Engineers modified Saccharomyces cerevisiae to produce pro-DALAP, a precursor of a dual GLP-1/GIP receptor agonist, reaching 4.05 mg per gram of dry biomass versus 1.27 mg/g in single-copy yeast. In vitro work confirmed GM1 binding, furin cleavage and activation of both receptors. In a 12-week open-label randomized trial of 98 overweight adults, enteric-coated yeast capsules produced no significant difference from dietary guidance alone: weight change was -0.76% versus -0.27%, waist change -3.60% versus -3.69%, and HbA1c favored controls. An early week-8 signal (-2.29% weight loss) vanished in the full analysis.
The disappearance of the interim signal is the instructive part: eight participants per group is far too few to trust, and regression toward the null is the expected outcome. The weight changes in the capsule arm are far below what injectable tirzepatide achieves (roughly 15-20% over 72 weeks), and nothing here shows the peptide reaches the bloodstream, since no validated pharmacokinetic data exist. Oral peptide delivery remains a hard problem; oral semaglutide works only with an absorption enhancer at high doses. The open-label design, lack of placebo and self-reported tolerability survey further limit interpretation. The authors deserve credit for reporting the null result candidly. This is a preprint awaiting peer review, and its conclusions could shift. For adults, the practical takeaway is simple: no yeast-based oral incretin product has demonstrated efficacy, and approved GLP-1 therapies remain the evidence-based route. Incremental engineering work, negative clinical finding.