Bedsores impose an important challenge to the healthcare system. Se-baring probiotics are considered effective agents in wound healing and inflammation reduction via several pathways. The present study focused on the administration of a Se-enriched probiotic, originally obtained from a traditional dairy product for bedsore healing. Daily doses of the probiotic were administered to 20 ICU patients for 14 days and the wound healing criteria were compared with those of the same group of ICU patients as control, both groups suffering from stages I and II bedsore (a randomized, double-blind, controlled clinical trial). The administered Se-enriched probiotic decreased the bedsore healing period significantly (on average by 2.4 days, P-value: 0.039), as well as bedsore size (on average by 7 mm2, nonsignificant) and bedsore grade (10%, nonsignificant) in the treatment group more efficiently than the control group. Some key laboratory parameters associated with inflammation were also improved in patients receiving the Se-supplemented probiotic. The limitations of this study include the low number of patients meeting inclusion criteria within the timeframe of the study, and the impossibility of following up patients after discharge from the ICU. In summary, this study revealed the effectiveness of the Se-enriched probiotic in bedsore improvement, suggesting consideration of the enriched probiotic as an auxiliary agent in bedsore management.

In this study, the transcriptome analysis was practiced to identify potential genes of probiotic Bacillus subtilis BSN313 involved in selenium (Se) enrichment metabolism. The transcriptomic variation of the strain was deliberated in presence of three different sodium selenite concentrations (0, 3, and 20 μg/mL). The samples were taken at 1 and 13 h subsequent to inoculation of selenite and gene expression profiles in Se metabolism were analyzed through RNA sequencing. The gene expression levels of the pre log phase were lower than the stationary phase. It is because, the bacteria has maximum grown with high concentration of Se (enriched with organic Se), at stationary phase. Bacterial culture containing 3 μg/mL concentration of inorganic Se (sodium selenite) has shown highest gene expression as compared to no or high concentration of Se. This concentration (3 μg/mL) of sodium selenite (as Se) in the medium promoted the upregulation of thioredoxin reductase expression, whereas its higher Se concentration inhibited the formation of selenomethionine (SeMet). The result of 5 L bioreactor fermentation showed that SeMet was also detected in the fermentation supernatant as the growth entered in the late stationary phase and reached up to 857.3 ng/mL. The overall intracellular SeMet enriched content in BSN313 was extended up to 23.4 μg/g dry cell weight. The other two selenoamino acids (Se-AAs), methyl-selenocysteine, and selenocysteine were hardly detected in medium supernatant. From this study, it was concluded that SeMet was the highest content of organic Se byproduct biosynthesized by B. subtilis BSN313 strain in Se-enriched medium during stationary phase. Thus, B. subtilis BSN313 can be considered a commercial probiotic strain that can be used in the food and pharmaceutical industries. This is because it can meet the commercial demand for Se-AAs (SeMet) in both industries.