A 2020 study in the British Journal of Nutrition found that drinking unpasteurised milk increases levels of Lactobacillus in the gut—beneficial bacteria that support digestion and immune health. Two studies in The Journal of Allergy and Clinical Immunology (2011 & 2015) linked raw milk to a significantly reduced risk of asthma, allergies, and respiratory infections in children.

A 2025 study published in Frontiers in Nutrition found that adults who consumed more live dietary microbes—like those in fermented foods—had significantly fewer migraines. The gut-brain connection suggests these microbes reduce inflammation and improve nervous system balance.

A 2025 double-blind, placebo-controlled study by Laterza et al. in Nutrients found that taking a multistrain probiotic with vitamin D significantly improved gut barrier function and microbiota balance in people with IBS. Benefits even lasted after treatment stopped.