Fermentation in vitro of a mixture of dietary fibers and cane molasses by the cecal microbiota: Application on mineral absorption through the laying hen's colonic epithelium

Effect of gum Arabic as natural prebiotic on intestinal ecosystem of post-hatched broiler chicks

The purpose of the current study was to investigate the effects of gum Arabic supplementation on short-chain fatty acids, cecal microbiota, immune-related gene expression, and small intestinal morphology in post-hatched broiler chicks. On the day of hatching, four hundred thirty-two commercial male broiler chicks were randomly allocated into six treatments with twelve cages as replicates of six chicks each for 24 days. Dietary treatments (T1 to T6) were supplemented with 0.0, 0.12, 0.25, 0.50, 0.75, and 1.0% gum Arabic to the basal diet, respectively. Performance parameters, short-chain fatty acid concentration, quantification of microbiota and immune response gene expression (pre-inflammatory cytokines, mucin-2, and secretory immunoglobulin A), and histomorphometry of the small intestine were measured. According to our results, daily weight gains in T2 and the production efficiency index increased in T2 to T4, whereas daily feed intake decreased in T2, T3, T5, and T6, but feed conversion ratio improved. Concentration of lactate, acetate, butyrate, and total short-chain fatty acid increased in T2, T3, T5, and T6. Propionate ‎in T2 T3, T4, and T6 and format in T2, T5, and T6 also increased. Lactobacillus spp. quantitatively increased from T3 to T6, whereas Bacteroides spp. decreased in T3 and T5. Other microbiota quantitatively showed no effect of dietary supplements. IL-1β, TNF-α, and MUC-2 decreased in T2 to T6 and IL-12 in T3, whereas INF-Y increased in T4 to T6 and SIgA in T4. All histometeric parameters of the duodenum, jejunum, and ileum improved with dietary supplementation. We conclude that the administration of gum Arabic resulted in an improvement in overall performance, fermentation metabolites, and modification of microbiota and immune response with improved histomorphometry in the intestines of young chicks.

Dietary starch structure modulates nitrogen metabolism in laying hens via modifying glucose release rate

The objective of this study was to investigate the effects of starch structure (Amylopectin/Amylose, AP/AM) in a low-protein diet on production performance, nitrogen utilization efficiency, and cecal flora in laying hens. Four hundred eighty 45-wk-age Hy-Line Gray laying hens were randomly allocated to five dietary groups and subjected to a 12-wk feeding trial. The AP/AM ratios of the five experiment diets were 1.0, 1.5, 2.0, 3.0, and 4.0. The results indicated that compared to other groups, laying hens fed with AP/AM 4.0 diets showed significantly improved average egg weight and feed conversion ratio (P < 0.05). Furthermore, as the AP/AM ratio increased, there was a significant linear enhancement in intestinal amino acids apparent digestibility, apparent metabolizable energy, and villus area (P < 0.05). Compared to the high AP groups, high-AM diets significantly increased eggshell thickness, crude protein digestibility, and reduced energy supply from amino acid oxidation in ileum (P < 0.05). Additionally, moderate-AM diets enriched with short-chain fatty acid-producing bacteria in the cecum, such as Lactobacillus, Rikenellaceae_RC9_gut_group, and Christensenellaceae_R-7_group, which are associated with the promoting nitrogen utilization. These findings may offer useful information on optimizing starch structure for the design of food products and relevant therapies due to the potential effects on nutrient metabolism and gut homeostasis.

Marine red yeast supplementation improves laying performance by regulating small intestinal homeostasis in aging chickens

Recent studies have shown that age-related aging evolution is accompanied by imbalances in intestinal homeostasis. Marine red yeast (MRY) is a functional probiotic that has been shown to have antioxidant, immune and other properties. Therefore, we chose 900 healthy Hy-Line Brown hens at 433 d old as the research subjects and evaluated the correlation between intestinal health, laying performance, and egg quality in aged hens through the supplementation of MRY. These laying hens were assigned into 5 groups and received diet supplementation with 0%, 0.5%, 1.0%, 1.5%, and 2% MRY for 12 weeks. The results showed that MRY supplementation increased egg production rate, average egg weight, and egg quality, and decreased feed conversion ratio and daily feed intake (P < 0.05). The MRY supplement improved antioxidant indicators such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), stimulated villus height, and increased the villus height to crypt depth ratio (V/C ratio) in the intestine (P < 0.05). It also regulated the expression of intestinal inflammatory factors (transforming growth factor-β [TGF-β], interleukin [IL]-1β, IL-8, tumor necrosis factor-α [TNF-α]) while increasing serum immunoglobulin G (IgG) levels (P < 0.05). Furthermore, MRY supplementation upregulated the mRNA expression of tight junction proteins (occludin and zonula occludens-1 [ZO-1]), anti-apoptotic gene (Bcl-2), and autophagy-related proteins (beclin-1 and light chain 3I [LC3I]) in the intestine (P < 0.05). The MRY supplement also led to an increase in the concentration of short-chain fatty acids in the cecum, and the relative abundance of the phylum Bacteroidetes, and genera Bacteroides and Rikenellaceae_RC9_gut_group. The LEfSe analysis revealed an enrichment of Sutterella and Akkermansia muciniphila. In conclusion, the results of this experiment indicated that the additional supplementation of MRY can improve the production performance of laying hens and may contribute to the restoration and balance of intestinal homeostasis, which supports the application potential of MRY as a green and efficient feed additive for improving the laying performance in chickens.

Effects of L-arginine, guanidinoacetic acid and L-citrulline supplementation in reduced-protein diets on bone morphology and mineralization of laying hens

The alterations in feed ingredients and the nutrient matrix to produce reduced-protein diets may affect bone morphology and mineralization in laying hens. This study was implemented to determine the effects of L-arginine (Arg), guanidinoacetic acid (GAA), and L-citrulline (Cit) supplementation to Arg-deficient reduced-protein diets on bone morphology, strength, and mineralization status of laying hens. Individually housed Hy-Line Brown laying hens were evenly distributed to five dietary treatments with 25 replicates per treatment from 20 to 40 wk of age. Treatments consisted of a standard protein diet (17% crude protein, SP), a reduced-protein diet deficient in Arg (13% crude protein, RP), and RP supplemented with Arg (0.35% Arg, RP-Arg), GAA (0.46% GAA equivalent to 0.35% Arg, RP-GAA), or Cit (0.35% Cit equivalent to 0.35% Arg, RP-Cit) to reach the Arg level of SP diets. Birds fed the SP diet had similar bone weight, ash, length, width, Seedor index, breaking strength, and serum mineral concentration, but higher toe B level (P < 0.001) compared to those fed the RP diet at wk 40. Birds fed the SP diet consumed more but also excreted more K and B compared to those fed the RP diet (P < 0.01). Birds fed the SP diet had lower Cu digestibility (P = 0.01) and higher B retention (P < 0.01) compared to those offered the RP diet. Supplementation of Arg, GAA, and Cit to the RP diet increased relative femur weight and length (P < 0.001). Citrulline supplementation also increased relative tibia and femur ash, and Zn digestibility (P < 0.05). Supplementation of GAA to the RP diet decreased serum Ca, P, and Mg levels, decreased tibia Fe and Mg levels and toe Mg level, but increased Al, Fe, Zn, and Mn digestibility (P < 0.05). The current findings demonstrated the capacity of laying hens to adapt to low mineral intake by increasing mineral utilization. Overall, bone morphology and breaking strength, and serum mineral level in laying hens were not influenced by dietary CP levels. Dietary Arg, GAA, or Cit supplementation were effective in improving bone morphology and mineralization in laying hens fed Arg-deficient RP diets.

Gut microbiota as a target in the bone health of livestock and poultry: roles of short-chain fatty acids

The regulation and maintenance of bone metabolic homeostasis are crucial for animal skeletal health. It has been established that structural alterations in the gut microbiota and ecological dysbiosis are closely associated with bone metabolic homeostasis. The gut microbiota and its metabolites, especially short-chain fatty acids (SCFAs), affect almost all organs, including the bone. In this process, SCFAs positively affect bone healing by acting directly on cells involved in bone repair after or by shaping appropriate anti-inflammatory and immunomodulatory responses. Additionally, SCFAs have the potential to maintain bone health in livestock and poultry because of their various biological functions in regulating bone metabolism, including immune function, calcium absorption, osteogenesis and osteolysis. This review primarily focuses on the role of SCFAs in the regulation of bone metabolism by gut microbiota and provides insight into studies related to bone health in livestock and poultry.

Effects of dietary dandelion (Taraxacum mongolicum Hand.-Mazz.) polysaccharides on the performance and gut microbiota of laying hens

This experiment was designed to evaluate the influences of dietary dandelion polysaccharides (DP) on the performance and cecum microbiota of laying hens. Three hundred laying hens were assigned to five treatment groups: the basal diet group (CK group), three DP groups (basal diets supplemented with 0.5, 1.0, and 1.5 % DP), and the inulin group (IN group, basal diet supplemented with 1.5 % inulin). Increased daily egg weight and a decreased feed conversion rate were observed when the diets were supplemented with inulin or DP. The calcium metabolism rate in the 0.5 % and 1.0 % DP groups was greater than that in the CK group. The DP groups increased the short-chain fatty acid concentration, decreased pH, and enhanced the relative abundances of Parabacteroides, Alloprevotella, and Romboutsia in the cecum. These results showed that DP supplementation in the diets of laying hens can improve their performance, which might be associated with the regulation of the cecal microbiota.

Comparative assessment of physicochemical, structural and functional properties of dietary fiber extracted from mango (Mangifera indica L.) and soursop (Annona muricata) peels

The potential of soursop, a less well-known tropical fruit, was assessed as a source of dietary fiber (DF) and compared to mango. After optimizing the conditions to maximize the extraction yield of soluble and insoluble DF, their structural, physicochemical, and functional properties were evaluated. The results showed that soursop excelled in total and insoluble DF content (50 % higher than mango). The antioxidant response and reducing sugar content obtained for soursop were significantly higher than in mango. Yet, the insoluble fraction in both fruits was characterized by higher antioxidant activity and phenolic content. The chemical composition of both fruits revealed that glucose and potassium were the main sugar and mineral, respectively. Lactic, formic, and acetic acids were the main short-chain fatty acids produced after in vitro colonic fermentation with Lacticaseibacillus casei and Lacticaseibacillus rhamnosus, and negligible amounts of butyric, propionic, and valeric acids were detected after 48-h-fermentation, independent of the fruit. Soursop is a promising rich source of DF that can be used together with mango to develop and enhance foods' textural and nutritional characteristics.

The Effect of Gum Arabic Supplementation on Growth Performance, Blood Indicators, Immune Response, Cecal Microbiota, and the Duodenal Morphology of Broiler Chickens

Gum Arabic (GA) belongs to the Fabaceae family and contains indigestible soluble fibers (80-85%) that could be fermented by commensal bacteria to enhance performance, immune response, and intestinal integrity. This study aimed to investigate the effects of GA on performance, serum biochemical indicators, microbiota, immune-related gene expression, and histological changes in chickens. Six GA levels (0.0, 0.12, 0.25, 0.5, 0.75, 1.0%) were allocated using a total of 432 1-day-old male chickens (12 replicates with 6 chickens each). Growth performance was evaluated on days 10 and 24 of age. Blood parameters, organ pH levels, and intestinal health were determined on day 10 of age. Results showed that GA at 0.12% increased weight gain and 0.12 to 1.0% decreased feed intake but was best in feed conversion ratio and production efficiency except for 1.0% on day 1-10 of age. There was an increase in the thymus weight at GA level 0.25 to 0.75%. GA decreased the pH value of the proventriculus (at 0.50 and 1.0%) as well as the duodenum and cecum (at 0.12 and 1.0%). Chickens fed GA between 0.25 to 1.0% had higher protein and HDL, but lower cholesterol, LDL, and creatinine. Globulin was increased at 0.50% GA, while glucose and triglycerides were decreased (at 0.25 and 0.75% GA, respectively). The immune-related gene expression was reduced, except for 0.25% GA, which increased IL-10. Furthermore, chickens fed GA (0.25 to 0.75%) had higher Lactobacillus spp. and lower Salmonella spp. and Escherichia coli. When chickens received GA, the villus length and length to crypt ratio were higher, which also improved the integrity of intestinal epithelial cells and early duodenal development. We conclude that using GA (0.25 to 0.75%) as a natural prebiotic positively affects the performance, microbiota, immune response, morphology, and gut health of post-hatched chickens. More studies are needed to determine the potential mechanism of GA on broiler chickens.

Evaluation of gum Arabic (Acacia Senegal) as a natural prebiotic to improve growth performance and health status of broiler chickens

Gum Arabic (GA) is a natural product containing soluble fiber that is indigestible in the gastrointestinal tract and has been used as a traditional medicine to treat many diseases such as intestinal inflammation, kidney disease, and liver disorders, which may be reflected in the improved performance of broiler chickens when used. Therefore, the main objective of the current study was to evaluate the effects of GA on the performance, immune system, visceral organs, functional tests, and histological changes of the ileum, liver, and kidneys of broilers. A total of 432 1-day-old male broilers were allocated to six dietary treatments (0.0, 0.12, 0.25, 0.5, 0.75, and 1.0% GA) for 35 days. Performance, internal organs, and blood biochemical indices were measured. Morphology and histometry of the intestine were also performed. Meanwhile, tissues of the ileum, liver, and kidney were examined and evaluated microscopically to observe histological changes. All levels of GA (0.12 to 1.0%) had a positive effect on growth performance and feed conversion ratio. In addition, GA had no effect on the relative weight of lymphoid and visceral organs, except for a linear response in the bursa and liver. The levels of GA (0.12 and 0.25%) showed the potential to decrease serum uric acid, creatinine, and alanine aminotransferase. The remarkable increase in small intestinal morphology of chickens fed GA and an increase in all histometric values of the ileum. All histological changes in the intestine, liver, and kidneys improved in chickens fed the basal diet containing 0.12 to 0.50% GA. These results provide useful evidence for the potential use of GA powder (Acacia senegal) as a natural prebiotic to improve performance and intestinal, liver, and kidney health in broiler chickens.

Intestinal microbiota of layer hens and its association with egg quality and safety

The intestinal microbiota has attracted tremendous attention in the field of the poultry industry due to its critical role in the modulation of nutrient utilization, immune system, and consequently the improvement of the host health and production performance. Accumulating evidence implies intestinal microbiota of laying hens is a potential mediator to improve the prevalent issues in terms of egg quality decline in the late phase of laying production. However, the regulatory effect of intestinal microbiota on egg quality in laying hens remains elusive, which requires consideration of microbial baseline composition and succession during their long lifespans. Notable, although Firmicutes, Bacteroidetes, and Proteobacteria form the vast majority of intestinal microbiota in layer hens, dynamic intestinal microbiota succession occurs throughout all laying periods. In addition to the direct effects on egg safety, intestinal microbiota and its metabolites such as short-chain fatty acids, bile acids, and tryptophan derivatives, are suggested to indirectly modulate egg quality through the microbiota-gut-liver/brain-reproductive tract axis. These findings can extend our understanding of the crosstalk between intestinal microbiota and the host to improve egg quality and safety. This paper reviews the compositions of intestinal microbiota in different physiological stages of laying hens and their effects on egg quality and proposes that intestinal microbiota may become a potential target for modulating egg quality and safety by nutritional strategies in the future.

Cane Molasses and Oligofructose in the Diet of Laying Hens Improves the Mineral Content of Eggs and Meat

Poultry-based foods contribute to human health due to their high nutrient value. Previously, it was shown that short-chain fatty acids (SCFAs) produced by in vitro intestinal fermentation of a molasses and oligofructose mixture (M-O) stimulated iron and calcium transport through the colonic epithelium of laying hens. However, the real impact of including M-O mixture in the diet on the mineral content of poultry products had not yet been demonstrated. In this study, Hy-Line W-36 leghorn hens were assigned into two groups that either received a conventional diet or a diet supplemented with cane molasse and oligofructose, over a period of 42 days. The weight of the animals and their eggs, blood parameters and intestinal epithelium integrity were determined. Intestinal bacteria, their fermentation products, and the mineral content of eggs, bones and muscles were also assessed. The experimental diet proved to be safe, favored the proliferation of SCFA producing bacteria in the intestines, led to higher concentration of acids (mainly SCFA) in the digesta, and induced the elongation of microvilli at the apical tip of enterocytes. Mineral content of eggs and meat were improved after four weeks of feeding with the experimental diet compared to the conventional one. Higher iron content was observed in the edible portion of eggs and leg muscle, and higher calcium content was observed in the egg edible portion and shell in hens fed the supplemented diet. This feeding strategy could be useful to improve the mineral content of poultry products and therefore human nutrition, while diversifying molasses applications.

Inulin improves the egg production performance and affects the cecum microbiota of laying hens

Egg production performance, egg quality, nutrient digestibility, and microbial composition as affected by dietary inulin supplementation were evaluated in laying hens. A total of 300 laying hens were divided into 5 groups and fed diets containing inulin at levels of 0 (control), 5, 10, 15 and 20 g/kg, respectively. The results showed that the 15 g/kg inulin supplementation level improved average egg weight by 2.54%, egg mass by 5.76%, and laying rate by 3.09%, and decreased the feed conversion ratio by 3.61% compared to those of the control during feeding weeks 1 to 8. Dietary inulin supplementation improved eggshell thickness, nutrient digestibility and cecum Bacteroidales_S24-7_ group abundance in the laying hens. In conclusion, dietary inulin supplementation, particularly at the level of 15 g/kg, improved the egg production performance and eggshell thickness of laying hens, mainly due to increased nutrient digestibility and selective modulations of the cecum microbial communities.

Phytase supplementation in diets rich in fiber from rapeseed enhances phosphorus and calcium digestibility but not retention in broiler chickens

Two experiments were conducted on broilers to assess the effect of dietary fiber from 00-rapeseed meal (RSM) on phosphorus (P) and calcium (Ca) apparent ileal digestibility (AID) and retention (AR) during the growing (Exp1: 10 to 21 d) or finishing period (Exp2: 21 to 31 d) in diets supplemented or not with microbial phytase. Each experiment involved 144 male Cobb 500 fed one of 8 diets. Fiber content was modulated by incorporating whole RSM, RSM from dehulled rapeseeds, either raw or supplemented with 2 levels of defatted rapeseed hulls. Diets were supplemented or not with 750 phytase units of microbial phytase per kg. Excreta were collected from d 14 to d 17 (Exp1) and from d 27 to d 30 (Exp2) to measure AR. At the end of experiments, digestive tracts were sampled and weighed. The distal ileum and tibias were collected to measure AID and bone mineralization, respectively. Age did not significantly alter the response of birds to the addition of dietary fiber. Inclusion of hulls decreased growth performance (P < 0.05). The weight of the proventriculus-gizzard (PG) increased with the dietary fiber content in Exp1: The decreased weight observed using dehulled RSM was reversed following the inclusion of hulls. In both trials, while the presence of phytase increased the AID of P (P < 0.001) but not Ca, the inclusion of hulls with phytase improved the AID of P and Ca [linear (Lin), P < 0.05]. This effect could depend on the effect of fiber on PG development and physiology. Hulls decreased the moisture content of excreta (P < 0.01), suggesting higher water retention or lower water consumption with fiber. The AR of P was lower than AID of P with hulls, contrary to Ca, suggesting a metabolic imbalance. The decrease of AR together with the decrease of bone characteristics indicates a lack of Ca in diets with hulls and suggests that P and Ca provision should be adapted to the level and the origin of fiber inclusion.

Lotus Seed Resistant Starch Regulates Gut Microbiota and Increases Short-Chain Fatty Acids Production and Mineral Absorption in Mice

Lotus seed resistant starch, known as resistant starch type 3 (LRS3), was orally administered to mice to investigate its effects on the gut microbiota, short-chain fatty acids (SCFAs) production, and mineral absorption. The results showed that mice fed LRS3 displayed a lower level of gut bacterial diversity than other groups. The numbers of starch-utilizing and butyrate-producing bacteria, such as Lactobacillus and Bifidobacterium and Lachnospiraceae, Ruminococcaceae, and Clostridium, respectively, in mice increased after the administration of medium and high doses of LRS3, while those of Rikenellaceae and Porphyromonadaceae decreased. Furthermore, SCFAs and lactic acid in mice feces were affected by LRS3, and lactate was fermented to butyrate by gut microbiota. LRS3 enhanced the intestinal absorption of calcium, magnesium, and iron, and this was dependent on the type and concentration of SCFAs, especially butyrate. Thus, LRS3 promoted the production of SCFAs and mineral absorption by regulating gut microbiota in mice.

Effect of Vanadium and Tea Polyphenols on Intestinal Morphology, Microflora and Short-Chain Fatty Acid Profile of Laying Hens

Vanadium (V) is a trace element which can induce dysfunction of gastro-intestine and egg quality deterioration of laying hens. This study was conducted to determine the effect of tea polyphenols (TP) on intestinal morphology, microflora, and short-chain fatty acid (SCFA) profile of laying hens fed vanadium containing diets. A total of 120 Lohman laying hens (67-week-old) were randomly divided into 4 groups with 6 replicates and 5 birds each for a 35-day feeding trial. The dietary treatments were as follows: (1) control (CON), fed a basal diet; (2) vanadium treatment (V10), CON +10 mg V/kg; (3) TP treatment 1 (TP1): V10 + 600 mg TP/kg; (4) TP treatment 2 (TP2): V10 + 1000 mg TP/kg. Fed 10 mg V/kg diets to laying hens did not affect the cecum flora diversity index (H), degree of homogeneity (EH), and richness (S), but hens fed TP2 diet decreased the H, EH, and S (P < 0.05). The cecum butyrate acid concentration was lower in V10 treatment and higher in TP2 treatment (P < 0.05). Addition of 10 mg/kg V resulted in an increased (P < 0.01) duodenal cell apoptosis rate, and 1000 mg/kg TP supplementation overcame (P < 0.01) this reduction effect induced by vanadium. The results indicated that supplementation of 10 mg/kg vanadium increased duodenal cell apoptosis and reduced cecum butyrate acid content. Addition of 1000 mg/kg TP increased the SCFA production to affect cecum flora ecology and protected the duodenal cell from excess apoptosis caused by vanadium.

Sweetpotato vines hydrolysate promotes single cell oils production of Trichosporon fermentans in high-density molasses fermentation

This study investigated the co-fermentation of molasses and sweetpotato vine hydrolysate (SVH) by Trichosporon fermentans. T. fermentans showed low lipid accumulation on pure molasses; however, its lipid content increased by 35% when 10% SVH was added. The strong influence of SVH on lipid production was further demonstrated by the result of sensitivity analysis on effects of factors based on an artificial neural network model because the relative importance value of SVH dosage for lipid production was only lower than that of fermentation time. Scanning electron microscope observation and flow cytometry of yeast cells grown in culture with and without SVH showed that less deformation cells were involved in the culture with SVH. The activity of malic enzyme, which plays a key role in fatty acid synthesis, increased from 2.4U/mg to 3.7U/mg after SVH added. All results indicated SVH is a good supplement for lipid fermentation on molasses.