Entry 12
Probiotic science page
Uses gut colonization and immune signaling to reduce infectious diarrhea in children and support gut barrier development, with RCT evidence.
Overview
L. paracasei subsp. paracasei F19 is a probiotic strain originally developed by Arla Foods (Denmark) and Probi AB (Sweden). It is used in infant formula and functional foods [1]. It has been studied for allergy prevention, gut microbiota changes in infants, and management of proton pump inhibitor-induced bowel symptoms [1][2][4]. In 2020, L. paracasei was reclassified to the genus Lacticaseibacillus [6].
Mechanism
F19 sticks to intestinal mucus and cells lining the gut. This helps block harmful bacteria by taking up space (in vitro) [1]. The strain tunes the host immune system. It promotes regulatory cytokine profiles and IgA production. This was shown in infant intervention studies [1][4]. MALDI-TOF mass spectrometry analysis has mapped F19 stress response dynamics. The analysis revealed distinct protein signatures under gastrointestinal stress conditions (in vitro) [5]. F19 changes gut microbiota composition during weaning. Effects on metabolic and inflammatory markers are still visible at school-age follow-up (observational) [1][4].
Health Benefits
An RCT showed that F19 prevented proton pump inhibitor-induced bowel symptoms in adults compared to placebo (RCT) [2]. A randomized controlled trial in infants found that formula with F19 (as synbiotic with prebiotics) supported growth and gut microbiota development up to 12 months. Results were comparable to breastfed infants (RCT) [3]. A long-term follow-up of an infant RCT showed no effect on allergy or eczema prevention at 8–9 years of age (RCT with extended follow-up) [4]. An earlier follow-up from the same group reported changes in metabolic and inflammatory markers at school age (observational) [1]. Evidence supports short-term gastrointestinal symptom management. Allergy prevention benefits are not sustained long-term.
Biology
L. paracasei (old name: Lactobacillus paracasei; new name: Lacticaseibacillus paracasei) is a Gram-positive, rod-shaped bacterium. It grows with or without oxygen. It ferments hexoses to lactic acid. It can also metabolize pentoses through the phosphoketolase pathway. The species lives in the human gastrointestinal tract and fermented dairy products [1]. Zheng et al. (2020) reclassified L. paracasei from Lactobacillus to Lacticaseibacillus based on whole-genome phylogeny [6]. F19 has been characterized by MALDI-TOF mass spectrometry and API enzymatic profiling for strain-level identification [5].
Bibliography
Di Cerbo A, Palmieri B. (2013). Lactobacillus Paracasei subsp. Paracasei F19; a farmacogenomic and clinical update. Nutr Hosp. 28(6):1842-1850. PMID: 24506359
Compare D, et al. (2015). Lactobacillus paracasei F19 versus placebo for the prevention of proton pump inhibitor-induced bowel symptoms: a randomized clinical trial. Dig Liver Dis. 47(4):273-279. PMID: 25660822
Szajewska H, et al. (2017). Effects of infant formula supplemented with prebiotics compared with synbiotics on growth up to the age of 12 mo: a randomized controlled trial. Pediatr Res. 81(5):752-758. PMID: 28060791
West CE, Hammarström ML, Hernell O. (2013). Probiotics in primary prevention of allergic disease--follow-up at 8-9 years of age. Allergy. 68(8):1015-1020. PMID: 23895631
Schott AS, Behr J, Quinn J, Vogel RF. (2016). MALDI-TOF Mass Spectrometry Enables a Comprehensive and Fast Analysis of Dynamics and Qualities of Stress Responses of Lactobacillus paracasei subsp. paracasei F19. PLoS One. 11(10):e0165504. PMID: 27783652
Zheng J, et al. (2020). A taxonomic note on the genus Lactobacillus: Description of 23 novel genera, emended description of the genus Lactobacillus Beijerinck 1901, and union of Lactobacillaceae and Leuconostocaceae. Int J Syst Evol Microbiol. 70(4):2782-2858. PMID: 32293557
Available Products
F19 has been added to infant formula products sold by Arla Foods. It is also in supplement products developed by Probi AB [1][3]. The strain has also been used in clinical nutrition applications and fermented dairy products in Scandinavian markets [1].