Could Dietary Supplementation with Different Sources of N-3 Polyunsaturated Fatty Acids Modify the Rabbit Gut Microbiota?

Susanna Draghi,Simona Mattioli,Filippo Biscarini,Federica Riva,Alessia Di Giancamillo,Paola Cremonesi,Alice Cartoni Mancinelli,Alda Quattrone,Bianca Castiglioni,Giulia Collodel,Elisa Cotozzolo,Stella Agradi,Silvia Clotilde Modina,Alessandro Dal Bosco,Laura Menchetti,Gabriele Brecchia,Cesare Castellini,Giulio Curone

doi:10.3390/antibiotics11020227

Abstract

The present study evaluated the effects of feed supplemented with two dietary sources of n-3 polyunsaturated fatty acids (PUFAs; fish oil and extruded flaxseed) on the gut microbiota, caecal fermentations, gastrointestinal histology, and histochemistry in rabbits. Fifteen male New Zealand White rabbits were divided into three groups (n = 5/group) and fed with different diets from weaning (35 days of age) until slaughtering (90 days of age): C group, fed with a commercial diet; F group, supplemented with 10% of extruded flaxseed; and O group, supplemented with 3.5% of fish oil. At slaughter, the content of the stomach, duodenum, jejunum, ileum, caecum, and colon was collected and analyzed by Next Generation 16S rRNA gene sequencing. Tissue samples of the same tracts were evaluated with histological and histochemical analysis. Ammonia and lactic acid in the caecum were also quantified. Twenty-nine operational taxonomic units (OTUs) were significantly different between groups. Groups receiving n-3 PUFAs supplementation showed an increase in Bacteroidetes and Lachnospiraceae in several gastrointestinal tracts, while Bacilli abundance, as well as Firmicutes/Bacteroidetes ratio, were reduced compared to the control group (for all p < 0.05). Caecal ammonia was lower in the F than C group (p < 0.032), whereas no difference was found for lactic acid. Finally, histological evaluations revealed a mild hemorrhagic infiltration and vessels ectasia in the stomach mucosa of both F and O groups, but no effect of nutritional treatment was evidenced by the histochemical analyses. In conclusion, n-3 PUFAs supplementation could modify the rabbit gut microbiota and fermentation. The increase in beneficial bacterial populations may, at least partially, explain the positive effects of n-3 PUFAs diet supplementation on human and animals’ health, although the appropriate dosage should be established.

Highlights

The microbial community that colonizes a particular district of the body and lives in a symbiotic relationship with the host is defined as microbiota [1]
White male rabbits were divided into three groups (n = 5/group) and fed three different diets (Table 3) until slaughter (90 days of age): control group (C), fed with a standard diet, flaxseed group (F), fed standard diet supplemented with 10% of extruded flaxseed, and fish oil group (O), fed standard diet supplemented with 3.5% of fish oil
This study provides novel evidence that the dietary supplementation of flaxseed and fish oil can have a beneficial impact on the composition of gut microbiota and cecal fermentation in rabbits

Summary

Introduction

The microbial community that colonizes a particular district of the body and lives in a symbiotic relationship with the host is defined as microbiota [1]. The gut microbiota composition has a strong impact on the general health and digestive functions of the host [3]. The maintenance of a normal microbial community requires a homeostatic equilibrium among the microbes as well as between the microbiota and the host [4]. The gut microbiota shows a high grade of resilience and resistance to changes, as it is quite stable against different perturbations. The disruption of the normal microflora composition and its metabolic activities could alter the microbiota homeostasis resulting in “dysbiosis” and in different diseases, localized to the gastrointestinal tract and at a systemic level [14,15,16]

Methods

Results

Discussion

Conclusion