of the delivery method: “The compound used in this study does just that and shows by correcting brain levels of hydrogen sulfide, we could successfully reverse some aspects of Alzheimer’s disease.”
Earlier research using advanced measurement techniques confirmed that sulfhydration levels in the brain decrease with age, a pattern that becomes more pronounced in Alzheimer’s patients. Some studies have even indicated that hydrogen sulfide concentrations vary between individuals, with certain research suggesting female flatulence contains higher levels than male flatulence.
While these experiments focused on mice, the results provide a foundation for developing new pharmaceutical approaches. Rather than depending solely on the body’s natural production, future treatments could specifically target declining hydrogen sulfide levels to slow or potentially reverse neurodegenerative damage associated with Alzheimer’s disease.
The research team stressed that additional studies are necessary to determine whether these same effects can be replicated safely and effectively in human patients.