Psychobiotics Linked to Better SF-36 in GI Cancer Chemotherapy
Key Takeaways
- Among people receiving adjuvant chemotherapy after gastrointestinal cancer surgery, SF-36 physical and mental summary scores favored psychobiotics over placebo at the final assessment.
- Treatment-group trajectories differed significantly across all eight SF-36 domains.
- Vitality and Mental Health group differences were significant at the later assessment, although they were not significant at treatment completion.
- Exploratory formal interaction tests found no evidence that treatment effects differed between subgroups.
Investigators examined Short Form-36 (SF-36) outcomes in the ProDeCa post hoc analysis in Nutrients, drawing on the randomized, double-blind, placebo-controlled ProDeCa trial (NCT06496438). The analysis included 266 participants receiving adjuvant chemotherapy after gastrointestinal cancer surgery; they received a four-strain psychobiotic formulation or placebo for four weeks.
Participants completed the SF-36 at baseline (V0), treatment completion (V1), and two months afterward (V2). Investigators used mixed models for repeated measures to assess trajectories across the questionnaire’s eight domains and its physical component summary (PCS) and mental component summary (MCS) scores.
Group-by-visit interactions differed across all eight SF-36 domains (all p < 0.001), indicating different trajectories over the assessment period, not necessarily significant between-group differences at every visit. Visit-specific adjusted comparisons generally favored psychobiotics. Between-group differences in Vitality and Mental Health were not statistically significant at V1 but were significant at V2.
At V2, the adjusted least-squares mean psychobiotic-versus-placebo difference in PCS was 16.79 points (95% confidence interval [CI], 15.69–17.88), favoring psychobiotics. The corresponding MCS difference was 9.66 points (95% CI, 8.49–10.84), also favoring psychobiotics. These adjusted between-group score differences do not establish a clinically important threshold.
HR-QoL was examined post hoc rather than as an established prespecified efficacy endpoint in this analysis. At V2, observations were available for 231–232 of the 266 analyzed participants, depending on the SF-36 outcome, so the later comparisons did not include everyone initially analyzed. Exploratory subgroup analyses found no evidence of differential treatment effects on formal interaction tests.
The authors concluded that psychobiotic treatment was associated with more favorable longitudinal HR-QoL during adjuvant chemotherapy after gastrointestinal cancer surgery. They called for larger multicenter randomized trials to examine whether those associations are confirmed.
Clinician Questions
Do the adjusted SF-36 differences with psychobiotics represent improvement for individual gastrointestinal cancer patients?
For people receiving psychobiotics or placebo during adjuvant chemotherapy after gastrointestinal cancer surgery, the later SF-36 physical and mental estimates compare adjusted scores between treatment groups. They do not measure each individual’s change or prove that a particular patient improved.
What safety outcomes were reported for four-strain psychobiotics during adjuvant chemotherapy after gastrointestinal cancer surgery?
Safety and adverse-event outcomes were not described for the four-strain psychobiotic given during adjuvant chemotherapy after gastrointestinal cancer surgery. The available findings therefore do not establish its safety in that population.