Probiotic Properties and Anti-inflammatory Activity of Bacillus spp. Isolated from Ethnically Fermented Soybean

Bacillus spp. probiotics used as feed additives can form spores and tolerate the harsh conditions of the human digestive system and are beneficial for the treatment of inflammatory bowel syndrome. Since reports on probiotics and anti-inflammatory properties of Bacillus spp. isolated from the fermented food of Northeast India have not been explored much. The present study focused on Bacillus spp. BN5, AY5, and AN8, possessing these desired properties. In the probiotics study, the isolates were screened for their tolerance to acid and bile salt, auto-aggregation, hydrophobicity, cholesterol assimilation, antibiotic resistance, and antagonistic properties. It was found that these isolates possessed the desirable probiotic traits. The Bacillus spp. culture and their supernatant were also screened for their ability to reduce LPS-induced inflammation in murine macrophage (RAW 264.7) cells. All the Bacillus spp. culture and their supernatant treatments were found to reduced the Nitric oxide (NO) production by LPS-induced cell lines. The supernatant of LPS-induced cell lines were also analyzed to measure the level of inflammatory cytokine production. It was found that the levels of TNF-α, IL-6, and IL-1β were reduced after co-treatment with LPS and Bacillus spp. culture or LPS and Bacillus spp. supernatant. Results suggested that the Bacillus spp. are potential probiotic candidates with anti-inflammatory properties.