(P27-030-24) Three Clostridium Species With Potential Health Imparting Properties: In Vitro Screening and Probiotic Assessment-A Proposal

Objectives: In two previous studies in obesity models (Sprague Dawley CD rats and C57BL6 mice) we have shown that a higher representation of genus Clostridium sensu stricto (Cluster I) correlates with lower body weight; resistance to diet induced obesity, inflammation, and insulin resistance.  Rodents that remained lean and insulin sensitive despite exposure to an obesogenic high fat diet had 3-50X higher amounts of Clostridium compared to those that easily developed obesity.  Among species identified were C. disporicum, C. celatum, and C. vincentii.  We hypothesize that metabolites of these bacteria impact lipid metabolism and/or inflammation pathways to protect against diet induced obesity. Being strict anaerobes, we explored use of spores to exploit their potential as probiotics.

Methods: We cultured the bacteria, allowed sporulation to occur, quantified spores and subjected them to air (oxygen) for 21 days, simulated gastric acid, and bile acids for 4 hours and different temperatures up to 100°C, before exposing them to favorable anaerobic conditions to check for resilience and ability to germinate and form colonies on agar plates.

In ongoing in vitro tests we aim at (i)  testing antibacterial activity (potential to inhibit the growth of pathogenic bacteria), (ii) triglyceride-lowering capacity, bile salt hydrolase activity and alpha-glucosidase inhibiting capacity all as a measure that can reduce fat or glucose absorption in cases of excesses in the diet, (iii) hemolytic activity and antibiotic susceptibility to ensure the safety as probiotics (v) will treat Caco-2 cells with bacteria cell free supernatant and screen the Toll-Like Receptor (TLRs) signaling pathway and inflammation pathways using the RT² profiler PCR Array.

Results: Spores from all 3 species survived exposure up to 70oc. After exposure to air/oxygen survival rates were 68.2%, 55.7% and 49.5% for C. celatum, C. disporicum and C. vincentii respectively. Survival after exposure to gastric juice was 86.7%, 65.0% 25.6% for C. celatum, C. disporicum and C. vincentii respectively. Survival after exposure to bile acids was 57.8%, 65% and 50.7% for C. celatum, C. disporicum and C. vincentii respectively.

Conclusions: The resilience of the spores to environmental and gut conditions demonstrates potential for successful oral administration and colonization of the three bacteria spores in the mammalian lower gut. The in vitro tests on potential health benefits are ongoing.

Funding Sources: New Laboratory startup funds, USDA–NIFA