Effects of the increased protein level in small intestine on the colonic microbiota, inflammation and barrier function in growing pigs

Chromium yeast promotes milk protein synthesis by regulating ruminal microbiota and amino acid metabolites in heat-stressed dairy cows

The intensifying global warming may increase the impact of heat stress on the dairy industry. Our previous study showed that chromium yeast (CY) alleviated the negative effects of heat stress and improved the lactation performance by increasing milk protein content and yield in mid-lactation dairy cows. This study further investigated whether the increased milk protein after CY supplementation results from the promotion of microbial crude protein (MCP) synthesis by regulating rumen microorganisms and amino acid metabolites. Twelve heat-stressed dairy cows were divided into two treatment groups: one with CY supplementation (0.36 mg Cr/kg DM) and the other without CY supplementation. Samples were collected after eight weeks of formal experiment in a hot summer with the mean temperature-humidity index of 79.0 ± 3.13. Dietary CY supplementation did not affect rumen pH, total volatile fatty acid, acetate, propionate, isobutyrate, butyrate, isovalerate, and valerate, but increased ruminal MCP concentration (P < 0.05). Simultaneously, the alpha or beta diversity of rumen microbial bacteria were not influenced by CY supplementation. At genus level, supplementation with CY increased the relative abundances of Olsenella, Lachnospiraceae _UCG-002, and Shuttleworthia (P < 0.05) and decreased those of Enterobacter, Escherichia-Shigella, Oribacterium, and Bacteroidetes_BD2-2 (P < 0.05). There were 17 up-regulated and 57 down-regulated differential metabolites in the CON and CY groups. The partial least-squares discriminant analysis (PLS-DA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) scores clearly distinguished the two groups. Chromium yeast supplementation reduced the concentrations of D-(+)-proline, DL-glutamic acid, DL-lysine, Gly-l-pro, L-(-)-serine, L-(+)-alanine, and L-(+)-aspartic acid (P < 0.05) in the ruminal fluid, which were involved in arginine biosynthesis (P = 0.029), glutathione metabolism (P = 0.047), lysine degradation (P = 0.069), and D-amino acid metabolism (P = 0.084). Spearman correlation analysis showed that milk protein content was positively correlated with MCP and negatively correlated with amino acid concentrations in the ruminal fluid (P < 0.05). Collectively, CY supplementation promoted the utilization of amino acids by rumen microorganisms to synthesize MCP, thereby increasing milk protein content and yield in heat-stressed dairy cows.

SUMO1 modification reduces oxidative stress and SUMO1ylated AKAP4 degradation affects frozen-thawed boar sperm quality

Low-temperature injury affects normal physiological function and viability of boar sperm during cryopreservation. Small ubiquitin-like modifier (SUMO) modification of proteins after translation is related to the cell stress response but the relationship between SUMO modification and oxidative stress in freeze-thawed sperm remains unclear. A-kinase ankyrin 4 (AKAP4) and its precursor proAKAP4 are two main proteins in mammalian sperm. Although AKAP4 expression has been studied in many species, its expression in porcine sperm has not been described in detail. In this study, liquid chromatography-mass spectrometry was used to determine the differentially expressed SUMO-modified proteins in porcine sperm after freezen and thawed. The results identified 26 down-regulated SUMO-modified proteins, with AKAP4 identified as one of the target proteins of SUMO1 under sperm stress. In addition, the level of SUMO1 protein increased significantly (P < 0.001) and the level of AKAP4 protein decreased (P < 0.05) after freezing and oxidative stress treatment. Inhibition of SUMO1 modification of AKAP4 protein did not affect its degradation (P > 0.05), indicating that SUMO1 is not involved in the degradation of AKAP4. The inhibition of SUMO1 modification by sperm protein decreased sperm motility (P < 0.05), ATP content, and DNA integrity (P < 0.05). In summary, cryopreservation and oxidative stress can induce SUMO modification of porcine sperm proteins and the modification of sperm protein SUMO1 can help sperm resist oxidative stress; and its role in protecting sperm quality is not via regulating the degradation of AKAP4. These findings provide new insights into the mechanisms underlying SUMO1 modifications during sperm cryopreservation and oxidative stress.

Konjac glucomannan and κ-carrageenan improve hepatic fatty acid metabolism and colonic microbiota in suckling piglet

Konjac glucomannan (KGM) and κ-carrageenan are polysaccharides that have garnered attention for their potential health benefits. This study aimed to evaluate the maternal supplementation of KGM and κ-carrageenan (SF) during later gestation and lactation on the effect of hepatic lipid metabolism and colonic microflora in offspring. Regarding antioxidant and inflammatory factors in the suckling piglet liver, our results showed that nuclear factor erythroid 2-related factor 2 (Nrf2) and interleukin (IL)-10 levels were significantly increased in the SF group (P < 0.05). In liver mitochondrial function, the mRNA levels of voltage-dependent anion channel 1 (VDAC1), fission 1 (Fis1), and peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) were significantly up-regulated in the SF group compared to the control (Con) group (P < 0.05). The mRNA level of peroxisome proliferator-activated receptor alpha (PPARα) was remarkably down-regulated in the SF group (P < 0.05). In the colonic microflora of suckling piglets, we found that the SF group increased the abundance of Megasphaera and reduced the abundance of Erysipelotrichaceae_unclassified. The occludin level was significantly increased in the SF group than in the Con group (P < 0.05). In summary, maternal supplementation with SF improves hepatic lipid metabolism and colonic microflora in suckling piglets.

Impact of initial postweaning feed intake on weanling piglet metabolism, gut health, and immunity

Low feed intake (FI) in weanling pigs can be hypothesized as both a cause and consequence of intestinal disturbances and metabolic stress. We explored the associations between individual daily FI patterns, metabolic status, and intestinal physiology. Female pigs (n = 24) were selected based on high or low cumulative FI between d1 and d3 relative to weaning (d0) from 12 pens equipped with electronic feeding stations at 1-wk after weaning for dissection and sampling. Four classes of pigs were created with pigs that started with a high or low FI (d1 to d3) and continued with a high or low FI (d4 to d6) (HH, HL, LH, and LL, respectively; n = 6) for data analysis. In plasma, HL pigs showed higher plasma glutamate dehydrogenase than LL pigs (P < 0.05). A low FI d1 to d3 increased plasma creatinine and lactate dehydrogenase, and reduced insulin-like growth factor (IGF-I), gastrointestinal organ weights, and jejunal villus surface area at 1 wk after weaning (P < 0.05). However, low FI d4 to d6 increased plasma haptoglobin, PigMAP, bile acids, and bilirubin levels and reduced jejunal villus length (P < 0.05). In jejunum tissue, HH pigs had the highest jejunal upregulated IGF-I receptor and a reduced local inflammatory gene expression when compared to HL pigs (MyD88), and similarly, when compared to all classes (FAXDC2). For the main effects, pigs classified as high FI d1 to d3 had upregulated immune systems including IL-6, TGFB1, TLR2, and TLR4 genes compared to low FI d1 to d3 pigs (P < 0.05). In a multivariate model, variance in average daily gain (R2 = 0.82) was mostly explained by positive correlations with FI d1 to d3, jejunal morphometrics, and plasma IGF-I, while negatively explained by histamine in digesta, and creatinine, PigMAP, triglycerides, and haptoglobin in plasma. In conclusion, pigs transitioning from high to a low FI showed distinct metabolic alterations and a subtle local inflammation masked by the vigorous local immune response in pigs with initial (d1 to d3) high FI. Pigs with an initial low FI had a fasting-like metabolic state, indicated by hepatic alterations pointing at shifting protein metabolism into energy production. Altogether, FI during the initial days postweaning significantly impacts pig growth, immunity, and metabolism, with a sustained low intake (i.e., up to 6 d) triggering a systemic inflammatory response.

Lactiplantibacillus plantarum L47 and inulin affect colon and liver inflammation in piglets challenged by enterotoxigenic Escherichia coli through regulating gut microbiota

Introduction

Infection by pathogenic bacteria during weaning is a common cause of diarrhea and intestinal inflammation in piglets. Supplementing the diet with synbiotics is beneficial for animal health. The strain of Lactiplantibacillus plantarum L47 (L47) isolated in our lab exhibited good probiotic properties when combined with inulin. Here, the effectiveness of combining L47 and inulin (CLN) in protecting against enterotoxigenic Escherichia coli (ETEC) induced colon and liver inflammation in weaned piglets was evaluated.

Methods

Twenty-eight piglets aged 21 days were randomly assigned into 4 groups: CON (control), LI47 (oral CLN culture fluid, 1010 CFU/d of L47 and 1 g/d of inulin), ECON (oral ETEC culture fluid, 1010 CFU/d), and ELI47 (oral CLN and ETEC culture fluid). After 24 days, the colon and liver samples were collected for further analysis.

Results and discussion

CLN alleviated colon damage caused by ETEC challenge, as evidenced by an increase of colonic crypt depth, mRNA expression of tight junction Claudin-1 and Occludin, GPX activity, the concentration of IL-10 and sIgA (p < 0.05). Moreover, there was a decrease in MDA activity, the load of E. coli, the concentration of LPS, gene expression of TLR4, and the concentration of TNF-α and IL-6 (p < 0.05) in colonic mucosa. Additionally, CLN counteracted liver damage caused by ETEC challenge by modulating pathways associated with immunity and disease occurrence (p < 0.05).

Conclusion

Supplementing with CLN alleviated colon inflammation induced by ETEC challenge by decreasing the E. coli/LPS/TLR4 pathway and regulating hepatic immune response and disease-related pathways, suggesting that CLN could protect intestinal and liver health in animals.

Swine farm environmental microbiome: exploring microbial ecology and functionality across farms with high and low sanitary status

Introduction

Stringent regulations in pig farming, such as antibiotic control and the ban on certain additives and disinfectants, complicate disease control efforts. Despite the evolution of microbial communities inside the house environment, they maintain stability over the years, exhibiting characteristics specific to each type of production and, in some cases, unique to a particular company or farm production type. In addition, some infectious diseases are recurrent in specific farms, while other farms never present these diseases, suggesting a connection between the presence of these microorganisms in animals or their environment. Therefore, the aim of this study was to characterise environmental microbiomes of farms with high and low sanitary status, establishing the relationships between both, health status, environmental microbial ecology and its functionality.

Methods

For this purpose, 6 pig farms were environmentally sampled. Farms were affiliated with a production company that handle the majority of the pigs slaughtered in Spain. This study investigated the relationship among high health and low health status farms using high throughput 16S rRNA gene sequencing. In addition, to identify ecologically relevant functions and potential pathogens based on the 16S rRNA gene sequences obtained, functional Annotation with PROkaryotic TAXa (FAPROTAX) was performed.

Results and Discussion

This study reveals notable differences in microbial communities between farms with persistent health issues and those with good health outcomes, suggesting a need for protocols tailored to address specific challenges. The variation in microbial populations among farms underscores the need for specific and eco-friendly cleaning and disinfection protocols. These measures are key to enhancing the sustainability of livestock farming, ensuring safer products and boosting competitive edge in the market.

Multiomics Analysis Reveals Leucine Deprivation Promotes Bile Acid Synthesis by Upregulating Hepatic CYP7A1 and Intestinal Turicibacter sanguinis in Mice

BACKGROUND

Leucine, a branched-chain amino acid, participates in the regulation of lipid metabolism and the composition of the intestinal microbiota. However, the related mechanism remains unclear.

OBJECTIVES

Here, we aimed to reveal the potential mechanisms by which hepatic CYP7A1 (a rate-limiting enzyme for bile acid [BA] synthesis) and gut microbiota coregulate BA synthesis under leucine deprivation.

METHODS

To this end, 8-wk-old C57BL/6J mice were fed with either regular diets or leucine-free diets for 1 wk. Then, we investigated whether secondary BAs were synthesized by Turicibacter sanguinis in 7-wk-old C57BL/6J germ-free mice gavaged with T. sanguinis for 2 wk by determining BA concentrations in the plasma, liver, and cecum contents using liquid chromatography-tandem mass spectrometry.

RESULTS

The results showed that leucine deprivation resulted in a significant increase in total BA concentration in the plasma and an increase in the liver, but no difference in total BA was observed in the cecum contents before and after leucine deprivation. Furthermore, leucine deprivation significantly altered BA profiles such as taurocholic acid and ω-muricholic acid in the plasma, liver, and cecum contents. CYP7A1 expression was significantly upregulated in the liver under leucine deprivation. Leucine deprivation also regulated the composition of the gut microbiota; specifically, it significantly upregulated the relative abundance of T. sanguinis, thus enhancing the conversion of primary BAs into secondary BAs by intestinal T. sanguinis in mice.

CONCLUSIONS

Overall, leucine deprivation regulated BA profiles in enterohepatic circulation by upregulating hepatic CYP7A1 expression and increasing intestinal T. sanguinis abundance. Our findings reveal the contribution of gut microbiota to BA metabolism under dietary leucine deprivation.

Effects of dietary protein level on intestinal function and inflammation in nursery pigs

High crude protein (CP; 21% to 26%) diets fed during the first 21 to 28 d postweaning are viewed negatively because of a perceived increase in the incidence rates of diarrhea due to increased intestinal protein fermentation and/or augmented enteric pathogen burden. This is thought to antagonize nursery pig health and growth performance. Therefore, our objective was to evaluate the impact of low vs. high dietary CP on 21-day postweaned pig intestinal function. Analyzed parameters included ex vivo intestinal barrier integrity (ileum and colon), ileal nutrient transport, tissue inflammation, and fecal DM. One hundred and twenty gilts and barrows (average body weight) were randomly assigned to one of two diets postweaning. Diets were fed for 21 d, in two phases. Phase 1 diets: low CP (17%) with a 1.4% standardized ileal digestible (SID) Lys (LCP), or high CP (24%) with a 1.4% SID Lysine (HCP). Phase 2: LCP (17%) and a 1.35% SID lysine, or HCP (24%) formulated to a 1.35% SID lysine. Pig growth rates, feed intakes, and fecal consistency did not differ (P > 0.05) due to dietary treatment. Six animals per treatment were euthanized for additional analyses. There were no differences in colonic epithelial barrier function as measured by transepithelial electrical resistance (TER) and fluorescein isothiocyanate (FITC)-dextran transport between treatments (P > 0.05). Interleukins (IL)-1α, IL-1β, IL-1ra, IL-2 IL-4, IL-6, and IL-12 were not different between treatments (P > 0.05). However, IL-8 and IL-18 were higher in HCP- vs. LCP-fed pigs (P < 0.05). There were no differences in fecal dry matter (DM; P > 0.05) between treatments. In the ileum, there was a tendency (P = 0.06) for TER to be higher in HCP-fed pigs, suggesting a more robust barrier. Interestingly, glucose and glutamine transport were decreased in HCP- vs. LCP-fed pigs (P < 0.05). FITC-dextran transport was not different between treatments (P > 0.05). There were also no differences in ileal cytokine concentrations between diets (P > 0.05). Taken together, the data show that low CP does not negatively impact colonic barrier function, fecal DM, or inflammation. In contrast, ileal barrier function and nutrient transport were altered, suggesting a regional effect of diet on overall intestinal function.

Effect of dietary calcium source, exogenous phytase, and formic acid on inositol phosphate degradation, mineral and amino acid digestibility, and microbiota in growing pigs

The choice of the calcium (Ca) source in pig diets and the addition of formic acid may affect the gastrointestinal inositol phosphate (InsP) degradation and thereby, phosphorus (P) digestibility in pigs. This study assessed the effects of different Ca sources (Ca carbonate, Ca formate), exogenous phytase, and chemical acidification on InsP degradation, nutrient digestion and retention, blood metabolites, and microbiota composition in growing pigs. In a randomized design, 8 ileal-cannulated barrows (24 kg initial BW) were fed 5 diets containing Ca formate or Ca carbonate as the only mineral Ca addition, with or without 1,500 FTU/kg of an exogenous hybrid 6-phytase. A fifth diet was composed of Ca carbonate with phytase but with 8 g formic acid/kg diet. No mineral P was added to the diets. Prececal InsP6 disappearance and P digestibility were lower (P ≤ 0.032) in pigs fed diets containing Ca formate. In the presence of exogenous phytase, InsP5 and InsP4 concentrations in the ileal digesta were lower (P ≤ 0.019) with Ca carbonate than Ca formate. The addition of formic acid to Ca carbonate with phytase diet resulted in greater (P = 0.027) prececal InsP6 disappearance (87% vs. 80%), lower (P = 0.001) InsP5 concentration, and greater (P ≤ 0.031) InsP2 and myo-inositol concentrations in the ileal digesta. Prececal P digestibility was greater (P = 0.004) with the addition of formic acid compared to Ca carbonate with phytase alone. Prececal amino acid (AA) digestibility of some AA was greater with Ca formate compared to Ca carbonate but only in diets with phytase (P ≤ 0.048). The addition of formic acid to the diet with Ca carbonate and phytase increased (P ≤ 0.006) the prececal AA digestibility of most indispensable AA. Exogenous phytase affected more microbial genera in the feces when Ca formate was used compared to Ca carbonate. In the ileal digesta, the Ca carbonate diet supplemented with formic acid and phytase led to a similar microbial community as the Ca formate diets. In conclusion, Ca formate reduced prececal InsP6 degradation and P digestibility, but might be of advantage in regard to prececal AA digestibility in pigs compared to Ca carbonate when exogenous phytase is added. The addition of formic acid to Ca carbonate with phytase, however, resulted in greater InsP6 disappearance, P and AA digestibility values, and changed ileal microbiota composition compared to Ca carbonate with phytase alone.

Variability in feed intake the first days following weaning impacts gastrointestinal tract development, feeding patterns, and growth performance in nursery pigs

The present study investigated the effects of voluntary feed intake (FI) the first days after weaning on gastrointestinal development and protein fermentation the first week after weaning and growth performance and feeding patterns during the nursery phase. A total of 144 mixed-sex weaned pigs (24 ± 2 d old; 7.2 ± 0.8 kg body weight [BW]) were allocated to 12 pens with 12 pigs/pen. Each pen was equipped with an electronic feeding station for monitoring individual FI during a 40-d study. Pigs were classified based on their cumulative FI over the initial 3 d after weaning (FId1-3) being above or below their pen median FId1-3 (high = 919 ± 244 g or low = 507 ± 222 g FId1-3). Similarly, weaning BW classes (BW0; high = 7.72 ± 0.59 kg or low = 6.62 ± 0.88 kg BW) were created to study interactions with FId1-3. Two female pigs with either a high or a low FId1-3 per pen (n = 24) were selected for sampling at d6 and were used to study gastrointestinal development and fermentation products in the small intestine. Feeding patterns per day, FI, and growth performance were measured individually. Low FId1-3 pigs had lower (P < 0.05) daily FI during d0 to d8, d8 to d15, and d22 to d28, BW on d15, d22, d29, and d40, and average daily gain during d0 to d8, d22 to d29, and d29 to d40 compared to high FId1-3. High FId1-3 pigs increased (P < 0.05) the number of visits to the feeder between d1 to d13 and d31 to d35, and the time spent per visit only for d1 to d4 (P < 0.05). The daily rate of FI (g/min) was higher (P < 0.05) for High FId1-3 pigs on d6, d8, d9, and d10, and again several days later (d20 to d39). In addition, the high FId1-3 × high BW0 interaction improved daily FI during d18 to d40 compared to low FId1-3 × low BW0 class (P < 0.05). For the sampling on d6, low FId1-3 pigs had a lighter small intestine, colon, and pancreas, and reduced villi length, smaller villi surface area, and a lower number of goblet cells size in jejunum (P < 0.05), while concentrations of lactic acid, histamine, and cadaverine in small intestinal content were increased (P < 0.05). In conclusion, pigs with high FId1-3 became faster eaters with higher FI and growth rates toward the second half of the nursery, which was similar and additive for pigs with higher weaning BW. High FId1-3 was also associated with greater development of the gastrointestinal tract and a reduced protein fermentation 1-wk after weaning.

Longitudinal change of gut microbiota in hypertensive disorders in pregnancy: a nested case-control and Mendelian randomization study

Mounting evidence has shown that gut microbiota (GM) is related to hypertensive disorders in pregnancy (HDP), however, most studies only focused on one time point in pregnancy. In this study, we conducted a nested case-control study utilizing a follow-up cohort, resulting in the collection of 47 HDP patients and 30 healthy controls. The GM profiles were explored using 16S rRNA sequencing at three time points during pregnancy. The diversity analysis of GM showed no significant difference between HDP patients and controls, however, we found 21 differential GM during pregnancy. Trend analysis showed that there are statistical differences in the relative abundance of Thermomonas, Xanthomonas, and Phenylobacteriumat during pregnancy in the gestational hypertension group, and of Xanthomonas, Polycyclovorans, and Phenylobacterium in the control group. The correlation study found that six genera of GM are related to blood pressure. Furthermore, the MR analysis identified the causal relationship between Methanobrevibacter and pre-eclampsia (PE). This study first explored the longitudinal change of GM in HDP patients during pregnancy, found the differential GM, and detected the causal association. Our findings may promote the prevention and treatment of HDP from the perspective of GM and provide valuable insights into the pathogenesis of HDP.

Effect of a High-Starch or a High-Fat Diet on the Milk Performance, Apparent Nutrient Digestibility, Hindgut Fermentation Parameters and Microbiota of Lactating Cows

In this study, changes in milk performance, nutrient digestibility, hindgut fermentation parameters and microflora were observed by inducing milk fat depression (MFD) in dairy cows fed with a high-starch or a high-fat diet. Eight Holstein cows were paired in a completely randomized cross-over design within two 35 d periods (18 d control period and 17d induction period). During the control period, all cows were fed the low-starch and low-fat diet (CON), and at the induction period, four of the cows were fed a high-starch diet with crushed wheat (IS), and the other cows were fed a high-fat diet with sunflower fat (IO). The results showed that, compared to when the cows were fed the CON diet, when cows were fed the IS or IO diet, they had lower milk fat concentrations, energy corrected milk, 3.5% fat-corrected milk yield, feed efficiency and apparent digestibility of NDF and ADF. However, cows fed the IO diet had a lower apparent digestibility of ether extracts. In addition, we observed that when cows were fed the high-starch (IS) or high-fat (IO) diet, they had a higher fecal concentration of propionate and acetate, and a lower NH3-N. Compared to when the cows were fed the CON diet, cows fed the IS diet had a lower pH, and cows fed the IO diet had a lower concentration of valerate in feces. In the hindgut microbiota, the relative abundance of Oscillospiraceae_UCG-005 was increased, while the Verrucomicrobiota and Lachnospiraceae_AC2044_group were decreased when cows were fed the IO diet. The relative abundance of Prevotellaceae_UCG-003 was increased, while the Alistipes and Verrucomicrobiota decreased, and the Treponema, Spirochaetota and Lachnospiraceae_AC2044_group showed a decreasing trend when cows were fed the IS diet. In summary, this study suggested that high-starch or high-fat feeding could induce MFD in dairy cows, and the high-fat diet had the greatest effect on milk fat; the high-starch or high-fat diet affected hindgut fermentation and apparent fiber digestibility. The changes in hindgut flora suggested that hindgut microbiota may be associated with MFD in cows.

Effect of antibiotics and low-crude protein diets on growth performance, health, immune response, and fecal microbiota of growing pigs

This study aimed to investigate the effects of diets with and without antibiotics supplementation and diets with 18.5% and 13.0% crude protein (CP) on growth performance, carcass characteristics, disease incidence, fecal microbiota, immune response, and antioxidant capacity of growing pigs. One hundred and eighty pigs (59-day-old; 18.5 ± 2.5 kg) were distributed in a randomized complete block design in a 2 × 2 factorial arrangement, nine replicates, and five pigs per pen. The factors were CP (18.5% or 13.0%) and antibiotics (none or 100 mg/kg tiamulin + 506 mg/kg oxytetracycline). Medicated diets were fed from days 59 to 73. After that, all pigs were fed their respective CP diets from 73 to 87 days. Data were analyzed using the Mixed procedure in SAS version 9.4. From days 59 to 73, pigs fed antibiotics diets had higher (P < 0.05) average daily feed intake (ADFI), average daily weight gain (ADG), gain to feed ratio (G:F), compared to the diets without antibiotics. From days 73 to 87 (postmedicated period), any previous supplementation of antibiotics did not affect pig growth performance. Overall (days 59 to 87), pigs-fed antibiotics diets had higher (P < 0.05) G:F compared to pigs-fed diets without antibiotics. In all periods evaluated, pigs fed 18.5% CP diets had higher (P < 0.05) ADG and G:F compared to pigs fed 13.0% CP. Pigs fed the 13.0% CP diets had lower (P < 0.05) fecal score and diarrhea incidence than those fed 18.5% CP. Pigs fed 18.5% CP diets had improved (P < 0.05) loin area compared to pigs-fed diets with 13.0% CP. At 66 days of age, pigs-fed antibiotics diets had lower (P < 0.05) alpha diversity estimated with Shannon and Simpson compared to the pig-fed diets without antibiotics. At family level, pigs fed 18.5% CP diets had higher (P < 0.05) relative abundance of Streptococcaceae, and lower (P < 0.05) relative abundance of Clostridiaceae at days 66 and 87 compared with pigs fed 13.0% CP. Pigs-fed antibiotics diets had lower (P < 0.05) immunoglobulin G and protein carbonyl concentrations at day 66 compared to the pigs-fed diets without antibiotics. The reduction of dietary CP from 18.5% to 13.0% reduced the growth performance and loin muscle area of growing pigs, although it was effective to reduce diarrhea incidence. Antibiotics improved growth performance, lowered diarrhea incidence, improved components of the humoral immune response, and reduced microbiota diversity. However, in the postmedicated period, we found no residual effect on the general health of the animals, and considering the overall period, only G:F was improved by the use of antibiotics.

Food Peptides, Gut Microbiota Modulation, and Antihypertensive Effects

The gut microbiota is increasingly important in the overall human health and as such, it is a target in the search of novel strategies for the management of metabolic disorders including blood pressure, and cardiovascular diseases. The link between microbiota and hypertension is complex and this review is intended to provide an overview of the mechanism including the production of postbiotics, mitigation of inflammation, and the integration of food biological molecules within this complex system. The focus is on hydrolyzed food proteins and peptides which are less commonly investigated for prebiotic properties. The analysis of available data showed that food peptides are multifunctional and can prevent gut dysbiosis by positively affecting the production of postbiotics or gut metabolites (short-chain fatty acids, polysaccharides, biogenic amines, bile acids). Peptides and the postbiotics then displayed antihypertensive effects via the renin-angiotensin system, the gut barrier, the endothelium, and reduction in inflammation and oxidative stress. Despite the promising antihypertensive effect of the food peptides via the modulation of the gut, there is a lack of human studies as most of the works have been conducted in animal models.