Benefits
Treadmill endurance time in untrained young adults
In four placebo-controlled papers with 8 to 18 adults per group, 6 weeks of live TWK10 (10 to 300 billion CFU a day where stated) lengthened treadmill time to exhaustion more than placebo. None named a primary outcome, all came from one lab working with the maker, and two of them share an ethics approval and probably a placebo group. In women with obesity, TWK10 alone did not change endurance.
Endurance time with heat-killed TWK10
Heat-killed TWK10 cells, which cannot grow, also lengthened treadmill time to exhaustion versus placebo after 6 weeks: at 300 billion cells a day in a three-group trial of 53 young adults (18 on heat-killed cells) and at 30 billion cells a day in 30 young men (about 24 percent longer). Both were run by the same lab with maker employees as authors, and each placebo group also appears, or likely appears, in another TWK10 paper.
Hand grip strength in healthy young men
In one trial with a shared placebo group of 15 men, grip strength after 6 weeks was about 9 to 12 percent higher than placebo with both heat-killed TWK10 (30 billion cells a day) and live TWK10 (10 billion CFU a day). In frail older adults, grip strength after 18 weeks did not differ from placebo.
Muscle mass measured by bioimpedance in young adults
On bioimpedance scales, muscle mass rose more than placebo with live TWK10 in three papers in young adults over 6 weeks, with gains of 0.64 and 0.9 kg where reported against falls of 0.15 and 0.7 kg on placebo; none named it a main outcome. Heat-killed TWK10 did not differ from placebo. In frail older adults and in a pea protein trial, DXA muscle or lean mass did not differ between groups.
Strength and power with pea protein and resistance training
In 32 young adults doing resistance training 3 times a week, 20 g of pea protein with 10 billion CFU of TWK10 a day for 28 days improved bench press, mid-thigh pull force, cycling power and muscle thickness more than pea protein alone. Blood amino acid levels after the shake also rose more. Lean mass by DXA did not differ.
Timed up and go test in frail older adults
In frail older adults (42 of 55 finished), 60 billion CFU a day for 18 weeks gave a timed up and go test about 32 percent faster than placebo, partly because the placebo group got slower. It was one of seven outcomes registered after the trial ended; grip strength, DXA muscle mass, bone density and the other walking tests did not differ between groups.
Mechanism of action
Energy storage and muscle fibers in animals
In mice, TWK10 raised muscle and liver glycogen, grip strength and swimming endurance, and increased the number of type I (slow) muscle fibers. These are animal results; muscle glycogen and fiber type were not measured in the human trials.
Lower lactate and ammonia during exercise
In several human trials, blood lactate and ammonia during and after a fixed-intensity treadmill run were lower than on placebo. These blood markers suggest a shift in fuel use during exercise but are not performance outcomes in themselves.
Gut bacteria and amino acid uptake
Live TWK10 changed the mix of gut bacteria in small trials, including more Akkermansiaceae, and in one trial blood levels of essential and branched-chain amino acids after a pea protein shake rose more than with pea protein alone. Whether these changes explain the performance results is not established.
Clinical trials
Two double-blind, placebo-controlled papers approved under the same ethics number (LSHIRB 18-004-A2), whose placebo groups of 18 report near-identical baseline age and VO2max values, so they may share placebo participants; the papers do not say. The first tested placebo or 30 or 90 billion CFU of live TWK10 a day; the second tested placebo, 300 billion CFU of live TWK10 or 300 billion heat-killed cells a day; both ran for 6 weeks with capsules made by Synbio Tech. Neither was registered or named a primary outcome. The first was funded by a National Taiwan Sport University university-industry fund, with four of nine authors at Synbio Tech; the second reported no external funding, with six of eight authors at Synbio Tech (Huang et al. 2019, Nutrients)
Healthy untrained adults aged 20 to 30: 54 in the first paper (27 men, 27 women, 18 per group) and 53 in the second (26 men, 27 women, 17 or 18 per group).
First paper: time to exhaustion at 85 percent of VO2max rose more than placebo at both doses (P = 0.0207 low dose, P < 0.001 high dose) and more with the high dose (P = 0.0336); on bioimpedance, fat mass fell versus placebo and muscle mass rose versus placebo with the high dose. Second paper: time to exhaustion was 17.55 minutes on live and 16.72 minutes on heat-killed TWK10 versus 12.23 minutes on placebo (P < 0.001 and P < 0.01); live TWK10 raised bioimpedance muscle mass by 0.64 kg versus a 0.15 kg fall on placebo (P < 0.001) and lowered body fat percentage more, while heat-killed TWK10 did not differ from placebo on body composition.
Double-blind, placebo-controlled trial, apparently reported in two papers that use the same ethics approval (LSHIRB 19-027-A2) and the same 15-man placebo group: heat-killed TWK10 at 30 billion cells a day (n=15) or live TWK10 at 10 billion CFU a day (n=15), two capsules daily for 6 weeks; no registration or named primary outcome; five of seven authors of the first paper were Synbio Tech employees, and the second paper was funded by Synbio Tech, with six of nine authors at the company, yet declared no competing interests (Cheng et al. 2023, Physiol Rep)
45 healthy untrained men aged 20 to 40: 15 on placebo (the group shared by both papers), 15 on heat-killed TWK10 and 15 on live TWK10.
Versus placebo, heat-killed TWK10 lengthened time to exhaustion 1.24-fold (P = 0.0028) and raised right and left grip strength (P = 0.0002 and P = 0.0140); its muscle mass rose only within the group, and body fat did not differ. In the companion paper, live TWK10 raised grip strength and time to exhaustion versus placebo (P < 0.01), muscle mass rose 0.9 kg versus a 0.7 kg fall (P < 0.001), and body fat percentage fell more (P < 0.05).
Double-blind, placebo-controlled trial of TWK10 or placebo for 6 weeks; the abstract does not give the dose, which two later papers cite as 100 billion CFU a day; two authors were at Synbio Tech, and the authors declared nothing to disclose (Huang et al. 2018, Chin J Physiol)
16 adults over 20 years of age, 8 per group.
Endurance in a maximal treadmill running test and blood glucose during exercise were higher on TWK10 than on placebo (P < 0.05). It is a very small trial.
Double-blind, placebo-controlled trial: maltodextrin placebo, 20 billion or 60 billion CFU of TWK10 a day for 18 weeks; registered NCT04893746 after the trial ended, listing grip strength, walking tests, DXA muscle mass, fat percentage and bone density as primary outcomes; funded by university-industry cooperation funds, Synbio Tech supplied the capsules and four authors were at Synbio Tech (Lee et al. 2021, Microorganisms)
55 residents of a Taipei senior home with mild frailty randomized (inclusion age 55 to 85; group mean ages 75.2 to 80.5); 42 completed (17, 12 and 13).
Grip strength and DXA muscle mass did not differ between groups at any time point; on the high dose they rose only versus baseline (muscle mass 37.1 to 38.2 kg). At 18 weeks the timed up and go test was 31.66 percent faster on the high dose than placebo (P = 0.0064), while the placebo group slowed over time. Chair stand and 10 m walk changes were within groups only, and bone density did not change.
Randomized, double-blind trial: 20 g pea protein with 10 billion CFU of TWK10, or pea protein alone, daily for 28 days with resistance training 3 times a week; registered NCT05412667 after the trial ended; funded by a National Taiwan Sport University university-industry fund, and four authors were Synbio Tech employees (Lee et al. 2024, Curr Res Food Sci)
32 healthy non-athlete adults aged 20 to 30 (16 men, 16 women).
Changes in bench press 1RM, mid-thigh pull peak force and rate of force development, cycling sprint power, and right quadriceps and left biceps thickness were larger than with pea protein alone (P < 0.001 to P = 0.006). Blood amino acid peaks rose more. Lean mass and fat mass by DXA did not differ between groups.
Double-blind, placebo-controlled 2 by 2 trial: 60 billion CFU of TWK10 a day or a yeast powder placebo, with or without high-intensity interval training 3 times a week, for 8 weeks; registered NCT06285578 in 2024, years after it ended; funded by Taiwan's Ministry of Science and Technology; the TWK10 came from Synbio Tech, but no authors were from the company (Chen et al. 2024, J Int Soc Sports Nutr)
47 women aged 35 to 55 with body fat above 35 percent (12, 12, 11 and 12 per group).
TWK10 alone did not change time to exhaustion, which rose with interval training with or without TWK10. Hip circumference fell more with training plus TWK10 than with placebo (P = 0.005 for rate of change). The registered body fat outcome could not be analyzed because the DXA scanner malfunctioned at the final test.