Author(s): REHRER, N., MURRAY, M., PATEL, L., ACKERMANN, G., AMBRE, M., BOCK, R., WRIGHT, G., CAO, J., LOEHR, J., VLIETSTRA, L., SIMS, S., KNIGHT, R., Institution: UNIVERSITY OF OTAGO, Country: NEW ZEALAND, Abstract-ID: 1181

INTRODUCTION:
The aim was to investigate effects of training and protein supplementation on the gut microbiome in untrained, healthy females.
METHODS:
A randomised controlled training (12 wk upper-body resistance training and HIIT cycling) study was conducted. Participants were assigned a protein (24 g protein, P) or equicaloric control (3 g protein, C) post-exercise supplement (510 kJ). Dietary intakes were taken at wk 0,4,8,12, body composition and faecal samples at wk 0, 12. Microbiome was analysed in N=22 (32±9 y, 70 ± 12 kg, BMI 26 ± 4, VO2max 27 ±4 ml/kg/min). DNA was extracted from ~20 mg of frozen faecal samples and 16S rRNA gene amplicon libraries were sequenced on an Illumina MiSeq (2×151 bp). Sequences were processed in Qiita (Gonzalez et al. 2018), filtered against the Greengenes2 reference phylogeny (v2024.09; McDonald et al. 2024). Differential abundance was assessed using BIRDMAn (v0.1.0) adjusting for age, BMI, and treatment group.
RESULTS:
Average 24h intakes of energy wk 4-12 in P and C were 7.0±1.1, 8.1±1.0 MJ, resp. p=0.03) and of protein (1.5±0.2, 1.2±0.2 g/kg resp. p=0.003). There was little change in body mass with training (p=0.92) and no significant difference between P and C (Δ 0.31±2.72 kg, 0.38±1.68, resp. p=0.95). Aerobic capacity, strength and lean mass increased, while fat mass decreased (Murray et al. 2025).
No significant differences in alpha diversity were observed between 0 and 12 wk or between groups. Beta diversity was greater in P than C at 12 wk (Bray Curtis, p=0.009) with no difference over time. Differential abundance analysis at the genus level demonstrated greater abundance in P than C in Lactococcus_A_346120, Prevotella, Megaspaera_A_38685, Clositridium_T, Fusobacterium_C and Lawsonibacter.
CONCLUSION:
There was no detectable effect of 12 wk training in untrained females on gut microbiome diversity. There was an effect of protein supplementation on diversity and in the differential abundance of specific genera. It is likely the small participant number precluded observation of a training effect and/ or that training load or duration was insufficient to provide a significant shift. These findings support early cross-sectional findings of increased diversity in athletes versus controls in which the diversity increase was associated with increased dietary protein in the athletes (Clarke et al. 2014).

Gonzalez, A. et al. (2018). Qiita: rapid, web-enabled microbiome meta-analysis. Nature Methods, 15(10), 796-798.

McDonald, D. et al. (2024). Greengenes2 unifies microbial data in a single reference tree. Nature Biotechnology, 42(5), 715-718.

Murray, M. et al. (2025). Post-Exercise Whey Protein Supplementation: Effects on IGF-1, Strength, and Body Composition in Pre-Menopausal Women, a Randomised Controlled Trial. Nutrients, 17(12), 2033

Clarke, S. F. et al. (2014). Exercise and associated dietary extremes impact on gut microbial diversity. Gut, 63(12), 1913-1920.