Safety assessment of the human milk-isolated probiotic Lactobacillus salivarius CECT5713.

2007-08
Journal of Dairy Science 90(8)
- F. Lara‐Villoslada
- S. Sierra
- M. Díaz-Ropero
- M. Olivares
- J. Xaus

PubMed: 17638967
DOI: 10.3168/JDS.2006-685

Study Design

Type: Randomized Controlled Trial (RCT)
Sample size: n = 50
Population: Balb/C mice
Methods: Controlled experimental study

Animal Study

Abstract

The potential probiotic bacteria Lactobacillus salivarius CECT5713 has recently been isolated from human milk and characterized. The objective of the present study was to evaluate the oral toxicity of this potential probiotic bacteria in mice. With this aim, 50 Balb/C mice were divided in 5 groups (n = 10). Three of these groups were treated orally with different doses of L. salivarius CECT5713: 5 x 10(8), 2 x 10(9), or 10(10) cfu/mouse per d for 28 d. One additional group was administered the vehicle alone and was used as a control. The last group were injected intraperitoneally with 10(8) cfu/mouse in a single dose and killed 2 (n = 5) and 5 (n = 5) d after intraperitoneal injection. Food intake, body weight, bacterial translocation, serum alpha-amyloid protein, and different biochemical parameters were analyzed. Oral administration of L. salivarius CECT5713 to mice had no adverse effects on mouse body weight or food intake. No bacteremia was shown and there was no treatment-associated bacterial translocation to the liver or spleen. Intraperitoneal administration caused a significant bacterial translocation to the liver and spleen, but not to the blood. However, this translocation was not related to illness or death at either d 2 or d 5, although an increase in plasma serum alpha-amyloid protein was observed at d 2. These results suggest that the strain L. salivarius CECT5713 is nonpathogenic for mice, even in doses 10,000 times higher (expressed per kilograms of body weight) than those normally consumed by humans. Thus, this strain is likely to be safe for human consumption.

Research Insights

Lactobacillus salivarius SD-5208→Increased Plasma Serum Alpha-Amyloid Protein
an increase in plasma serum alpha-amyloid protein was observed at d 2.
Effect
Neutral
Effect size
Moderate
Lactobacillus salivarius SD-5208→No Adverse Effects on Body Weight or Food Intake
Oral administration of L. salivarius CECT5713 to mice had no adverse effects on mouse body weight or food intake.
Effect
Neutral
Effect size
Moderate
Lactobacillus salivarius SD-5208→No Bacteremia or Translocation of Bacteria to Vital Organs
No bacteremia was shown and there was no treatment-associated bacterial translocation to the liver or spleen.
Effect
Neutral
Effect size
Small
Lactobacillus salivarius UALb-07→Absence of Bacterial Translocation to Liver or Spleen
No bacteremia was shown and there was no treatment-associated bacterial translocation to the liver or spleen.
Effect
Neutral
Effect size
Moderate
Lactobacillus salivarius UALb-07→Increased Serum Amyloid Protein
Intraperitoneal administration caused a significant bacterial translocation to the liver and spleen, but not to the blood. However, this translocation was not related to illness or death at either d 2 or d 5, although an increase in plasma serum alpha-amyloid protein was observed at d 2.
Effect
Harmful
Effect size
Large
Lactobacillus salivarius UALb-07→No Adverse Effects on Body Weight or Food Intake
Oral administration of L. salivarius CECT5713 to mice had no adverse effects on mouse body weight or food intake.
Effect
Neutral
Effect size
Moderate
Lactobacillus salivarius UALs07→Absence of Bacteremia
No bacteremia was shown and there was no treatment-associated bacterial translocation to the liver or spleen.
Effect
Neutral
Effect size
Small
Lactobacillus salivarius UALs07→Ensured Safety for Human Consumption
Thus, this strain is likely to be safe for human consumption.
Effect
Beneficial
Effect size
Moderate
Lactobacillus salivarius UALs07→Maintained Body Weight
Oral administration of L. salivarius CECT5713 to mice had no adverse effects on mouse body weight or food intake.
Effect
Neutral
Effect size
Large
Lactobacillus salivarius UALs07→No Hepatic or Splenic Translocation with Oral Administration
No bacteremia was shown and there was no treatment-associated bacterial translocation to the liver or spleen.
Effect
Neutral
Effect size
Small
Lactobacillus salivarius UALs07→No Illness or Death Despite Bacterial Translocation
However, this translocation was not related to illness or death at either d 2 or d 5.
Effect
Neutral
Effect size
Small
Lactobacillus salivarius UALs07→Nonpathogenic Condition
These results suggest that the strain L. salivarius CECT5713 is nonpathogenic for mice, even in doses 10,000 times higher (expressed per kilograms of body weight) than those normally consumed by humans.
Effect
Neutral
Effect size
Small
Lactobacillus salivarius UALs07→Reduced Bacterial Translocation
No bacteremia was shown and there was no treatment-associated bacterial translocation to the liver or spleen.
Effect
Beneficial
Effect size
Large