The best evidence for proving cause-and-effect comes from randomized clinical trials. However, they are expensive and difficult to perform. The natural assortment of gene variants at birth can mimic randomization in some circumstances and yield important clinical information that can help physicians better care for their patients.
Read the article: Mendelian Randomization
Bacteriophages are viruses that infect and kill bacteria. When they were first discovered in the early part of the 20th century, there was great enthusiasm for their potential use to treat all sorts of bacterial infections. They were supplanted by antibiotics and although they remained critically important in research that led to the understanding of DNA and how it works, bacteriophages never really made it in the therapeutic world. Now that multiple-drug-resistant bacteria are becoming increasingly common, there is renewed interest in using bacteriophages to treat bacterial infection.
Links:
YouTube video summarizing the career and science of Félix d'Hérelle-one of the discoverers of bacteriophages
Dr. Felix d'Herelle Canadian Medical Hall of Fame Laureate 2007
Detailed history of the development of bacteriophage research in Georgia
A Stalinist Antibiotic Alternative from New York Times Magazine, February 6, 2000
Reprint of Twort’s initial description of a substance killing bacteria discovered while trying to grow viruses. Although Twort did not identify bacteriophages in his experiment, he believed there was some toxic entity that killed bacteria present in his experiments.
An investigation on the nature of ultra-microscopic viruses1 by Twort FW, L.R.C.P. Lond., M.R.C.S.
Reprint and translation of d’Herelle’s original 1917 description of bacteriophages isolated from soldiers recovering from dysentery.
On an invisible microbe antagonistic to dysentery bacilli. Note by M. F. d’Herelle, presented by M. Roux. Comptes Rendus Academie des Sciences 1917; 165:373–5
Review of the non-English-language literature on bacteriophage therapy of infection
Bacteriophage Therapy Antimicrob Agents Chemother. 2001 Mar; 45(3): 649–659.
Review of the history bacteriophage research and its effect on scientific development and clinical medicine
The Murky Origin of Snow White and Her T-Even Dwarfs Genetics 155: 481–486 (June 2000)
News report from UC San Diego on treatment of the patient described in the podcast
Novel Phage Therapy Saves Patient with Multidrug-Resistant Bacterial Infection
2017 JAMA Medical News article on the use of bacteriophage to treat a patient with multidrug-resistant Acinetobacter infection
Phage Therapy’s Role in Combating Antibiotic-Resistant Pathogens