Science: If You Do This When You Pass Gas, It Could Actually Be Good for Your Brain

It’s…not a pleasant thought, but maybe it’s a little like the recent research that suggested 90% of us pick our noses in private: If you sniff your stinkers for curiosity or health clues, you’re almost certainly in fair company. Now, research even suggests that when that whiff hits your brain, there could be some protective benefit.

Let’s start with a little science lesson: National experts have said the smelly molecule the body produces is hydrogen sulfide—2024 insight from the Agency for Toxic Substances and Disease Registry stated: “Bacteria found in your mouth and digestive tract produce hydrogen sulfide during the digestion of food containing vegetable or animal proteins.” The agency added that “very high levels can result in sudden unconsciousness or death”—which sounds a little like what your sibling would have cried out in childhood.

In that case, you could get the last laugh. An October 2025 scientific review published in the journal Neuroscience described this gas as a “silent neuroprotector,” citing evidence that it may help counter several key processes involved in Alzheimer’s disease, including inflammation, oxidative stress, and protein damage in brain cells.

That builds on earlier findings. In 2014, pharmacology research noted the gas plays a role in cell communication and blood flow. Then, a 2021 study at Johns Hopkins Medicine published in Proceedings of the National Academies of Science found that hydrogen sulfide may help slow or even reverse cognitive decline engineered to mimic Alzheimer’s disease in mice.

Researchers injected the genetically engineered mice with a hydrogen sulfide-carrying compound called NaGYY. The compound slowly released passenger hydrogen sulfide molecules while it traveled throughout the body. From there, the researchers tested the mice for any changes in their memory and motor function over 12 weeks.

According to a news release, the hydrogen sulfide improved cognitive and motor function by 50% compared to the mice that were not injected with the NaGYY compound. The treated mice were able to “better remember the locations of platform exits and appeared more physically active” than the untreated mice.

According to the researchers, these results showed that “the behavioral outcomes of Alzheimer’s disease” may be reversed by introducing hydrogen sulfide. Hydrogen sulfide appeared to interfere with a damaging chain reaction involving an enzyme called GSK3β and a protein known as tau. In Alzheimer’s disease, tau proteins become abnormally modified and clump together inside neurons, disrupting communication between brain cells. Hydrogen sulfide helped prevent this excessive tau modification, preserving healthier brain signaling.

“Our new data firmly link aging, neurodegeneration, and cell signaling using hydrogen sulfide and other gaseous molecules within the cell,” commented Bindu Paul, M.Sc., Ph.D., faculty research instructor in neuroscience in the Solomon H. Snyder Department of Neuroscience at the Johns Hopkins University School of Medicine.

The growing discoveries may serve as evidence that even for the most seemingly undesirable bodily functions, nature has a purposeful design.

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