High nutrient availability reduces the diversity and stability of the equine caecal microbiota

• Main Authors: Naja C. K. Hansen, Ekaterina Avershina, Liv T. Mydland, Jon A. Næsset, Dag Austbø, Birgitte Moen, Ingrid Måge, Knut Rudi
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2015-08-01
• Series: Microbial Ecology in Health and Disease
• Subjects: 16S rDNA; caecal microbiota; hay; whole oats; equine
• Online Access: http://www.microbecolhealthdis.net/index.php/mehd/article/view/27216/41395

Background: It is well known that nutrient availability can alter the gut microbiota composition, while the effect on diversity and temporal stability remains largely unknown. Methods: Here we address the equine caecal microbiota temporal stability, diversity, and functionality in response to diets with different levels of nutrient availability. Hay (low and slower nutrient availability) versus a mixture of hay and whole oats (high and more rapid nutrient availability) were used as experimental diets. Results: We found major effects on the microbiota despite that the caecal pH was far from sub-clinical acidosis. We found that the low nutrient availability diet was associated with a higher level of both diversity and temporal stability of the caecal microbiota than the high nutrient availability diet. These observations concur with general ecological theories, suggesting a stabilising effect of biological diversity and that high nutrient availability has a destabilising effect through reduced diversity. Conclusion: Nutrient availability does not only change the composition but also the ecology of the caecal microbiota.