Loudon M. Douglas

Loudon M. Douglas (1864–1944) is credited as the author of The Bacillus of Long Life, a book that examines fermented milks, their preparation, and the long tradition of using them for dietary purposes. The book was later preserved by Project Gutenberg, which identifies him as “Douglas, Loudon M., 1864–1944.”

In that work, he brings together history, food culture, and early scientific interest in bacteria, discussing drinks and foods such as koumiss, kefir, and yogurt. The book reflects a moment when ideas about digestion, nutrition, and longevity were attracting wide public attention.

Reliable biographical details about his personal life and career are limited in the sources I could confirm here, so it is safest to remember him primarily through this surviving work and its contribution to popular writing on health and fermented foods.