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Lactobacillus Acidophilus W37

Also known as: Lactobacillus acidophilus, probiotic lactic acid bacteria, Lactobacillus acidophilus W37

Overview

Lactobacillus acidophilus W37 is a specific probiotic strain of the L. acidophilus species, which is naturally present in the human gastrointestinal tract and various fermented foods. It is primarily utilized as a dietary supplement to support intestinal health, enhance immune function, and potentially improve vaccine efficacy and resistance against pathogens. Key characteristics of this strain include its ability to support the integrity of the intestinal barrier, modulate immune responses, and influence the composition of the gut microbiota. While research on L. acidophilus W37 is still emerging, it is supported by in vitro, animal, and some human studies. However, clinical evidence specifically for the W37 strain is more limited compared to the broader L. acidophilus species. The quality of evidence varies, with well-designed animal and in vitro studies, but fewer randomized controlled trials (RCTs) in humans and a lack of large-scale meta-analyses focused exclusively on W37.

Benefits

Lactobacillus acidophilus W37 has demonstrated several promising benefits, primarily in animal models and in vitro studies. Its most significant effect is the enhancement of vaccination efficacy against Salmonella Typhimurium in piglets, where it doubled protection during pathogen challenge when combined with prebiotics like long-chain inulin. This suggests a strong immunomodulatory role. Furthermore, the strain supports intestinal epithelial barrier integrity during bacterial challenge in vitro, which is crucial for preventing pathogen translocation. Secondary benefits include the modulation of gut microbiota composition, leading to an increase in beneficial bacteria such as Prevotellaceae and a reduction in potentially harmful Lactobacillaceae shifts during infection. It also induces Th1 cytokines and increases IFN-γ producing T cells, indicating a positive influence on cell-mediated immunity. While these findings are robust in animal and in vitro settings, direct human clinical data on W37 are currently lacking, limiting the ability to confirm these benefits in humans or specify population-specific advantages. The evidence quality is moderate for animal studies but insufficient for human clinical application.

How it works

Lactobacillus acidophilus W37 exerts its effects primarily within the gut lumen. It enhances intestinal barrier function by potentially strengthening epithelial tight junctions, thereby reducing the translocation of pathogens across the gut lining. The strain modulates innate immune receptors, such as Toll-like receptors (TLRs), which influences downstream immune signaling pathways. This modulation promotes Th1 immune responses, characterized by cell-mediated immunity, and can reduce regulatory T cells, shifting the immune balance towards more effective pathogen clearance. Additionally, L. acidophilus W37 favorably alters the gut microbiota composition, especially during pathogen challenges, contributing to a healthier gut environment. As a probiotic, it acts locally in the gastrointestinal tract and is not absorbed systemically into the bloodstream.

Side effects

Lactobacillus acidophilus W37, like other L. acidophilus strains, is generally recognized as safe (GRAS) for healthy populations. No significant adverse effects have been reported in animal studies or in vitro models specifically for the W37 strain. When considering the broader L. acidophilus species, common side effects are typically mild gastrointestinal symptoms, such as bloating or gas, occurring in less than 5% of individuals. Rare risks associated with probiotics in general include systemic infection in severely immunocompromised individuals, but there are no specific reports of such incidents linked to L. acidophilus W37. Furthermore, no known drug interactions or contraindications have been identified specifically for this strain. Overall, its safety profile appears favorable, particularly for healthy individuals, though caution is advised for those with compromised immune systems.

Dosage

Currently, there is no standardized or established dosing guideline specifically for Lactobacillus acidophilus W37 due to the limited availability of human clinical data. Animal studies, particularly those involving piglets, have utilized daily supplementation starting early in life and continuing for several weeks. For the broader L. acidophilus species, typical human probiotic dosing ranges from 1 billion to 10 billion Colony Forming Units (CFU) per day. However, these recommendations do not directly apply to the W37 strain. The timing of supplementation, especially in relation to vaccination or pathogen exposure, appears to be critical, as demonstrated in animal models. Without specific human trials, it is not possible to provide precise dosage ranges, optimal timing, or upper safety limits for L. acidophilus W37.

FAQs

Is L. acidophilus W37 effective in humans?

Direct human clinical evidence for L. acidophilus W37 is limited. Benefits have primarily been demonstrated in animal models and in vitro studies, suggesting potential but requiring further human research.

Is L. acidophilus W37 safe?

Yes, L. acidophilus W37 is generally considered safe for healthy individuals. No serious adverse effects have been reported specifically for this strain in studies to date.

How long does it take to see benefits from L. acidophilus W37?

In animal studies, benefits were observed over several weeks of supplementation. Human data are insufficient to determine a specific time frame for observing effects.

Can L. acidophilus W37 prevent infections?

L. acidophilus W37 may support immune responses and gut barrier function, potentially reducing infection risk. However, human evidence is currently insufficient to confirm its ability to prevent infections.

Research Sources

https://www.nature.com/articles/s41598-019-54353-1 – This RCT in piglets investigated the combined effect of long-chain inulin and L. acidophilus W37. It found that this combination doubled vaccination efficacy against Salmonella Typhimurium, improved gut barrier integrity, and modulated microbiota, suggesting promising immunomodulatory and protective effects in an animal model.
https://www.frontiersin.org/journals/gastroenterology/articles/10.3389/fgstr.2022.983075/full – This systematic review focused on probiotics, including L. acidophilus, and their impact on intestinal barrier function and inflammation. It concluded that probiotics generally improve these aspects, but it did not specifically isolate or provide detailed findings for the W37 strain.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10165082/ – This meta-analysis reviewed the effects of probiotic treatment, including L. acidophilus and L. bulgaricus, on diarrhea incidence. It found that probiotic treatment reduced diarrhea compared to placebo, but the analysis combined species and did not specify or isolate the effects of the W37 strain.
https://pmc.ncbi.nlm.nih.gov/articles/PMC12029412/ – This source provides general information on Lactobacillus acidophilus and its uses. It does not contain specific research findings or studies related to the W37 strain, but rather discusses the broader species.
https://academic.oup.com/nutritionreviews/article/83/2/e4/7606372 – This source discusses general aspects of nutrition and health. It does not contain specific research findings or studies related to the W37 strain, but rather provides broader context on nutritional science.