Safety evaluation of Veillonella atypica FB0054 with genotoxicity and subchronic toxicological studies.

Veillonella atypica is a nonmotile, nonsporulating anaerobic bacteria commonly found in various human biofilms. V. atypica FB0054 was isolated from the gastrointestinal tract of marathon runners, who have increased amounts of this species after athletic events. Interestingly, the consumption of this strain by rodents has been shown to increase their treadmill endurance, leading to the hypothesis that consumption of this species may improve athletic performance in humans as well. Further evaluation, in humans, of the usefulness of this strain should be preceded by safety studies. Therefore, the genotoxic and subchronic toxicological potential was evaluated as a contribution to this effort. Genotoxicity investigation was performed using the in vivo comet assay and in vivo mammalian micronucleus assay due to the anaerobic characteristic of the strain. A 90-day, repeated-dose oral toxicity study was performed in rats up to 2200 mg/kg bw/d to investigate general toxicity and identify any target organs. Mitsuoka buffer, a solution shown to preserve the viability of anaerobic bacteria, was used as the vehicle. All three studies revealed no toxicological effects from exposure to FB0054 was isolated from the gastrointestinal tract of marathon runners, who have increased amounts of this species after athletic events. Interestingly, the consumption of this strain by rodents has been shown to increase their treadmill endurance, leading to the hypothesis that consumption of this species may improve athletic performance in humans as well. Further evaluation, in humans, of the usefulness of this strain should be preceded by safety studies. Therefore, the genotoxic and subchronic toxicological potential was evaluated as a contribution to this effort. Genotoxicity investigation was performed using the in vivo comet assay and in vivo mammalian micronucleus assay due to the anaerobic characteristic of the strain. A 90-day, repeated-dose oral toxicity study was performed in rats up to 2200 mg/kg bw/d to investigate general toxicity and identify any target organs. Mitsuoka buffer, a solution shown to preserve the viability of anaerobic bacteria, was used as the vehicle. All three studies revealed no toxicological effects from exposure to FB0054 at the highest doses tested.

A toxicological evaluation of monomethylsilanetriol (MMST) stabilized in acacia gum, a novel silicon preparation.

Monomethylsilanetriol (MMST), a silicon-containing compound, has been sold in dietary supplements. However, toxicological studies on its safety profile are not readily available. To assess the safety of MMST stabilized in acacia gum, a novel delivery form of MMST, in accordance with internationally accepted standards, the genotoxic potential and repeated-dose oral toxicity of Living Silica® Acacia Gum Stabilized Monomethylsilanetriol (formerly known as Orgono Acacia Gum Powder®), a food grade product consisting of 80 ± 10% acacia gum and 2.8% (SD ± 10%) elemental silicon from MMST, was investigated. A bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, an in vivo mammalian micronucleus test, and a 90-day repeated-dose oral toxicity study in rats were performed. No evidence of mutagenicity or genotoxic activity was observed under the applied test systems. In the 90-day study, male and female Hsd.Han Wistar rats were administered daily doses of 0, 500, 1000, and 2000 mg/kg bw/day by gavage. No mortality or treatment-related adverse effects were observed, and no target organs were identified. Therefore, the no observed adverse effects level (NOAEL) was determined as 2000 mg/kg bw/day (201 mg MMST/kg bw/day), the highest dose tested.

Assessment of toxicological potential of sodium carboxymethyl beta-glucan, a novel beta-glucan.

In this experimental work, sodium carboxymethyl beta-glucan (CMBG), a chemically altered beta-glucan, is evaluated for mutagenicity and sub-acute oral toxicity. Specifically, the tested material was CM-Glucan Nu, a food grade powder ≥90% CMBG derived from Saccharomyces cerevisiae. A bacterial reverse mutation test was performed and resulted in no mutagenicity. A 28-day, repeated-dose, oral (gavage) toxicity test on rats was performed at dose levels of 0, 500, 1000, and 2000 mg/kg bw/day. No mortality, target organs or other treatment related effects were observed. The no observed adverse effect level (NOAEL) was 2000 mg/kg bw/day, the highest dose tested, for both male and female Han:WIST rats.