Although there is no consensus on what constitutes a health-associated microbiota, some hallmarks have been proposed:
- Increased species richness and/or diversity: the number of different species and how different they are in a specific habitat (e.g., the digestive tract) is considered a hallmark of gut health.
- Resistance, resilience and stability over time: the ability to resist perturbation (e.g., antibiotic treatment or imbalanced diets) and to recover a stable state.
- High gut microbial gene richness: the number of microbial genes in the gut has been suggested as an indicator of good metabolic and overall health.
Digestive ailments, obesity, diabetes, allergies, cancer and even neurodegenerative diseases have been linked to an imbalance in gut microbiota composition or function (a situation scientists call ‘dysbiosis’).
Thus, targeting the gut microbiota emerges as a potential way of dealing with many chronic diseases that are on the rise in Western society.