“This helpful resource sets itself apart from health books that offer unfounded and even speculative claims by staking a position firmly in the medical mainstream.”

Best of 2016 books, Publishers Weekly


 “A must-read for parents, teachers and any healthcare provider for children, Let Them Eat Dirt takes you inside a child’s gut, and shows you how to give kids the best immune start early in life.”

—William Sears, M.D, co-author, The Baby Book


“This book might change your perspective on real cleanliness…and along the way help you to raise healthier kids.”

—Giulia Enders, author of the international bestseller Gut


“What a triumph. This book should be read by every pregnant woman, every parent, every pediatrician.”

—Margaret McFall-Ngai, Director, Pacific Biosciences Research Center, University of Hawaii


“As a parent and a microbiologist, I appreciated the up-to-date and actionable science that “Let Them Eat Dirt” highlights, including the groundbreaking work conducted in the authors’ own lab. As a Professor of Pediatrics, I appreciated the accessible format and writing style that makes this wealth of information and its limitations easy to understand for the increasing crowd parents who are concerned about their children and their growing microbiomes. “Let Them Eat Dirt” gives an entertaining, engaging and accurate view of what we’re discovering about the microbiome and why it matters for you and your children.”
— Rob Knight, Professor of Pediatrics and Computer Science & Engineering, and Director, Center for Microbiome Innovation, UC San Diego, and author of “Follow Your Gut: The Enormous Impact of Tiny Microbes”

“Pioneer researchers Brett Finlay and Claire Arrieta help parents to understand the real nature of microbes and then to act to improve their children’s health.”

—Martin Blaser, Director, NYU Human Microbiome program and author of Missing Microbes


“Great book! Very clear, down to earth, and interesting; it reads like a story! Let Them Eat Dirt takes an important and complex subject and makes it less scary.”

  —Eran Elinav, M.D., Ph.D., Principal Investigator,  Host-microbiome Interaction Research Group at the Weizmann Institute of Science, Israel


“Solid, easily assimilated evidence showing how microbes are an integral part of a child’s healthy life.”

Kirkus Reviews


“Finlay and Arrieta explain, in illuminating detail, the importance of the gut microbiome…They hope to restore the powerful benefits of microbe transfer from the environment to the young child, benefits lost as a side effect of efforts to reduce infectious disease risk and of cultural attitudes that conflate dirt with disease….The focus on practical choices before and during birth makes this book a good resource for expectant parents.”

Publishers Weekly