New perspectives for mechanisms, ingredients, and their preparation for promoting the formation of beneficial bacterial biofilm

Biofilm is a complex community of microorganisms with a more stable form compared to planktonic bacteria. Probiotic strains in biofilms have been found to have beneficial effects in numerous studies. The formation process and the regulatory mechanisms of biofilm were introduced. Strategies to promote biofilm growth were reviewed in categories. And the extraction and purification process of natural products in exogenous substances was also sorted out and summarized. The research found that different modes of action of the promoting biofilm molecules discussed were facilitated by interfering with the quorum sensing pathways, adhesion mechanisms, the two-component system, influencing extracellular polymers, and secondary messengers involved in various signaling pathways. The studies showed that the strength of the biofilm can be promoted by altering the adhesion surface material and nutrient sources. Probiotics and their secondary metabolites made critical impacts. Further studies found that the ingredients that can promote the formation of bacterial biofilms include hormones, inorganic ions (Mn²⁺, Cu²⁺, Fe³⁺), and natural extracts (inulin, fructooligosaccharides, malic acid, catechins, genistein, cranberry extract, resveratrol, propolis ethanolic extract, bioactive peptides, etc.). The method of extraction and purification prefers safe and low-harm solvents such as ethanol and water. Physical methods were also used to improve yields, such as microwaves, ultra-high pressure, column chromatography, etc. A multi-point, staggered, and all-round examination of the development of probiotic biofilms was directed. The exploration of probiotic biofilm will be a significant advancement heading in the field of probiotic research.