The effect of boosting dietary lactobacillus and phytochemical rich foods on biomarkers of longevity: a phase II randomised placebo controlled trial

As men age, systemic inflammation increases, whereas grip strength (GS) and testosterone levels tend to fall. This rate of decline is known to be influenced by gut microbial health, lifestyle and diet but the role for interventions to slow this decline are less well established. This double-blind randomised controlled trial evaluated the impact, and explored the synergistic potential, of boosting phytochemical rich foods and Lactobacillus probiotics on these physical and biological markers. Two hundred and eight men with untreated early prostate cancer managed with observation only (average age 74 years) received a phytochemical rich supplement (PRS) containing concentrated broccoli, green tea, pomegranate, ginger, cranberries and turmeric (YourPhyto). In addition, they were randomised to either a 5-blend Lactobacillus probiotic (PB) capsule (YourGutplus) or a placebo (P). Average GS improved by 2.5 kg from baseline to trial completion, at 4 months in men taking PRS +P (95% CI 1.8–3.4, p < 0.001). In the PRS+PB arm, GS improved by 4.4 kg (95% CI 3.6–5.2, p < 0.001). The odds of grip strength improving was 11.8% greater (p = 0.002, OR = 1.11, 95% CI 1.04–1.20) in the PRS+PB arm. Improvements in systemic inflammation were better in the PRS+PB arm (−0.41 vs. +0.39, p = 0.04). Four-month testosterone levels were greater in the PRS+PB arms (14.75 vs. 13.02 ng/L, 95% CI 0.23 to 3.33 ng/L p = 0.046). In conclusion, boosting dietary phytochemicals was associated with improved GS. The addition of this blend of Lactobacillus further enhanced GS, and reduced markers of inflammation. These data justify longer studies exploring the synergy between phytochemicals and probiotics, on more objective markers of longevity.