Hydrogen Gas Reduces Lung Damage and Improves Breathing in Mice
The effects of inhaling hydrogen gas on macrophage polarization, fibrosis, and lung function in mice with bleomycin-induced lung injury
Research hubs: Respiratory System
This research was done in animals. Results in animals often don't carry over to people.
- Evidence type
- Animal study (mouse)
- Authors
- Toshiyuki Aokage, Mizuki Seya, Takahiro Hirayama, Tsuyoshi Nojima, Masumi Iketani, Michiko Ishikawa, Yasuhiro Terasaki, Akihiko Taniguchi, Nobuaki Miyahara, Atsunori Nakao, Ikuroh Ohsawa, Hiromichi Naito
- Journal
- BMC Pulmonary Medicine
- Year
- 2021
- PMID
- 34719405
- Study Type
- Mouse
- Delivery
- Gas
- Dose
- 3.2% hydrogen in air for 6 hours daily for 7 or 21 days
- H₂ concentration
- 3.2% H2 in air
- Duration
- 3 weeks
- Outcome
- Positive
- Peer Reviewed
- Yes
- Cited by
- 24 (OpenAlex, as of November 2026)
- Country
- Japan
TL;DR
Breathing in hydrogen gas daily may help reduce lung damage and scarring in mice with a lung injury similar to severe respiratory distress in humans.
Key Finding
Mice with bleomycin-induced lung injury that inhaled hydrogen gas daily for 21 days had significantly better lung function and less lung scarring than untreated mice, along with reduced inflammatory markers.
Summary
Researchers gave mice a lung injury using a drug called bleomycin, then exposed some mice to hydrogen gas (mixed with air) for 6 hours daily for 21 days, while others breathed regular air. Mice that inhaled hydrogen gas showed better lung function (their lungs were more flexible and easier to inflate) and less scarring compared to mice that only breathed air. The hydrogen treatment also reduced inflammatory markers (chemical signals that cause swelling and damage) in the lungs.
Practical Takeaway
This early-stage mouse study suggests hydrogen gas inhalation may help prevent lung scarring and preserve breathing function after severe lung injury. However, this is animal research only—human studies would be needed to determine if these benefits apply to people with acute lung injury or ARDS. The findings are promising but not yet applicable to clinical practice.
Abstract (excerpt)
Background: Acute respiratory distress syndrome, which is caused by acute lung injury, is a destructive respiratory disorder caused by a systemic inflammatory response. Persistent inflammation results in irreversible alveolar fibrosis. Because hydrogen gas possesses anti-inflammatory properties, we…