Fig. 1: Study time line, CONSORT flow diagram and study progression.

A After screening and informed consent, participants were allocated to receive either placebo (chilli pepper solution) or a total of 20 (L3-20) or 40 (L3-40) N. americanus hookworm larvae delivered to the skin over 2 occasions, at month 0 and month 2. Participants underwent evaluation visits every 6 months, where physical and vitals exams were undertaken, adverse events were reviewed, and biological samples and questionnaires were collected for analysis of safety, pathology, well-being, diet and exercise habits. B CONSORT chart showing flow of patients through the clinical trial, and reasons for early termination. C Kaplan–Meier analysis of rates of trial continuation (percentage survival and standard error of the mean) in each group during the 2-year study (Placebo n = 13, L3-20 n = 14, L3-40 n = 13; Log-rank test for trend, p = 0.832). Source data are provided as a Source Data File.