The rapid decline in the world’s biodiversity has been in the news due to the historic COP15 meeting of the United Nations Biodiversity Conference in Montreal. Nearly 200 countries pledged to conserve 30% of their land and water by year 2030 as an effort to halt the escalating numbers of earth’s creatures becoming extinct due to human activity.

If you need evidence that humans are decimating the environment, you need look no further than your own backyard. Witness:

  • When we were children, earthworms would be all over the soil and pavement after a rain. They were so dense that you had to tiptoe your way to cross the street, for instance. Now, you see almost none, even after a major downpour. To acquire bait to go fishing, I used to just lift up some rocks and uncover dozens of earthworms. Lift up a big rock today and you’re lucky to see just one.
  •  Walking to elementary school for me meant dodging hundreds of grasshoppers who jumped in front of my path. I believe I’ve seen two grasshoppers in the last 30 years.
  • As kids, we would try to capture some of the fireflies that lit up the backyard during summer. I haven’t seen more than a handful over the last several decades.
  • Butterflies used to be everywhere, flitting from flower to flower, tree to tree. In my neighborhood nowadays, butterflies are rare. Moths used to be so ubiquitous that we’d find them in our clothing—remember mothballs?

Biologists have been tracking the decline in species experiencing extinction for decades and the numbers are shocking. You’ve likely heard, for instance, of the dramatic decline in fish due to overfishing. More than a third of shark and ray species in the oceans are at imminent risk of extinction. Add declining bumblebees to the list.

Why am I discussing the external environment in this blog devoted to unique concepts in human health? Well, the loss of diversity in the external environment has been paralleled by a similar loss of diversity in our internal ecosystems, i.e., our microbiomes. We have not lost grasshoppers or earthworms, of course, but we’ve lost hundreds of important species that performed important functions for us. The causes of the loss of species in our internal microbiomes are different, also. Antibiotics, glyphosate (an antibiotic as well as an herbicide), antimicrobial food preservatives, emulsifying agents, synthetic sweeteners like aspartame, stomach acid-blocking drugs, and non-steroidal anti-inflammatory drugs are among the factors that have changed the human gastrointestinal (GI) microbiome. The losses differ, also, from person to person. One person may have lost numerous species of Lactobacillus such as L. reuteri and L. gasseri, losses that allow the proliferation and ascent of fecal microbes into the 24-feet of small intestine: small intestinal bacterial overgrowth, SIBO. Another person may have lost Akkermansia and Faecalibacterium that are responsible for metabolic health; losing them contributes to obesity, type 2 diabetes, and fatty liver. Another person may have lost Turicibacter and allowed species like E. coli and Klebsiella to proliferate, all leading to intractable depression poorly responsive to conventional antidepressants.

How to restore something closer to the natural and lush biodiversity that humans used to have before modern disrupters became prevalent? Start by avoiding all the factors listed above that disrupt the human microbiome. (Complete avoidance, unfortunately, is no longer possible, only a reduction in exposure.) Consider working with soil but avoiding use of synthetic chemicals such as herbicides and pesticides. Make a habit of consuming fermented foods filled with microbes like Leuconostoc mesenteroides and Pediococcus pentosaceus that help restore diversity. Restore the microbes like L. reuteri and L. gasseri that play outsized roles in the microbiome and in numerous aspects of human health. If all of this is Greek to you, please read the many blog posts about these topics. Consider joining our live conversations in my Inner Circle on or, of course, read my Super Gut book that tells the entire story.