Are Probiotics Effective for Healthy People? Study Sheds Light

A recent study published in the journal Advances In Nutrition reviewed the evidence of the benefits of probiotics for healthy people.

Probiotics are microbes that confer health benefits to the host. Various studies have examined the use of probiotics for diverse conditions for patients and healthy individuals. Clinical trials have also investigated different outcomes of probiotic use. However, a common question remains: should everyone take probiotics? This study reviewed the available evidence to assess the outcomes of probiotic use in healthy people.

The research team assembled experts to explore the evidence. The review primarily focused on healthy individuals and also considered population subgroups. The study explored whether probiotics could prevent infections of the vaginal, respiratory, gastrointestinal (GI), or urinary tract, reduce antibiotic use, or improve cardiovascular risk factors.

Urinary tract infections (UTIs) are the most common bacterial infections, especially in females. Studies have shown that probiotics can help reduce the recurrence of UTIs. For example, a year-long trial found that weekly vaginal suppositories containing Lactobacillus strains reduced UTI recurrence. Another study found that young females taking Lactobacillus crispatus had fewer UTIs compared to a placebo group.

Probiotics also show promise in treating vaginal infections. One trial using Lactobacillus crispatus for bacterial vaginosis (BV) found reduced recurrence rates. Another study indicated that probiotics like Streptococcus thermophilus and Lactobacillus acidophilus could lower BV recurrence compared to placebo.

Probiotics are beneficial in preventing antibiotic-associated diarrhea (AAD). Various studies have reported that probiotics, such as Lactobacillus rhamnosus GG and Saccharomyces boulardii, can reduce AAD risk by 37%.

For diarrhea, probiotics have been shown to reduce incidence. Additionally, probiotics can help lower the risk and incidence of respiratory tract infections (RTIs) in both adults and children.

In terms of cardiovascular disease (CVD) risk factors, probiotics have been found to improve metabolic factors such as cholesterol levels, blood pressure, and body weight. A meta-analysis showed that synbiotics (prebiotics and probiotics) could increase good cholesterol (HDL) and reduce insulin, bad cholesterol (LDL), total cholesterol, triglycerides, systolic blood pressure, body weight, and waist circumference.

In summary, the current efficacy data are insufficient to provide definitive preventive recommendations for probiotics. The field of probiotic research is relatively new, and while there is some evidence of their benefits, more research is needed to confirm their preventive potential.

Reference: Merenstein DJ, Tancredi DJ, Karl JP, et al. Is there evidence to support probiotic use for healthy people? Advances in Nutrition, 2024, OI: 10.1016/j.advnut.2024.100265, https://www.sciencedirect.com/science/article/pii/S2161831324000991