Gut microbiota: role, nutrition and health

By Ichrak Haddad•1/31/2026
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Table of Contents

Definition of the gut microbiota

All microorganisms in the digestive tract

  • All microorganisms in the digestive tract
  • Role in digestion, immunity, vitamin synthesis

Composition of the gut microbiota

Bacteria, viruses, fungi, archaea

  • Bacteria, viruses, fungi, archaea
  • Diversity and balance are essential

Factors influencing the microbiota

Diet, antibiotics, stress, age

  • Diet, antibiotics, stress, age
  • Fiber, polyphenols, probiotics promote diversity

Dysbiosis

Microbiota imbalance (dysbiosis)

  • Microbiota imbalance (dysbiosis)
  • Linked to digestive, metabolic, immune diseases

Nutrition and microbiota

Fiber (fruits, vegetables, whole grains)

  • Fiber (fruits, vegetables, whole grains)
  • Probiotics (yogurt, kefir, fermented foods)
  • Polyphenols (tea, cocoa, berries)

Impact on health

Impact on digestion, immunity, mood, weight

  • Impact on digestion, immunity, mood, weight
  • Link with chronic diseases (diabetes, obesity, IBD)

Improve the microbiota

Increase fiber, fermented foods, limit sugars and saturated fats

  • Increase fiber, fermented foods, limit sugars and saturated fats
  • Avoid unnecessary antibiotics

Conclusion

The microbiota is a key player in overall health

  • The microbiota is a key player in overall health
  • A varied, fiber-rich diet supports its balance

Scientific references

NIH – Human Microbiome Project

  • NIH – Human Microbiome Project
  • EFSA – Gut health and nutrition
  • ANSES – Gut microbiota
  • Lancet – Microbiota and chronic disease