Dr. Axe Wire · Study decoded · health

Antibiotics Linked to Worse Survival in 97,850 Immunotherapy Patients

A massive new analysis links antibiotic use to worse survival in cancer patients on immune checkpoint inhibitor therapy.

By Dr. Josh Axe · October 31, 2026 · 1 source · Watch

Photo: Pexels

At a glance

What they found: Antibiotic exposure linked to 49% higher risk of death and 44% higher risk of progression.
Who was studied: 97,850 cancer patients treated with immune checkpoint inhibitor immunotherapy across 116 patient cohorts worldwide.

Antibiotic use, which disrupts the gut microbiome, was linked to a 49% higher risk of death in cancer patients treated with immune checkpoint inhibitors, according to a meta-analysis published October 27, 2026 in Cancer Cell.

97,850patients

49%higher death risk

44%higher progression risk

116patient groups

The meta-analysis, published October 27, 2026 in Cancer Cell, pooled data from 116 cohorts totaling 97,850 cancer patients treated with immune checkpoint inhibitors (ICI), a type of cancer immunotherapy drug. Patients exposed to antibiotics had a 49% higher risk of death (hazard ratio 1.49) and a 44% higher risk of cancer progression (hazard ratio 1.44) than those not exposed.

The authors note that nearly 30% of patients receiving these immunotherapy drugs are also prescribed antibiotics, and as cancer immunotherapy use expands into more conditions, the overlap is becoming more common.

The authors describe biological mechanisms by which antibiotic-induced dysbiosis, an imbalance in gut bacteria, contributes to resistance against checkpoint inhibitor therapy. The gut microbiome, the community of microbes living in the gut, has been shown in prior work to shape how well the immune system responds to these cancer drugs; wiping out broad swaths of gut bacteria with antibiotics appears to blunt that immune activation.

Antibiotic Exposure Linked to Worse Immunotherapy Outcomes

97,850 cancer patients, 116 cohorts, hazard ratios

Risk of death

1.49 hazard ratio

Risk of progression

1.44 hazard ratio

Cancer Cell, 2026, Porcari et al.

This is a review and meta-analysis of observational cohorts, not a randomized trial, so it cannot show antibiotics caused the worse outcomes rather than reflecting sicker patients needing more antibiotics; timing, type and duration of antibiotic use varied across the pooled studies, and absolute survival differences were not reported in the abstract.

Dr. Axe’s Take

The root cause here is the gut. These immunotherapy drugs lean on a healthy, diverse gut microbiome, and gut damage is a known side effect of antibiotics. Across almost 98,000 patients, antibiotic use was linked to a 49% higher risk of death on immunotherapy. Antibiotics are sometimes necessary for a real infection. If you're on immunotherapy, I'd ask your oncology team whether a narrower antibiotic will do, and rebuild your gut afterward with fiber-rich vegetables and fermented foods like sauerkraut and kefir. Keep taking any prescribed medication, and make changes only with your prescriber, based on your numbers.

— Dr. Axe

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Study summary

Who: 97,850 cancer patients treated with immune checkpoint inhibitor immunotherapy across 116 patient cohorts worldwide.
Design: Updated meta-analysis pooling cohort data; observational, not a randomized trial.
Dose: Antibiotic exposure versus no antibiotic exposure around the time of immunotherapy; specific regimens and timing not detailed in the abstract.
Primary result: Antibiotic exposure linked to 49% higher risk of death (HR 1.49, 95% CI 1.34-1.65) and 44% higher risk of progression (HR 1.44, 95% CI 1.31-1.58).
Secondary: Nearly 30% of ICI-treated patients receive antibiotics; authors outline antibiotic stewardship and microbiome-repair strategies as next steps.
Funding / conflicts: Funders listed in the journal record: Italian Government Ministry of Health; Bristol-Myers Squibb Company; Pfizer Inc; European Research Council; Airc Italian Foundation for Cancer Research; Catholic University of the Sacred Heart; Horizon Europe; Seerave Foundation; MSD Italia S.r.l.; Joint Programming Initiative on Antimicrobial Resistance; Ministero dell'Istruzione dell'Università e della Ricerca. Competing interests: Authors consult for a company.
Date: Oct 27, 2026