Food safety assessment and 28-day toxicity study of the synbiotic medical food consortium SBD121.

The human gut microbiome plays a crucial role in immune function. The synbiotic consortium or Defined Microbial Assemblage™ (DMA™) Medical Food product, SBD121, consisting of probiotic microbes and prebiotic fibers was designed for the clinical dietary management of rheumatoid arthritis. A 28-day repeated administration study was performed to evaluate the oral toxicity of SBD121 in male and female rats (age/weight at study start: 60 days/156-264 g) administered levels of 0, 4.96 x 1010, 2.48 x 1011, or 4.96 x 1011 colony forming units (CFU)/kg-bw. No treatment related changes were observed in ophthalmological effects, mortality, morbidity, general health and clinical observations, urinalysis, hematology, serum chemistry, absolute or relative organ weights, gross necropsy, or histopathology. A significant decrease in body weight was reported in females in the low and high-concentration groups, which corresponded in part with a significant decrease in food consumption. Results of the functional observation battery indicated front grip strength was significantly greater in the high-concentration males compared to the controls; however, this effect was not considered adverse. Based on these findings, the administration of the Medical Food SBD121 to male and female rats has a no-observable adverse effect level (NOAEL) at the highest level tested of 4.96 x 1011 CFU/kg-bw.

The edible plant microbiome: evidence for the occurrence of fruit and vegetable bacteria in the human gut.

Diversity of the gut microbiota is crucial for human health. However, whether fruit and vegetable associated bacteria contribute to overall gut bacterial diversity is still unknown. We reconstructed metagenome-assembled genomes from 156 fruit and vegetable metagenomes to investigate the prevalence of associated bacteria in 2,426 publicly available gut metagenomes. The microbiomes of fresh fruits and vegetables and the human gut are represented by members in common such as Enterobacterales, Burkholderiales, and Lactobacillales. Exposure to bacteria via fruit and vegetable consumption potentially has a beneficial impact on the functional diversity of gut microbiota particularly due to the presence of putative health-promoting genes for the production of vitamin and short-chain fatty acids. In the human gut, they were consistently present, although at a low abundance, approx. 2.2%. Host age, vegetable consumption frequency, and the diversity of plants consumed were drivers favoring a higher proportion. Overall, these results provide one of the primary links between the human microbiome and the environmental microbiome. This study revealed evidence that fruit and vegetable-derived microbes could be found in the human gut and contribute to gut microbiome diversity.

Food safety assessment and toxicity study of the synbiotic consortium SBD111.

The human gut microbiome plays a crucial role in skeletal homeostasis. The synbiotic consortium or Defined Microbial Assemblage™ (DMA™) food product, SBD111, consisting of probiotic microbes and prebiotic fibers was designed to promote bone health based on its capacity to produce short chain fatty acids (SCFA), the presence of genes for vitamin K2 production, and its ability to degrade plant fibers. A 28-day repeated administration study was performed to evaluate the oral toxicity of SBD111 in female rats (age/weight at study start: 5-7 weeks/120-180 g) administered levels of 0, 2.0 x 1010, 9.8 x 1010, or 2.0 x 1011 colony forming units (CFU)/kg-bw. No mortality or morbidity occurred during the study. There were no significant differences in body weights, hematology, serum chemistry, coagulation, organ weights, or food consumption in the test groups compared to the controls. Liver weight to body weight ratios were signficantly decreased at 9.8 x 1010 CFU/kg-bw when compared to controls. No treatment related changes in motor activity, sensory stimuli, or grip strength were observed. Based on these findings, SBD111 administered to female rats has a no-observable adverse effect level (NOAEL) at the highest level tested of 2.0 x 1011 CFU/kg-bw.

Development of a synbiotic that protects against ovariectomy-induced trabecular bone loss.

The gut microbiome has the capacity to regulate bone mass. The aim of this study was to develop a nutritional synbiotic dietary assemblage at an optimal dose to maintain bone mass in ovariectomized (Ovx) mice. We performed genomic analyses and in vitro experiments in a large collection of bacterial and fungal strains (>4,000) derived from fresh fruit and vegetables to identify candidates with the synergistic capacity to produce bone-protective short-chain fatty acids (SCFA) and vitamin K2. The candidate SBD111-A, composed of Lactiplantibacillus plantarum, Levilactobacillus brevis, Leuconostoc mesenteroides, Pseudomonas fluorescens, and Pichia kudriavzevii together with prebiotic dietary fibers, produced high levels of SCFA in vitro and protected against Ovx-induced trabecular bone loss in a dose-dependent manner in mice. Metagenomic sequencing revealed that SBD111-A changed the taxonomic composition and enriched specific pathways for synthesis of bone-protective SCFA, vitamin K2, and branched-chain amino acids in the gut microbiome.NEW & NOTEWORTHY We performed genomic analyses and in vitro experiments in a collection of bacterial and fungal strains. We identified a combination (SBD111-A) that produced high levels of SCFA in vitro and protected against ovariectomy-induced bone loss in a dose-dependent manner in mice. Metagenomic sequencing revealed that SBD111-A changed the taxonomic composition and function of the gut microbiome and enriched pathways for synthesis of bone-protective SCFA, vitamin K2, and branched-chain amino acids.