Modern Microbes Under Siege - Probiotics

Modern Microbes Under Siege


Once upon a time, our human ancestors ate mostly plants. Microbes evolved in tandem, metabolizing fibers and forging a genome to coexist nicely with byproducts such as short-chain fatty acids.

Today our microbial communities look quite different.

They struggle mightily to adapt to high fat and sugar diets processed with a litany of additives. Overuse of antibiotics washes them out completely. The barrage continues with other trappings of modern life.

It’s important to note that while our microbes can change quickly, the human genome, in its inimitable Darwinian fashion, needs more time, even generations to adapt. This lag may contribute to the rise in purely modern health problems. Diabetes, heart disease, cancers and autoimmune disorders may reflect the damage.

Erica D. Sonnenburg and Justin L. Sonnenburg recently took a broad look at the subject in The ancestral and industrialized gut microbiota and implications for human health  which appeared in Nature Reviews Microbiology.

Ancestral vs. industrialized

Key changes in microbiota according to the authors:

  • trio of bacterial taxa that were prevalent in traditional microbiota is rare today in industrialized regions. Prevotellaceae, Spirochaetaceae and Succinivibrionaceae, once quite common taxa are now almost absent. Dietary changes are one major  cause of the absence. Food fibers have been replaced by large helpings of protein, fat and sugar as well as non-food chemicals, including preservatives, pesticides, additives and emulsifiers. The switch has had a big impact on host–microbiota interactions. Species which degrade fibers have faltered.
  • Another change is the absence or low presence of mucus-degrading enzymes and mucus-consuming species which result in maladaptive response such as inflammation.
  • Antibiotic use results in drastic, acute changes in the microbiota, and the effects can be persistent. Bacterial species that harbor antibiotic-resistant genes have emerged.

Read article here: 6.

The research: