21/11/2025
This study links the use of prescription medications to gut microbiome damage. Although the study has been done on humans the principles apply equally to horses. The damage to the gut microbiome is extensive and in some cases permanent. Facts we have know for some time but now there is more published research to support the concerns 😱
🚨 New Stanford Research Reveals How Over 140 Common Medications May Fuel the Rise in Early-Onset Colorectal Cancer
A landmark study published this week in Cell from Stanford University has uncovered a disturbing mechanism linking everyday medications to lasting gut microbiome damage, and potentially to the alarming surge in colorectal cancer among people under 50.
Researchers led by Dr. Handuo Shi and Dr. KC Huang screened 707 clinically approved drugs against complex human gut microbial communities (originally sourced from a human donor, transplanted into germ-free mice, and then studied in vitro).
The results were stark: more than one in five drugs profoundly disrupted the microbiome in ways that favor cancer development.
📊 Key findings:
• 141 drugs strongly suppressed beneficial bacteria, including all 51 antibiotics tested plus dozens of non-antibiotics such as certain antifungals, chemotherapeutic agents, and antipsychotics routinely prescribed for bipolar disorder and schizophrenia.
• These medications selectively eliminate vulnerable species, flooding the gut with excess nutrients (sugars, amino acids, heme, and other metabolites).
• Drug-resistant, pro-inflammatory bacteria rapidly exploit this surplus, outcompeting and replacing the original healthy community.
• The resulting dysbiosis triggers chronic colon inflammation, compromises the intestinal barrier, and boosts production of genotoxic compounds (e.g., colibactin from certain E. coli strains); all well-established drivers of colorectal carcinogenesis.
• Critically, in most cases the microbiome did not recover its original composition even after the drug was withdrawn, indicating the disruption can be long-lasting or permanent.
This work provides a plausible biological explanation for why colorectal cancer incidence in younger adults has been rising 2–12% annually in many countries despite improvements in diet and screening access in some populations.
📋 The full list of the 141 microbiome-disrupting medications (including all 51 antibiotics plus non-antibiotics) is in
Supplementary Table 1 (an Excel file).
🔗 https://www.cell.com/cell/abstract/S0092-8674(25)01243-7
Download it from the "Supplementary Information" section on the page—no paywall required.
