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Last Updated: 30.05.23

Dr. Eran Elinav on Microbiome Insights into Personalized Response to Diet, Obesity, and Leaky Gut

Eran Elinav, MD, PhD, is an immunology professor and principal investigator at the Weizmann Institute of Science in Tel Aviv, Israel. He co-​​directs the Personalized Nutrition Project and conducts research at the German Cancer Research Center in Heidelberg, Germany. His work centers on the intricate interplay between gut bacteria and human health, investigating its impact on disease and overall well-being.

Key Takeaways

Gut bacteria have their own circadian rhythms

  • Timing of diet impacts composition and function of gut microbes
  • Microbes change activity based on when we eat or don’t eat

Disrupting microbial circadian activity can lead to obesity and type 2 diabetes

  • Shift workers at higher risk due to disrupted wake-​​sleep patterns

Time-​​restricted feeding can restore disrupted microbial behavior

Macronutrients can affect gut microbes in various ways:

  • Serve as an energy source for microbes
  • Influence bacterial communication within the gut ecosystem
  • Affect host behavior and conditions, which in turn impact microbial composition and function

Loss of diversity in the microbiome has been linked to modern risks of developing diseases such as obesity, type 2 diabetes, fatty liver, and cancer

First three years of life are a critical window for shaping the adult configuration of the microbiome

  • Factors such as breast milk, diet, antibiotic use, and environmental exposure to bacteria can influence the development of a child’s microbiome

Overly sterile conditions may harm children by not allowing their microbiome to develop properly, increasing the risk of diseases such as asthma and obesity later in life

The mother’s microbiome can indeed affect the child’s microbiome

Study with 500 healthy individuals compared the influence of human genome and environment on microbiome composition and function

  • 1.9% of microbiome variability explained by differences in human genes
  • 99% of microbiome variability explained by environmental factors

Study in mice showed gut microbiome remained disturbed after successful dieting

  • Post-​​dieting microbiome stored a metabolic memory of past obesity, predisposing mice to exaggerated weight regain
  • Microbiome drove weight regain by altering its ability to degrade dietary compounds called isoflavonoids

Replacing the “bad memory microbiome” with a healthier one through fecal microbiome transplantation helped reset mice to avoid yo-​​yo obesity

  • Ongoing trial in humans to study the effects of metabolite supplementation and microbiome impact on recurrent obesity

Periodic food restrictions (e.g., 16:8 diets) may have positive metabolic effects, potentially mediated by the microbiome

Beneficial metabolites: short-​​chain fatty acids (e.g., butyrate, propionate, acetate)

  • Modulate the immune system, affect T regulatory cell activity/​​production

Harmful metabolites: contribute to leaky gut/​​intestinal permeability

  • Can play a role in cardiovascular disease risk

Leaky gut: disruption of the gut barrier, allowing foreign molecules to enter the body

  • Can contribute to heart disease, cancers, autoimmune disorders

Probiotic effectiveness varies among individuals due to the indigenous microbiome

  • In some cases, the indigenous microbiome is hostile and does not allow probiotics to colonize the gut
  • In other cases, the indigenous microbiome is more welcoming, allowing probiotics to colonize and have significant impacts

Colonization of exogenous probiotics is highly individualized and determined by the composition and function of the indigenous microbiome

Microbiome interactions are complex and poorly understood

Disrupting the indigenous microbiome with antibiotics can allow probiotics to colonize the gut

  • However, this can lead to a chronic disturbance in the gut microbiome composition
  • Probiotics may aggressively colonize and prevent the indigenous microbiome from repopulating

High doses of probiotics may have a transient therapeutic effect, but more evidence is needed to recommend them for specific conditions

Bacteriophages are viruses that only infect bacteria

Bacteriophages could be used to target specific bacteria in the microbiome without harming the entire microbial community

  • Phages are specific in their targets and can attack certain families of bacteria

Clinical trials underway for targeted bacterial treatments

Healthy sleep patterns have profound effects on the microbiome

Consuming fibers generally beneficial for gut health

Cigarette-​​related chemicals reach systemic circulation, penetrate the gut, and impact the microbiome

Disturbed microbiome composition and function can increase the risk of developing obesity after attempting to quit smoking

Day Two

  • Spinoff company that licensed the technology from the Weitzman Institute of Science
  • Performed over 100,000 tests on 100,000 people
  • Allows individuals to provide a stool sample and some clinical parameters to receive accurate predictions of their glycemic responses to food

Some scientists and physicians are against continuous glucose monitors, claiming they may discourage people from eating healthy foods that elevate blood glucose levels


  • Dr. Eran Elinav on Microbiome Insights into Personalized Response to Diet, Obesity, and Leaky Gut

    Found My Fitness #70

    Eran Elinav, MD, PhD, is an immunology professor at the Weizmann Institute of Science. His research examines gut bacteria’s role in human health and disease.

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