Individuals who consumed foods with medium and high levels of live bacteria had better health markers, including lower blood pressure, BMI, and insulin levels, according to a recent study published in the Journal of Nutrition.

Significant Improvements

"There were generally modest but statistically significant improvements in health-related outcomes associated with increased food intake for all physiological parameters evaluated..." the authors wrote, except for total cholesterol and LDL, which remained consistent.

The authors used a 24-hour dietary recall component and NHANES analysis for the intake of foods containing live bacteria. 46,091 participants were included in the analysis.

All foods consumed within a 24-hour period were recorded for participants aged 19 and over who were not pregnant or breastfeeding. The content of live bacteria was estimated using a preexisting framework, and regression analyses estimated the associations between them and physiological parameters.

Live Bacteria in Foods

Foods were grouped based on their estimated live microbial content, with low, medium, and high categories. Low-content foods had less than 10,000 CFU per gram, medium had between 10,000 and 10,000,000 CFU per gram, and high had more than 10,000,000 CFU per gram.

In a previous study, the authors described lower-category foods as processed foods, such as cooked meat and peeled products, medium-category as vegetables, fruits, and dairy, and high-category as primarily fermented dairy.

Out of the 46,091 participants, 29,348 consumed foods from the medium or high categories for live bacteria. Participants were fairly evenly divided between not consuming MedHi foods, consuming below average, and consuming above average. Fermented foods were consumed less frequently, with 79% of participants not consuming them.

Health Benefits

The authors analyzed health data such as C-reactive protein, plasma glucose and insulin, blood pressure, BMI, weight, blood lipids, and waist circumference. For those who consumed foods with live bacteria, a decrease in blood pressure, BMI, waist circumference, insulin, glucose, C-reactive protein, and triglyceride levels was observed.

The authors also noted higher levels of HDL cholesterol. The authors wrote, "The estimated effects were generally modest and directionally favorable to population health." When only fermented foods were examined, similar results were found for all parameters except plasma glucose and insulin.

"Overall, these findings provide further evidence supporting a link between live bacteria and more favorable blood pressure, anthropometric measures, and biomarkers," the authors write.

However, they note that since their study analyzed food intake rather than the numerical value of microbes, other food components may have contributed to the results.

Another important note from the authors is that a recommendation for daily intake of live bacteria may not be far off. They write that such a recommendation could follow the already existing recommendations for daily fiber intake.

(Source: Journal of Nutrition 2023, 153(4), 1143-1149; doi: 10.1016/j.tjnut.2023.02.019 "Positive health outcomes associated with intake of live bacteria in foods, including fermented foods, evaluated using the NHANES database" Authors: C. Hill, et al.)