Probiotic supplementation affects the glycan composition of mucins secreted by Brunner's glands of the pig duodenum

Positive Influence of a Probiotic Mixture on the Intestinal Morphology and Microbiota of Farmed Guinea Fowls (Numida meleagris)

To understand the effectiveness of a probiotic mixture on intestinal morphology, mucus layer composition, and cecal microbiota diversity, 40 10-day-old Guinea fowls (Numida meleagris) were assigned to two groups: the control group (C), receiving drinking water, and the treated group (P), receiving water plus a commercial multi-strain probiotic (Slab51®, 2 × 10¹¹ CFU/L). Birds were slaughtered after 4 months, and the intestines were collected. Samples from the duodenum, ileum, and cecum were processed for morphological and morphometric studies, and conventional glycohistochemistry. Cecal samples were also used to assess the microbiota by 16S metataxonomic approach. Group P showed significant increase in the villus height (p < 0.001 in the duodenum and p < 0.05 in the ileum and cecum), villus width (p < 0.05 in all investigated tracts), depth of crypts (p < 0.001 in the duodenum and cecum; p < 0.05 in the ileum), and goblet cells per villus (p < 0.001 in all investigated tracts) compared with group C. Cecal microbiota of the birds varied considerably and comparing the relative abundance of the main observational taxonomic units (OTUs), a positive enrichment of several beneficial taxa, such as Oscillospira, Eubacterium, Prevotella, and members of the Ruminococcaceae, was observed. The enrichment of those taxa can improve microbiota stability and resilience facing environmental stresses, enhancing its resistance against invading pathogens. Ruminococcaceae, which represent the most important taxon in both groups, and Prevotella have a key role in the gut physiology due to the production of short-chain fatty acids (SCFAs), which are a vital energy source for enterocytes, improve glucose metabolism, and exert an overall anti-inflammatory effect. Probiotic administration enriches the presence of Coprococcus, Oscillospira, and Eubacterium taxa that produce butyrate, which exerts a beneficial effect on growth performance, structure of villi, and pathogen control and has anti-inflammatory properties too. This study indicates that Slab51® supplementation positively affects the morphology and microbiota diversity of the guinea fowl intestine.

Intestinal Microbiota Mediates High-Fructose and High-Fat Diets to Induce Chronic Intestinal Inflammation

An unhealthy diet has been linked to increased incidence of chronic diseases. To investigate the relationship between diet and intestinal inflammation, mice in two experimental groups were fed on a high-fat diet or high-fructose diet, respectively. The result showed that the defecation volume of the experimental groups was significantly reduced compared with that of the control group, and the levels of pro-inflammatory cytokines (interleukin (IL)-1β and IL-6) and IgG in serum were increased significantly. In addition, inflammatory cell infiltration was observed in intestinal tissue, indicating that a high-fructose or high-fat diet can lead to constipation and inflammation. Further analysis showed that the microbial composition of the experimental groups changed significantly, including a decrease of the Bacteroidetes/Firmicutes ratio and increased levels of Bacteroides, Akkermansia, Lactobacillus, and Ruminococcus, which might be associated with inflammation. The results of pro-inflammatory metabolites analysis showed that the levels of arachidonic acid, stearic acid, and indoxylsulfuric acid were significantly increased in the experimental groups, which were related significantly to Bacteroides, Enterococcus, and Akkermansia. Meanwhile, the content of 5-hydroxytryptamine (5-HT) was significantly decreased, which might cause constipation by reducing intestinal peristalsis. Moreover, transplantation of fecal bacteria from inflammatory mice caused constipation and inflammation in normal mice, which could be relieved by feeding a normal diet. The results of the present study indicated that changes in intestinal microbiota and microbial metabolites may underlie chronic intestinal inflammation and constipation caused by high-fructose and high-fat diets.

Modulation of Morphology and Glycan Composition of Mucins in Farmed Guinea Fowl (Numida meleagris) Intestine by the Multi-Strain Probiotic Slab51®

Probiotics have become highly recognized as supplements for poultry.Since gut health can be considered synonymous withanimal health, the effects of probiotic Slab51® on the morphology and the glycan composition of guineafowlintestine were examined. The probiotics were added in drinking water (2 × 1011 UFC/L) throughout the grow-out cycle.Birds were individually weighed andslaughtered after four months. Samples from the duodenum, ileum and caecum were collected and processed for morphological, morphometric, conventional and lectin glycohistochemical studies.The results were analyzed for statistical significance by Student's t test. Compared with control samples, probiotic group revealed (1) significant increase in villus height (p < 0.001 in duodenum and ileum; p < 0.05 in caecum), crypt depth (p < 0.001 in duodenum and caecum; p < 0.05 in ileum) and goblet cells (GCs) per villus (p < 0.001) in all investigated tracts; (2) increase in galactoseβl,3N-acetylgalacyosamine(Galβl,3GalNAc)terminating O-glycans and αl,2-fucosylated glycans secretory GCs in the duodenum; (3) increase in α2,6-sialoglycans and high-mannose N-linked glycans secretory GCs but reduction in GCs-secreting sulfoglycans in the ileum; (4) increase in Galβl,3GalNAc and high-mannose N-linked glycans secretory GCs and decrease in GCs-producing sulfomucins in the caecum; (5) increase in the numbers of crypt cells containing sulfate and non-sulfated acidic glycans. Overall, dietary Slab51® induces morphological and region-specific changes in glycoprotein composition of guinea fowl intestine, promoting gut health.

High-fat Diet Alters the Glycosylation Patterns of Duodenal Mucins in a Murine Model

High-fat diet (HFD) alters the glycosylation patterns of intestinal mucins leading to several health problems. We studied by histochemical and lectin-binding methods mucin alterations in the duodenum of mice fed a HFD for 25 weeks. Histochemical methods included periodic acid-Schiff, alcian blue pH 2.5, and high-iron diamine. Lectin-binding experiments were performed with SBA, PNA, WGA, MAA-II, SNA, ConA, UEA-I, LTA, and AAA. SBA, PNA, WGA, MAA-II, and SNA were tested also after desulfation and ConA after periodate-sodium borohydrate treatments (paradoxical ConA). Duodenal mucins are secreted by Brunner's glands and goblet cells in the villi. Brunner's glands of HFD mice showed increased secreting activity and a general reduction of glycosylated residuals, such as fucose and terminal α1,4-linked GlcNAc. Moreover, a general reduction of glycosylated residuals in the goblet cells of villi such as the fucosylated and sulfated ones was observed. Since the cited residuals are involved in cytoprotective and cytostatic functions, as well as in interactions with the intestinal microbiota and protection against parasites and inflammatory disorders, we conclude that HFD can predispose duodenum to several possible health disorders.

Microscopic features of lamina muscularis mucosae of the goose gut

The aim of work was to determine the features of the microscopic structure of the lamina muscularis mucosae of the goose gut during the postnatal ontogenesis. According to the review of the literature, during the characterisation of the structure of the intestinal mucosa, researchers first pay attention to the condition of the villi, crypts, epithelial layer and their morphometric parameters, leaving the lamina muscularis mucosae aside. The intestinal lamina muscularis mucosae is an under-researched structure of the intestinal wall, the information on which is fragmentary and contradictory. The middle parts of the duodenum, jejunum, ileum, cecum and rectum of large grey geese of 13 age groups were investigated. The classic histological methods of staining by hematoxylin and eosin, aniline blue – orange (by Mallory), as well as azure II – eosin were used. It was established that the lamina muscularis mucosae of the goose’s small intestine is formed by two layers of unstriated muscle tissue: internal and external. In contradistinction to mammals, the thicker inner layer of the LMM has not a circular, but a longitudinal direction of cell location while by contrast the thinner outer layer is located in a circular direction. According to results of our research, the thickness of the lamina muscularis mucosae of the small intestine of the geese rapidly increased with age. The thickness of the duodenum corresponded to the value of adult geese at 60 days of age; jejunum, ileum, and rectum – at 21 days, cecum – at 7 days age. The lamina muscularis mucosae was thinnest in the duodenum, and it was thickest in the ileum. The lamina muscularis mucosa of the large intestine of geese is represented by only one longitudinal layer. By contrast, the thinner outer layer is located in a circular direction. Detailed information of the microscopic structure of the lamina muscularis mucosae of the intestine of geese can be useful for specialists, both morphologists and physiologists, for analyzing the histological preparations of the intestine of birds by the action of biotic and abiotic factors, as well as a basis of comparison with such structure in other species of animals. The description of the construction of this important microscopic structure of the intestine can serve a morphological basis for elucidating its function.