Supplementation With Bacillus clausii UBBC-07 Enhances Circulating Essential Amino Acids in Young Adults: A Double-Blind, Randomized, Controlled Trial

Background and aim Probiotics have been linked to improved gastrointestinal health and essential nutrient absorption. This study aimed to assess the impact of <i>Bacillus clausii</i>(<i>Shouchella clausii</i>) UBBC-07 plus whey protein supplementation on the bioavailability of circulating essential amino acids (EAAs) in physically active young adults. Methods In this double-blind, randomized, controlled trial, 70 physically active male participants (21.46±3.19 years) were instructed to ingest either a probiotic supplement containing two billion colony-forming unit (CFU) <i>Bacillus clausii</i> UBBC-07 + 20 g of whey protein or a control supplement containing placebo + 20 g of whey protein once daily for 60 days. All the participants followed a supervised exercise protocol. The circulating amino acid levels were determined using a high-performance liquid chromatography with fluorescence detection (HPLC-FLD) assay and compared using the student's t-test and a repeated measures analysis of variance (ANOVA). Results After 60 days, a significant improvement in the probiotic group was observed compared to the control group in terms of total levels of circulating EAAs (mean change: 258 pmol/μl, 95% CI: 161.5-354.4 vs. 76.4 pmol/μl, 95% CI: 16.5-136.4; p=0.002) and branched-chain amino acids or BCAAs (mean change: 144.2 pmol/μl, 95% CI: 89-199.3 vs. 37.5 pmol/μl, 95% CI: 7.3-67.8; p=0.001) as well as levels of isoleucine (p=0.003), leucine (p>0.001), and valine (p=0.001). Total plasma free amino acids (PFAAs) were also increased in the probiotic group (p<0.001). The improvement in the one-repetition maximum (RM) leg press was higher in the probiotic group as compared to the control group (mean change: 20.46 kg, 95% CI: 14.73-26.19 vs. 14.09 kg, 95% CI: 8.44, 19.73; p=0.045). A trend towards improvement in deadlift and vertical jump was also observed in the former group. No probiotic-mediated gastrointestinal upsets and respiratory symptoms or any other adverse events were observed. Conclusion A significant improvement in circulating EAA levels in the probiotic group suggests an enhancement of protein absorption with <i>Bacillus clausii</i> UBBC-07 supplementation. The effect of BCAAs, which enhance muscle strength, is evident in the significant improvement in leg press and a trend towards improvement in deadlift and vertical jump in the probiotic group. This has positive implications for individuals involved in sports activities.