Probiotic Biofilm: A Novel Approach to Produce a New Generation of Probiotics and Probiotic Foods

Abstract Background Probiotic biofilm is considered a new version of an advanced natural protection method recently placed on researchers’ agenda as the fourth generation of probiotics. In several studies, probiotic biofilms have been produced exclusively in the bacterial culture medium, but in this study, the biofilm of Lactobacillus plantarum PTCC 1745 and Lactobacillus rhamnosus PTCC 1637 were formed in food (milk) and evaluated for the first time. Methods The biofilm was produced in milk then was transferred to yogurt in whole and crushed forms to be tested in real conditions as probiotic bacteria carriers. Survival was assessed for 21 days as well as gastrointestinal conditions. Results Results demonstrate that the number of bacteria in biofilm did not change significantly during 21 days of refrigerated storage. In contrast, planktonic bacteria was decreased by about 2.8 log simultaneously. Another significant result is that the biofilm could appropriately protect the bacteria in the stomach and intestine simulated conditions. So, no significant reduction was observed in the number of bacteria during 120 min, but planktonic cells were destroyed after 30 min. Conclusions In conclusion results indicated that L. plantarum and L. rhamnosus could form a very desirable and strong biofilm in vitro and milk that can have a good protective effect on yogurt’s probiotic survival process and storage. Therefore, the probiotic biofilm technique can introduce a new generation of probiotics to the food and pharmaceutical industries