Is Lactobacillus (lactic acid bacteria) a pathogen?

From the Guidelines

Lactobacillus is generally not considered a pathogen, and its use as a probiotic has been associated with various health benefits, including the prevention of necrotizing enterocolitis in preterm infants and the reduction of mortality and morbidity in this population. The evidence from recent studies, such as the 2020 AGA clinical practice guidelines on the role of probiotics in the management of gastrointestinal disorders 1, suggests that certain strains of lactobacillus, including Lactobacillus rhamnosus and Lactobacillus acidophilus, can be beneficial in preventing infections and promoting gut health. The guidelines recommend the use of probiotics, including lactobacillus, in preterm infants to prevent necrotizing enterocolitis, a serious gastrointestinal condition that can be life-threatening. Additionally, the guidelines suggest that lactobacillus may be beneficial in reducing the duration of diarrhea and preventing infections in certain populations.

Some key points to consider when evaluating the potential benefits and risks of lactobacillus include:

• The strain of lactobacillus used, as different strains may have different effects on the body
• The population being treated, as lactobacillus may be more beneficial in certain populations, such as preterm infants
• The potential for lactobacillus to cause infections in severely immunocompromised individuals or those with underlying health conditions
• The overall safety profile of lactobacillus, which is generally considered to be well established and safe for use as a probiotic.

Overall, the evidence suggests that lactobacillus is not a pathogen and can be a beneficial probiotic in certain contexts, particularly in the prevention of necrotizing enterocolitis in preterm infants. The use of lactobacillus as a probiotic should be guided by the latest clinical practice guidelines and evidence-based recommendations.

From the Research

Lactobacillus as a Pathogen

• Lactobacillus can be considered a pathogen in certain cases, as it has been reported to cause various types of infections, including endocarditis, bacteremia, peritonitis, abscesses, and meningitis 2.
• The species casei and rhamnosus are the most common Lactobacillus species associated with infections, and they tend to be sensitive to erythromycin and clindamycin, but resistant to vancomycin 2.
• Lactobacillus bacteremia is infrequent, but it has a higher risk of mortality, especially in patients with severe underlying diseases, immune system suppression, or those admitted to intensive care units 3.
• The use of probiotics containing Lactobacillus species has been linked to an increased risk of bacteremia, especially in patients with compromised immune systems or underlying medical conditions 3, 4.

Risk Factors and Associations

• Polymicrobial infection is a significant risk factor for mortality in patients with Lactobacillus infections, and inadequate treatment can also increase the risk of mortality 2.
• The use of central venous catheters and probiotics can also increase the risk of Lactobacillus bacteremia 3.
• Certain Lactobacillus species, such as Lacticaseibacillus rhamnosus GG, Lactiplantibacillus plantarum, and Lacticaseibacillus paracasei, have been directly linked to blood isolates from bacteremia patients using molecular identification assays 3.

Therapeutic Use and Safety

• Lactobacilli have been used as therapeutic agents for various pathological conditions, including kidney support, pancreas health, and cancer treatment, with an overall positive safety profile 4.
• However, there is a risk of translocation and subsequent sepsis or bacteremia following probiotic administration, especially in patients with inflammatory diseases or compromised gut mucosa 4.
• The use of postbiotics and parabiotics from lactobacilli has emerged as a promising approach for managing and treating diarrheal diseases, with potential benefits in reducing morbidity and mortality rates associated with infectious diarrhea 5.