Lactococcus lactis subsp. lactis IL1403

Lactococcus lactis subsp. lactis IL1403 is a gram-positive lactic acid bacterium whose genome has been fully sequenced, revealing prophage elements and autolytic enzyme systems that govern cell wall degradation. It serves primarily as a laboratory reference strain for microbiological and genomic research rather than as a clinically validated probiotic or supplement ingredient.

Origin & History

Lactococcus lactis subsp. lactis IL1403 is a plasmid-free laboratory strain of lactic acid bacteria containing six prophage-like elements that comprise 6.7% of its chromosome. This fully-sequenced strain is derived from the species commonly used in buttermilk and cheese production. IL1403 serves primarily as a research model organism rather than a commercial probiotic preparation.

Historical & Cultural Context

No traditional or historical medicinal use of IL1403 specifically is documented in the available research. While the parent species L. lactis has been used in dairy fermentation, IL1403 itself is a modern laboratory strain without established traditional applications.

Health Benefits

• No clinical health benefits documented - available research focuses solely on microbiological characteristics
• Laboratory studies show the strain modifies bacterial growth and survival properties (no human evidence)
• Contains prophage elements that affect autolytic properties (relevance to human health unknown)
• Parent species L. lactis is used in dairy fermentation (no specific IL1403 clinical data)
• Genetic composition includes various phage-related functions (no translation to health outcomes established)

How It Works

IL1403 carries multiple prophage elements, including phages bIL285, bIL286, bIL309, and bIL310, which modulate the expression of autolysin enzymes such as AcmA, a major N-acetylmuramidase responsible for peptidoglycan hydrolysis and cell autolysis. Prophage-encoded proteins interact with the host's cell wall remodeling machinery, altering bacterial growth kinetics and lysis rates under laboratory conditions. These mechanisms have been characterized at the genomic level in vitro and have not been studied in the context of human gastrointestinal physiology or host-microbiome interaction.

Scientific Research

No human clinical trials, randomized controlled trials, or meta-analyses were found in the available research for IL1403 as a probiotic supplement. The existing literature consists entirely of microbiological and genomic characterization studies focused on its laboratory properties rather than clinical applications.

Clinical Summary

No human clinical trials have investigated Lactococcus lactis subsp. lactis IL1403 for any health outcome. All available research consists of in vitro microbiological studies and genomic analyses, most notably the landmark 2001 whole-genome sequencing study by Bolotin et al. published in Genome Research, which characterized its 2.37 Mb genome and 2,310 protein-coding genes. No randomized controlled trials, observational cohort studies, or safety pharmacology studies in human subjects have been conducted with this specific strain. The evidence base does not support any clinical health claims, and IL1403 should not be conflated with other L. lactis strains that have separately documented probiotic properties.

Nutritional Profile

Lactococcus lactis subsp. lactis IL1403 is a bacterial strain consumed in negligible biomass quantities; direct macronutrient contribution to human diet is effectively zero in typical probiotic or fermented food contexts. At the cellular composition level, consistent with L. lactis species data: protein constitutes approximately 55-60% of dry cell weight (predominantly enzymatic and structural proteins including glycolytic enzymes and cell wall-associated proteins); lipids account for approximately 15-20% of dry cell weight (primarily membrane phospholipids including phosphatidylglycerol and cardiolipin, with no cholesterol as a gram-positive bacterium); carbohydrates/cell wall components (peptidoglycan, polysaccharides) represent approximately 10-15% of dry cell weight. IL1403 genome sequencing confirms biosynthetic capacity for riboflavin (vitamin B2) and folate (vitamin B9) production, traits shared with parent L. lactis species, though quantitative output specific to IL1403 in food matrices has not been independently measured. The strain produces lactic acid as primary metabolite via homofermentation. Bioactive compounds of note include bacteriocin-related gene clusters identified in genome sequence, though IL1403 is documented as a bacteriocin-negative reference strain. Prophage elements (6 identified prophages: bIL285, bIL286, bIL309, bIL310, bIL311, bIL312) influence autolytic enzyme (autolysin) expression, which may affect intracellular compound release during fermentation. No human bioavailability data exists specific to IL1403; general L. lactis bioavailability principles apply wherein bacterial-synthesized B-vitamins may contribute marginally to host nutrition in fermented food contexts.

Preparation & Dosage

No clinically studied dosage ranges exist for IL1403 in humans. This strain has not been evaluated in clinical trials for supplement use. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

No synergistic ingredients identified due to lack of clinical data

Safety & Interactions

IL1403 has no established safety profile in humans, as it has not been evaluated in human clinical or toxicological studies. As a lactic acid bacterium generally regarded as safe within the broader L. lactis species, serious pathogenicity is considered unlikely, but this specific strain carries intact and remnant prophage elements whose behavior in a human host is uncharacterized. No drug interactions, contraindications, or pregnancy safety data exist for IL1403. Individuals considering any L. lactis-based probiotic product should confirm the specific strain designation, as safety data from one strain cannot be extrapolated to IL1403.