What the Research Says
Probiotics (Lactobacillus) are beneficial bacteria that have demonstrated diverse applications in human health. Among the most studied strains is *Lactobacillus rhamnosus* GG, which has been shown to effectively prevent antibiotic-associated diarrhea (AAD). A systematic review and meta-analysis involving 39 randomized controlled trials with 9,955 participants found that probiotics significantly reduced the incidence of Clostridium difficile-associated diarrhea compared to controls (Goldenberg et al., 2017).
Recent studies have expanded the understanding of *Lactobacillus* strains beyond traditional gastrointestinal applications. For instance, *Lactobacillus plantarum* GKM3 has been shown to improve bowel movement frequency and reduce gastroesophageal reflux symptoms in overweight individuals, as demonstrated in a randomized clinical trial (Tsai et al., 2025). Additionally, next-generation probiotics have been explored for their potential in addressing metabolic dysfunction-associated steatotic liver disease (MASLD), with a double-blind, placebo-controlled trial indicating improvements in liver function and body weight reduction (Won et al., 2025).
The strain specificity of *Lactobacillus* is a critical factor, as clinical benefits are often tied to specific strains rather than the genus as a whole. This principle underscores the importance of selecting appropriate strains for targeted health outcomes. The American Gastroenterological Association (AGA) has conditionally recommended *Lactobacillus rhamnosus* GG for AAD prevention and *Lactobacillus reuteri* for infantile colic based on moderate-quality evidence, highlighting the genus's therapeutic potential across various conditions.
Overall, probiotics of the *Lactobacillus* genus offer a versatile approach to improving digestive health, metabolic function, and overall well-being, with ongoing research continuing to uncover their broader applications.