Impact of personalized diet and probiotic supplementation on inflammation, nutritional parameters and intestinal microbiota - The "RISTOMED project": Randomized controlled trial in healthy older people.

Open-label, randomized, multicenter trial conducted in France, Germany and Italy. Participants were healthy community-dwelling older adults aged 65–85 years (BMI 22–30 kg/m2; ECOG 0–2; male or female) with internet access. Four parallel arms were randomized (69 participants; 34 to diet alone, 35 to diet plus VSL#3); 62 completed; per-protocol analyses focused on diet alone vs diet plus VSL#3.

VSL#3 probiotic capsules; 2 capsules daily for 8 weeks; taken orally on an empty stomach (at least 30 minutes before lunch and dinner).

Eight-week personalized diet (RISTOMED) alone reduced ESR by ~6 mm/h (p=0.02), total cholesterol by p<0.01, and glucose by p=0.03. Addition of VSL#3 reduced ESR (p=0.05) and increased folate (p=0.007) and vitamin B12 (p=0.001), while decreasing homocysteine (p<0.001). Primary outcome hsCRP did not change with either regimen. In participants with baseline low-grade inflammation (hsCRP ≥3 mg/L; n=21), VSL#3 increased bifidobacteria more often and improved folate (p=0.015) and B12 (p=0.035) than diet alone; folate and B12 changes correlated with bifidobacterial changes (folate p=0.023; B12 p=0.001). Homocysteine reductions correlated negatively with folate (r=-0.629, p=0.002) and B12 (r=-0.482, p=0.026). Net effect: VSL#3 plus diet enhanced bifidobacteria and helped maintain adequate folate/B12 and lower homocysteine in those with low-grade inflammation, indicating potential protection against aging-related cardiovascular or neurological diseases. Longer-term, placebo-controlled trials are needed to confirm clinical significance.

Open-label design; small sample size; short duration; per-protocol analysis; lack of placebo control; generalizability limited to healthy older adults; subgroup analyses involve smaller numbers and may be underpowered.