The study, which involved 16 national top-level male cross-country skiing athletes from the Shanxi Provincial Winter Sports Management Center, China (aged 19.4 ± 0.9), aimed to examine the effects of 8 weeks of Bifidobacterium animalis supplementation on lipid metabolism and exercise performance, and the relationship between them by metabolomics and metagenomics.
The findings underscore the significant benefits of supplementing with a probiotic alongside exercise training, for improving exercise parameters.
The authors link the discovered exercise improvements to the probiotic's ability to further elevate DHA, adrenic acid, linoleic acid, and acetic acid levels, alongside reduced glycodeoxycholic acid and glycochenodeoxycholic acid concentrations.
They conclude: "Our study suggested that 8-week Bifidobacterium lactis BL-99 supplementation combined with training may help improve the lipid metabolism and sports performance of cross-country skiers by increasing the abundance of Bifidobacterium, which potentially promotes the generation of SCFAs and unsaturated fatty acids, and inhibits the synthesis of bile acids. In the future, coaches and athletes may consider use BL-99 to help improve the performance and lipid metabolism."
Research has previously found that both exercise and probiotic supplementation interventions exert an impact on lipid metabolism. It's understood the gut microbiota can affect lipid metabolism in the body by regulating the production of SCFAs, unsaturated fatty acids, and bile acids.
What’s more, prior evidence reveals supplementation with probiotics has positive effects on aerobic metabolism, muscle strength, exercise endurance performance, and post-exercise muscle damage recovery. Probiotics, prebiotics, SCFAs, and bacterial products have therefore been suggested as potential novel therapeutic agents for enhancing muscle mass and physical performance.
The potential mechanisms by which the microbiome modulates muscle mainly relate to cellular metabolism, inflammation, neuromuscular junctions, and mitochondrial function.
Lactobacillus and Bifidobacterium supplementation have been found to alleviate low-grade inflammation in the elderly by regulating the gut microbiota strains that ameliorate age-related muscle loss.
However the authors of the current study note that there are few studies investigating the relationship between VO2max and Bifidobacterium supplementation.
The 16 participants (15 completed the trial) were randomly divided into a C group (control, n = 8) and E group (experiment, n = 8).
The C group only received ordinary yogurt and the E group received the same yogurt with the addition of 1 × 109 CFU of Bifidobacterium animalis subsp. Lactis BL-99 (BL-99). The solution was administered for eight weeks, four times per day - with each of three meals and at 21:00 before going to sleep.
The participants in each group were asked not to consume other yogurts or nutritional supplements and not to change daily dietary habits.
The subject’s dietary intake and total daily energy consumption were recorded. Blood and stool samples were collected before and after the 8-week intervention, and body composition, muscle strength, blood biochemical parameters, plasma-targeted metabolomic data, and faecal metagenomic data were then analysed.
Blood samples were analysed for albumin (ALB), globulin (GLOB), total cholesterol (T-CHO), triglycerides (TG), high-density lipoprotein (HDL-C), and low-density lipoprotein (LDL-C).
The researchers found that after 8 weeks of supplementation, the Bifidobacterium animalis abundance in the intestinal flora had increased two-fold in the C group and forty-fold in the E group.
Compared to C group, the increase of DHA, adrenic acid, linoleic acid, acetic acid in the E group is significantly higher and the decrease in glycocholic acid and glycodeoxycholic acid in the E group was significantly higher.
Discussing the microbial differences, the authors state: “Our investigation demonstrated that following an 8-week period of BL-99 supplementation, the population of Bifidobacterium animalis increased two-fold within the C group and a remarkable fortyfold within the E group. These findings suggest that an 8-week regimen of BL-99 supplementation is effective in substantially elevating Bifidobacterium levels, while not significantly influencing gut microbiota diversity.”
When looking at performance outcomes, the data suggests the VO2max was significantly increased in both the C and E groups but was increased significantly more in the E group.
The 180°/s knee joint extensor strength increased in both the C and E groups over the course of supplementation but the 60°/s knee joint flexor and extensor strength in the E group was significantly increased in comparison to the C group.
The TG in both the C and E groups had significantly decreased. In addition, in the E group, the ALB levels significantly decreased and the LDL-C level significantly decreased.
The researchers analysed the correlation between the most regulated metabolites with lipid-metabolism-related indicators and sports performance.
They found there were marked decreases in triglycerides, LDL-C, and bile acids, accompanied by substantial increases in SCFAs and polyunsaturated fatty acids (PUFAs) in both the C and E groups. The report states: “This hints at the possibility that exercise in isolation could lead to improvements in athletes’ lipid metabolism.”
The authors note a potential limitation of the study being the lack of an exercise only intervention group.
“Although our study did not include a separate exercise-training-only group, the changes in multiple indicators in the E group were significantly higher than those in the C group; this also supports the theory that Bifidobacterium supplementation combined with training can improve sports performance.”
They conclude: “Our preliminary and pilot study suggests that 8 weeks of BL-99 supplementation combined with training can improve lipid metabolism and exercise performance, and SCFAs may play an intermediary role in this process, but the mechanisms remain to be further explored.”
"Eight Weeks of Bifidobacterium lactis BL-99 Supplementation Improves Lipid Metabolism and Sports Performance through Short-Chain Fatty Acids in Cross-Country Skiers: A Preliminary Study"
Authors: Li, T.; Rui, Z.; Mao, L.; Chang, Y.; Shao, J.; Chen, Y.; Han, Q.; Sui, X.; An, N.; Li, H.; et al.