Oxygen is one of the body’s most powerful weapons against infection, and hyperbaric therapy dramatically increases how much of it reaches infected tissue. HBOT has been used as an adjunct for serious infections since the 1960s, and several of its most well-established medical indications are infection-related. Understanding which infections benefit and how the mechanism works separates legitimate clinical use from overhyped applications. It is one of several chronic conditions treated with hyperbaric oxygen that researchers are actively investigating.
How Does HBOT Work for Infections?
Direct Toxicity to Anaerobic Bacteria
Many of the most dangerous soft tissue infections are caused by anaerobic bacteria: organisms that not only don’t require oxygen but are actively harmed by it. Clostridium perfringens (the cause of gas gangrene), Bacteroides, and other anaerobes are killed or inhibited by high oxygen tensions. At the partial pressures of oxygen achieved in a hyperbaric chamber (up to 1500 mmHg at 2.0 ATA), anaerobic bacterial growth is directly suppressed. This makes HBOT uniquely useful for anaerobic infections in a way that antibiotic therapy alone may not achieve in poorly perfused tissue.1
Enhanced White Blood Cell Function
Neutrophils and macrophages kill bacteria primarily through oxidative killing: generating reactive oxygen species (free radicals) that destroy bacterial cell walls. This process is oxygen-dependent, and in the chronically ischemic tissue where serious infections often occur, white blood cell killing capacity is significantly impaired by low oxygen levels. HBOT restores and enhances this killing capacity, allowing immune cells to more effectively clear the infection.4
Improved Antibiotic Penetration
Antibiotics work better in well-oxygenated tissue. Aminoglycosides (gentamicin, tobramycin) require oxygen-driven active transport to enter bacterial cells, and their efficacy is dramatically reduced in hypoxic environments. HBOT improves tissue oxygenation in infected, ischemic areas, restoring antibiotic efficacy in places where antibiotics alone may have failed. This synergistic effect between HBOT and antibiotics is particularly important in chronic osteomyelitis and diabetic foot infections.4
Gas Gangrene (Clostridial Myonecrosis)
This is HBOT’s clearest infection indication. Gas gangrene is a rapidly progressive, life-threatening infection caused by Clostridium perfringens that destroys muscle tissue and produces gas bubbles. Without immediate intervention, it is fatal. Treatment is emergency surgical debridement combined with HBOT and antibiotics. HBOT is FDA-cleared for this indication and is considered a standard-of-care adjunct when facilities are available.
HBOT’s mechanism here is direct: the anaerobic Clostridium bacteria are killed by the high oxygen tensions in the treated tissue, stopping toxin production and slowing the spread of infection while surgery removes already-destroyed tissue. Tissue oxygen of 250 mmHg is required to halt alpha-toxin production, a level achievable only through HBOT.1
Necrotizing Fasciitis
Necrotizing fasciitis (“flesh-eating bacteria”) is a life-threatening infection of the fascia and soft tissue that spreads rapidly along fascial planes. It can be caused by a mix of aerobic and anaerobic organisms. The treatment is emergency surgical debridement, often requiring extensive tissue removal. HBOT is used as an adjunct in many centers, theoretically improving outcomes by reducing the spread of anaerobic infection, enhancing immune function in the involved tissue, and supporting healing of the traumatic wound left by surgery.
A retrospective analysis of 28 necrotizing fasciitis patients treated with HBOT at 2.4 ATA (90 min, twice daily, average 13 sessions) plus surgery and antibiotics showed overall mortality of 14.3%, comparing favorably to other published series.3 HBOT is not a substitute for emergency surgery in this condition.
Chronic Osteomyelitis
Chronic bone infection (osteomyelitis) involves bacteria embedded in avascular, ischemic bone that resists antibiotic penetration and immune clearance. HBOT is an FDA-cleared adjunct for refractory osteomyelitis, used following surgical debridement to improve tissue oxygenation, enhance antibiotic efficacy, and support bone healing. Protocols typically involve 40 to 60 sessions following definitive surgery.
The bone healing and HBOT article covers osteomyelitis and other bone healing applications in detail. The wound healing connection is also covered in the wound healing article.
Diabetic Foot Infections
Diabetic foot infections complicate diabetic foot ulcers and are a leading cause of amputation. The combination of impaired circulation, neuropathy, and immune dysfunction in diabetes creates an environment where infections are hard to clear and wounds heal poorly. HBOT is used as an adjunct for severe diabetic foot infections, improving tissue oxygenation in ischemic tissue and supporting the healing process during and after antibiotic therapy. The diabetes and HBOT article covers this population in full.
HBOT for Chronic Lyme Disease?
One of the more controversial infection-related HBOT claims involves Lyme disease, particularly chronic or post-treatment Lyme disease syndrome. The theoretical basis involves Borrelia burgdorferi’s relative sensitivity to oxygen, and HBOT has been marketed aggressively to this patient community. The evidence does not support it. A single small case report from 2014 showed some benefit, but it has not been replicated, and mainstream infectious disease guidelines do not recommend HBOT for Lyme disease. The claims exceed the evidence significantly.
What HBOT Is Not For (Infection Context)
Common infections (pneumonia, urinary tract infections, skin infections responsive to antibiotics, viral infections) have no established evidence base for HBOT. HBOT is not an antibiotic substitute and is not effective against viral pathogens in the way that it is against anaerobic bacteria. Using HBOT for routine infections is neither evidence-based nor clinically appropriate.
HBOT in Necrotizing Infections: Practical Realities
In the real-world management of necrotizing soft tissue infections, HBOT is often not available when it’s most needed. Many hospitals, including level I trauma centers, don’t have hyperbaric chambers on site. Emergency surgery can’t wait for transfer to a distant facility. This practical limitation has contributed to HBOT remaining an adjunct rather than a first-line intervention in necrotizing infections, and it explains why the evidence base for HBOT in these conditions consists primarily of retrospective data from centers that happen to have hyperbaric facilities, rather than prospective trials.
Chronic Wound Infections and HBOT
Below the threshold of life-threatening emergencies, chronic infected wounds, including diabetic foot infections, pressure ulcers with bone involvement, and post-surgical wound infections in compromised tissue, represent a large and growing clinical challenge. HBOT’s role in these chronic wound infections is well-established through its oxygen-dependent mechanisms: improved immune cell killing, enhanced antibiotic efficacy, and support for tissue healing in ischemic environments. The wound healing article and diabetes article cover these applications in detail.
Biofilm and HBOT
Biofilm-forming bacteria, which encase themselves in a protective matrix and are highly resistant to antibiotics and immune clearance, are a major challenge in chronic infections. Research has shown that high oxygen tensions disrupt biofilm formation in some bacterial species and improve the penetration of antibiotics into biofilm-protected communities. This biofilm-disrupting potential is another mechanism through which HBOT may benefit chronic wound and bone infections beyond its direct effects on immune function, and it’s an active area of preclinical investigation.
HBOT and Antibiotic Combinations
The synergy between HBOT and antibiotics in hypoxic infected tissue is one of the better-documented aspects of HBOT’s infection applications. Aminoglycoside antibiotics (gentamicin, tobramycin, amikacin) are oxygen-dependent in their bactericidal mechanism: they enter bacteria through oxygen-requiring active transport, and their effectiveness drops dramatically in low-oxygen environments. Fluoroquinolones and some other antibiotic classes also show improved efficacy in high-oxygen environments.4
In chronic osteomyelitis and deep tissue infections where the infected tissue is chronically hypoxic, the bacteria living in that tissue may be effectively sheltered from antibiotic killing even with appropriate serum drug levels, simply because the drug can’t work properly in the local oxygen-deficient environment. HBOT restores the oxygen tension needed for antibiotic efficacy in these environments, which is one of the reasons the combination of appropriate antibiotics, surgery, and HBOT produces better outcomes in refractory osteomyelitis than any single approach alone.
Frequently Asked Questions
Does HBOT work against antibiotic-resistant bacteria?
HBOT’s effect on anaerobic bacteria is independent of antibiotic resistance, as it works through direct oxygen toxicity rather than the mechanisms antibiotics use. For aerobic antibiotic-resistant organisms (like MRSA), HBOT’s effect is indirect, improving the immune and antibiotic environment rather than killing bacteria directly. The combination of improved antibiotic penetration and enhanced immune function may improve outcomes in resistant infections when combined with appropriate antibiotics and surgery.
How quickly must HBOT be started for gas gangrene?
Emergency surgery is the immediate priority. HBOT should follow as quickly as possible after initial surgical debridement. In centers with hyperbaric facilities, first treatment is typically within hours of surgery. Time is critical: every hour of delay allows Clostridial toxin production to continue and the infection to spread.
Can HBOT prevent infection after surgery?
Evidence suggests HBOT reduces post-surgical infection rates in some populations (colon surgery patients, diabetic patients) by enhancing the oxidative killing capacity of immune cells in the early post-operative period. However, this is not a standard clinical use, and HBOT is not recommended as a routine infection prophylaxis for most surgical procedures.
Does HBOT help with fungal infections?
There is limited evidence for HBOT specifically for fungal infections. Certain molds and fungi have aerobic metabolic requirements that might be disrupted by high oxygen tensions, but this has not been well-studied clinically. HBOT is not recommended as a treatment for fungal infections based on current evidence.
Sources
- Undersea and Hyperbaric Medical Society. HBO Therapy Indications, 13th Edition, 2020. UHMS
- Jallali N, Withey S, Butler PE. Hyperbaric oxygen as adjuvant therapy in the management of necrotizing fasciitis. Am J Surg. 2005. DOI: 10.1016/J.AMJSURG.2005.01.012
- Anwar M, et al. Retrospective analysis of necrotizing fasciitis patients treated with HBOT. 2008.
- Kaide CG, Khandelwal S. Hyperbaric oxygen: applications in infectious disease. Emerg Med Clin North Am. 2008. DOI: 10.1016/j.emc.2008.01.005
- Outcome of necrotizing fasciitis with HBOT (N=192 NSTI patients). PMC9356491. 2022.
Medical Disclaimer
The content on BaricBoost.com is for informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
Author
Seph Fontane Pennock is the founder of BaricBoost.com and Regenerated.com, a clinic directory for regenerative medicine serving 10,000+ providers across the United States. He previously built and sold PositivePsychology.com, which grew to 19 million users and became the largest evidence-based positive psychology resource on the web. Seph brings direct experience as an HBOT patient, having completed protocols at clinics across three continents while navigating mold illness, systemic inflammation, and autoimmune conditions. His treatment journey includes hyperbaric oxygen therapy, peptide protocols, NAD+ therapy, and consultations with specialists from Dubai to Cape Town to Mexico. This combination of entrepreneurial track record and lived patient experience shapes everything published on BaricBoost.com. Every article is grounded in peer-reviewed research, informed by real clinical encounters, and written for patients making high-stakes treatment decisions. Seph's focus is on bringing transparency, scientific rigor, and practical guidance to the hyperbaric oxygen therapy space.
