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Lactobacillus salivarius LS33

Also known as: Lactobacillus salivarius (strain Ls-33), L. salivarius Ls-33, probiotic Lactobacillus salivarius, Lactobacillus salivarius

Overview

Lactobacillus salivarius Ls-33 is a specific strain of probiotic bacteria naturally found in the human gastrointestinal tract and oral cavity. It is utilized as a dietary supplement ingredient with the primary aim of modulating gut microbiota composition. Research on Ls-33 has explored its potential roles in conditions such as obesity, lipid metabolism, and oral health. While it has shown promise in altering gut bacterial ratios, particularly in obese adolescents, its direct impact on clinical markers like BMI or metabolic syndrome parameters has been limited. The evidence base for Ls-33 is moderate, with several randomized controlled trials, but comprehensive meta-analyses specifically on this strain are still emerging. It is generally considered safe and is available in various supplement forms, typically as capsules or powders, for daily oral administration.

Benefits

Lactobacillus salivarius Ls-33 offers several potential benefits, primarily centered around its ability to modulate gut microbiota and its antimicrobial properties. In a 12-week double-blind randomized controlled trial involving 50 obese adolescents, L. salivarius Ls-33 significantly altered the ratio of certain fecal bacterial groups (Bacteroides-Prevotella-Porphyromonas to Firmicutes clusters). However, this change did not translate into improvements in metabolic syndrome parameters or obesity measures like BMI or waist circumference, indicating a specific effect on microbiota composition rather than direct weight loss. Broader research on the Lactobacillus genus, including a meta-analysis of 13-15 RCTs, suggests a modest, statistically significant reduction in total cholesterol (mean reduction ~0.26 mmol/L) and LDL cholesterol (~0.23 mmol/L), though specific effects of Ls-33 alone on lipid profiles are not yet isolated. For oral health, studies indicate that L. salivarius strains can reduce pathogenic oral bacteria and biofilm mass, suggesting potential in preventing dental caries, although specific clinical trials on Ls-33 are limited. Additionally, while not specific to Ls-33, probiotic mixtures containing Lactobacillus species have shown clinical benefits in children with atopic dermatitis, hinting at possible immunomodulatory effects.

How it works

Lactobacillus salivarius Ls-33 exerts its effects primarily through modulating the gut microbiota. It appears to shift the balance of gut bacterial populations, specifically increasing the ratio of Bacteroides-related groups to Firmicutes clusters, which may indirectly influence metabolic pathways. Beyond microbiota modulation, L. salivarius produces bacteriocins and other antimicrobial substances that inhibit the growth of pathogenic bacteria in both the gut and oral cavity, contributing to its probiotic and anti-cariogenic effects. As a live bacterial supplement, Ls-33 transiently colonizes the gut, interacting with resident microbiota and mucosal immune cells. This interaction can lead to immune modulation, potentially reducing inflammation and benefiting conditions such as atopic dermatitis.

Side effects

Lactobacillus salivarius Ls-33 is generally considered safe for consumption, with clinical trials reporting no significant adverse effects. Mild gastrointestinal symptoms, such as bloating or gas, are possible but are uncommon and typically transient. There are no documented significant drug interactions or contraindications specifically for Ls-33. However, as with any probiotic, individuals with severely compromised immune systems or those with central venous catheters should exercise caution and consult a healthcare professional before use, due to the theoretical risk of bacteremia, though this is extremely rare with Lactobacillus species. Most studies on Ls-33 have focused on adolescents, so its safety profile in other special populations, such as pregnant or breastfeeding women, or very young children, requires further dedicated research. Overall, Ls-33 has a favorable safety profile based on current evidence.

Dosage

The precise effective dosage of Lactobacillus salivarius Ls-33 can vary, but clinical trials, such as the one in obese adolescents, typically involve a 12-week supplementation period. While the exact CFU (colony-forming unit) dose was not specified in the summary, typical probiotic doses for similar strains range from 10^8 to 10^10 CFU per day. Ls-33 is usually administered daily, and the timing relative to meals is not considered critical, although taking it with food may enhance its survival through the acidic environment of the stomach. It is commonly available in capsule or powder forms. For optimal efficacy, the strain's ability to survive gastric acid and bile is crucial, and some formulations may include specific encapsulation technologies to improve viability. There are no established upper limits or safety thresholds that indicate toxicity, given its generally recognized as safe (GRAS) status.

FAQs

Does L. salivarius Ls-33 help with weight loss?

Current research indicates that L. salivarius Ls-33 can modify gut microbiota composition, but it has not been shown to significantly reduce BMI or waist circumference in obese adolescents.

Can it improve cholesterol levels?

While the broader Lactobacillus genus has shown a modest ability to reduce total and LDL cholesterol, specific evidence for L. salivarius Ls-33 alone in improving cholesterol is currently lacking.

Is L. salivarius Ls-33 safe for children?

Yes, clinical trials involving adolescents have reported a good safety profile for L. salivarius Ls-33, indicating it is generally safe for this age group.

How long does it take to see effects from L. salivarius Ls-33?

Studies typically assess the effects of L. salivarius Ls-33 over periods of 12 weeks or longer to observe changes in microbiota and clinical outcomes.

Research Sources

https://pubmed.ncbi.nlm.nih.gov/23510724/ – This randomized controlled trial with 50 obese adolescents found that L. salivarius Ls-33 altered fecal microbiota composition by increasing the Bacteroides-Prevotella-Porphyromonas to Firmicutes ratio. However, it did not lead to significant improvements in metabolic syndrome markers or obesity measures like BMI or waist circumference.
https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0178868 – This systematic review and meta-analysis of 13-15 RCTs on various Lactobacillus strains (not exclusively Ls-33) found no significant effect on triglycerides or HDL cholesterol. However, it demonstrated a modest, statistically significant reduction in total cholesterol and LDL cholesterol, highlighting a general lipid-lowering potential within the Lactobacillus genus.
https://www.mdpi.com/2072-6643/9/11/1242 – This source discusses the potential of L. salivarius strains to reduce pathogenic oral bacteria and biofilm mass, suggesting anti-cariogenic effects. While specific clinical trials on Ls-33 are limited, the findings indicate a promising role for L. salivarius in oral health.
https://www.e-cep.org/journal/view.php?number=20125555623 – This citation refers to the same study as the first source, confirming that L. salivarius Ls-33 altered gut microbiota composition in obese adolescents without affecting metabolic syndrome parameters or short-chain fatty acids. It reinforces the finding that while microbiota changes occurred, clinical obesity markers were not significantly impacted.
https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2021.833666/full – This source broadly discusses the clinical benefits of probiotic mixtures, including Lactobacillus species, in children with atopic dermatitis over 6 months. While not specific to Ls-33, it suggests potential immunomodulatory effects of Lactobacillus probiotics that could be relevant to this strain.