Gut Bacteria Hydrogen May Slow Cellular Aging and Prevent Senescence
- Authors
- Takahiro Sakai, Ryosuke Kurokawa, Shin-Ichi Hirano, Jun Imai
- Journal
- International Journal of Molecular Sciences
- Year
- 2019
- DOI
- 10.3390/ijms20020456
- Study Type
- Cell Culture
- Outcome
- Positive
- Peer Reviewed
- Yes
- Country
- Japan
- Health Condition
- Cellular Senescence
- Body System
- Digestive
TL;DR
Gut bacteria may help slow down aging by producing hydrogen gas that protects our cells from damage.
Key Finding
Hydrogen gas suppressed cellular aging by neutralizing harmful hydroxyl radicals in cells, which prevented the accumulation of hydrogen peroxide and blocked two major aging-related signaling pathways (ATM/p53 and HRI/eIF2α).
Summary
This cell culture study investigated how hydrogen gas (H2) produced by gut bacteria might protect cells from aging. Researchers exposed cells to a substance that creates harmful molecules called hydroxyl radicals, which trigger cellular aging. When they added hydrogen gas to the cell culture, it reduced the buildup of hydrogen peroxide (a damaging byproduct) and prevented the cells from entering a senescent (aged) state by blocking specific aging-related signaling pathways.
Practical Takeaway
This is early laboratory research in cells only, not human studies, so it cannot yet support any health claims about hydrogen water and aging. The findings suggest a potential mechanism by which gut bacteria-produced hydrogen might influence cellular aging, but much more research—including animal and human studies—would be needed to determine if hydrogen water has any practical anti-aging benefits.
Abstract
Bacteria inhabiting the human gut metabolize microbiota-accessible carbohydrates (MAC) contained in plant fibers and subsequently release metabolic products. Gut bacteria produce hydrogen (H2), which scavenges the hydroxyl radical (•OH). Because H2 diffuses within the cell, it is hypothesized that H2 scavenges cytoplasmic •OH (cyto •OH) and suppresses cellular senescence. However, the mechanisms of cyto •OH-induced cellular senescence and the physiological role of gut bacteria-secreted H2 have not been elucidated. Based on the pyocyanin-stimulated cyto •OH-induced cellular senescence model, the mechanism by which cyto •OH causes cellular senescence was investigated by adding a supersaturated concentration of H2 into the cell culture medium. Cyto •OH-generated lipid peroxide caused glutathione (GSH) and heme shortage, increased hydrogen peroxide (H2O2), and induced cellular senescence via the phosphorylation of ataxia telangiectasia mutated kinase serine 1981 (p-ATMser1981)/p53 serine 15 (p-p53ser15)/p21 and phosphorylation of heme-regulated inhibitor (p-HRI)/phospho-eukaryotic translation initiation factor 2 subunit alpha serine 51 (p-eIF2α)/activating transcription factor 4 (ATF4)/p16 pathways. Further, H2 suppressed increased H2O2 by suppressing cyto •OH-mediated lipid peroxide formation and cellular senescence induction via two pathways. H2 produced by gut bacteria diffuses throughout the body to scavenge cyto •OH in cells. Therefore, it is highly likely that gut bacteria-produced H2 is involved in intracellular maintenance of the redox state, thereby suppressing cellular senescence and individual aging. Hence, H2 produced by intestinal bacteria may be involved in the suppression of aging