Meanwhile, focal infection theory has gained renewed attention, as dental infections apparently are widespread and significant contributors to systemic diseases, although mainstream attention is on ordinary periodontal disease, not on hypotheses of stealth infections via dental "treatment". Despite some doubts renewed in the 1990s by conventional dentistry's critics, dentistry scholars maintain that endodontic therapy can be performed without creating focal infections. In ancient Greece, Hippocrates reported cure of an arthritis case by tooth extraction. Yet modern focal infection theory awaited Robert Koch's establishment of medical bacteriology in the late 1870s to early 1880s. In 1890, Willoughby D Miller attributed a set of oral diseases to infections, and a set of general diseases—as of lung, stomach, brain abscesses, and other conditions—to those infectious oral diseases. In 1894, Miller became the first to reveal existence of bacteria in samples of dental pulp. Miller advised root canal therapy. Yet focal infection theory met a cultural climate where ancient and folk ideas, long entrenched via Galenic humoral medicine, found new outlets through bacteriology—a pillar of the new "scientific medicine". Emigrating from Russia in 1886, international scientific celebrity Elie Metchnikoff—discoverer of phagocytes, mediating innate immunity—was embraced in Paris by Louis Pasteur, who granted him an entire floor for research once the Pasteur Institute, the globe's first biomedical institute, opened in 1888. Later the Institute's director and 1908 Nobelist, Metchnikoff believed, as did his rival Paul Ehrlich—theorist on antibody, mediating acquired immunity—and as did Pasteur, that nutrition influenced immunity. Sharing Pasteur's view of science as a means to suppress the problems plaguing humankind, Metchnikoff brought into France its first cultures of yogurt for probiotic microorganisms to foster health and longevity by suppressing the colon's putrefactive microorganisms alleged to foster the colon's toxic seepage, "autointoxication". As the 20th century opened, British surgeons were still knife-happy, and called for "surgical bacteriology". Surgical pioneer Sir Arbuthnot Lane, famed for an emergency appendectomy performed on England's royalty, drew from Metchnikoff and clinical observation to issue dire warnings about "chronic intestinal stasis"—that is, constipation—its "flooding of the circulation with filthy material" and causing autointoxication, which Lane then treated with colon bypass and colectomy. In America, alleged "bowel sepsis" wreaking degeneration and disease had been targeted since 1875 by John Harvey Kellogg in Michigan at his huge Battle Creek Sanitarium—he coined the term "sanitarium"—yearly receiving several thousand patients, including US Presidents and celebrities, and advertising itself as the "University of Health".