The Gut-Health Connection: Blackcurrant's emerging role for athletes and general wellbeing

Blackcurrants are quickly gaining recognition for digestive wellbeing - especially for athletes. Rich in polyphenols like anthocyanins, these vibrant berries not only nourish the microbiome but are increasingly recognized by scientists for their ability to support gut health, enhance digestion, and promote overall wellness.

New Rugby Study Reveals Gut Health Benefits in Hard-Training Athletes

An exciting new study from Japan put New Zealand blackcurrant extract to the test in male university rugby players, a population known for the gut challenges that arise from heavy training and high-protein, low-fibre diets. These athletes often face a state called dysbiosis, an unhealthy shift in gut bacteria that can increase inflammation and digestive issues.

For four weeks, participants took either blackcurrant extract, a prebiotic guar gum, both, or a placebo. The most encouraging news came for those rugby players who started with signs of gut dysbiosis: after supplementation, they showed a marked increase in short-chain fatty acids (SCFAs) - vital compounds produced by beneficial bacteria that help maintain the gut lining and reduce inflammation.

Blackcurrant extract was directly linked to boosts in specific “helpful” bacteria, even though the overall gut microbial balance remained stable. These changes reflected improved gut microbial function and pivotal anti-inflammatory effects - offering athletes a natural strategy to counteract the gut disturbances often triggered by intense training.

Reference

Miura, H.; Oda, M.; Abe, K.; Ikeda, H.; Fujibayashi, M.; Oda, N.; Segawa, T.; Abe, A.; Ueta, N.; Tsukahara, T.; et al. Effects of Blackcurrant Extract and Partially Hydrolyzed Guar Gum Intake on Gut Dysbiosis in Male University Rugby Players. Microorganisms 2025, 13, 1561. https://doi.org/10.3390/microorganisms13071561

CurraNZ and the Evidence for Microbiome Modulation

Backed by peer-reviewed research, blackcurrant polyphenols - specifically from extracts like CurraNZ - are proven to directly influence the composition and function of the intestinal microbiota. Supplementation can increase populations of friendly bacteria such as Lactobacillus and Bifidobacterium, while reducing certain unfavorable strains, including some Clostridia and Bacteroides. This microbiome boost can contribute to better digestion, reduced inflammation, and robust gut health.

Reference

Molan AL, Liu Z, Plimmer G. Evaluation of the effect of blackcurrant products on gut microbiota and on markers of risk for colon cancer in humans. Phytother Res. 2014 Mar;28(3):416-22. doi: 10.1002/ptr.5009. Epub 2013 May 15. PMID: 23674271.

GI Protection for Athletes Exposed to Heat Stress

Another recent trial found that just seven days of CurraNZ supplementation significantly reduced markers of small intestinal permeability and enterocyte (gut lining cell) damage during physical stress. By helping to maintain gut barrier integrity and curb gut-derived inflammation, blackcurrants provide tangible, research-backed support for gastrointestinal resilience in both training and competition.

Reference

Lee, B. J., Flood, T. R., Hiles, A. M., Walker, E. F., Wheeler, L. E., Ashdown, K. M., Willems, M. E., Costello, R., Greisler, L. D., Romano, P. A., Hill, G. W., & Kuennen, M. R. (2022)Anthocyanin-rich blackcurrant extract [CurraNZ] preserves gastrointestinal barrier permeability and reduces enterocyte damage but has no effect on microbial translocation and inflammation after exertional heat stress, Human Kinetics, 2022 https://doi.org/10.1123/ijsnem.2021-0330

Beyond Gut: Benefits for Women’s Bone Health

The benefits of blackcurrants don’t stop at digestion. In a double-blind, placebo-controlled study, six months of daily blackcurrant extract significantly reduced bone mineral density (BMD) loss in peri- and early postmenopausal women. Those taking higher doses of CurraNZ saw actual increases in whole-body BMD, while placebo users continued to lose bone mass. These effects were most pronounced in women at higher risk of bone loss, highlighting blackcurrants’ remarkable ability to support healthy ageing via the gut-bone axis.

Reference

 Briana M. Nosal, Staci N. Thornton, Manije Darooghegi Mofrad, Junichi R. Sakaki, Kyle J. Mahoney, Zachary Macdonald, Lauren Daddi, Thi Dong Binh Tran, George Weinstock, Yanjiao Zhou, Elaine Choung-Hee Lee, Ock K. Chun, Blackcurrants shape gut microbiota profile and reduce risk of postmenopausal osteoporosis via the gut-bone axis: Evidence from a pilot randomized controlled trial, The Journal of Nutritional Biochemistry, Volume 133, 2024, https://doi.org/10.1016/j.jnutbio.2024.109701.

Conclusion

Blackcurrants stand out for their natural prebiotic power, science-backed capacity to support a balanced microbiome, and their role in safeguarding digestive and even skeletal health. As more research emerges, these berries remain a top choice for athletes and health-minded individuals aiming to enhance gut health safely and naturally.