Dairy product consumption is associated with a lower risk of all-cause mortality. However, the evidence regarding probiotic-fermented milk products remains unclear. This study examined the association between the intake of fermented milk products containing lactic acid bacteria, including Lacticaseibacillus paracasei strain Shirota (LcS), and all-cause mortality.

A total of 1,280 community-dwelling Japanese aged ≥65 years (519 men, 761 women; mean age 73.5 years) were included in the analyses. Participants were categorized in two groups based on the retrospectively recalled intake frequency of fermented milk products (<3 or ≥3 days/week) over 5- and 10-year periods. All-cause mortality risk was evaluated using Cox proportional hazards regression analyses in the full sample and propensity score-matched subsamples.

During the 9.3-year follow-up period (112.05 months), deaths occurred in 147 men (28.3%) and 114 women (15.0%). Among men, consumption of fermented milk products containing LcS for ≥3 days/week over five years was significantly associated with a lower risk of all-cause mortality in both full sample analysis (hazard ratio [HR] 0.648, 95% confidence interval [CI] 0.438–0.958, p = 0.030) and matched analysis (HR 0.640, 95% CI 0.434–0.943, p = 0.024), compared with those consuming <3 days/week. Similar associations were observed for overall fermented milk products, including the LcS products. No associations were found among women for either LcS or overall fermented milk products.

Habitual intake of fermented milk products containing LcS was associated with a lower risk of all-cause mortality in older Japanese men.