AIM-TEST: microbiome-Targeted Nutrition for Functional Secondary Hypogonadism

AIM‐TEST is a Phase II, proof‐of‐concept study designed to evaluate whether afixed‐formula, microbiome‐targeted nutritional intervention can improve endogenoustestosterone production in men with functional secondary hypogonadism. The study is basedon the hypothesis that modulation of microbiome‐related metabolic, inflammatory,intestinal‐barrier, and neuroendocrine pathways may influence the physiologicalregulation of the hypothalamic‐pituitary‐gonadal axis. However, the causal role of thegut microbiome in human testosterone regulation has not been established. The studyproduct is therefore being evaluated as an investigational nutritional intervention andis not intended to replace established hormonal therapy, etiological investigation, orother clinically indicated management.The study population includes men aged 30 to 65 years with symptoms compatible withandrogen deficiency and repeatedly confirmed low morning testosterone concentrationsaccompanied by low or inappropriately normal gonadotropin levels. Participants may beincluded irrespective of body mass index or obesity status. The study focuses onfunctional secondary hypogonadism, meaning that no primary testicular failure oridentified organic hypothalamic or pituitary disorder is present and that studyparticipation would not delay clinically indicated investigation or management. Obesity,metabolic status, body composition, and other potentially relevant clinicalcharacteristics will be recorded and evaluated as possible modifiers of the interventionresponse rather than used as mandatory defining features of the study population.The investigational intervention is a fixed‐formula oral nutritional supplement developedthrough an AI‐guided evaluation of microbiome‐related biological pathways and candidatenutritional components. All participants assigned to the active intervention group willreceive the same standardized formulation; the intervention is not personalized ormodified during the study according to an individual participant's microbiome results.Artificial intelligence is used during the pretrial development of the formulation and isnot used to determine eligibility, assign study groups, make clinical decisions, or adaptthe intervention during the study.Participants will be assigned in a 1:1 ratio to receive either the active intervention ora matched placebo once daily for 12 weeks. Group allocation will be concealed, andparticipants, investigators, clinical personnel, outcome assessors, laboratory personnel,and the primary study statistician will remain masked to allocation. The placebo will bematched as closely as feasible in appearance, packaging, weight, taste, odor, mouthfeel,and administration schedule. Because fermentable nutritional components may producegastrointestinal effects that cannot be completely reproduced by an inactive placebo,gastrointestinal tolerability and participants' and investigators' allocation guesseswill be prospectively recorded to evaluate the integrity of masking.Testosterone status will be assessed using standardized morning blood sampling. Repeatedmeasurements will be used where specified to reduce the effect of normal day‐to‐daybiological and analytical variation. Total testosterone will be accompanied byassessments of sex hormone‐binding globulin, albumin, calculated free testosterone,gonadotropins, and other relevant hormonal measures. The study will also evaluateandrogen‐deficiency symptoms, sexual function, anthropometric and metaboliccharacteristics, inflammatory markers, safety, gastrointestinal tolerability, adherenceto the assigned intervention, and changes in the gut microbiome. Microbiome analyses areexploratory and are intended to investigate biological associations and generatemechanistic hypotheses rather than establish that microbiome changes mediate any observedclinical effect.Following the 12‐week intervention period, participants will enter a 12‐week periodwithout the study product. Assessments during this follow‐up period will explore whetherany biochemical, symptomatic, metabolic, or microbiome‐related effects observed at theend of the intervention are maintained after discontinuation. Safety and the need forclinically indicated rescue evaluation or management will be monitored throughout thestudy. Participants who develop severe biochemical deficiency, clinically importantdeterioration, pituitary warning features, or another condition requiring standard carewill be referred for appropriate clinical management.The primary analysis will estimate the effect of assignment to the active interventioncompared with placebo on morning total testosterone at Week 12, with adjustment for thecorresponding baseline value and prespecified randomization factors. The primaryassignment‐based analysis will include all randomized participants according to theirallocated study group, irrespective of adherence to or discontinuation of the assignedintervention, subject to consent and applicable data‐protection requirements.Between‐group effects will be reported with confidence intervals, and prespecifiedsensitivity analyses will assess the potential influence of missing data, major protocoldeviations, clinically indicated rescue management, and assumptions underlying theprimary statistical model.The initial planned enrollment is 112 participants. The protocol includes oneprespecified blinded sample‐size reassessment based only on pooled nuisance parameters,including outcome variability, the relationship between baseline and follow‐upmeasurements, and the availability of valid primary‐outcome data. The reassessment willnot examine group‐specific outcomes, the between‐group difference, statisticalsignificance, conditional power, efficacy, or futility. Enrollment may be increased, butnot decreased, up to a prespecified maximum of 152 participants if the originalvariability or missing‐data assumptions are not supported.The study is designed primarily to determine whether the intervention produces a crediblebiochemical efficacy signal and to provide estimates for the design of a subsequentconfirmatory study. A statistically significant increase in testosterone would constitutebiochemical proof of concept but would not, by itself, establish patient‐importantclinical benefit. Symptomatic and sexual‐function findings will therefore be interpretedseparately. The study is not intended to support use of the intervention in men withnormal testosterone concentrations or in individuals requiring established hormonaltherapy, fertility‐directed management, pituitary intervention, or other disease‐specificclinical care.