# Lactococcus lactis subsp. lactis IL1403

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/lactococcus-lactis-subsp-lactis-il1403
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-04-03
**Evidence Score:** 2 / 10
**Category:** Fermented/Probiotic
**Also Known As:** IL1403, L. lactis IL1403, Lactococcus lactis IL1403, plasmid-free L. lactis strain, laboratory strain IL1403

## Overview

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](/ingredients/condition/gut-health) or supplement ingredient.

## 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)

## Mechanism of Action

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](/ingredients/condition/gut-health) interaction.

## 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](/ingredients/condition/gut-health) 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](/ingredients/condition/gut-health) 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.

## Dosage & Preparation

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.

## Safety & Drug 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](/ingredients/condition/gut-health) product should confirm the specific strain designation, as safety data from one strain cannot be extrapolated to IL1403.

## Scientific Research

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

## 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.

## Synergistic Combinations

No synergistic ingredients identified due to lack of clinical data

## Frequently Asked Questions

### Is Lactococcus lactis subsp. lactis IL1403 a probiotic supplement?

No, IL1403 is not used as a commercial probiotic supplement and has no documented clinical health benefits in humans. It functions as a scientific reference strain, most widely used following its complete genome sequencing in 2001. Consumers should not confuse it with other L. lactis strains that appear in some probiotic formulations.

### What are the prophage elements in Lactococcus lactis IL1403 and why do they matter?

The IL1403 genome contains six prophage or prophage-like elements, including bIL285, bIL286, bIL309, and bIL310, which together constitute approximately 6% of the genome. These elements influence the expression of autolysin AcmA, altering how and when the bacterium breaks down its own cell wall during growth cycles. This makes IL1403 a model organism for studying bacteriophage-host interactions in lactic acid bacteria, but this has no established relevance to human health.

### How does Lactococcus lactis IL1403 differ from other L. lactis strains used in food or supplements?

IL1403 is a laboratory reference strain selected for genomic research, whereas strains like L. lactis subsp. lactis NCDO 2118 or subsp. cremoris have documented roles in dairy fermentation and some probiotic applications. IL1403's prophage complement and specific autolysin expression profile distinguish it genetically from food-grade strains. No head-to-head clinical comparisons exist, and IL1403 is not manufactured or quality-controlled for human consumption.

### What did the Bolotin 2001 genome study reveal about IL1403?

The Bolotin et al. 2001 study published in Genome Research sequenced the complete 2.365 Mb circular chromosome of IL1403, identifying 2,310 predicted protein-coding sequences and revealing a minimal metabolic repertoire reflecting adaptation to nutrient-rich dairy environments. The study identified six prophage elements and mapped the AcmA autolysin gene, establishing IL1403 as the primary genomic reference for the L. lactis species. This foundational genomic data has driven subsequent in vitro research but has not translated into clinical investigations.

### Are there any health risks associated with Lactococcus lactis IL1403?

No formal toxicology or human safety studies have been conducted on IL1403, so quantified risk data do not exist. The broader L. lactis species is considered non-pathogenic and is associated with GRAS (Generally Recognized As Safe) status in food contexts, but IL1403's prophage elements represent an uncharacterized variable in a human host setting. Immunocompromised individuals in particular should avoid experimental or non-validated bacterial strains, and no regulatory body has approved IL1403 for therapeutic or dietary supplement use.

### What is the current research status on Lactococcus lactis subsp. lactis IL1403 for human health applications?

Clinical research on IL1403 specifically for human health benefits is currently absent; available scientific literature focuses exclusively on its genomic and microbiological characteristics rather than therapeutic efficacy. The strain has been studied primarily in laboratory and fermentation contexts, with no peer-reviewed human clinical trials demonstrating health benefits. Any health claims made about IL1403 should be approached with caution due to the lack of human evidence supporting safety or effectiveness for medical purposes.

### Can Lactococcus lactis subsp. lactis IL1403 be naturally obtained from food sources?

IL1403 is not a naturally occurring or commercially established food culture strain in dairy or fermented foods—it is a laboratory reference strain primarily used in research settings. While the parent species L. lactis is extensively used in yogurt and cheese fermentation, IL1403 specifically has not been incorporated into commercial food production. If IL1403 appears in supplements, it would be added as a cultured ingredient rather than derived from traditional fermented food sources.

### Who should avoid taking supplements containing Lactococcus lactis subsp. lactis IL1403?

Because no safety or clinical efficacy data exists for IL1403 in human supplementation, individuals with compromised immune systems, those taking immunosuppressant medications, and patients with serious infections should consult healthcare providers before use. Pregnant and nursing women should also exercise caution given the complete absence of safety studies in these populations. People with documented allergies to L. lactis or dairy fermentation cultures should avoid products containing this strain.

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