(This is an excerpt of the Health Rounds newsletter, where we present latest medical studies on Tuesdays and Thursdays.)
By Nancy Lapid
Sept 4 (Reuters) – Today we feature two early studies, one that points toward a possible way to prevent nerve damage from chemotherapy drugs and another that reveals previously unrecognized effects of bacteria that are known to make adults very sick but that were thought to be harmless to babies.
PSYCHEDELIC DRUG MAY PREVENT CHEMOTHERAPY NERVE DAMAGE
The psychedelic drug psilocybin may help prevent the nerve damage that often accompanies chemotherapy, studies in mice suggest.
Chemotherapy-related peripheral neuropathy can result in pain, numbness, increased sensitivity to cold, and loss of sensation that linger long after treatment ends and are often irreversible.
In mice, two doses of psilocybin given before chemotherapy prevented hypersensitivity to cold, protected sensory nerve endings and preserved touch sensation without affecting chemotherapy’s antitumor activity, researchers reported on Thursday in Science.
Psilocybin directly affects the peripheral nervous system through brain cell surface proteins called serotonin 5-HT2A receptors. Blocking the 5-HT2A pathway reversed the drug’s neuroprotective effects, while using a non-hallucinogenic compound that activates the same brain-cell surface proteins produced similar protection to psilocybin.
Psilocybin also helped protect nerve cells’ mitochondria – their “energy factories” – from the damaging effects of chemotherapy drugs, the researchers found.
“There is an urgent need for treatments that prevent nerve injury without interfering with lifesaving chemotherapy,” study leader Dr. Moran Amit of the University of Texas MD Anderson Cancer Center said in a statement. “These findings offer important insights into how psilocybin may protect nerves before damage occurs, rather than treating symptoms after they become persistent.”
His team’s findings are the basis for an upcoming mid-stage trial evaluating psilocybin during chemotherapy in patients with multiple cancer types to determine whether the mechanisms observed in the lab translate to clinically meaningful reductions in peripheral neuropathy in patients.
IN BABIES, C. DIFF BACTERIA CAUSE DAMAGE WITHOUT SYMPTOMS
“C. diff” infections in infants don’t produce the severe gastrointestinal symptoms the bacteria cause in adults, and so the fact that 40% to 90% of infants in industrialized countries have the organisms in their intestines hasn’t worried doctors – until now.
Without causing symptoms, the Clostridioides difficile bacterium can reshape the developing infant gut and induce changes with long-term consequences, researchers have discovered.
In adults, toxins produced by C. diff cause symptoms ranging from severe diarrhea to fatal colonic inflammation. Around half a million patients are infected in the U.S. annually, resulting in approximately 30,000 fatal cases.
Infants, however, always seemed to be resistant to the effects of the bacterium.
“But… does asymptomatic really mean inconsequential? Could a toxin-producing pathogen actually be reshaping the developing gut without causing obvious symptoms?” study leader Joseph Zackular of Children’s Hospital of Philadelphia (CHOP) said in a statement.
In studies of mice and in lab tests of intestinal biopsy samples from human infants and mini-intestines made from human tissue in test-tubes, the researchers found the presence of C. diff led to remodeling of the epithelium — the layer of cells that line the gut – and reshaping of the immune system that protects the intestines’ moist inner surfaces.
These effects were also observed in the intestines of human infants colonized with C. diff, the researchers reported on Thursday in Science.
“The infant gut epithelium is still building itself, so C. diff doesn’t just injure it; it can alter the developmental trajectory of the tissue in ways that may last into adulthood,” study co-author Kathryn Hamilton, also at CHOP, said in a statement.
The authors add that the long-term consequences of these effects need to be studied in more detail.
They also hope to develop a maternal vaccine that would target C. diff, similar to vaccines already in use that immunize mothers to protect newborns against RSV and pertussis.
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(Reporting by Nancy Lapid; Editing by Aurora Ellis)
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