Review shows promise of live dietary microbes in supporting health

A broad review of science on how foods with live dietary microbes like yogurt impact health shows more health benefits than not while pointing to the promise of conducting more research.

Researchers reviewed 282 publications with almost 300,000 test subjects against the question "Does consumption of live dietary microbes improve health?"

Among the cases where the microbes were metabolically active like in yogurt and kimchi, "4 reported negative outcomes, 56 reported neutral outcomes and 66 reported positive outcomes," according to the study.

For freeze-dried live dietary microbes (metabolically inactive), "2 cases reported negative outcomes, 60 reported neutral outcomes, and 90 reported positive outcomes."

For probiotics research, "6 reported negative outcomes, 104 reported neutral outcomes, and 141 reported positive outcomes."

Across the above reviews, positive outcomes were found in 52%, 59%, and 58% of the surveys, respectively, underscoring the promise of conducting more research in these areas.

Of the studies, 71 related to gastrointestinal health, 69 related to immunological health, 36 related to cardiovascular health and metabolic syndrome, and 35 related to antibiotic associated diarrhea.

The new study "The Impact of Live Dietary Microbes on Health: A Scoping Review" looks at research published from 2000-2023 and appears in the Journal of Food Science. The research was supported by IAFNS' Nutrition for Gut Health Committee.

The authors call for high-caliber dietary microbe research both on general health and in specific disease areas that show promise on general health and "More high-quality research is required investigating the role of dietary microbes in maintaining general health, particularly in the health categories of urogenital health, weight management, and cancer prevention," according to the paper.

According to Teagasc's Paul Cotter, senior author of the review, "Our scoping review aimed to offer an overview, consolidating the elements relating to the impact of live dietary microbes on health that are currently well-understood, while highlighting opportunities for future research endeavors."

According to lead author Ajay Iyer, "Through an extensive analysis of the existing literature, we found that the consumption of dietary microbes was associated with positive health outcomes in older population groups with a median age of 39 years."

In addition to the main findings on health, the paper includes numerous supplements and additional resources in tables and figures geared toward researchers and professionals.